diff options
| author |   Stephane Desneux <stephane.desneux@iot.bzh> | 2018-10-16 13:10:46 +0200 |
|---|---|---|
| committer | Stephane Desneux <stephane.desneux@iot.bzh> | 2018-10-16 13:13:14 +0200 |
| commit | 0eba225fb27ec0b87bfa80361314fec5ab901caa (patch) | |
| tree | 02baf13e25b4d8989dc25051ff7ce3256ffb7bbd /security-blueprint | |
| parent | 536b42be464af2f29fc5061489821c8903a6690a (diff) | |
Import from docs-agl/docs
Change-Id: Id524561d87410e5463cddd123b30eb63d75b62bd
Signed-off-by: Stephane Desneux <stephane.desneux@iot.bzh>
Diffstat (limited to 'security-blueprint')
41 files changed, 0 insertions, 3663 deletions
diff --git a/security-blueprint/README.md b/security-blueprint/README.md deleted file mode 100644 index a3cf24c..0000000 --- a/security-blueprint/README.md +++ /dev/null @@ -1,158 +0,0 @@ -# Introduction - -Modern cars have become a lot more technologically sophisticated and different than those of the past. We are seeing a wider range of new features and functionality, with a lot more complex software. It is fair to say that the cars being introduced to the market today have much more in common with computing devices like cell phones, than their predecessors did. Modern car manufacturers are also integrating support for a broad range of communication technologies for these “connected” cars. With the advent of such vehicles, Linux has become a natural choice for the software platform, with Automotive Grade Linux as a promising example. - -From a security point of view, the remote capabilities of a connected car results in a much larger attack surface. This opens a whole new world of security vulnerabilities that need to be considered during the architectural design. History shows that physical access to a device is sufficient for a hacker to gain root privileges. This makes the car a hostile environment. - -The Security Blueprint documents the security features that are included as part of Automotive Grade Linux (AGL) and identifies areas that need to be addressed from a security perspective as part of AGL. It also gives guidance around existing technologies and solutions. - -Security domains will allow us to create a set of tests verifying the security of Automotive Grade Linux. - -This document is firstly based on an existing AGL security-blueprint. - -**For security to be effective, the concepts must be simple. And by default, anything that is not allowed is forbidden.** - -We will cover topics starting from the lowest level (_Hardware_) up to the highest levels (_Connectivity_ and _Application_). We will move quickly on _Hardware_ and _Connectivity_ because this is not supported at our level. Solutions of connectivity problems concern updates and secured settings while hardware securing is related to the manufacturers. - -The document is filled with tags to easily identify important points: - -<!-- section-config --> - -- The _config_ tag quickly identifies the configurations and the recommendations to take. - -<!-- end-section-config --><!-- section-note --> - -- The _note_ tag allows you to notify some additional details. - -<!-- end-section-note --><!-- section-todo --> - -- The _todo_ tag shows the possible improvements. - -<!-- end-section-todo --> - -In annexes of this document, you can find all the _config_ and _todo_ notes. - -## Adversaries - -Adversaries and attackers within the Automotive space. - -- Enthusiast Attackers - -Enthusiast attackers have physical access to the Engine Control Units (ECUs) at the circuit board level. They can solder ‘mod chips’ onto the board and have access to probing tools. They also have information on ECUs that have been previously compromised and have access to softwares and instructions developed by other members of car modification forums. The goal of the enthusiast hacker could be, but is not limited to, adding extra horse power to the car or hacking it just for fun. - -- Corrupt Automotive Dealers - -Corrupt automotive dealers are attackers that have access to the same capabilities as enthusiasts, but also have access to the car manufacturer’s (OEM) dealer network. They may also have access to standard debugging tools provided by the car manufacturer. Their goal may be to support local car theft gangs or organized criminals. - -- Organized Criminals - -Organized criminals have access to all of the above tools but may also have some level of control over the internal network at many dealerships. They may have hacked and gained temporary control of the Over-The-Air (OTA) servers or the In-Vehicle Infotainment (IVI) systems. This is very much like the role of organized criminals in other industries such as paid media today. Their goal is to extort money from OEMs and/or governments by threatening to disable multiple vehicles. - -- Malware Developers - -Malware developers have developed malicious software to attack and compromise a large number of vehicles. The malicious software is usually designed to spread from one vehicle to another. Usually, the goal is to take control of multiple machines and then sell access to them for malicious purposes like denial-of-service (DoS) attacks or theft of private information and data. - -- Security Researchers - -Security researchers are ‘self-publicized’ security consultants trying to make a name for themselves. They have access to standard tools for software security analysis. They also have physical access to the vehicle and standard hardware debugging tools (Logic Analyzers, Oscilloscopes, etc). Their goal is to publicize attacks for personal gain or just to gain personal understanding with a sense of helping make things more secure. - -## Attack Goals - -In today’s connected vehicle, more and more functionality is moving to software control, meaning that the threat of attack becomes greater and greater. We see car features like navigation and summoning, car access/engine start, and motor/ECU upgrades all controlled through software and connections to the cloud. The risk of attack is high because there are high value targets in play. - -Here, we outline some of the major threats categories along with some sample attackers, example attacks, and a relative importance. These threat categories are intended to be general examples. There can be many nuances to threat types. Additionally, there can be many sub-attacks that eventually lead to these higher level attack goals. - -| Threat Category | Sample Attacker | Example Attacks | Relative Importance | -|-------------------------------|-----------------------------------------|-------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------| -| Vehicle theft | Individual, organized criminals | Send the car to an unplanned destination, get a key for the car, gain control of the unlock mechanism | Reduced likelihood of future vehicle purchases (Profit Later), bad press (Brand Integrity) | -| Reduced vehicle functionality | Terrorist groups, disgruntled employees | Lock the driver out of the car, cause the car to crash, block access to infotainment system | Inability sell paid-for apps and content (Profit Now), bad press (Brand Integrity), possible loss of life (Physical Injury) | -| Vehicle hacking | Vehicle owner, competitor | Get content without paying, modify DRM licenses, unlock of after-market features, theft of IP | Loss of sales for content and features (Profit Now), lawsuits from content owners (Profit Later), loss of competitive advantage (Profit Later) | -| Sensitive asset theft | Organized criminals, blackmailers | Steal credit card numbers, health information, camera data, steal bandwidth | Bad press (Brand Integrity), lawsuits from vehicle owners (Profit Later) | - -The Automotive Grade Linux (AGL) initiative builds upon open-source software including Linux and Tizen to offer a flexible application framework. However, the security provisions of the app framework, Cynara, and the security manager only go so far in keeping the biggest threats at bay. As experience has shown, providing a constrained app (like that in the Android Open Source Platform) and store development flow, signature verification, DAC sandboxing, and MAC (SMACK) controls over the platform can have a certain amount of success with the security of the system. However, the openness of the system invites many researchers, hobbyists and hackers and financially motivated attackers to compromise the system for their own gains. - -As AGL arrives on modern automobiles, this is inevitably inviting many capable actors to modify, attack, and compromise these well thought-out systems and their applications. With concerns like safety and security, the auto industry cannot afford to go the way of consumer devices like phones and tablets where security problems are encountered on a frequent basis. It is imperative to use a layered approach and defense-in-depth to protect the system from inevitable attack. - -## Assets and Security Categorization - -This section outlines some of the assets that are likely to be found in the vehicle and their relative sensitivity from an attack point of view. Additionally, the final column on the right lists some of the recommended protection types that can be applied to these types of assets (Note that the empty cells refer to the cells above them). A good protection approach will give priority to the most sensitive assets, using a defense-in-depth approach to cover these assets. Less sensitive assets are treated at a lower priority, typically protected with fewer protection techniques. A more fine-grained prioritization of the the assets in a concrete vehicle network can be achieved with detailed threat analysis which considers the topology of the vehicle network and access-controls that are in-place. e.g. the EVITA framework for attack trees. - -| Asset Category | Examples | Sensitivity | Recommended Protection Types | -|-------------------|--------------------------------------------------------------------------------|-------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| -| Software | ECU software, infotainment software, OS images | Critical | Key Management, Mutual Asymmetric Authentication, HSM and WhiteBox Encryption, Message Integrity Checks, Hardening/SW Protection, Program Transforms/ Obfuscation, Integrity Verification, Secure OS | -| Car Access | Biometric data, car keys | | | -| Payment Data | Credit cards, User profile critical data | | | -| Recordings | Internal camera recording, internal audio recording, external camera recording | High | Encryption, Message Integrity Checks, Hardening/SW Protection, Program Transforms / Obfuscation | -| User Profile | Usernames and passwords, customization, calendar, contacts | | | -| Location | GPS coordinates, vehicle usage data | | | -| Purchased Content | Video, audio, licenses | | | -| Teleconference | Chat, audio, video | Medium | SW Protection, Program Transforms / Obfuscation, Authenticated encryption for transmission | -| Vehicle data | Vehicle info, sensor data | | | -| Navigation data | Static and dynamic maps | | | -| 3rd party data | Home automation commands, cloud game data | | | - -## Hardening term - -The term Hardening refers to the tools, techniques and processes required in order to reduce the attack surface on an embedded system, such as an embedded control unit (**ECU**) or other managed devices. The target for all hardening activities is to prevent the execution of invalid binaries on the device, and to prevent copying of security related data from the device. - -<!-- pagebreak --> - -## AGL security overview - -AGL roots are based on security concepts. Those concepts are implemented by the security framework as shown in this picture: - - - --------------------------------------------------------------------------------- - -# Acronyms and Abbreviations - -The following table lists the strongest terms utilized within all this document. - -| Acronyms or Abbreviations | Description | -|---------------------------|-------------------------------------| -| _AGL_ | **A**utomotive **G**rade **L**inux | -| _ECU_ | **E**lectronic **C**ontrol **U**nit | - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -# References - -- [security-blueprint](http://docs.automotivelinux.org/docs/architecture/en/dev/reference/security/01-overview.html). - - _http:// docs.automotivelinux.org/docs/architecture/en/dev/reference/security/01-overview.html_ -- **[2017]** - [kernel security](https://www.kernel.org/doc/Documentation/security/). - - _https:// www.kernel.org/doc/Documentation/security/_ -- **[2017]** - [Systemd integration and user management](http://iot.bzh/download/public/2017/AMM-Dresden/AGL-systemd.pdf). - - _http:// iot.bzh/download/public/2017/AMM-Dresden/AGL-systemd.pdf_ -- **[2017]** - [AGL - Application Framework Documentation](http://iot.bzh/download/public/2017/SDK/AppFw-Documentation-v3.1.pdf). - - _http:// iot.bzh/download/public/2017/SDK/AppFw-Documentation-v3.1.pdf_ -- **[2017]** - [Improving Vehicle Cybersecurity](https://access.atis.org/apps/group_public/download.php/35648/ATIS-I-0000059.pdf). - - _https:// access.atis.org/apps/group_public/download.php/35648/ATIS-I-0000059.pdf_ -- **[2016]** - [AGL framework overview](http://docs.automotivelinux.org/docs/apis_services/en/dev/reference/af-main/0-introduction.html). - - _http:// docs.automotivelinux.org/docs/apis_services/en/dev/reference/af-main/0-introduction.html_ -- **[2016]** - [SecureBoot-SecureSoftwareUpdates](http://iot.bzh/download/public/2016/publications/SecureBoot-SecureSoftwareUpdates.pdf). - - _http:// iot.bzh/download/public/2016/publications/SecureBoot-SecureSoftwareUpdates.pdf_ -- **[2016]** - [Linux Automotive Security](http://iot.bzh/download/public/2016/security/Linux-Automotive-Security-v10.pdf). - - _http:// iot.bzh/download/public/2016/security/Linux-Automotive-Security-v10.pdf_ -- **[2016]** - [Automotive Security Best Practices](https://www.mcafee.com/it/resources/white-papers/wp-automotive-security.pdf). - - _https:// www.mcafee.com/it/resources/white-papers/wp-automotive-security.pdf_ -- **[2016]** - [Gattacking Bluetooth Smart Devices](http://gattack.io/whitepaper.pdf). - - _http:// gattack.io/whitepaper.pdf_ -- **[2015]** - [Comprehensive Experimental Analysis of Automotive Attack Surfaces](http://www.cs.wayne.edu/fengwei/15fa-csc6991/slides/8-CarHackingUsenixSecurity.pdf). - - _http:// www.cs.wayne.edu/fengwei/15fa-csc6991/slides/8-CarHackingUsenixSecurity.pdf_ -- **[2015]** - [Security in Automotive Bus Systems](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.92.728&rep=rep1&type=pdf). - - _http:// citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.92.728&rep=rep1&type=pdf_ -- **[2014]** - [IOActive Remote Attack Surface](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf). - - _https:// www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf_ -- **[2011]** - [A practical attack against GPRS/EDGE/UMTS/HSPA mobile data communications](https://media.blackhat.com/bh-dc-11/Perez-Pico/BlackHat_DC_2011_Perez-Pico_Mobile_Attacks-wp.pdf). - - _https:// media.blackhat.com/bh-dc-11/Perez-Pico/BlackHat_DC_2011_Perez-Pico_Mobile_Attacks-wp.pdf_ -- **[2011]** - [Comprehensive Experimental Analyses of Automotive Attack Surfaces](http://www.autosec.org/pubs/cars-usenixsec2011.pdf). - - _http:// www.autosec.org/pubs/cars-usenixsec2011.pdf_ -- **[2010]** - [Relay Attacks on Passive Keyless Entry and Start Systems in Modern Cars](https://eprint.iacr.org/2010/332.pdf). - - _https:// eprint.iacr.org/2010/332.pdf_ -- **[2010]** - [Wifi attacks wep wpa](https://matthieu.io/dl/wifi-attacks-wep-wpa.pdf). - - _https:// matthieu.io/dl/wifi-attacks-wep-wpa.pdf_ -- **[2008]** - [SMACK](http://schaufler-ca.com/yahoo_site_admin/assets/docs/SmackWhitePaper.257153003.pdf). - - _http:// schaufler-ca.com/yahoo_site_admin/assets/docs/SmackWhitePaper.257153003.pdf_ diff --git a/security-blueprint/WhiteBoxArchi.png b/security-blueprint/WhiteBoxArchi.png Binary files differdeleted file mode 100644 index d984d1a..0000000 --- a/security-blueprint/WhiteBoxArchi.png +++ /dev/null diff --git a/security-blueprint/annexes/0_Abstract.md b/security-blueprint/annexes/0_Abstract.md deleted file mode 100644 index 9db5fee..0000000 --- a/security-blueprint/annexes/0_Abstract.md +++ /dev/null @@ -1,7 +0,0 @@ -# Annexes - -The first part resumed all the configurations you must implement without any -explications since all the explanations are given as and when in the document. - -The second one allows to visualize all the todo notes in order to have a global -vision of the possible improvements of the document. diff --git a/security-blueprint/annexes/ConfigNotes.md b/security-blueprint/annexes/ConfigNotes.md deleted file mode 100644 index b3770fa..0000000 --- a/security-blueprint/annexes/ConfigNotes.md +++ /dev/null @@ -1,485 +0,0 @@ -# Config notes -<!-- section-config --> - -Domain | Object | Recommendations --------------------- | ---------- | ---------------------------------- -Hardware-Integrity-1 | Bootloader | Must control bootloader integrity. -Hardware-Integrity-2 | Board | Must use a HSM. -Hardware-Integrity-3 | RTC | Must not be alterable. - -Domain | Object | Recommendations ----------------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- -Hardware-Certificate-1 | System | Shall allow storing dedicated certificates. -Hardware-Certificate-2 | ECU | The ECU must verify the certification authority hierarchy. -Hardware-Certificate-3 | System | Allow the modification of certificates only if the source can be authenticated by a certificate already stored or in the higher levels of the chain of trust. - -Domain | Object | Recommendations ------------------ | ---------- | ------------------------------------------------------------------------------------ -Hardware-Memory-1 | ECU | The ECU shall never expose the unencrypted key in RAM when using cryptographic keys. -Hardware-Memory-2 | Bootloader | Internal NVM only -Hardware-Module-3 | - | HSM must be used to secure keys. - -Domain | _Variable_ / `Config` name | `Value` ----------------------- | -------------------------- | ------- -Boot-Image-Selection-1 | `CONFIG_BOOTDELAY` | `-2` -Boot-Image-Selection-2 | _bootdelay_ | `-2` - -Domain | `Config` name | _State_ -------------------------- | ---------------------------- | -------- -Boot-Image-Authenticity-1 | `CONFIG_FIT` | _Enable_ -Boot-Image-Authenticity-2 | `CONFIG_FIT_SIGNATURE` | _Enable_ -Boot-Image-Authenticity-3 | `CONFIG_RSA` | _Enable_ -Boot-Image-Authenticity-4 | `CONFIG_OF_CONTROL` | _Enable_ -Boot-Image-Authenticity-5 | `CONFIG_OF_SEPARATE` | _Enable_ -Boot-Image-Authenticity-6 | `CONFIG_DEFAULT_DEVICE_TREE` | _Enable_ - -Domain | Communication modes | _State_ --------------------- | ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- -Boot-Communication-1 | `USB` | _Disabled_ and _Compiled-out_ if not required. -Boot-Communication-2 | `USB` | Else, Kernel should be configured to only enable the minimum required USB devices and filesystems should be treated with special care. -Boot-Communication-3 | `Ethernet` | _Disabled_ -Boot-Communication-4 | U-boot and sboot `DOCSIS` | _Disabled_ -Boot-Communication-5 | `Serial ports` | _Disabled_ - -Domain | `Config` name | _State_ ------------------------- | ----------------------- | ------------- -Boot-Communication-USB-1 | `CONFIG_CMD_USB` | _Not defined_ -Boot-Communication-USB-2 | `CONFIG_USB_UHCI` | _Not defined_ -Boot-Communication-USB-3 | `CONFIG_USB_KEYBOARD` | _Not defined_ -Boot-Communication-USB-4 | `CONFIG_USB_STORAGE` | _Not defined_ -Boot-Communication-USB-5 | `CONFIG_USB_HOST_ETHER` | _Not defined_ - -Domain | Communication modes | _State_ --------------------- | -------------------- | --------------------------------------------------------------------------------------------- -Boot-Communication-1 | `Network interfaces` | Preferably _no network interface is allowed_, otherwise, restrict the services to those used. - -Domain | Object | Recommendations --------------------- | --------------------------------- | ------------------------------------------------------------- -Boot-Communication-1 | `Services`, `ports` and `devices` | Restrict the `services`, `ports` and `devices` to those used. - -Domain | `Command` name | _State_ --------------------------- | -------------- | --------- -Boot-Communication-Flash-1 | `do_nand` | _Disable_ - -Domain | `Config` name | `Value` ----------------------- | --------------------------------------- | --------- -Boot-Consoles-Serial-1 | `CONFIG_SILENT_CONSOLE` | `Disable` -Boot-Consoles-Serial-2 | `CONFIG_SYS_DEVICE_NULLDEV` | `Disable` -Boot-Consoles-Serial-3 | `CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC` | `Disable` - -Domain | `Environment variable` name | _State_ ----------------------- | --------------------------- | ------------- -Boot-Consoles-Serial-1 | `INC_DEBUG_PRINT` | _Not defined_ - -Domain | `Config` name | _State_ --------------------------- | ---------------------------- | --------- -Boot-Consoles-Variables-1 | `CONFIG_ENV_IS_IN_MMC` | `#undef` -Boot-Consoles-Variables-2 | `CONFIG_ENV_IS_IN_EEPROM` | `#undef` -Boot-Consoles-Variables-3 | `CONFIG_ENV_IS_IN_FLASH` | `#undef` -Boot-Consoles-Variables-4 | `CONFIG_ENV_IS_IN_DATAFLASH` | `#undef` -Boot-Consoles-Variables-5 | `CONFIG_ENV_IS_IN_FAT` | `#undef` -Boot-Consoles-Variables-6 | `CONFIG_ENV_IS_IN_NAND` | `#undef` -Boot-Consoles-Variables-7 | `CONFIG_ENV_IS_IN_NVRAM` | `#undef` -Boot-Consoles-Variables-8 | `CONFIG_ENV_IS_IN_ONENAND` | `#undef` -Boot-Consoles-Variables-9 | `CONFIG_ENV_IS_IN_SPI_FLASH` | `#undef` -Boot-Consoles-Variables-10 | `CONFIG_ENV_IS_IN_REMOTE` | `#undef` -Boot-Consoles-Variables-11 | `CONFIG_ENV_IS_IN_UBI` | `#undef` -Boot-Consoles-Variables-12 | `CONFIG_ENV_IS_NOWHERE` | `#define` - -Domain | `Command` name | _State_ ------------------------ | -------------- | ---------- -Boot-Consoles-MemDump-1 | `md` | _Disabled_ -Boot-Consoles-MemDump-2 | `mm` | _Disabled_ -Boot-Consoles-MemDump-3 | `nm` | _Disabled_ -Boot-Consoles-MemDump-4 | `mw` | _Disabled_ -Boot-Consoles-MemDump-5 | `cp` | _Disabled_ -Boot-Consoles-MemDump-6 | `mwc` | _Disabled_ -Boot-Consoles-MemDump-7 | `mdc` | _Disabled_ -Boot-Consoles-MemDump-8 | `mtest` | _Disabled_ -Boot-Consoles-MemDump-9 | `loopw` | _Disabled_ - -Domain | `Config` name | `Value` --------------------- | -------------- | -------------------------------------- -Kernel-General-MAC-1 | CONFIG_IP_NF_SECURITY | m -Kernel-General-MAC-2 | CONFIG_IP6_NF_SECURITY | m -Kernel-General-MAC-3 | CONFIG_EXT2_FS_SECURITY | y -Kernel-General-MAC-4 | CONFIG_EXT3_FS_SECURITY | y -Kernel-General-MAC-5 | CONFIG_EXT4_FS_SECURITY | y -Kernel-General-MAC-6 | CONFIG_SECURITY | y -Kernel-General-MAC-7 | CONFIG_SECURITY_SMACK | y -Kernel-General-MAC-8 | CONFIG_TMPFS_XATTR | y - -Domain | `Config` name | `Value` ----------------------- | -------------- | ------- -Kernel-General-kexec-1 | `CONFIG_KEXEC` | `n` - -Domain | `Config` name | `Value` ---------------------------- | --------------- | ------- -Kernel-General-IPAutoConf-1 | `CONFIG_IP_PNP` | `n` - -Domain | `Config` name | `Value` -------------------------------- | ----------------------- | ------- -Kernel-General-SysCtl_SysCall-1 | `CONFIG_SYSCTL_SYSCALL` | `n` - -Domain | `Config` name | `Value` ----------------------------- | --------------- | ------- -Kernel-General-LegacyLinux-1 | `CONFIG_USELIB` | `n` - -Domain | `Config` name | `Value` ---------------------------- | ------------------------------ | ------- -Kernel-General-FirmHelper-1 | `CONFIG_FW_LOADER_USER_HELPER` | `n` - -Domain | `Config` name | `Value` ----------------------------- | ---------------------- | ------- -Kernel-General-PanicOnOOPS-1 | `CONFIG_PANIC_ON_OOPS` | `y` - -Domain | `Config` name | `Value` --------------------------- | -------------------- | ------- -Kernel-General-SocketMon-1 | `CONFIG_PACKET_DIAG` | `n` -Kernel-General-SocketMon-2 | `CONFIG_UNIX_DIAG` | `n` - -Domain | `Config` name | `Value` ------------------------- | ---------------- | ------- -Kernel-General-BPF_JIT-1 | `CONFIG_BPF_JIT` | `n` - -Domain | `Config` name | `Value` ------------------------------- | ------------------------- | ------- -Kernel-General-ModuleSigning-1 | `CONFIG_MODULE_SIG_FORCE` | `y` - -Domain | `Variable` name | `Value` ------------------------------- | ------------------------- | ------- -Kernel-General-ModuleSigning-2 | `kernel.modules_disabled` | `1` - -Domain | Object | _State_ ------------------------- | ------------------- | ---------- -Kernel-General-Drivers-1 | `USB` | _Disabled_ -Kernel-General-Drivers-2 | `PCMCIA` | _Disabled_ -Kernel-General-Drivers-3 | Other `hotplug` bus | _Disabled_ - -Domain | `compiler` and `linker` options | _State_ --------------------------------- | ------------------------------- | -------- -Kernel-General-IndependentExec-1 | `-pie -fpic` | _Enable_ - -Domain | `compiler` and `linker` options | _State_ ---------------------------------- | ------------------------------- | -------- -Kernel-General-OverwriteAttacks-1 | `-z,relro` | _Enable_ -Kernel-General-OverwriteAttacks-2 | `-z,now` | _Enable_ - -Domain | Object | Recommendations -------------------------------- | --------------- | -------------------------------- -Kernel-General-LibraryLinking-1 | Dynamic linking | Should generally not be allowed. - -Domain | `Config` name | `Value` ------------------------------- | ---------------- | ------- -Kernel-Memory-RestrictAccess-1 | `CONFIG_DEVKMEM` | `n` - -Domain | `Config` name | `Value` ------------------------- | ------------------- | ------- -Kernel-Memory-CoreDump-1 | `CONFIG_PROC_KCORE` | `n` - -Domain | `Config` name | `Value` --------------------- | ------------- | ------- -Kernel-Memory-Swap-1 | `CONFIG_SWAP` | `n` - -Domain | `Config` name | `Value` ------------------------------- | --------------------- | ------- -Kernel-Memory-LoadAllSymbols-1 | `CONFIG_KALLSYMS` | `n` -Kernel-Memory-LoadAllSymbols-2 | `CONFIG_KALLSYMS_ALL` | `n` - -Domain | `Config` name | `Value` ---------------------- | -------------------------- | ------- -Kernel-Memory-Stack-1 | `CONFIG_CC_STACKPROTECTOR` | `y` - -Domain | `Config` name | `Value` ----------------------- | --------------- | ------- -Kernel-Memory-Access-1 | `CONFIG_DEVMEM` | `n` - -Domain | `Config` name | `Value` ------------------------------- | --------------------- | ------- -Kernel-Memory-CrossMemAttach-1 | `CROSS_MEMORY_ATTACH` | `n` - -Domain | `compiler` and `linker` options | _State_ ------------------------------ | ------------------------------- | -------- -Kernel-Memory-StackSmashing-1 | `-fstack-protector-all` | _Enable_ - -Domain | `compiler` options and `config` name | `Value` -------------------------------- | ------------------------------------ | ------- -Kernel-Memory-BufferOverflows-1 | `-D_FORTIFY_SOURCE` | `2` -Kernel-Memory-BufferOverflows-2 | `CONFIG_FORTIFY_SOURCE` | `y` - -Domain | `Config` name | `Value` ------------------------- | ---------------------------- | ------- -Kernel-Consoles-Serial-1 | `CONFIG_SERIAL_8250` | `n` -Kernel-Consoles-Serial-2 | `CONFIG_SERIAL_8250_CONSOLE` | `n` -Kernel-Consoles-Serial-3 | `CONFIG_SERIAL_CORE` | `n` -Kernel-Consoles-Serial-4 | `CONFIG_SERIAL_CORE_CONSOLE` | `n` - -Domain | `Config` name | `Value` ------------------------------ | ------------------------- | ----------------------------------- -Kernel-Consoles-CommandLine-1 | `CONFIG_CMDLINE_BOOL` | `y` -Kernel-Consoles-CommandLine-2 | `CONFIG_CMDLINE` | `"insert kernel command line here"` -Kernel-Consoles-CommandLine-3 | `CONFIG_CMDLINE_OVERRIDE` | `y` - -Domain | `Config` name | `Value` ----------------------- | ------------- | ------- -Kernel-Consoles-KDBG-1 | `CONFIG_KGDB` | `n` - -Domain | `Config` name | `Value` ------------------------ | -------------------- | ------- -Kernel-Consoles-SysRQ-1 | `CONFIG_MAGIC_SYSRQ` | `n` - -Domain | `Config` name | `Value` ------------------------------- | -------------------- | ------- -Kernel-Consoles-BinaryFormat-1 | `CONFIG_BINFMT_MISC` | `n` - -Domain | `Config` name | `Value` ----------------------- | ------------------- | ------- -Kernel-Debug-Symbols-1 | `CONFIG_DEBUG_INFO` | `n` - -Domain | `Config` name | `Value` ----------------------- | ---------------- | ------- -Kernel-Debug-Kprobes-1 | `CONFIG_KPROBES` | `n` - -Domain | `Config` name | `Value` ----------------------- | --------------- | ------- -Kernel-Debug-Tracing-1 | `CONFIG_FTRACE` | `n` - -Domain | `Config` name | `Value` ------------------------- | ------------------ | ------- -Kernel-Debug-Profiling-1 | `CONFIG_OPROFILE` | `n` -Kernel-Debug-Profiling-2 | `CONFIG_PROFILING` | `n` - -Domain | `Config` name | `Value` ------------------------- | ------------------------- | ------- -Kernel-Debug-OOPSOnBUG-1 | `CONFIG_DEBUG_BUGVERBOSE` | `n` - -Domain | `Config` name | `Value` ------------------- | --------------------- | ------- -Kernel-Debug-Dev-1 | `CONFIG_DEBUG_KERNEL` | `n` -Kernel-Debug-Dev-2 | `CONFIG_EMBEDDED` | `n` - -Domain | `Config` name | `Value` -------------------------- | ----------------- | ------- -Kernel-Debug-FileSystem-1 | `CONFIG_DEBUG_FS` | `n` - -Domain | `Config` name | `Value` ------------------- | ------------- | ------- -Kernel-Debug-BUG-1 | `CONFIG_BUG` | `n` - -Domain | `Config` name | `Value` ------------------------- | ----------------- | ------- -Kernel-Debug-CoreDumps-1 | `CONFIG_COREDUMP` | `n` - -Domain | `File` name | `Value` ----------------------------- | -------------------------------- | ------- -Kernel-Debug-AdressDisplay-1 | `/proc/sys/kernel/kptr_restrict` | `1` - -Domain | `File` or `Directorie` name | _State_ ----------------------------- | --------------------------- | ----------------------------- -Kernel-Debug-AdressDisplay-1 | `/boot/vmlinuz*` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-2 | `/boot/System.map*` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-3 | `/sys/kernel/debug/` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-4 | `/proc/slabinfo` | _Readable Only for root user_ - -Domain | `File` name | `Value` --------------------- | --------------------------------- | ------- -Kernel-Debug-DMESG-1 | `/proc/sys/kernel/dmesg_restrict` | `1` - -Domain | `Config` name | `Value` ---------------------- | ----------------- | ------- -Kernel-Debug-Config-1 | `CONFIG_IKCONFIG` | `n` - -Domain | `Config` name | `Value` ------------------------- | --------------- | ------- -Kernel-FileSystems-NFS-1 | `CONFIG_NFSD` | `n` -Kernel-FileSystems-NFS-2 | `CONFIG_NFS_FS` | `n` - -Domain | `Partition` | `Value` --------------------------- | ------------------- | ----------------------------------------------------------------- -Kernel-FileSystems-Mount-1 | `/boot` | `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-2 | `/var` & `/tmp` | In `/etc/fstab` or `vfstab`, add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-3 | _Non-root local_ | If type is `ext2` or `ext3` and mount point not '/', add `nodev`. -Kernel-FileSystems-Mount-4 | _Removable storage_ | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-5 | _Temporary storage_ | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-6 | `/dev/shm` | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-7 | `/dev` | Add `nosuid` and `noexec`. - -Domain | `Config` name | _State_ or `Value` --------------------------- | ----------------------- | ----------------------------------------------------------------------- -Kernel-FileSystems-Mount-1 | `CONFIG_DEVTMPFS_MOUNT` | _Disabled_ or add remount with `noexec` and `nosuid` to system startup. - -Domain | `Label` name | Recommendations ------------------- | ------------ | ----------------------------------------------------------- -Kernel-MAC-Floor-1 | `^` | Only for privileged system services. -Kernel-MAC-Floor-2 | `*` | Used for device files or `/tmp` Access restriction via DAC. - -Domain | `Label` name | Recommendations -------------------- | ---------------- | ------------------------------------------------------------------------------------------------------------- -Kernel-MAC-System-1 | `System` | Process should write only to file with transmute attribute. -Kernel-MAC-System-2 | `System::run` | Files are created with the directory label from user and system domain (transmute) Lock is implicit with `w`. -Kernel-MAC-System-3 | `System::Shared` | Files are created with the directory label from system domain (transmute) User domain has locked privilege. -Kernel-MAC-System-4 | `System::Log` | Some limitation may impose to add `w` to enable append. -Kernel-MAC-System-5 | `System::Sub` | Isolation of risky Subsystem. - -Domain | `Label` name | Recommendations -------------------- | ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- -Kernel-MAC-System-1 | `User::Pkg::$AppID` | Only one Label is allowed per App. A data directory is created by the AppFw in `rwx` mode. -Kernel-MAC-System-2 | `User::Home` | AppFw needs to create a directory in `/home/$USER/App-Shared` at first launch if not present with label app-data access is `User::App-Shared` without transmute. -Kernel-MAC-System-3 | `User::App-Shared` | Shared space between all App running for a given user. - -Domain | Object | Recommendations ------------------- | -------------- | ------------------------------------ -Platform-SystemD-1 | Security model | Use Namespaces for containerization. -Platform-SystemD-2 | Security model | Use CGroups to organise processes. - -Domain | Object | Recommendations ---------------- | -------------- | ------------------------------------ -Platform-DBus-1 | Security model | Use D-Bus as IPC. -Platform-DBus-2 | Security model | Apply D-BUS security patches: [D-Bus CVE](https://www.cvedetails.com/vulnerability-list/vendor_id-13442/D-bus-Project.html) - -Domain | `Tool` name | _State_ --------------------- | ----------- | ------- -Platform-Utilities-1 | `connman` | _Used_ as a connection manager. -Platform-Utilities-2 | `bluez` | _Used_ as a Bluetooth manager. -Platform-Utilities-3 | `gstreamer` | _Used_ to manage multimedia file format. -Platform-Utilities-4 | `alsa` | _Used_ to provides an API for sound card device drivers. - -Domain | Object | Recommendations ----------------------- | -------------- | -------------------------------- -Platform-AGLFw-AppFw-1 | Security model | Use the AppFw as Security model. - -Domain | Object | Recommendations ------------------------ | ----------- | ------------------------------------- -Platform-AGLFw-Cynara-1 | Permissions | Use Cynara as policy-checker service. - -Domain | `Tool` name | _State_ --------------------- | ----------- | ---------------------------------------------------------------------- -Platform-Utilities-1 | `busybox` | _Used_ to provide a number of tools. Do not compile development tools. - -Domain | `Utility` name and normal `path` | _State_ ---------------------- | ---------------------------------------------------- | ---------- -Platform-Utilities-1 | `chgrp` in `/bin/chgrp` | _Disabled_ -Platform-Utilities-2 | `chmod` in `/bin/chmod` | _Disabled_ -Platform-Utilities-3 | `chown` in `/bin/chown` | _Disabled_ -Platform-Utilities-4 | `dmesg` in `/bin/dmesg` | _Disabled_ -Platform-Utilities-5 | `Dnsdomainname` in `/bin/dnsdomainname` | _Disabled_ -Platform-Utilities-6 | `dropbear`, Remove "dropbear" from `/etc/init.d/rcs` | _Disabled_ -Platform-Utilities-7 | `Editors` in (vi) `/bin/vi` | _Disabled_ -Platform-Utilities-8 | `find` in `/bin/find` | _Disabled_ -Platform-Utilities-9 | `gdbserver` in `/bin/gdbserver` | _Disabled_ -Platform-Utilities-10 | `hexdump` in `/bin/hexdump` | _Disabled_ -Platform-Utilities-11 | `hostname` in `/bin/hostname` | _Disabled_ -Platform-Utilities-12 | `install` in `/bin/install` | _Disabled_ -Platform-Utilities-13 | `iostat` in `/bin/iostat` | _Disabled_ -Platform-Utilities-14 | `killall` in `/bin/killall` | _Disabled_ -Platform-Utilities-15 | `klogd` in `/sbin/klogd` | _Disabled_ -Platform-Utilities-16 | `logger` in `/bin/logger` | _Disabled_ -Platform-Utilities-17 | `lsmod` in `/sbin/lsmod` | _Disabled_ -Platform-Utilities-18 | `pmap` in `/bin/pmap` | _Disabled_ -Platform-Utilities-19 | `ps` in `/bin/ps` | _Disabled_ -Platform-Utilities-20 | `ps` in `/bin/ps` | _Disabled_ -Platform-Utilities-21 | `rpm` in `/bin/rpm` | _Disabled_ -Platform-Utilities-22 | `SSH` | _Disabled_ -Platform-Utilities-23 | `stbhotplug` in `/sbin/stbhotplug` | _Disabled_ -Platform-Utilities-24 | `strace` in `/bin/trace` | _Disabled_ -Platform-Utilities-25 | `su` in `/bin/su` | _Disabled_ -Platform-Utilities-26 | `syslogd` in (logger) `/bin/logger` | _Disabled_ -Platform-Utilities-27 | `top` in `/bin/top` | _Disabled_ -Platform-Utilities-28 | `UART` in `/proc/tty/driver/` | _Disabled_ -Platform-Utilities-29 | `which` in `/bin/which` | _Disabled_ -Platform-Utilities-30 | `who` and `whoami` in `/bin/whoami` | _Disabled_ -Platform-Utilities-31 | `awk` (busybox) | _Enabled_ -Platform-Utilities-32 | `cut` (busybox) | _Enabled_ -Platform-Utilities-33 | `df` (busybox) | _Enabled_ -Platform-Utilities-34 | `echo` (busybox) | _Enabled_ -Platform-Utilities-35 | `fdisk` (busybox) | _Enabled_ -Platform-Utilities-36 | `grep` (busybox) | _Enabled_ -Platform-Utilities-37 | `mkdir` (busybox) | _Enabled_ -Platform-Utilities-38 | `mount` (vfat) (busybox) | _Enabled_ -Platform-Utilities-39 | `printf` (busybox) | _Enabled_ -Platform-Utilities-40 | `sed` in `/bin/sed` (busybox) | _Enabled_ -Platform-Utilities-41 | `tail` (busybox) | _Enabled_ -Platform-Utilities-42 | `tee` (busybox) | _Enabled_ -Platform-Utilities-43 | `test` (busybox) | _Enabled_ - -Domain | Object | Recommendations ---------------------- | ---------------- | ----------------------------------------------------- -Platform-Users-root-1 | Main application | Should not execute as root. -Platform-Users-root-2 | UI | Should run in a context on a user with no capability. - -Domain | `Utility` name | _State_ ---------------------- | -------------- | ------------- -Platform-Users-root-3 | `login` | _Not allowed_ -Platform-Users-root-4 | `su` | _Not allowed_ -Platform-Users-root-5 | `ssh` | _Not allowed_ -Platform-Users-root-6 | `scp` | _Not allowed_ -Platform-Users-root-7 | `sftp` | _Not allowed_ - -Domain | Object | Recommendations --------------------------- | --------- | ----------------------------------------------------------------------- -Application-Installation-1 | AppFw | Provide offline-mode in order to install app with the base image. -Application-Installation-2 | Integrity | Allow the installation of applications only if their integrity is good. - -Domain | Tech name | Recommendations ----------------------------------- | --------- | -------------------------------------------------------------------------- -Connectivity-BusAndConnector-Bus-1 | CAN | Implement hardware solution in order to prohibit sending unwanted signals. - -Domain | Tech name | Recommendations ------------------------------------------ | --------- | ---------------------------------------------------------------------- -Connectivity-BusAndConnector-Connectors-1 | USB | Must be disabled. If not, only enable the minimum require USB devices. -Connectivity-BusAndConnector-Connectors-2 | USB | Confidential data exchanged with the ECU over USB must be secure. -Connectivity-BusAndConnector-Connectors-3 | USB | USB Boot on a ECU must be disable. -Connectivity-BusAndConnector-Connectors-4 | OBD-II | Must be disabled outside garages. - -Domain | Object | Recommendations ------------------------ | ------ | ------------------------------------------------------------------ -Connectivity-Wireless-1 | Update | Always follow the latest updates of remote communication channels. - -Domain | Tech name or object | Recommendations ----------------------------- | ------------------- | ------------------------------------------------------------------------- -Connectivity-Wireless-Wifi-1 | WEP, PSK, TKIP | Disabled -Connectivity-Wireless-Wifi-2 | WPA2 and AES-CCMP | Used -Connectivity-Wireless-Wifi-3 | WPA2 | Should protect data sniffing. -Connectivity-Wireless-Wifi-4 | PSK | Changing regularly the password. -Connectivity-Wireless-Wifi-5 | Device | Upgraded easily in software or firmware to have the last security update. - -Domain | Tech name | Recommendations ---------------------------------- | ------------- | ------------------------------------------------------------ -Connectivity-Wireless-Bluetooth-1 | BLE | Use with caution. -Connectivity-Wireless-Bluetooth-2 | Bluetooth | Monitoring -Connectivity-Wireless-Bluetooth-3 | SSP | Avoid using the "Just Works" association model. -Connectivity-Wireless-Bluetooth-4 | Visibility | Configured by default as undiscoverable. Except when needed. -Connectivity-Wireless-Bluetooth-5 | Anti-scanning | Used, inter alia, to slow down brute force attacks. - -Domain | Tech name | Recommendations --------------------------------- | --------- | -------------------------- -Connectivity-Wireless-Cellular-1 | GPRS/EDGE | Avoid -Connectivity-Wireless-Cellular-2 | UMTS/HSPA | Protected against Jamming. - -Domain | Tech name | Recommendations ------------------------------ | --------- | -------------------------------------------- -Connectivity-Wireless-Radio-1 | RDS | Only audio output and meta concerning radio. - -Domain | Tech name | Recommendations ---------------------------- | --------- | ------------------------------------------------------ -Connectivity-Wireless-NFC-1 | NFC | Protected against relay and replay attacks. -Connectivity-Wireless-NFC-2 | Device | Disable unneeded and unapproved services and profiles. - -Domain | Object | Recommendations ----------------------------- | -------------- | -------------------------------------- -Application-Cloud-Download-1 | authentication | Must implement authentication process. -Application-Cloud-Download-2 | Authorization | Must implement Authorization process. - -Domain | Object | Recommendations ----------------------------------- | ------------- | ---------------------------------------------------------- -Application-Cloud-Infrastructure-1 | Packet | Should implement a DPI. -Application-Cloud-Infrastructure-2 | DoS | Must implement a DoS protection. -Application-Cloud-Infrastructure-3 | Test | Should implement scanning tools like SATS and DAST. -Application-Cloud-Infrastructure-4 | Log | Should implement security tools (IDS and IPS). -Application-Cloud-Infrastructure-5 | App integrity | Applications must be signed by the code signing authority. - -Domain | Object | Recommendations ------------------------------ | ----------------------------------------- | --------------------------------- -Application-Cloud-Transport-1 | Integrity, confidentiality and legitimacy | Should implement IPSec standards. - -<!-- end-section-config --> diff --git a/security-blueprint/annexes/todoNotes.md b/security-blueprint/annexes/todoNotes.md deleted file mode 100644 index d1d4b6f..0000000 --- a/security-blueprint/annexes/todoNotes.md +++ /dev/null @@ -1,80 +0,0 @@ -# Todo notes -<!-- section-todo --> - -Domain | Improvement ---------------- | ---------------------------------------------------- -Boot-Abstract-1 | More generic and add examples (The chain of trust). - -Domain | Improvement ---------------- | ------------------------------------------- -Boot-Abstract-1 | Review the definition of the "boot loader". - -Domain | Improvement ---------------- | ------------------------------------ -Boot-Consoles-1 | Secure loader: No reference earlier? - -Domain | Improvement ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- -Hypervisor-Abstract-1 | Complete Hypervisor part ([jailhouse](https://github.com/siemens/jailhouse) / [KVM](https://www.linux-kvm.org/page/Main_Page) / [Xen](https://www.xenproject.org/developers/teams/embedded-and-automotive.html)). - -Domain | Improvement --------------------------------- | ----------------------------- -Kernel-General-IndependentExec-1 | Kernel or/and platform part ? - -Domain | Improvement -------------------------------- | --------------- -Kernel-General-LibraryLinking-1 | Keep this part? - -Domain | Improvement -------------------- | -------------------------------- -Platform-Abstract-1 | Create a graphics and sound part. - -Domain | Improvement -------------------- | ----------- -Platform-Services-1 | SystemD ? -Platform-Services-2 | Secure daemon ? - -Domain | Improvement ------------------------------ | ------------------------ -Platform-Users-Capabilities-1 | Kernel or Platform-user? -Platform-Users-Capabilities-2 | Add config note. - -Domain | Improvement --------------------------- | ------------------------------ -Application-Installation-1 | Talk about AppFw offline mode. - -Domain | Improvement ------------------------ | ---------------------------------------------------------- -Application-Signature-1 | Add content (see secure build in Secure development part). - -Domain | Improvement ----------------------- | ------------ -Application-Services-1 | Add content (Which services?). -Application-Services-2 | Add Binder. - -Domain | Improvement ------------------------ | ----------------- -Connectivity-Abstract-1 | Improve abstract. - -Domain | Improvement ------------------------ | ------------------------------------------- -Connectivity-Wireless-1 | Add communication channels (RFID, ZigBee?). - -Domain | Improvement -------------- | ----------------- -Update-SOTA-1 | Part to complete. - -Domain | Improvement ------------------------ | ------------ -SecureDev-SecureBuild-1 | Add content. - -Domain | Improvement ----------------------- | ------------ -SecureDev-Signatures-1 | Add content. - -Domain | Improvement ---------------------- | ----------------------------------------------------- -SecureDev-CodeAudit-1 | Add CVE analyser. -SecureDev-CodeAudit-2 | [OSSTMM](http://www.isecom.org/mirror/OSSTMM.3.pdf). - -<!-- end-section-todo --> diff --git a/security-blueprint/index.md b/security-blueprint/index.md deleted file mode 100644 index 1ca88b3..0000000 --- a/security-blueprint/index.md +++ /dev/null @@ -1,22 +0,0 @@ ---- - -title : security-blueprint -date : 2017-12-07 -version : 4.99.4 -category: security -tags: security, architecture, automotive, linux -layout: techdoc - ---- - -## [Intro](./intro.html) -## [Hardware](./part-1/0_Abstract.html) -## [Secure Boot](./part-2/0_Abstract.html) -## [Hypervisor](./part-3/0_Abstract.html) -## [Kernel](./part-4/0_Abstract.html) -## [Platform](./part-5/0_Abstract.html) -## [Application](./part-6/0_Abstract.html) -## [Connectivity](./part-7/0_Abstract.html) -## [Update (OTA)](./part-8/0_Abstract.html) -## [Secure development](./part-9/0_Abstract.html) -## [Annexes](./annexes/0_Abstract.html) diff --git a/security-blueprint/part-1/0_Abstract.md b/security-blueprint/part-1/0_Abstract.md deleted file mode 100644 index e13c464..0000000 --- a/security-blueprint/part-1/0_Abstract.md +++ /dev/null @@ -1,77 +0,0 @@ -# Part 1 - Hardware - -## Abstract - -The Automotive Grade Linux platform is a Linux distribution with **AGL** compliant applications and services. -The platform includes the following hardware: - -- SoC (System-on-Chip). -- Memory (RAM, ROM, storage, etc.). -- Peripherals. - -You will find in this first part everything that concerns the hardware security. -The goal is to protect system against all attacks that are trying to gain -additional privileges by recovering and/or changing cryptographic keys in order -to alter the integrity of the boot. We should also prevent hardware modifications -in order to achieve this goal. We will expose below some examples of possible -configurations. - --------------------------------------------------------------------------------- - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | -------------------------------------- -_HSM_ | **H**ardware **S**ecurity **M**odule -_NVM_ | **N**on-**V**olatile **M**emory -_SHE_ | **S**ecure **H**ardware **E**xtensions - --------------------------------------------------------------------------------- - -## Integrity - -The board must store hardcoded cryptographic keys in order to verify among others -the _integrity_ of the _bootloader_. Manufacturers can use **HSM** and **SHE** to -enhance the security of their board. - -<!-- section-config --> - -Domain | Object | Recommendations --------------------- | ---------- | ---------------------------------- -Hardware-Integrity-1 | Bootloader | Must control bootloader integrity. -Hardware-Integrity-2 | Board | Must use a HSM. -Hardware-Integrity-3 | RTC | Must not be alterable. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Certificates - -<!-- section-config --> - -Domain | Object | Recommendations ----------------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- -Hardware-Certificate-1 | System | Shall allow storing dedicated certificates. -Hardware-Certificate-2 | ECU | The ECU must verify the certification authority hierarchy. -Hardware-Certificate-3 | System | Allow the modification of certificates only if the source can be authenticated by a certificate already stored or in the higher levels of the chain of trust. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Memory - -<!-- section-config --> - -Domain | Object | Recommendations ------------------ | ---------- | ------------------------------------------------------------------------------------ -Hardware-Memory-1 | ECU | The ECU shall never expose the unencrypted key in RAM when using cryptographic keys. -Hardware-Memory-2 | Bootloader | Internal NVM only -Hardware-Module-3 | - | HSM must be used to secure keys. - -<!-- end-section-config --> diff --git a/security-blueprint/part-2/0_Abstract.md b/security-blueprint/part-2/0_Abstract.md deleted file mode 100644 index fa99d89..0000000 --- a/security-blueprint/part-2/0_Abstract.md +++ /dev/null @@ -1,64 +0,0 @@ -# Part 2 - Secure boot - -## Abstract - -<!-- section-todo --> - -Domain | Improvement ---------------- | ---------------------------------------------------- -Boot-Abstract-1 | More generic and add examples (The chain of trust). - -<!-- end-section-todo --> - -Secure boot refers to preventing malicious software applications and -“unauthorized” operating systems from loading during the system start-up process. -The goal is to protect users from rootkits and other low-level malware attacks. -Modern bootloaders come with features that can be used to enable secure boot in the system. - -**Boot Hardening**: Steps/requirements to configure the boot sequence, in order -to restrict the device from executing anything other than the approved software -image. - -In this part, we will see a series of settings that will allow us to improve -security during boot phase. For the purposes of reference and explanation, we -are providing guidance on how to configure an embedded device that runs with a -3.10.17 Linux kernel. If the integrity is not checked or if a critical error -occurs, the system must boot on a very stable backup image. - -**Requirements**: These requirements must be met even if an alternative version -of the Linux kernel is chosen. - -**Recommendations**: Detailed best practices that should be applied in order to -secure a device. Although they are not currently listed as hard requirements, -they may be upgraded to requirements status in the future. In addition, specific -operators may change some of these recommendations into requirements based on -their specific needs and objectives. - -<!-- section-todo --> - -Domain | Improvement ---------------- | ------------------------------------------- -Boot-Abstract-1 | Review the definition of the "boot loader". - -<!-- end-section-todo --> - -**Boot loader**: The boot loader consists of the Primary boot loader residing -in **OTP** memory, sboot, U-Boot and Secure loader residing in external flash -(NAND or SPI/NOR flash memory). The CPU on power on or reset executes the -primary boot loader. The **OTP** primary boot loader makes the necessary initial -system configuration and then loads the secondary boot loader sboot from -external flash memory to ram memory. The sboot then loads the U-Boot along with -the Secure loader. U-Boot then verifies the Kernel/system image integrity, then -loads the Kernel/system image before passing control to it. - --------------------------------------------------------------------------------- - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | ----------------------------------------------------------------------- -_FUSE_ | **F**ilesystem in **U**ser**S**pac**E** -_OTP_ | **O**ne-**T**ime-**P**rogrammable -_DOCSIS_ | **D**ata **O**ver **C**able **S**ervice **I**nterface **S**pecification diff --git a/security-blueprint/part-2/1-Image.md b/security-blueprint/part-2/1-Image.md deleted file mode 100644 index 453b397..0000000 --- a/security-blueprint/part-2/1-Image.md +++ /dev/null @@ -1,52 +0,0 @@ -# Image - -## Image selection - -The boot process shall be uninterruptible and shall irrevocably boot the image -as specified in the boot environment. - -In U-Boot set the "_bootdelay_" environment variable and/or define -`CONFIG_BOOTDELAY` to _-2_. - -<!-- section-config --> - -Domain | _Variable_ / `Config` name | `Value` ----------------------- | -------------------------- | ------- -Boot-Image-Selection-1 | `CONFIG_BOOTDELAY` | `-2` -Boot-Image-Selection-2 | _bootdelay_ | `-2` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Image authenticity - -It shall not be possible to boot from an unverified image. The secure boot -feature in U-Boot shall be enabled. The secure boot feature is available from -U-Boot 2013.07 version. To enable the secure boot feature, enable the following -features: - -``` -CONFIG_FIT: Enables support for Flat Image Tree (FIT) uImage format. -CONFIG_FIT_SIGNATURE: Enables signature verification of FIT images. -CONFIG_RSA: Enables RSA algorithm used for FIT image verification. -CONFIG_OF_CONTROL: Enables Flattened Device Tree (FDT) configuration. -CONFIG_OF_SEPARATE: Enables separate build of u-Boot from the device tree. -CONFIG_DEFAULT_DEVICE_TREE: Specifies the default Device Tree used for the run-time configuration of U-Boot. -``` - -Generate the U-Boot image with public keys to validate and load the image. It -shall use RSA2048 and SHA256 for authentication. - -<!-- section-config --> - -Domain | `Config` name | _State_ -------------------------- | ---------------------------- | -------- -Boot-Image-Authenticity-1 | `CONFIG_FIT` | _Enable_ -Boot-Image-Authenticity-2 | `CONFIG_FIT_SIGNATURE` | _Enable_ -Boot-Image-Authenticity-3 | `CONFIG_RSA` | _Enable_ -Boot-Image-Authenticity-4 | `CONFIG_OF_CONTROL` | _Enable_ -Boot-Image-Authenticity-5 | `CONFIG_OF_SEPARATE` | _Enable_ -Boot-Image-Authenticity-6 | `CONFIG_DEFAULT_DEVICE_TREE` | _Enable_ - -<!-- end-section-config --> diff --git a/security-blueprint/part-2/2-Communication-modes.md b/security-blueprint/part-2/2-Communication-modes.md deleted file mode 100644 index 268da5d..0000000 --- a/security-blueprint/part-2/2-Communication-modes.md +++ /dev/null @@ -1,89 +0,0 @@ -# Communication modes - -## Disable USB, Serial and DOCSIS Support - -To disable USB support in U-Boot, following config's shall not be defined: - -``` -CONFIG_CMD_USB: Enables basic USB support and the usb command. -CONFIG_USB_UHCI: Defines the lowlevel part. -CONFIG_USB_KEYBOARD: Enables the USB Keyboard. -CONFIG_USB_STORAGE: Enables the USB storage devices. -CONFIG_USB_HOST_ETHER: Enables USB Ethernet adapter support. -``` - -In addition, disable unnecessary communication modes like Ethernet, Serial -ports, DOCSIS in U-Boot and sboot that are not necessary. - -Linux Kernel support for USB should be compiled-out if not required. If it is -needed, the Linux Kernel should be configured to only enable the minimum -required USB devices. User-initiated USB-filesystems should be treated with -special care. Whether or not the filesystems are mounted in userspace -(**FUSE**), restricted mount options should be observed. - -<!-- section-config --> - -Domain | Communication modes | _State_ --------------------- | ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- -Boot-Communication-1 | `USB` | _Disabled_ and _Compiled-out_ if not required. -Boot-Communication-2 | `USB` | Else, Kernel should be configured to only enable the minimum required USB devices and filesystems should be treated with special care. -Boot-Communication-3 | `Ethernet` | _Disabled_ -Boot-Communication-4 | U-boot and sboot `DOCSIS` | _Disabled_ -Boot-Communication-5 | `Serial ports` | _Disabled_ - -<!-- end-section-config --> <!-- section-config --> - -Domain | `Config` name | _State_ ------------------------- | ----------------------- | ------------- -Boot-Communication-USB-1 | `CONFIG_CMD_USB` | _Not defined_ -Boot-Communication-USB-2 | `CONFIG_USB_UHCI` | _Not defined_ -Boot-Communication-USB-3 | `CONFIG_USB_KEYBOARD` | _Not defined_ -Boot-Communication-USB-4 | `CONFIG_USB_STORAGE` | _Not defined_ -Boot-Communication-USB-5 | `CONFIG_USB_HOST_ETHER` | _Not defined_ - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable all unused Network Interfaces - -Only used network interfaces should be enabled. -Where possible, services should also be limited to those necessary. - -<!-- section-config --> - -Domain | Communication modes | _State_ --------------------- | -------------------- | --------------------------------------------------------------------------------------------- -Boot-Communication-1 | `Network interfaces` | Preferably _no network interface is allowed_, otherwise, restrict the services to those used. - -<!-- end-section-config --> - -## Remove or Disable Unnecessary Services, Ports, and Devices - -Restrict the `services`, `ports` and `devices` to those used. - -<!-- section-config --> - -Domain | Object | Recommendations --------------------- | --------------------------------- | ------------------------------------------------------------- -Boot-Communication-1 | `Services`, `ports` and `devices` | Restrict the `services`, `ports` and `devices` to those used. - -<!-- end-section-config --> - -## Disable flash access - -**Recommendation**: - -In U-Boot following flash memory commands shall be disabled: - -**NAND**: Support for nand flash access available through `do_nand` has to be disabled. - -<!-- section-config --> - -Domain | `Command` name | _State_ --------------------------- | -------------- | --------- -Boot-Communication-Flash-1 | `do_nand` | _Disable_ - -<!-- end-section-config --> - -Similarly sboot should disable flash access support through command line if any. diff --git a/security-blueprint/part-2/3-Consoles.md b/security-blueprint/part-2/3-Consoles.md deleted file mode 100644 index 0a8faed..0000000 --- a/security-blueprint/part-2/3-Consoles.md +++ /dev/null @@ -1,107 +0,0 @@ -# Consoles - -## Disable serial console - -Serial console output shall be disabled. To disable console output in U-Boot, -set the following macros: - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | --------------------------------------- | --------- -Boot-Consoles-Serial-1 | `CONFIG_SILENT_CONSOLE` | `Disable` -Boot-Consoles-Serial-2 | `CONFIG_SYS_DEVICE_NULLDEV` | `Disable` -Boot-Consoles-Serial-3 | `CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC` | `Disable` - -<!-- end-section-config --> <!-- section-todo --> - -Domain | Improvement ---------------- | ------------------------------------ -Boot-Consoles-1 | Secure loader: No reference earlier? - -<!-- end-section-todo --> - -And set "**silent**" environment variable. For the Secure loader, -disable the traces by not defining the below macro: - -<!-- section-config --> - -Domain | `Environment variable` name | _State_ ----------------------- | --------------------------- | ------------- -Boot-Consoles-Serial-1 | `INC_DEBUG_PRINT` | _Not defined_ - -<!-- end-section-config --> - -For sboot proper configuration needs to be done to disable the serial console. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Immutable environment variables - -In U-Boot, ensure Kernel command line, boot commands, boot delay and other -environment variables are immutable. This will prevent side-loading of alternate -images, by restricting the boot selection to only the image in FLASH. - -The environment variables shall be part of the text region in U-Boot as default -environment variable and not in non-volatile memory. - -Remove configuration options related to non-volatile memory, such as: - -<!-- section-config --> - -Domain | `Config` name | _State_ --------------------------- | ---------------------------- | --------- -Boot-Consoles-Variables-1 | `CONFIG_ENV_IS_IN_MMC` | `#undef` -Boot-Consoles-Variables-2 | `CONFIG_ENV_IS_IN_EEPROM` | `#undef` -Boot-Consoles-Variables-3 | `CONFIG_ENV_IS_IN_FLASH` | `#undef` -Boot-Consoles-Variables-4 | `CONFIG_ENV_IS_IN_DATAFLASH` | `#undef` -Boot-Consoles-Variables-5 | `CONFIG_ENV_IS_IN_FAT` | `#undef` -Boot-Consoles-Variables-6 | `CONFIG_ENV_IS_IN_NAND` | `#undef` -Boot-Consoles-Variables-7 | `CONFIG_ENV_IS_IN_NVRAM` | `#undef` -Boot-Consoles-Variables-8 | `CONFIG_ENV_IS_IN_ONENAND` | `#undef` -Boot-Consoles-Variables-9 | `CONFIG_ENV_IS_IN_SPI_FLASH` | `#undef` -Boot-Consoles-Variables-10 | `CONFIG_ENV_IS_IN_REMOTE` | `#undef` -Boot-Consoles-Variables-11 | `CONFIG_ENV_IS_IN_UBI` | `#undef` -Boot-Consoles-Variables-12 | `CONFIG_ENV_IS_NOWHERE` | `#define` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## (Recommendation) Removal of memory dump commands - -In U-Boot, following commands shall be disabled to avoid memory dumps: - -``` -md : Memory Display command. -mm : Memory modify command - auto incrementing address. -nm : Memory modify command - constant address. -mw : Memory write. -cp : Memory copy. -mwc : Memory write cyclic. -mdc : Memory display cyclic. -mtest : Simple ram read/write test. -loopw : Infinite write loop on address range. -``` - -<!-- section-config --> - -Domain | `Command` name | _State_ ------------------------ | -------------- | ---------- -Boot-Consoles-MemDump-1 | `md` | _Disabled_ -Boot-Consoles-MemDump-2 | `mm` | _Disabled_ -Boot-Consoles-MemDump-3 | `nm` | _Disabled_ -Boot-Consoles-MemDump-4 | `mw` | _Disabled_ -Boot-Consoles-MemDump-5 | `cp` | _Disabled_ -Boot-Consoles-MemDump-6 | `mwc` | _Disabled_ -Boot-Consoles-MemDump-7 | `mdc` | _Disabled_ -Boot-Consoles-MemDump-8 | `mtest` | _Disabled_ -Boot-Consoles-MemDump-9 | `loopw` | _Disabled_ - -<!-- end-section-config --> - -Similarly, memory dump support shall be disabled from sboot. diff --git a/security-blueprint/part-3/0_Abstract.md b/security-blueprint/part-3/0_Abstract.md deleted file mode 100644 index c6e3942..0000000 --- a/security-blueprint/part-3/0_Abstract.md +++ /dev/null @@ -1,18 +0,0 @@ -# Part 3 - Hypervisor - -Definition: "A hypervisor or virtual machine monitor (VMM) is computer software, -firmware or hardware that creates and runs virtual machines". - -It must include a signature verification (possibly delegated). - -<!-- section-todo --> - -Domain | Improvement ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- -Hypervisor-Abstract-1 | Complete Hypervisor part ([jailhouse](https://github.com/siemens/jailhouse) / [KVM](https://www.linux-kvm.org/page/Main_Page) / [Xen](https://www.xenproject.org/developers/teams/embedded-and-automotive.html)). - -<!-- end-section-todo --> - -## Native or Bare-metal hypervisors - -These hypervisors run directly on the host's hardware to control the hardware and to manage guest operating systems. Those are the ones we're interested in. diff --git a/security-blueprint/part-4/0_Abstract.md b/security-blueprint/part-4/0_Abstract.md deleted file mode 100644 index 01957e4..0000000 --- a/security-blueprint/part-4/0_Abstract.md +++ /dev/null @@ -1,60 +0,0 @@ -# Part 4 - Kernel - -## Abstract - -**System Hardening:** Best practices associated with the configuration of an -embedded Linux based operating system. This section includes both hardening of -the kernel itself, as well as specific configurations and patches used to -protect against known vulnerabilities within the build and configuration of the -root filesystem. - -At the Kernel level, we must ensure that no console can be launched. It could be -used to change the behavior of the system or to have more information about it. -Another aspect is the protection of the memory used by the Kernel. - -The next sub-sections contain information on various kernel configuration -options to enhance the security in the kernel (3.10.17) and also for -applications compiled to take advantage of these security features. -Additionally, there are also configuration options that protect from known -vulnerable configuration options. Here's a high level summary of various kernel -configurations that shall be required for deployment. - -## Kernel Version - -The choice of kernel version for the AGL system is essential to its security. -Depending on the type of board and eventual production system, different kernel -versions are used. For example, one of the systems under study uses the -Linux kernel version 3.10, while another uses the Linux kernel version 4.4. -For the Linux kernel version 3.10.31, there are 25 known vulnerabilities. -These vulnerabilities would allow an attacker to gain privileges, -bypass access restrictions, allow memory to be corrupted, or cause denial of service. -In contrast, the Linux kernel version of 4.4 has many fewer known vulnerabilities. -For this reason, we would in general recommend the later kernel version as a basis -for the platform. - -Note that, although there are fewer known vulnerabilities in the most recent kernel -versions there may be many unknown vulnerabilities underlying. -A rule of thumb is to update the kernel as much as possible to avoid the problems -you do know, but you should not be complacent in the trust that you place in it. -A defense-in-depth approach would then apply. - -If there are constraints and dependencies in upgrading to a newer kernel version -(e.g. device drivers, board support providers) and you are forced to an older -Linux kernel version, there need to be additional provisions made to reduce -the risk of kernel exploits, which can include memory monitoring, watch-dog services, -and system call hooking. In this case, further defense-in-depth techniques -may be required to mitigate the risk of attacks to known vulnerabilities, -which can also include runtime integrity verification of components -that are vulnerable to tampering. - -## Kernel Build Configuration - -The kernel build configuration is extremely important for determining the level -of access to services and to reduce the breadth of the attack surface. -Linux contains a great and flexible number of capabilities and this is only controlled -through the build configuration. For example, the `CONFIG_MODULES` parameter -allows kernel modules to be loaded at runtime extending the capabilities of the kernel. -This capability needs to be either inhibited or controlled at runtime through -other configuration parameters. For example, `CONFIG_MODULE_SIG_FORCE=y` ensures -that only signed modules are loaded. There is a very large number of kernel -configuration parameters, and these are discussed in detail in this section. diff --git a/security-blueprint/part-4/1-General.md b/security-blueprint/part-4/1-General.md deleted file mode 100644 index 54c7ea8..0000000 --- a/security-blueprint/part-4/1-General.md +++ /dev/null @@ -1,278 +0,0 @@ -# General configuration - -## Mandatory Access Control - -Kernel should controls access with labels and policy. - -<!-- section-config --> - -Domain | `Config` name | `Value` --------------------- | -------------- | -------------------------------------- -Kernel-General-MAC-1 | CONFIG_IP_NF_SECURITY | m -Kernel-General-MAC-2 | CONFIG_IP6_NF_SECURITY | m -Kernel-General-MAC-3 | CONFIG_EXT2_FS_SECURITY | y -Kernel-General-MAC-4 | CONFIG_EXT3_FS_SECURITY | y -Kernel-General-MAC-5 | CONFIG_EXT4_FS_SECURITY | y -Kernel-General-MAC-6 | CONFIG_SECURITY | y -Kernel-General-MAC-7 | CONFIG_SECURITY_SMACK | y -Kernel-General-MAC-8 | CONFIG_TMPFS_XATTR | y - -<!-- end-section-config --> - -Please also refer to the [**Mandatory Access Control** documentation in Platform](../part-5/1-MAC.html) part. -You can also find useful documentation and links on wikipedia about [**MAC**](https://en.wikipedia.org/wiki/Mandatory_access_control) -and about [**SMACK**](https://en.wikipedia.org/wiki/Simplified_Mandatory_Access_Control_Kernel). - --------------------------------------------------------------------------------- - -## Disable kexec - -**Kexec** is a system call that enables you to load and boot into another kernel from the currently running kernel. This feature is not required in a production environment. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | -------------- | ------- -Kernel-General-kexec-1 | `CONFIG_KEXEC` | `n` - -<!-- end-section-config --> - -<!-- section-note --> - -**kexec** can load arbitrary kernels but signing of new kernel can be enforced like it is can be enforced for new modules. - -<!-- end-section-note --> - --------------------------------------------------------------------------------- - -## Disable kernel IP auto-configuration - -It is preferable to have an IP configuration performed using a user-space tool as these tend to have more validation. We do not want the network interface coming up until the system has come up properly. - -<!-- section-config --> - -Domain | `Config` name | `Value` ---------------------------- | --------------- | ------- -Kernel-General-IPAutoConf-1 | `CONFIG_IP_PNP` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable Sysctl syscall support - -Enabling this will result in code being included that is hard to maintain and not well tested. - -<!-- section-config --> - -Domain | `Config` name | `Value` -------------------------------- | ----------------------- | ------- -Kernel-General-SysCtl_SysCall-1 | `CONFIG_SYSCTL_SYSCALL` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable Legacy Linux Support - -There are some Kernel Configs which are present only to support legacy binaries. See also "Consoles" part in order to disabling support for legacy binary formats. The `uselib` system call, in particular, has no valid use in any `libc6` or `uclibc` system in recent times. This configuration is supported in **Linux 3.15 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------------- | --------------- | ------- -Kernel-General-LegacyLinux-1 | `CONFIG_USELIB` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable firmware auto-loading user mode helper - -The firmware auto loading helper, which is a utility executed by the kernel on `hotplug` events requiring firmware, can to be set `setuid`. As a result of this, the helper utility is an attractive target for attackers with control of physical ports on the device. Disabling this configuration that is supported in **Linux 3.9 and greater**. - -<!-- section-config --> - -Domain | `Config` name | `Value` ---------------------------- | ------------------------------ | ------- -Kernel-General-FirmHelper-1 | `CONFIG_FW_LOADER_USER_HELPER` | `n` - -<!-- end-section-config --> - -<!-- section-note --> - -It doesn't strictly need to be `setuid`, there is an option of shipping firmware builtin into kernel without initrd/filesystem. - -<!-- end-section-note --> - --------------------------------------------------------------------------------- - -## Enable Kernel Panic on OOPS - -When fuzzing the kernel or attempting kernel exploits attackers are likely to trigger kernel OOPSes. Setting the behavior on OOPS to PANIC can impede their progress. - -This configuration is supported in **Linux 3.5 and greater** and thus should only be enabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------------- | ---------------------- | ------- -Kernel-General-PanicOnOOPS-1 | `CONFIG_PANIC_ON_OOPS` | `y` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable socket monitoring interface - -These monitors can be used to inspect shared file descriptors on Unix Domain sockets or traffic on 'localhost' which is otherwise assumed to be confidential. - -The `CONFIG_PACKET_DIAG` configuration is supported in **Linux 3.7 and greater** and thus should only be disabled for such versions. - -The `CONFIG_UNIX_DIAG` configuration is supported in **Linux 3.3 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` --------------------------- | -------------------- | ------- -Kernel-General-SocketMon-1 | `CONFIG_PACKET_DIAG` | `n` -Kernel-General-SocketMon-2 | `CONFIG_UNIX_DIAG` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable BPF JIT - -The BPF JIT can be used to create kernel-payloads from firewall table rules. - -This configuration for is supported in **Linux 3.16 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ---------------- | ------- -Kernel-General-BPF_JIT-1 | `CONFIG_BPF_JIT` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Enable Enforced Module Signing - -The kernel should never allow an unprivileged user the ability to load specific kernel modules, -since that would provide a facility to unexpectedly extend the available attack surface. - -To protect against even privileged users, systems may need to either disable -module loading entirely, or provide signed modules -(e.g. `CONFIG_MODULE_SIG_FORCE`, or dm-crypt with LoadPin), to keep from having -root load arbitrary kernel code via the module loader interface. - -This configuration is supported in **Linux 3.7 and greater** and thus should only be enabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------- | ------------------------- | ------- -Kernel-General-ModuleSigning-1 | `CONFIG_MODULE_SIG_FORCE` | `y` - -<!-- end-section-config --> - -It is also possible to block the loading of modules after startup with "kernel.modules_disabled". - -<!-- section-config --> - -Domain | `Variable` name | `Value` ------------------------------- | ------------------------- | ------- -Kernel-General-ModuleSigning-2 | `kernel.modules_disabled` | `1` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable all USB, PCMCIA (and other `hotplug` bus) drivers that aren't needed - -To reduce the attack surface, the driver enumeration, probe, and operation happen in the kernel. The driver data is parsed by the kernel, so any logic bugs in these drivers can become kernel exploits. - -<!-- section-config --> - -Domain | Object | _State_ ------------------------- | ------------------- | ---------- -Kernel-General-Drivers-1 | `USB` | _Disabled_ -Kernel-General-Drivers-2 | `PCMCIA` | _Disabled_ -Kernel-General-Drivers-3 | Other `hotplug` bus | _Disabled_ - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Position Independent Executables - -<!-- section-todo --> - -Domain | Improvement --------------------------------- | ----------------------------- -Kernel-General-IndependentExec-1 | Kernel or/and platform part ? - -<!-- end-section-todo --> - -<!-- section-config --> - -Domain | `compiler` and `linker` options | _State_ --------------------------------- | ------------------------------- | -------- -Kernel-General-IndependentExec-1 | `-pie -fpic` | _Enable_ - -<!-- end-section-config --> - -Produce a position independent executable on targets which supports it. - --------------------------------------------------------------------------------- - -## Prevent Overwrite Attacks - -`-z,relro` linking option helps during program load, several ELF memory sections need to be written by the linker, but can be turned read-only before turning over control to the program. This prevents some Global Offset Table GOT overwrite attacks, or in the dtors section of the ELF binary. - -<!-- section-config --> - -Domain | `compiler` and `linker` options | _State_ ---------------------------------- | ------------------------------- | -------- -Kernel-General-OverwriteAttacks-1 | `-z,relro` | _Enable_ -Kernel-General-OverwriteAttacks-2 | `-z,now` | _Enable_ - -<!-- end-section-config --> - -During program load, all dynamic symbols are resolved, allowing for the complete GOT to be marked read-only (due to `-z relro` above). This prevents GOT overwrite attacks. For very large application, this can incur some performance loss during initial load while symbols are resolved, but this shouldn't be an issue for daemons. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Library linking - -<!-- section-todo --> - -Domain | Improvement -------------------------------- | --------------- -Kernel-General-LibraryLinking-1 | Keep this part? - -<!-- end-section-todo --> - -It is recommended that dynamic linking should generally not be allowed. This will avoid the user from replacing a library with malicious library. - -<!-- section-config --> - -Domain | Object | Recommendations -------------------------------- | --------------- | -------------------------------- -Kernel-General-LibraryLinking-1 | Dynamic linking | Should generally not be allowed. - -<!-- end-section-config --> - -<!-- section-note --> - -Linking everything statically doesn't change anything wrt security as binaries will live under same user:group as libraries and setuid executables ignore `LD_PRELOAD/LD_LIBRARY_PATH`. It also increases RSS footprint and creates problems with upgrading. - -<!-- end-section-note --> diff --git a/security-blueprint/part-4/2-Memory.md b/security-blueprint/part-4/2-Memory.md deleted file mode 100644 index d7af446..0000000 --- a/security-blueprint/part-4/2-Memory.md +++ /dev/null @@ -1,156 +0,0 @@ -# Memory - -## Restrict access to kernel memory - -The /dev/kmem file in Linux systems is directly mapped to kernel virtual memory. This can be disastrous if an attacker gains root access, as the attacker would have direct access to kernel virtual memory. - -To disable the /dev/kmem file, which is very infrequently used by applications, the following kernel option should be set in the compile-time kernel configuration: - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------- | ---------------- | ------- -Kernel-Memory-RestrictAccess-1 | `CONFIG_DEVKMEM` | `n` - -<!-- end-section-config --> - -In case applications in userspace need /dev/kmem support, it should be available only for authenticated applications. - --------------------------------------------------------------------------------- - -## Disable access to a kernel core dump - -This kernel configuration disables access to a kernel core dump from user space. If enabled, it gives attackers a useful view into kernel memory. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ------------------- | ------- -Kernel-Memory-CoreDump-1 | `CONFIG_PROC_KCORE` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable swap - -If not disabled, attackers can enable swap at runtime, add pressure to the memory subsystem and then scour the pages written to swap for useful information. - -<!-- section-config --> - -Domain | `Config` name | `Value` --------------------- | ------------- | ------- -Kernel-Memory-Swap-1 | `CONFIG_SWAP` | `n` - -<!-- end-section-config --> - -<!-- section-note --> - -- Enabling swap at runtime require `CAP_SYS_ADMIN`. -- Swap block device is usually under root:disk. -- Linux never swaps kernel pages. -- If swap disabling is not possible, swap encryption should be enabled. - -<!-- end-section-note --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable "Load All Symbols" - -There is a /proc/kallsyms file which exposes the kernel memory space address of many kernel symbols (functions, variables, etc...). This information is useful to attackers in identifying kernel versions/configurations and in preparing payloads for the exploits of kernel space. - -Both `KALLSYMS_ALL` and `KALLSYMS` shall be disabled; - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------- | --------------------- | ------- -Kernel-Memory-LoadAllSymbols-1 | `CONFIG_KALLSYMS` | `n` -Kernel-Memory-LoadAllSymbols-2 | `CONFIG_KALLSYMS_ALL` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Stack protection - -To prevent stack-smashing, similar to the stack protector used for ELF programs in user-space, the kernel can protect its internal stacks as well. - -This configuration is supported in **Linux 3.11 and greater** and thus should only be enabled for such versions. - -This configuration also requires building the kernel with the **gcc compiler 4.2 or greater**. - -<!-- section-config --> - -Domain | `Config` name | `Value` ---------------------- | -------------------------- | ------- -Kernel-Memory-Stack-1 | `CONFIG_CC_STACKPROTECTOR` | `y` - -<!-- end-section-config --> - -Other defenses include things like shadow stacks. - --------------------------------------------------------------------------------- - -## Disable access to /dev/mem - -The /dev/mem file in Linux systems is directly mapped to physical memory. This can be disastrous if an attacker gains root access, as the attacker would have direct access to physical memory through this convenient device file. It may not always be possible to disable such file, as some applications might need such support. In that case, then this device file should be available only for authenticated applications. - -This configuration is supported in **Linux 4.0 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | --------------- | ------- -Kernel-Memory-Access-1 | `CONFIG_DEVMEM` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable cross-memory attach - -Disable the process_vm_*v syscalls which allow one process to peek/poke the virtual memory of another. - -This configuration is supported in **Linux 3.5 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------- | --------------------- | ------- -Kernel-Memory-CrossMemAttach-1 | `CROSS_MEMORY_ATTACH` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Stack Smashing Attacks - -<!-- section-config --> - -Domain | `compiler` and `linker` options | _State_ ------------------------------ | ------------------------------- | -------- -Kernel-Memory-StackSmashing-1 | `-fstack-protector-all` | _Enable_ - -<!-- end-section-config --> - -Emit extra code to check for buffer overflows, such as stack smashing attacks. - --------------------------------------------------------------------------------- - -## Detect Buffer Overflows - -<!-- section-config --> - -Domain | `compiler` options and `config` name | `Value` -------------------------------- | ------------------------------------ | ------- -Kernel-Memory-BufferOverflows-1 | `-D_FORTIFY_SOURCE` | `2` -Kernel-Memory-BufferOverflows-2 | `CONFIG_FORTIFY_SOURCE` | `y` - -<!-- end-section-config --> - -Helps detect some buffer overflow errors. diff --git a/security-blueprint/part-4/3-Consoles.md b/security-blueprint/part-4/3-Consoles.md deleted file mode 100644 index c6cf80a..0000000 --- a/security-blueprint/part-4/3-Consoles.md +++ /dev/null @@ -1,78 +0,0 @@ -# Serial - -## Disable serial console - -The serial console should be disabled to prevent an attacker from accessing this powerful interface. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ---------------------------- | ------- -Kernel-Consoles-Serial-1 | `CONFIG_SERIAL_8250` | `n` -Kernel-Consoles-Serial-2 | `CONFIG_SERIAL_8250_CONSOLE` | `n` -Kernel-Consoles-Serial-3 | `CONFIG_SERIAL_CORE` | `n` -Kernel-Consoles-Serial-4 | `CONFIG_SERIAL_CORE_CONSOLE` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Bake-in the kernel command-line - -The kernel command-line is used to control many aspects of the booting kernel, and is prone to tampering as they are passed in RAM with little to no reverse validation on these parameters. To prevent this type of attack, the kernel shall be configured to ignore commands line arguments, and use pre-configured (compile time) options instead. - -Set the kernel command line in the `CONFIG_CMDLINE KConfig` item and then pass no arguments from the bootloader. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------ | ------------------------- | ----------------------------------- -Kernel-Consoles-CommandLine-1 | `CONFIG_CMDLINE_BOOL` | `y` -Kernel-Consoles-CommandLine-2 | `CONFIG_CMDLINE` | `"insert kernel command line here"` -Kernel-Consoles-CommandLine-3 | `CONFIG_CMDLINE_OVERRIDE` | `y` - -<!-- end-section-config --> - -It is recommended that any per-device settings (e.g: MAC addresses, serial numbers, etc.) be stored and accessed from read-only memory (or files), and that any such parameters be verified (signature checking) prior to their use. - --------------------------------------------------------------------------------- - -## Disable KGDB - -The Linux kernel supports KGDB over USB and console ports. These mechanisms are controlled by the `kgdbdbgp` and `kgdboc` kernel command-line parameters. It is important to ensure that no shipping product contains a kernel with KGDB compiled-in. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | ------------- | ------- -Kernel-Consoles-KDBG-1 | `CONFIG_KGDB` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable magic sysrq support - -On a few architectures, you can access a powerful debugger interface from the keyboard. The same powerful interface can be present on the serial console (responding to serial break) of Linux on other architectures. Disable to avoid potentially exposing this powerful backdoor. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------ | -------------------- | ------- -Kernel-Consoles-SysRQ-1 | `CONFIG_MAGIC_SYSRQ` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable support for binary formats other than ELF - -This will make possible to plug wrapper-driven binary formats into the kernel. It enables support for binary formats other than ELF. Providing the ability to use alternate interpreters would assist an attacker in discovering attack vectors. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------------- | -------------------- | ------- -Kernel-Consoles-BinaryFormat-1 | `CONFIG_BINFMT_MISC` | `n` - -<!-- end-section-config --> diff --git a/security-blueprint/part-4/4-Debug.md b/security-blueprint/part-4/4-Debug.md deleted file mode 100644 index cce5fc0..0000000 --- a/security-blueprint/part-4/4-Debug.md +++ /dev/null @@ -1,208 +0,0 @@ -# Debug - -No debuggers shall be present on the file system. This includes, but is not limited to, the GNU Debugger client/server (commonly known in their short form names such as the `gdb` and `gdbserver` executable binaries respectively), the `LLDB` next generation debugger or the `TCF` (Target Communications Framework) agnostic framework. Including these binaries as part of the file system will facilitate an attacker's ability to reverse engineer and debug (either locally or remotely) any process that is currently executing on the device. - -## Kernel debug symbols - -Debug symbols should always be removed from production kernels as they provide a lot of information to attackers. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | ------------------- | ------- -Kernel-Debug-Symbols-1 | `CONFIG_DEBUG_INFO` | `n` - -<!-- end-section-config --> - -These kernel debug symbols are enabled by other config items in the kernel. Care should be taken to disable those also. If `CONFIG_DEBUG_INFO` cannot be disabled, then enabling `CONFIG_DEBUG_INFO_REDUCED` is second best. - -<!-- section-note --> - -At least `CONFIG_DEBUG_INFO_REDUCED` should be always enabled for developers to convert addresses in oops messages to line numbers. - -<!-- end-section-note --> - --------------------------------------------------------------------------------- - -## Disable Kprobes - -Kprobes enables you to dynamically break into any kernel routine and collect debugging and performance information non-disruptively. You can trap at almost any kernel code address, specifying a handler routine to be invoked when the breakpoint is hit. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | ---------------- | ------- -Kernel-Debug-Kprobes-1 | `CONFIG_KPROBES` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable Tracing - -FTrace enables the kernel to trace every kernel function. Providing kernel trace functionality would assist an attacker in discovering attack vectors. - -<!-- section-config --> - -Domain | `Config` name | `Value` ----------------------- | --------------- | ------- -Kernel-Debug-Tracing-1 | `CONFIG_FTRACE` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable Profiling - -Profiling and OProfile enables profiling the whole system, include the kernel, kernel modules, libraries, and applications. Providing profiling functionality would assist an attacker in discovering attack vectors. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ------------------ | ------- -Kernel-Debug-Profiling-1 | `CONFIG_OPROFILE` | `n` -Kernel-Debug-Profiling-2 | `CONFIG_PROFILING` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable OOPS print on BUG() - -The output from OOPS print can be helpful in Return Oriented Programming (ROP) when trying to determine the effectiveness of an exploit. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ------------------------- | ------- -Kernel-Debug-OOPSOnBUG-1 | `CONFIG_DEBUG_BUGVERBOSE` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable Kernel Debugging - -There are development-only branches of code in the kernel enabled by the `DEBUG_KERNEL` conf. This should be disabled to compile-out these branches. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------- | --------------------- | ------- -Kernel-Debug-Dev-1 | `CONFIG_DEBUG_KERNEL` | `n` -Kernel-Debug-Dev-2 | `CONFIG_EMBEDDED` | `n` - -<!-- end-section-config --> - -In some kernel versions, disabling this requires also disabling `CONFIG_EMBEDDED`, and `CONFIG_EXPERT`. Disabling `CONFIG_EXPERT` makes it impossible to disable `COREDUMP`, `DEBUG_BUGVERBOSE`, `NAMESPACES`, `KALLSYMS` and `BUG`. In which case it is better to leave this enabled than enable the others. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable the kernel debug filesystem - -The kernel debug filesystem presents a lot of useful information and means of manipulation of the kernel to an attacker. - -<!-- section-config --> - -Domain | `Config` name | `Value` -------------------------- | ----------------- | ------- -Kernel-Debug-FileSystem-1 | `CONFIG_DEBUG_FS` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable BUG() support - -The kernel will display backtrace and register information for BUGs and WARNs in kernel space, making it easier for attackers to develop exploits. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------- | ------------- | ------- -Kernel-Debug-BUG-1 | `CONFIG_BUG` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Disable core dumps - -Core dumps provide a lot of debug information for hackers. So disabling core dumps are recommended in production builds. - -This configuration is supported in **Linux 3.7 and greater** and thus should only be disabled for such versions. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | ----------------- | ------- -Kernel-Debug-CoreDumps-1 | `CONFIG_COREDUMP` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Kernel Address Display Restriction - -When attackers try to develop "run anywhere" exploits for kernel vulnerabilities, they frequently need to know the location of internal kernel structures. By treating kernel addresses as sensitive information, those locations are not visible to regular local users. - -**/proc/sys/kernel/kptr_restrict is set to "1"** to block the reporting of known kernel address leaks. - -<!-- section-config --> - -Domain | `File` name | `Value` ----------------------------- | -------------------------------- | ------- -Kernel-Debug-AdressDisplay-1 | `/proc/sys/kernel/kptr_restrict` | `1` - -<!-- end-section-config --> - -Additionally, various files and directories should be readable only by the root user: `/boot/vmlinuz*`, `/boot/System.map*`, `/sys/kernel/debug/`, `/proc/slabinfo` - -<!-- section-config --> - -Domain | `File` or `Directorie` name | _State_ ----------------------------- | --------------------------- | ----------------------------- -Kernel-Debug-AdressDisplay-1 | `/boot/vmlinuz*` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-2 | `/boot/System.map*` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-3 | `/sys/kernel/debug/` | _Readable Only for root user_ -Kernel-Debug-AdressDisplay-4 | `/proc/slabinfo` | _Readable Only for root user_ - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## DMESG Restrictions - -When attackers try to develop "run anywhere" exploits for vulnerabilities, they frequently will use `dmesg` output. By treating `dmesg` output as sensitive information, this output is not available to the attacker. - -**/proc/sys/kernel/dmesg_restrict can be set to "1"** to treat dmesg output as sensitive. - -<!-- section-config --> - -Domain | `File` name | `Value` --------------------- | --------------------------------- | ------- -Kernel-Debug-DMESG-1 | `/proc/sys/kernel/dmesg_restrict` | `1` - -<!-- end-section-config --> - -Enable the below compiler and linker options when building user-space applications to avoid stack smashing, buffer overflow attacks. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Disable /proc/config.gz - -It is extremely important to not expose the kernel configuration used on a production device to a potential attacker. With access to the kernel config, it could be possible for an attacker to build a custom kernel for the device that may disable critical security features. - -<!-- section-config --> - -Domain | `Config` name | `Value` ---------------------- | ----------------- | ------- -Kernel-Debug-Config-1 | `CONFIG_IKCONFIG` | `n` - -<!-- end-section-config --> diff --git a/security-blueprint/part-4/5-FileSystems.md b/security-blueprint/part-4/5-FileSystems.md deleted file mode 100644 index 78f2050..0000000 --- a/security-blueprint/part-4/5-FileSystems.md +++ /dev/null @@ -1,60 +0,0 @@ -# File System - -## Disable all file systems not needed - -To reduce the attack surface, file system data is parsed by the kernel, so any logic bugs in file system drivers can become kernel exploits. - -### Disable NFS file system - -NFS FileSystems are useful during development phases, but this can be a very helpful way for an attacker to get files when you are in production mode, so we must disable them. - -<!-- section-config --> - -Domain | `Config` name | `Value` ------------------------- | --------------- | ------- -Kernel-FileSystems-NFS-1 | `CONFIG_NFSD` | `n` -Kernel-FileSystems-NFS-2 | `CONFIG_NFS_FS` | `n` - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Partition Mount Options - -There are several security restrictions that can be set on a filesystem when it is mounted. Some common security options include, but are not limited to: - -`nosuid` - Do not allow set-user-identifier or set-group-identifier bits to take effect. - -`nodev` - Do not interpret character or block special devices on the filesystem. - -`noexec` - Do not allow execution of any binaries on the mounted filesystem. - -`ro` - Mount filesystem as read-only. - -The following flags shall be used for mounting common filesystems: - -<!-- section-config --> - -Domain | `Partition` | `Value` --------------------------- | ------------------- | ----------------------------------------------------------------- -Kernel-FileSystems-Mount-1 | `/boot` | `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-2 | `/var` & `/tmp` | In `/etc/fstab` or `vfstab`, add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-3 | _Non-root local_ | If type is `ext2` or `ext3` and mount point not '/', add `nodev`. -Kernel-FileSystems-Mount-4 | _Removable storage_ | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-5 | _Temporary storage_ | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-6 | `/dev/shm` | Add `nosuid`, `nodev` and `noexec`. -Kernel-FileSystems-Mount-7 | `/dev` | Add `nosuid` and `noexec`. - -<!-- end-section-config --> <!-- section-note --> - -If `CONFIG_DEVTMPFS_MOUNT` is set, then the kernel will mount /dev and will not apply the `nosuid`, `noexec` options. Either disable `CONFIG_DEVTMPFS_MOUNT` or add a remount with `noexec` and `nosuid` options to system startup. - -<!-- end-section-note --> <!-- section-config --> - -Domain | `Config` name | _State_ or `Value` --------------------------- | ----------------------- | ----------------------------------------------------------------------- -Kernel-FileSystems-Mount-1 | `CONFIG_DEVTMPFS_MOUNT` | _Disabled_ or add remount with `noexec` and `nosuid` to system startup. - -<!-- end-section-config --> diff --git a/security-blueprint/part-5/0_Abstract.md b/security-blueprint/part-5/0_Abstract.md deleted file mode 100644 index ddf7d2a..0000000 --- a/security-blueprint/part-5/0_Abstract.md +++ /dev/null @@ -1,103 +0,0 @@ -# Part 5 - Platform - -## Abstract - -The Automotive Grade Linux platform is a Linux distribution with **AGL** compliant applications and services. -The platform includes the following software: - -- Linux **BSP** configured for reference boards. -- Proprietary device drivers for common peripherals on reference boards. -- Application framework. -- Windows/layer management (graphics). -- Sound resource management. -- An atomic software update system (chapter Update). -- Building and debug tools (based on Yocto project). - -<!-- section-todo --> - -Domain | Improvement -------------------- | -------------------------------- -Platform-Abstract-1 | Create a graphics and sound part. - -<!-- end-section-todo --> - -This part focuses on the AGL platform including all tools and techniques used to -upgrade the security and downgrade the danger. It must be possible to apply the -two fundamental principles written at the very beginning of the document. First -of all, security management must remain simple. You must also prohibit -everything by default, and then define a set of authorization rules. As cases -to deal with, we must: - -- Implement a **MAC** for processes and files. -- Limit communication between applications (_SystemBus_ and _SystemD_ part). -- Prohibit all tools used during development mode (_Utilities_ and _Services_ part). -- Manage user capabilities (_Users_ part). -- Manage application permissions and policies (_AGLFw_ part). - -<!-- section-note --> - -The tools and concepts used to meet these needs are only examples. -Any other tool that meets the need can be used. - -<!-- end-section-note --> - -In AGL, as in many other embedded systems, different security mechanisms settle -in the core layers to ensure isolation and data privacy. While the Mandatory -Access Control layer (**SMACK**) provides global security and isolation, other -mechanisms like **Cynara** are required to check application's permissions at -runtime. Applicative permissions (also called "_privileges_") may vary depending -on the user and the application being run: an application should have access to -a given service only if it is run by the proper user and if the appropriate -permissions are granted. - -## Discretionary Access Control - -**D**iscretionary **A**ccess **C**ontrol (**DAC**) is the traditional Linux method of separating -users and groups from one another. In a shared environment where multiple users -have access to a computer or network, Unix IDs have offered a way to contain access -within privilege areas for individuals, or shared among the group or system. -The Android system took this one step further, assigning new user IDs for each App. -This was never the original intention of Linux UIDs, but was able to provide -Android’s initial security element: the ability to sandbox applications. - -Although AGL mentions use of **DAC** for security isolation, the weight of the -security responsibility lies in the **M**andatory **A**ccess **C**ontrol (**MAC**) and **Cynara**. -Furthermore, there are system services with unique UIDs. however,the system -does not go to the extreme of Android, where every application has its own UID. -All sandboxing (app isolation) in AGL is handled in the **MAC** contexts. - -## Mandatory Access Control - -**M**andatory **A**ccess **C**ontrol (**MAC**) is an extension to **DAC**, -whereby extended attributes (xattr) are associated with the filesystem. -In the case of AGL, the smackfs filesystem allows files and directories -to be associated with a SMACK label, providing the ability of further -discrimination on access control. A SMACK label is a simple null terminated -character string with a maximum of 255 bytes. While it doesn’t offer the -richness of an SELinux label, which provides a user, role,type, and level, -the simplicity of a single value makes the overall design far less complex. -There is arguably less chance of the security author making mistakes in the policies set forth. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | -------------------------------------------------------------- -_ACL_ | **A**ccess **C**ontrol **L**ists -_alsa_ | **A**dvanced **L**inux **S**ound **A**rchitecture -_API_ | **A**pplication **P**rogramming **I**nterface -_AppFw_ | **App**lication **F**rame**w**ork -_BSP_ | **B**oard **S**upport **P**ackage -_Cap_ | **Cap**abilities -_DAC_ | **D**iscretionary **A**ccess **C**ontrol -_DDOS_ | **D**istributed **D**enial **O**f **S**ervice -_DOS_ | **D**enial **O**f **S**ervice -_IPC_ | **I**nter-**P**rocess **C**ommunication -_MAC_ | **M**andatory **A**ccess **C**ontrol -_PAM_ | **P**luggable **A**uthentication **M**odules -_SMACK_ | **S**implified **M**andatory **A**ccess **C**ontrol **K**ernel diff --git a/security-blueprint/part-5/1-MAC.md b/security-blueprint/part-5/1-MAC.md deleted file mode 100644 index 73543e9..0000000 --- a/security-blueprint/part-5/1-MAC.md +++ /dev/null @@ -1,165 +0,0 @@ -# Mandatory Access Control - -<!-- section-note --> - -We decided to put the **MAC** protection on the platform part despite the fact -that it applies to the kernel too, since its use will be mainly at the platform -level (except floor part). - -<!-- end-section-note --> - -**M**andatory **A**ccess **C**ontrol (**MAC**) is a protection provided by the -Linux kernel that requires a **L**inux **S**ecurity **M**odule (**LSM**). AGL -uses an **LSM** called **S**implified **M**andatory **A**ccess **C**ontrol -**K**ernel (**SMACK**). This protection involves the creation of **SMACK** -labels as part of the extended attributes **SMACK** labels to the file extended -attributes. And a policy is also created to define the behaviour of each label. - -The kernel access controls is based on these labels and this policy. If there -is no rule, no access will be granted and as a consequence, what is not -explicitly authorized is forbidden. - -There are two types of **SMACK** labels: - -- **Execution SMACK** (Attached to the process): Defines how files are - _accessed_ and _created_ by that process. -- **File Access SMACK** (Written to the extended attribute of the file): Defines - _which_ process can access the file. - -By default a process executes with its File Access **SMACK** label unless an -Execution **SMACK** label is defined. - -AGL's **SMACK** scheme is based on the _Tizen 3 Q2/2015_. It divides the System -into the following domains: - -- Floor. -- System. -- Applications, Services and User. - -See [AGL security framework review](http://iot.bzh/download/public/2017/AMMQ1Tokyo/AGL-security-framework-review.pdf) and [Smack White Paper](http://schaufler-ca.com/yahoo_site_admin/assets/docs/SmackWhitePaper.257153003.pdf) -for more information. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Floor - -The _floor_ domain includes the base system services and any associated data and -libraries. This data remains unchanged at runtime. Writing to floor files or -directories is allowed only in development mode or during software installation -or upgrade. - -The following table details the _floor_ domain: - -Label | Name | Execution **SMACK** | File Access **SMACK** ------ | ----- | ------------------- | --------------------------------------- -`-` | Floor | `r-x` for all | Only kernel and internal kernel thread. -`^` | Hat | `---` for all | `rx` on all domains. -`*` | Star | `rwx` for all | None - -<!-- section-note --> - -- The Hat label is Only for privileged system services (currently only - systemd-journal). Useful for backup or virus scans. No file with this label - should exist except in the debug log. - -- The Star label is used for device files or `/tmp` Access restriction managed - via **DAC**. Individual files remain protected by their **SMACK** label. - -<!-- end-section-note --> <!-- section-config --> - -Domain | `Label` name | Recommendations ------------------- | ------------ | ----------------------------------------------------------- -Kernel-MAC-Floor-1 | `^` | Only for privileged system services. -Kernel-MAC-Floor-2 | `*` | Used for device files or `/tmp` Access restriction via DAC. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## System - -The _system_ domain includes a reduced set of core system services of the OS and -any associated data. This data may change at runtime. - -The following table details the _system_ domain: - -Label | Name | Execution **SMACK** | File Access **SMACK** ----------------- | --------- | ----------------------------------------------- | --------------------- -`System` | System | None | Privileged processes -`System::Run` | Run | `rwxatl` for User and System label | None -`System::Shared` | Shared | `rwxatl` for system domain `r-x` for User label | None -`System::Log` | Log | `rwa` for System label `xa` for user label | None -`System::Sub` | SubSystem | Subsystem Config files | SubSystem only - -<!-- section-config --> - -Domain | `Label` name | Recommendations -------------------- | ---------------- | ------------------------------------------------------------------------------------------------------------- -Kernel-MAC-System-1 | `System` | Process should write only to file with transmute attribute. -Kernel-MAC-System-2 | `System::run` | Files are created with the directory label from user and system domain (transmute) Lock is implicit with `w`. -Kernel-MAC-System-3 | `System::Shared` | Files are created with the directory label from system domain (transmute) User domain has locked privilege. -Kernel-MAC-System-4 | `System::Log` | Some limitation may impose to add `w` to enable append. -Kernel-MAC-System-5 | `System::Sub` | Isolation of risky Subsystem. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Applications, Services and User - -The _application_, _services_ and _user_ domain includes code that provides -services to the system and user, as well as any associated data. All code -running on this domain is under _Cynara_ control. - -The following table details the _application_, _services_ and _user_ domain: - -Label | Name | Execution **SMACK** | File Access **SMACK** -------------------- | ------ | --------------------------------------------------------------------------- | --------------------------- -`User::Pkg::$AppID` | AppID | `rwx` (for files created by the App). `rx` for files installed by **AppFw** | $App runtime executing $App -`User::Home` | Home | `rwx-t` from System label `r-x-l` from App | None -`User::App-Shared` | Shared | `rwxat` from System and User domains label of $User | None - -<!-- section-config --> - -Domain | `Label` name | Recommendations -------------------- | ------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- -Kernel-MAC-System-1 | `User::Pkg::$AppID` | Only one Label is allowed per App. A data directory is created by the AppFw in `rwx` mode. -Kernel-MAC-System-2 | `User::Home` | AppFw needs to create a directory in `/home/$USER/App-Shared` at first launch if not present with label app-data access is `User::App-Shared` without transmute. -Kernel-MAC-System-3 | `User::App-Shared` | Shared space between all App running for a given user. - -<!-- end-section-config --> - -## Attack Vectors - -There are 4 major components to the system: - -- The LSM kernel module. -- The `smackfs` filesystem. -- Basic utilities for policy management and checking. -- The policy/configuration data. - -As with any mandatory access system, the policy management needs to be carefully separated -from the checking, as the management utilities can become a convenient point of attack. -Dynamic additions to the policy system need to be carefully verified, as the ability to -update the policies is often needed, but introduces a possible threat. Finally, -even if the policy management is well secured, the policy checking and failure response -to that checking is also of vital importance to the smooth operation of the system. - -While **MAC** is a certainly a step up in security when compared to DAC, there are still -many ways to compromise a SMACK-enabled Linux system. Some of these ways are as follows: - -- Disabling SMACK at invocation of the kernel (with command-line: security=none). -- Disabling SMACK in the kernel build and redeploying the kernel. -- Changing a SMACK attribute of a file or directory at install time. -- Tampering with a process with the CAP_MAC_ADMIN privilege. -- Setting/Re-setting the SMACK label of a file. -- Tampering with the default domains (i.e. /etc/smack/accesses.d/default-access-domains). -- Disabling or tampering with the SMACK filesystem (i.e. /smackfs). -- Adding policies with `smackload` (adding the utility if not present). -- Changing labels with `chsmack` (adding the utility if not present). diff --git a/security-blueprint/part-5/2-SystemD.md b/security-blueprint/part-5/2-SystemD.md deleted file mode 100644 index 35abe16..0000000 --- a/security-blueprint/part-5/2-SystemD.md +++ /dev/null @@ -1,60 +0,0 @@ -# SystemD - -`afm-system-daemon` is used to: - -- Manage users and user sessions. -- Setup applications and services (_CGroups_, _namespaces_, autostart, permissions). -- Use of `libsystemd` for its programs (event management, **D-Bus** interface). - -<!-- section-config --> - -Domain | Object | Recommendations ------------------- | -------------- | ------------------------------------ -Platform-SystemD-1 | Security model | Use Namespaces for containerization. -Platform-SystemD-2 | Security model | Use CGroups to organise processes. - -<!-- end-section-config --> - -See [systemd integration and user management](http://iot.bzh/download/public/2017/AMM-Dresden/AGL-systemd.pdf) for more information. - -## Benefits - -- Removal of one privileged process: **afm-user-daemon** -- Access and use of high level features: - - - Socket activation. - - Management of users and integration of **PAM**. - - Dependency resolution to services. - - `Cgroups` and resource control. - - `Namespaces` containerization. - - Autostart of required API. - - Permissions and security settings. - - Network management. - -<!-- pagebreak --> - -## CGroups - -Control Groups offer a lot of features, with the most useful ones you can -control: Memory usage, how much CPU time is allocated, how much device I/O is -allowed or which devices can be accessed. **SystemD** uses _CGroups_ to organise -processes (each service is a _CGroups_, and all processes started by that -service use that _CGroups_). By default, **SystemD** automatically creates a -hierarchy of slice, scope and service units to provide a unified structure for -the _CGroups_ tree. With the `systemctl` command, you can further modify this -structure by creating custom slices. Currently, in AGL, there are 2 slices -(**user.slice** and **system.slice**). - -## Namespaces - -### User side - -There are several ways of authenticating users (Key Radio Frequency, Phone, -Gesture, ...). Each authentication provides dynamic allocation of **uids** to -authenticated users. **Uids** is used to ensure privacy of users and **SMACK** -for applications privacy. - -First, the user initiates authentication with **PAM** activation. **PAM** -Standard offers highly configurable authentication with modular design like -face recognition, Voice identification or with a password. Then users should -access identity services with services and applications. diff --git a/security-blueprint/part-5/3-SystemBus.md b/security-blueprint/part-5/3-SystemBus.md deleted file mode 100644 index e2af387..0000000 --- a/security-blueprint/part-5/3-SystemBus.md +++ /dev/null @@ -1,24 +0,0 @@ -# D-Bus - -D-Bus is a well-known **IPC** (Inter-Process Communication) protocol (and -daemon) that helps applications to talk to each other. The use of D-Bus is great -because it allows to implement discovery and signaling. - -The D-Bus session is by default addressed by environment variable -`DBUS_SESSION_BUS_ADDRESS`. Using **systemd** variable `DBUS_SESSION_BUS_ADDRESS` -is automatically set for user sessions. D-Bus usage is linked to permissions. - -D-Bus has already had several [security issues](https://www.cvedetails.com/vulnerability-list/vendor_id-13442/D-bus-Project.html) -(mostly **DoS** issues), to allow applications to keep talking to each other. -It is important to protect against this type of attack to keep the system more -stable. - - -<!-- section-config --> - -Domain | Object | Recommendations ---------------- | -------------- | ------------------------------------ -Platform-DBus-1 | Security model | Use D-Bus as IPC. -Platform-DBus-2 | Security model | Apply D-BUS security patches: [D-Bus CVE](https://www.cvedetails.com/vulnerability-list/vendor_id-13442/D-bus-Project.html) - -<!-- end-section-config --> diff --git a/security-blueprint/part-5/4-Services.md b/security-blueprint/part-5/4-Services.md deleted file mode 100644 index 013f693..0000000 --- a/security-blueprint/part-5/4-Services.md +++ /dev/null @@ -1,37 +0,0 @@ -# System services and daemons - -<!-- section-todo --> - -Domain | Improvement -------------------- | ----------- -Platform-Services-1 | SystemD ? -Platform-Services-2 | Secure daemon ? - -<!-- end-section-todo --> - -## Tools - -- **connman**: An internet connection manager designed to be slim and to use as - few resources as possible. It is a fully modular system that can be extended, - through plug-ins, to support all kinds of wired or wireless technologies. -- **bluez** is a Bluetooth stack. Its goal is to program an implementation of - the Bluetooth wireless standards specifications. In addition to the basic stack, - the `bluez-utils` and `bluez-firmware` packages contain low level utilities such - as `dfutool` which can interrogate the Bluetooth adapter chipset in order to - determine whether its firmware can be upgraded. -- **gstreamer** is a pipeline-based multimedia framework. It can be used to build - a system that reads files in one format, processes them, and exports them in - another format. -- **alsa** is a software framework and part of the Linux kernel that provides an - **API** for sound card device drivers. - -<!-- section-config --> - -Domain | `Tool` name | _State_ --------------------- | ----------- | ------- -Platform-Utilities-1 | `connman` | _Used_ as a connection manager. -Platform-Utilities-2 | `bluez` | _Used_ as a Bluetooth manager. -Platform-Utilities-3 | `gstreamer` | _Used_ to manage multimedia file format. -Platform-Utilities-4 | `alsa` | _Used_ to provides an API for sound card device drivers. - -<!-- end-section-config --> diff --git a/security-blueprint/part-5/5-AppFw.md b/security-blueprint/part-5/5-AppFw.md deleted file mode 100644 index e92a0c6..0000000 --- a/security-blueprint/part-5/5-AppFw.md +++ /dev/null @@ -1,315 +0,0 @@ -# Application framework/model (**AppFw**) - -The AGL application framework consists of several inter-working parts: - -- **SMACK**: The kernel level **LSM** (**L**inux **S**ecurity **M**odule) that performs extended access control of the system. -- **Cynara**: the native gatekeeper daemon used for policy handling, updating to the database and policy checking. -- Security Manager: a master service, through which all security events are intended to take place. -- Several native application framework utilities: `afm-main-binding`, `afm-user-daemon`, `afm-system-daemon`. - -The application framework manages: - -- The applications and services management: Installing, Uninstalling, Listing, ... -- The life cycle of applications: Start -> (Pause, Resume) -> Stop. -- Events and signals propagation. -- Privileges granting and checking. -- API for interaction with applications. - -<!-- section-note --> - -- The **security model** refers to the security model used to ensure security - and to the tools that are provided for implementing that model. It's an - implementation detail that should not impact the layers above the application - framework. - -- The **security model** refers to how **DAC** (**D**iscretionary **A**ccess **C**ontrol), - **MAC** (Mandatory Access Control) and `Capabilities` are used by the system to - ensure security and privacy. It also includes features of reporting using - audit features and by managing logs and alerts. - -<!-- end-section-note --> - -The **AppFw** uses the security model to ensure the security and the privacy of -the applications that it manages. It must be compliant with the underlying -security model. But it should hide it to the applications. - -<!-- section-config --> - -Domain | Object | Recommendations ----------------------- | -------------- | -------------------------------- -Platform-AGLFw-AppFw-1 | Security model | Use the AppFw as Security model. - -<!-- end-section-config --> - -See [AGL AppFw Privileges Management](http://docs.automotivelinux.org/docs/devguides/en/dev/reference/iotbzh2016/appfw/03-AGL-AppFW-Privileges-Management.pdf) and [AGL - Application Framework Documentation](http://iot.bzh/download/public/2017/SDK/AppFw-Documentation-v3.1.pdf) for more -information. - -<!-- pagebreak --> - -The Security Manager communicates policy information to **Cynara**, -which retains information in its own database in the format of a text -file with comma-separated values (CSV). There are provisions to retain -a copy of the CSV text file when the file is being updated. - -Runtime checking occurs through **Cynara**. Each application that is -added to the framework has its own instantiation of a SMACK context -and D-bus bindings. The afb_daemon and Binder form a web-service that -is communicated to through http or a websocket from the application-proper. -This http or websocket interface uses a standard unique web token for API communication. - - - -## Cynara - -There's a need for another mechanism responsible for checking applicative -permissions: Currently in AGL, this task depends on a policy-checker service -(**Cynara**). - -- Stores complex policies in databases. -- "Soft" security (access is checked by the framework). - -Cynara interact with **D-Bus** in order to deliver this information. - -Cynara consists of several parts: - -- Cynara: a daemon for controlling policies and responding to access control requests. -- Database: a spot to hold policies. -- Libraries: several static and dynamic libraries for communicating with Cynara. - -The daemon communicates to the libraries over Unix domain sockets. -The database storage format is a series of CSV-like files with an index file. - -There are several ways that an attacker can manipulate policies of the Cynara system: - -- Disable Cynara by killing the process. -- Tamper with the Cynara binary on-disk or in-memory. -- Corrupt the database controlled by Cynara. -- Tamper with the database controlled by Cynara. -- Highjack the communication between Cynara and the database. - -The text-based database is the weakest part of the system and although there are some -consistency mechanisms in place (i.e. the backup guard), these mechanisms are weak at best -and can be countered by an attacker very easily. - -<!-- section-config --> - -Domain | Object | Recommendations ------------------------ | ----------- | ------------------------------------- -Platform-AGLFw-Cynara-1 | Permissions | Use Cynara as policy-checker service. - -<!-- end-section-config --> - -### Policies - -- Policy rules: - - - Are simple - for pair [application context, privilege] there is straight - answer (single Policy Type): [ALLOW / DENY / ...]. - - No code is executed (no script). - - Can be easily cached and managed. - -- Application context (describes id of the user and the application credentials) - It is build of: - - - UID of the user that runs the application. - - **SMACK** label of application. - -## Holding policies - -Policies are kept in buckets. Buckets are set of policies which have additional -a property of default answer, the default answer is yielded if no policy matches -searched key. Buckets have names which might be used in policies (for directions). - -## Attack Vectors - -The following attack vectors are not completely independent. While attackers may -have varying levels of access to an AGL system, experience has shown that a typical -attack can start with direct access to a system, find the vulnerabilities, -then proceed to automate the attack such that it can be invoked from less accessible -standpoint (e.g. remotely). Therefore, it is important to assess all threat levels, -and protect the system appropriately understanding that direct access attacks -are the door-way into remote attacks. - -### Remote Attacks - -The local web server interface used for applications is the first point of attack, -as web service APIs are well understood and easily intercepted. The local web server -could potentially be exploited by redirecting web requests through the local service -and exploiting the APIs. While there is the use of a security token on the web -service API, this is weak textual matching at best. This will not be difficult to spoof. -It is well known that [API Keys do not provide any real security](http://nordicapis.com/why-api-keys-are-not-enough/). - -It is likely that the architectural inclusion of an http / web-service interface -provided the most flexibility for applications to be written natively or in HTML5. -However, this flexibility may trade-off with security concerns. For example, -if a native application were linked directly to the underlying framework services, -there would be fewer concerns over remote attacks coming through the web-service interface. - -Leaving the interface as designed, mitigations to attacks could include further -securing the interface layer with cryptographic protocols: -e.g. encrypted information passing, key exchange (e.g. Elliptic-Curve Diffie-Hellman). - -### User-level Native Attacks - -- Modifying the CSV data-base -- Modifying the SQLite DB -- Tampering with the user-level binaries -- Tampering with the user daemons -- Spoofing the D-bus Interface -- Adding executables/libraries - -With direct access to the device, there are many security concerns on the native level. -For example, as **Cynara** uses a text file data-base with comma-separated values (CSV), -an attacker could simply modify the data-base to escalate privileges of an application. -Once a single application has all the privileges possible on the system, exploits can -come through in this manner. Similarly the SQLite database used by the Security Manager -is not much different than a simple text file. There are many tools available to add, -remove, modify entries in an SQLite data-base. - -On the next level, a common point of attack is to modify binaries or daemons for exploiting -functionality. There are many Linux tools available to aid in this regard, -including: [IDA Pro](https://www.hex-rays.com/products/ida/index.shtml), -and [radare2](https://rada.re/r/). With the ability to modify binaries, -an attacker can do any number of activities including: removing calls to security checks, -redirecting control to bypass verification functionality, ignoring security policy handling, -escalating privileges, etc. - -Additionally, another attack vector would be to spoof the D-bus interface. D-bus is a -message passing system built upon Inter-Process Communication (IPC), where structured -messages are passed based upon a protocol. The interface is generic and well documented. -Therefore, modifying or adding binaries/libraries to spoof this interface is a relatively -straight-forward process. Once the interface has been spoofed, the attacker can issue any -number of commands that lead into control of low-level functionality. - -Protecting a system from native attacks requires a methodical approach. First, the system -should reject processes that are not sanctioned to run. Signature-level verification at -installation time will help in this regard, but run-time integrity verification is much better. -Signatures need to originate from authorized parties, which is discussed further -in a later section on the Application Store. - -On the next level, executables should not be allowed to do things where they have not been -granted permission. DAC and SMACK policies can help in this regard. On the other hand, -there remain concerns with memory accesses, system calls, and other process activity -that may go undetected. For this reason, a secure environment which monitors all activity -can give indication of all unauthorized activity on the system. - -Finally, it is very difficult to catch attacks of direct tampering in a system. -These types of attacks require a defense-in-depth approach, where complementary software -protection and hardening techniques are needed. Tamper-resistance and anti-reverse-engineering -technologies include program transformations/obfuscation, integrity verification, -and white-box cryptography. If applied in a mutually-dependent fashion and considering -performance/security tradeoffs, the approach can provide an effective barrier -to direct attacks to the system. Furthermore, the use of threat monitoring provides a -valuable telemetry/analytics capability and the ability to react and renew a system under attack. - -### Root-level Native Attacks - -- Tampering the system daemon -- Tampering Cynara -- Tampering the security manager -- Disabling SMACK -- Tampering the kernel - -Once root-level access (i.e. su) has been achieved on the device, there are many ways -to compromise the system. The system daemon, **Cynara**, and the security manager are -vulnerable to tampering attacks. For example, an executable can be modified in memory -to jam a branch, jump to an address, or disregard a check. This can be as simple as replacing -a branch instruction with a NOP, changing a memory value, or using a debugger (e.g. gdb, IDA) -to change an instruction. Tampering these executables would mean that policies can be -ignored and verification checks can be bypassed. - -Without going so far as to tamper an executable, the **SMACK** system is also vulnerable to attack. -For example, if the kernel is stopped and restarted with the *security=none* flag, -then SMACK is not enabled. Furthermore, `systemd` starts the loading of **SMACK** rules during -start-up. If this start-up process is interfered with, then **SMACK** will not run. -Alternatively, new policies can be added with `smackload` allowing unforseen privileges -to alternative applications/executables. - -Another intrusion on the kernel level is to rebuild the kernel (as it is open-source) -and replace it with a copy that has **SMACK** disabled, or even just the **SMACK** filesystem -(`smackfs`) disabled. Without the extended label attributes, the **SMACK** system is disabled. - -Root-level access to the device has ultimate power, where the entire system can be compromised. -More so, a system with this level access allows an attacker to craft a simpler *point-attack* -which can operate on a level requiring fewer privileges (e.g. remote access, user-level access). - -## Vulnerable Resources - -### Resource: `afm-user-daemon` - -The `afm-user-daemon` is in charge of handling applications on behalf of a user. Its main tasks are: - -- Enumerate applications that the end user can run and keep this list available on demand. -- Start applications on behalf of the end user, set user running environment, set user security context. -- List current runnable or running applications. -- Stop (aka pause), continue (aka resume), terminate a running instance of a given application. -- Transfer requests for installation/uninstallation of applications to the corresponding system daemon afm-system-daemon. - -The `afm-user-daemon` launches applications. It builds a secure environment for the application -before starting it within that environment. Different kinds of applications can be launched, -based on a configuration file that describes how to launch an application of a given kind within -a given launching mode: local or remote. Launching an application locally means that -the application and its binder are launched together. Launching an application remotely -translates in only launching the application binder. - -The UI by itself has to be activated remotely by a request (i.e. HTML5 homescreen in a browser). -Once launched, running instances of the application receive a `runid` that identifies them. -`afm-user-daemon` manages the list of applications that it has launched. -When owning the right permissions, a client can get the list of running instances and details -about a specific running instance. It can also terminate, stop or continue a given application. -If the client owns the right permissions, `afm-user-daemon` delegates the task of -installing and uninstalling applications to `afm-system-daemon`. - -`afm-user-daemon` is launched as a `systemd` service attached to a user session. -Normally, the service file is located at /usr/lib/systemd/user/afm-user-daemon.service. - -Attacker goals: - -- Disable `afm-user-daemon`. -- Tamper with the `afm-user-daemon` configuration. - - /usr/lib/systemd/user/afm-user-daemon.service. - - Application(widget) config.xml file. - - /etc/afm/afm-launch.conf (launcher configuration). - -- Escalate user privileges to gain more access with `afm-user-daemon`. -- Install malicious application (widget). -- Tamper with `afm-user-daemon` on disk or in memory. - -### Resource: `afm-system-daemon` - -The `afm-system-daemon` is in charge of installing applications on the AGL system. Its main tasks are: - -- Install applications and setup security framework for newly installed applications. -- Uninstall applications. - -`afm-system-daemon` is launched as a `systemd` service attached to system. Normally, -the service file is located at /lib/systemd/system/afm-systemdaemon.service. - -Attacker goals: - -- Disable `afm-system-daemon`. -- Tamper with the `afm-system-daemon` configuration. -- Tamper `afm-system-daemon` on disk or in memory. - -### Resource `afb-daemon` - -`afb-binder` is in charge of serving resources and features through an HTTP interface. -`afb-daemon` is in charge of binding one instance of an application to the AGL framework -and AGL system. The application and its companion binder run in a secured and isolated -environment set for them. Applications are intended to access to AGL system through the binder. -`afb-daemon` binders serve files through HTTP protocol and offers developers the capability -to expose application API methods through HTTP or WebSocket protocol. - -Binder bindings are used to add APIs to `afb-daemon`. The user can write a binding for `afb-daemon`. -The binder `afb-daemon` serves multiple purposes: - -1. It acts as a gateway for the application to access the system. -2. It acts as an HTTP server for serving files to HTML5 applications. -3. It allows HTML5 applications to have native extensions subject to security enforcement for accessing hardware resources or for speeding up parts of algorithm. - -Attacker goals: - -- Break from isolation. -- Disable `afb-daemon`. -- Tamper `afb-demon` on disk or in memory. -- Tamper **capabilities** by creating/installing custom bindings for `afb-daemon`.
\ No newline at end of file diff --git a/security-blueprint/part-5/6-Utilities.md b/security-blueprint/part-5/6-Utilities.md deleted file mode 100644 index 309cbc4..0000000 --- a/security-blueprint/part-5/6-Utilities.md +++ /dev/null @@ -1,78 +0,0 @@ -# Utilities - -- **busybox**: Software that provides several stripped-down Unix tools in a - single executable file. Of course, it will be necessary to use a "production" - version of **busybox** in order to avoid all the tools useful only in - development mode. - -<!-- section-config --> - -Domain | `Tool` name | _State_ --------------------- | ----------- | ---------------------------------------------------------------------- -Platform-Utilities-1 | `busybox` | _Used_ to provide a number of tools. Do not compile development tools. - -<!-- end-section-config --> - -## Functionalities to exclude in production mode - -In production mode, a number of tools must be disabled to prevent an attacker -from finding logs for example. This is useful to limit the visible surface and -thus complicate the fault finding process. The tools used only in development -mode are marked by an '**agl-devel**' feature. When building in production mode, -these tools will not be compiled. - -<!-- section-config --> - -Domain | `Utility` name and normal `path` | _State_ ---------------------- | ---------------------------------------------------- | ---------- -Platform-Utilities-1 | `chgrp` in `/bin/chgrp` | _Disabled_ -Platform-Utilities-2 | `chmod` in `/bin/chmod` | _Disabled_ -Platform-Utilities-3 | `chown` in `/bin/chown` | _Disabled_ -Platform-Utilities-4 | `dmesg` in `/bin/dmesg` | _Disabled_ -Platform-Utilities-5 | `Dnsdomainname` in `/bin/dnsdomainname` | _Disabled_ -Platform-Utilities-6 | `dropbear`, Remove "dropbear" from `/etc/init.d/rcs` | _Disabled_ -Platform-Utilities-7 | `Editors` in (vi) `/bin/vi` | _Disabled_ -Platform-Utilities-8 | `find` in `/bin/find` | _Disabled_ -Platform-Utilities-9 | `gdbserver` in `/bin/gdbserver` | _Disabled_ -Platform-Utilities-10 | `hexdump` in `/bin/hexdump` | _Disabled_ -Platform-Utilities-11 | `hostname` in `/bin/hostname` | _Disabled_ -Platform-Utilities-12 | `install` in `/bin/install` | _Disabled_ -Platform-Utilities-13 | `iostat` in `/bin/iostat` | _Disabled_ -Platform-Utilities-14 | `killall` in `/bin/killall` | _Disabled_ -Platform-Utilities-15 | `klogd` in `/sbin/klogd` | _Disabled_ -Platform-Utilities-16 | `logger` in `/bin/logger` | _Disabled_ -Platform-Utilities-17 | `lsmod` in `/sbin/lsmod` | _Disabled_ -Platform-Utilities-18 | `pmap` in `/bin/pmap` | _Disabled_ -Platform-Utilities-19 | `ps` in `/bin/ps` | _Disabled_ -Platform-Utilities-20 | `ps` in `/bin/ps` | _Disabled_ -Platform-Utilities-21 | `rpm` in `/bin/rpm` | _Disabled_ -Platform-Utilities-22 | `SSH` | _Disabled_ -Platform-Utilities-23 | `stbhotplug` in `/sbin/stbhotplug` | _Disabled_ -Platform-Utilities-24 | `strace` in `/bin/trace` | _Disabled_ -Platform-Utilities-25 | `su` in `/bin/su` | _Disabled_ -Platform-Utilities-26 | `syslogd` in (logger) `/bin/logger` | _Disabled_ -Platform-Utilities-27 | `top` in `/bin/top` | _Disabled_ -Platform-Utilities-28 | `UART` in `/proc/tty/driver/` | _Disabled_ -Platform-Utilities-29 | `which` in `/bin/which` | _Disabled_ -Platform-Utilities-30 | `who` and `whoami` in `/bin/whoami` | _Disabled_ -Platform-Utilities-31 | `awk` (busybox) | _Enabled_ -Platform-Utilities-32 | `cut` (busybox) | _Enabled_ -Platform-Utilities-33 | `df` (busybox) | _Enabled_ -Platform-Utilities-34 | `echo` (busybox) | _Enabled_ -Platform-Utilities-35 | `fdisk` (busybox) | _Enabled_ -Platform-Utilities-36 | `grep` (busybox) | _Enabled_ -Platform-Utilities-37 | `mkdir` (busybox) | _Enabled_ -Platform-Utilities-38 | `mount` (vfat) (busybox) | _Enabled_ -Platform-Utilities-39 | `printf` (busybox) | _Enabled_ -Platform-Utilities-40 | `sed` in `/bin/sed` (busybox) | _Enabled_ -Platform-Utilities-41 | `tail` (busybox) | _Enabled_ -Platform-Utilities-42 | `tee` (busybox) | _Enabled_ -Platform-Utilities-43 | `test` (busybox) | _Enabled_ - -<!-- end-section-config --> <!-- section-note --> - -The _Enabled_ Unix/Linux utilities above shall be permitted as they are often -used in the start-up scripts and for USB logging. If any of these utilities are -not required by the device then those should be removed. - -<!-- end-section-note --> diff --git a/security-blueprint/part-5/7-Users.md b/security-blueprint/part-5/7-Users.md deleted file mode 100644 index af5a686..0000000 --- a/security-blueprint/part-5/7-Users.md +++ /dev/null @@ -1,77 +0,0 @@ -# Users - -The user policy can group users by function within the car. For example, we can -consider a driver and his passengers. Each user is assigned to a single group to -simplify the management of space security. - -## Root Access - -The main applications, those that provide the principal functionality of the -embedded device, should not execute with root identity or any capability. - -If the main application is allowed to execute at any capability, then the entire -system is at the mercy of the said application's good behaviour. Problems arise -when an application is compromised and able to execute commands which could -consistently and persistently compromise the system by implanting rogue -applications. - -It is suggested that the middleware and the UI should run in a context on a user -with no capability and all persistent resources should be maintained without any -capability. - -One way to ensure this is by implementing a server-client paradigm. Services -provided by the system's drivers can be shared this way. The other advantage of -this approach is that multiple applications can share the same resources at the -same time. - -<!-- section-config --> - -Domain | Object | Recommendations ---------------------- | ---------------- | ----------------------------------------------------- -Platform-Users-root-1 | Main application | Should not execute as root. -Platform-Users-root-2 | UI | Should run in a context on a user with no capability. - -<!-- end-section-config --> - -Root access should not be allowed for the following utilities: - -<!-- section-config --> - -Domain | `Utility` name | _State_ ---------------------- | -------------- | ------------- -Platform-Users-root-3 | `login` | _Not allowed_ -Platform-Users-root-4 | `su` | _Not allowed_ -Platform-Users-root-5 | `ssh` | _Not allowed_ -Platform-Users-root-6 | `scp` | _Not allowed_ -Platform-Users-root-7 | `sftp` | _Not allowed_ - -<!-- end-section-config --> - -Root access should not be allowed for the console device. The development -environment should allow users to login with pre-created user accounts. - -Switching to elevated privileges shall be allowed in the development environment -via `sudo`. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Capabilities - -<!-- section-todo --> - -Domain | Improvement ------------------------------ | ------------------------ -Platform-Users-Capabilities-1 | Kernel or Platform-user? -Platform-Users-Capabilities-2 | Add config note. - -<!-- end-section-todo --> - -The goal is to restrict functionality that will not be useful in **AGL**. They -are integrated into the **LSM**. Each privileged transaction is associated with -a capability. These capabilities are divided into three groups: - -- e: Effective: This means the capability is “activated”. -- p: Permitted: This means the capability can be used/is allowed. -- i: Inherited: The capability is kept by child/subprocesses upon execve() for example. diff --git a/security-blueprint/part-5/App-flow.png b/security-blueprint/part-5/App-flow.png Binary files differdeleted file mode 100644 index 7b87c29..0000000 --- a/security-blueprint/part-5/App-flow.png +++ /dev/null diff --git a/security-blueprint/part-6/0_Abstract.md b/security-blueprint/part-6/0_Abstract.md deleted file mode 100644 index 3617dbd..0000000 --- a/security-blueprint/part-6/0_Abstract.md +++ /dev/null @@ -1,80 +0,0 @@ -# Part 6 - Application - -## Abstract - -**Application Hardening**: Best practices to apply to the build and release of -user space applications, in order to reduce the number of attack surfaces used -by potential attackers. - -The term of Application (App) has a very wide definition in **AGL**. Almost -anything which is not in the core Operating System (OS) is an Application. -Applications can be included in the base software package (image) or can be -added at run-time. - -Application containment is achieved using the following protections: - -- Linux Native protection - - Mandatory Access Control (**MAC**) -- AGL Platform protections - - Origin Tracking and Validation - - Application Privilege Management and Enforcement via Cynara - - Authenticated Transport via D-Bus - -## Application Types - -AGL provides a framework for applications to be written in different forms: - -- Web application: HTML5 + JavaScript -- Qt application: in a QML file -- Native application: in C - -While there is no harm in providing multiple types of applications, from a -security perspective this does increase the attack surface for an intruder. -The application framework (**AppFw**) consists of a number of utilities and -daemons which provide context for the applications. -Isolation is provided through **SMACK** labels. - -## Application Store - -Although the Tizen system has defined a [system of App signing and signing flow](https://wiki.tizen.org/Security/Tizen_3.X_Overview#Application_Singing_and_Certificates) -to avoid the spread of unauthorized Apps that might contain malware. -At this point, it is unclear how much of this flow AGL will adopt. -However, judging from the experience, it is an essential topic. For example, -the Google Play Store controls the authorization of Apps through signing, and still, -there are [many accounts of Apps containing malware on the store](http://www.eweek.com/mobile/researchers-find-132-malware-infected-android-apps-on-google-play). - -Tizen defines 5 levels of certificates and signing at each level, including an author, -testing distributor, public level store distributor, partner level store distributor, -and platform level store distributor. AGL may define a different number of third parties, -but at a minimum an author and store distributor should be defined. - - - -Once the number of signatures has been established, verification of those signatures needs -to be done at a minimum at installation time on the AGL device. It is important to ensure -the robustness/integrity of the public key used for signature verification. If the public key is modified, -then this compromised key can be used to verify an attacker's private key signature. - -Further to this, installation-time verification is limited. Attacks can happen to apps in-memory -at runtime. Any modifications made after installation will be missed by installation-time verification. -Integrity verification that runs during execution makes for a more complete security story. - --------------------------------------------------------------------------------- - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | ---------------------------------------------------- -_3GPP_ | **3**rd **G**eneration **P**artnership **P**roject -_CASB_ | **C**loud **A**ccess **S**ecurity **B**roker -_DAST_ | **D**ynamic **A**pplication **S**ecurity **T**esting -_DPI_ | **D**eep **P**acket **I**nspection -_IDS_ | **I**ntrusion **D**etection **S**ystems -_IPS_ | **I**ntrusion **P**revention **S**ystems -_IPSec_ | **I**nternet **P**rotocol **Sec**urity -_LSM_ | **L**inux **S**ecurity **M**odule -_MITM_ | **M**an **I**n **T**he **M**iddle -_OSI_ | **O**pen **S**ystems **I**nterconnection -_SATS_ | **S**tatic **A**pplication **S**ecurity **T**esting diff --git a/security-blueprint/part-6/1-Installation.md b/security-blueprint/part-6/1-Installation.md deleted file mode 100644 index e2972ce..0000000 --- a/security-blueprint/part-6/1-Installation.md +++ /dev/null @@ -1,29 +0,0 @@ -# Local - -<!-- section-todo --> - -Domain | Improvement --------------------------- | ------------------------------ -Application-Installation-1 | Talk about AppFw offline mode. - -<!-- end-section-todo --> - -## Installation - -Applications can be delivered and installed with the base image using a special -offline-mode provided by the **AppFw**. Apps can also be installed at run time. - -<!-- section-note --> - -During early release, default Apps are installed on the image at first boot. - -<!-- end-section-note --> - -<!-- section-config --> - -Domain | Object | Recommendations --------------------------- | --------- | ----------------------------------------------------------------------- -Application-Installation-1 | AppFw | Provide offline-mode in order to install app with the base image. -Application-Installation-2 | Integrity | Allow the installation of applications only if their integrity is good. - -<!-- end-section-config --> diff --git a/security-blueprint/part-6/2-PrivilegeManagement.md b/security-blueprint/part-6/2-PrivilegeManagement.md deleted file mode 100644 index 2f2455a..0000000 --- a/security-blueprint/part-6/2-PrivilegeManagement.md +++ /dev/null @@ -1,7 +0,0 @@ -# Local - -## Privilege Management - -Application privileges are managed by **Cynara** and the security manager in -the **AppFw**. For more details, please refer to the **AppFw** documentation -in Platform part. diff --git a/security-blueprint/part-6/3-Signature.md b/security-blueprint/part-6/3-Signature.md deleted file mode 100644 index f7b48db..0000000 --- a/security-blueprint/part-6/3-Signature.md +++ /dev/null @@ -1,9 +0,0 @@ -# App Signature - -<!-- section-todo --> - -Domain | Improvement ------------------------ | ---------------------------------------------------------- -Application-Signature-1 | Add content (see secure build in Secure development part). - -<!-- end-section-todo --> diff --git a/security-blueprint/part-6/4-Services.md b/security-blueprint/part-6/4-Services.md deleted file mode 100644 index d0414f0..0000000 --- a/security-blueprint/part-6/4-Services.md +++ /dev/null @@ -1,10 +0,0 @@ -# Services - -<!-- section-todo --> - -Domain | Improvement ----------------------- | ------------ -Application-Services-1 | Add content (Which services?). -Application-Services-2 | Add Binder. - -<!-- end-section-todo --> diff --git a/security-blueprint/part-6/App_signing_flow.png b/security-blueprint/part-6/App_signing_flow.png Binary files differdeleted file mode 100644 index 56a7c23..0000000 --- a/security-blueprint/part-6/App_signing_flow.png +++ /dev/null diff --git a/security-blueprint/part-7/0_Abstract.md b/security-blueprint/part-7/0_Abstract.md deleted file mode 100644 index f7acbe5..0000000 --- a/security-blueprint/part-7/0_Abstract.md +++ /dev/null @@ -1,52 +0,0 @@ -# Part 7 - Connectivity - -## Abstract - -This part shows different Connectivity attacks on the car. - -<!-- section-todo --> - -Domain | Improvement ------------------------ | ----------------- -Connectivity-Abstract-1 | Improve abstract. - -<!-- end-section-todo --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | --------------------------------------------------------------------------------- -_ARP_ | **A**ddress **R**esolution **P**rotocol -_BLE_ | **B**luetooth **L**ow **E**nergy -_CAN_ | **C**ar **A**rea **N**etwork -_CCMP_ | **C**ounter-Mode/**C**BC-**M**ac **P**rotocol -_EDGE_ | **E**nhanced **D**ata **R**ates for **GSM** **E**volution - Evolution of **GPRS** -_GEA_ | **G**PRS **E**ncryption **A**lgorithm -_GPRS_ | **G**eneral **P**acket **R**adio **S**ervice (2,5G, 2G+) -_GSM_ | **G**lobal **S**ystem for **M**obile Communications (2G) -_HSPA_ | **H**igh **S**peed **P**acket **A**ccess (3G+) -_IMEI_ | **I**nternational **M**obile **E**quipment **I**dentity -_LIN_ | **L**ocal **I**nterconnect **N**etwork -_MOST_ | **M**edia **O**riented **S**ystem **T**ransport -_NFC_ | **N**ear **F**ield **C**ommunication -_OBD_ | **O**n-**B**oard **D**iagnostics -_PATS_ | **P**assive **A**nti-**T**heft **S**ystem -_PKE_ | **P**assive **K**eyless **E**ntry -_PSK_ | **P**hase-**S**hift **K**eying -_RDS_ | **R**adio **D**ata **S**ystem -_RFID_ | **R**adio **F**requency **I**dentification -_RKE_ | **R**emote **K**eyless **E**ntry -_SDR_ | **S**oftware **D**efined **R**adio -_SSP_ | **S**ecure **S**imple **P**airing -_TKIP_ | **T**emporal **K**ey **I**ntegrity **P**rotocol -_TPMS_ | **T**ire **P**ressure **M**onitoring **S**ystem -_UMTS_ | **U**niversal **M**obile **T**elecommunications **S**ystem (3G) -_USB_ | **U**niversal **S**erial **B**us -_WEP_ | **W**ired **E**quivalent **P**rivacy -_WPA_ | **W**ifi **P**rotected **A**ccess diff --git a/security-blueprint/part-7/1-BusAndConnectors.md b/security-blueprint/part-7/1-BusAndConnectors.md deleted file mode 100644 index 5ab9ab8..0000000 --- a/security-blueprint/part-7/1-BusAndConnectors.md +++ /dev/null @@ -1,68 +0,0 @@ -# Bus - -We only speak about the **CAN** bus to take an example, because the different -attacks on bus like _FlewRay_, _ByteFlight_, _Most_ and _Lin_ use retro -engineering and the main argument to improve their security is to encrypt data -packets. We just describe them a bit: - -- **CAN**: Controller Area Network, developed in the early 1980s, is an - event-triggered controller network for serial communication with data rates - up to one MBit/s. **CAN** messages are classified over their respective - identifier. **CAN** controller broadcast their messages to all connected nodes - and all receiving nodes decide independently if they process the message. -- **FlewRay**: Is a deterministic and error-tolerant high-speed bus. With a data - rate up to 10 MBit/s. -- **ByteFlight**: Is used for safety-critical applications in motor vehicles - like air-bags. Byteflight runs at 10Mbps over 2 or 3 wires plastic optical - fibers. -- **Most**: Media Oriented System Transport, is used for transmitting audio, - video, voice, and control data via fiber optic cables. The speed is, for the - synchronous way, up to 24 MBit/s and asynchronous way up to 14 MBit/s. - **MOST** messages include always a clear sender and receiver address. -- **LIN**: Local Interconnect Network, is a single-wire subnet work for - low-cost, serial communication between smart sensors and actuators with - typical data rates up to 20 kBit/s. It is intended to be used from the year - 2001 on everywhere in a car, where the bandwidth and versatility of a **CAN** - network is not required. - -On just about every vehicle, **ECU**s (**E**lectronic **C**ontrol **U**nits) -communicate over a CAN bus, which is a two-wire bus using hardware arbitration -for messages sent on the shared medium. This is essentially a *trusted* network -where all traffic is visible to all controllers and any controller can send any message. - -A malicious **ECU** on the CAN bus can easily inject messages destined for any -other device, including things like the instrument cluster and the head unit. -There are common ways for hardware to do USB to CAN and open source software to send -and receive messages. For example, there is a driver included in the Linux kernel -that can be used to send/receive CAN signals. A malicious device on the CAN bus can -cause a great number of harmful things to happen to the system, including: sending -bogus information to other devices, sending unintended commands to ECUs, -causing DOS (Denial Of Service) on the CAN bus, etc. - -<!-- section-config --> - -Domain | Tech name | Recommendations ----------------------------------- | --------- | -------------------------------------------------------------------------- -Connectivity-BusAndConnector-Bus-1 | CAN | Implement hardware solution in order to prohibit sending unwanted signals. - -<!-- end-section-config --> - -See [Security in Automotive Bus Systems](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.92.728&rep=rep1&type=pdf) for more information. - -# Connectors - -For the connectors, we supposed that they were disabled by default. For example, -the **USB** must be disabled to avoid attacks like BadUSB. If not, configure the -Kernel to only enable the minimum require **USB** devices. The connectors used -to diagnose the car like **OBD-II** must be disabled outside garages. - -<!-- section-config --> - -Domain | Tech name | Recommendations ------------------------------------------ | --------- | ---------------------------------------------------------------------- -Connectivity-BusAndConnector-Connectors-1 | USB | Must be disabled. If not, only enable the minimum require USB devices. -Connectivity-BusAndConnector-Connectors-2 | USB | Confidential data exchanged with the ECU over USB must be secure. -Connectivity-BusAndConnector-Connectors-3 | USB | USB Boot on a ECU must be disable. -Connectivity-BusAndConnector-Connectors-4 | OBD-II | Must be disabled outside garages. - -<!-- end-section-config --> diff --git a/security-blueprint/part-7/2-Wireless.md b/security-blueprint/part-7/2-Wireless.md deleted file mode 100644 index d3fda8b..0000000 --- a/security-blueprint/part-7/2-Wireless.md +++ /dev/null @@ -1,244 +0,0 @@ -# Wireless - -In this part, we talk about possible remote attacks on a car, according to the -different areas of possible attacks. For each communication channels, we -describe attacks and how to prevent them with some recommendations. The main -recommendation is to always follow the latest updates of these remote -communication channels. - -<!-- section-config --> - -Domain | Object | Recommendations ------------------------ | ------ | ------------------------------------------------------------------ -Connectivity-Wireless-1 | Update | Always follow the latest updates of remote communication channels. - -<!-- end-section-config --> - -We will see the following parts: - -- [Wifi](#wifi) - -- [Bluetooth](#bluetooth) - -- [Cellular](#cellular) - -- [Radio](#radio) - -- [NFC](#nfc) - -<!-- section-todo --> - -Domain | Improvement ------------------------ | ------------------------------------------- -Connectivity-Wireless-1 | Add communication channels (RFID, ZigBee?). - -<!-- end-section-todo --> - --------------------------------------------------------------------------------- - -For existing automotive-specific means, we take examples of existing system -attacks from the _IOActive_ document ([A Survey of Remote Automotive Attack Surfaces](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf)) -and from the ETH document ([Relay Attacks on Passive Keyless Entry and Start Systems in Modern Cars](https://eprint.iacr.org/2010/332.pdf)). - -- [Telematics](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf#%5B%7B%22num%22%3A40%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C60%2C720%2C0%5D) - -- [Passive Anti-Theft System (PATS)](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf#%5B%7B%22num%22%3A11%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C60%2C574%2C0%5D) - -- [Tire Pressure Monitoring System (TPMS)](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf#%5B%7B%22num%22%3A17%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C60%2C720%2C0%5D) - -- [Remote Keyless Entry/Start (RKE)](https://www.ioactive.com/pdfs/IOActive_Remote_Attack_Surfaces.pdf#%5B%7B%22num%22%3A26%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C60%2C720%2C0%5D) - -- [Passive Keyless Entry (PKE)](https://eprint.iacr.org/2010/332.pdf) - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Wifi - -### Attacks - -We can differentiate existing attacks on wifi in two categories: Those on -**WEP** and those on **WPA**. - -- **WEP** attacks: - - - **FMS**: (**F**luhrer, **M**antin and **S**hamir attack) is a "Stream cipher - attack on the widely used RC4 stream cipher. The attack allows an attacker - to recover the key in an RC4 encrypted stream from a large number of - messages in that stream." - - **KoreK**: "Allows the attacker to reduce the key space". - - **PTW**: (**P**yshkin **T**ews **W**einmann attack). - - **Chopchop**: Found by KoreK, "Weakness of the CRC32 checksum and the lack - of replay protection." - - **Fragmentation** - -- **WPA** attacks: - - - **Beck and Tews**: Exploit weakness in **TKIP**. "Allow the attacker to - decrypt **ARP** packets and to inject traffic into a network, even - allowing him to perform a **DoS** or an **ARP** poisoning". - - [KRACK](https://github.com/kristate/krackinfo): (K)ey (R)einstallation - (A)tta(ck) ([jira AGL SPEC-1017](https://jira.automotivelinux.org/browse/SPEC-1017)). - -### Recommendations - -- Do not use **WEP**, **PSK** and **TKIP**. - -- Use **WPA2** with **CCMP**. - -- Should protect data sniffing. - -<!-- section-config --> - -Domain | Tech name or object | Recommendations ----------------------------- | ------------------- | ------------------------------------------------------------------------- -Connectivity-Wireless-Wifi-1 | WEP, PSK, TKIP | Disabled -Connectivity-Wireless-Wifi-2 | WPA2 and AES-CCMP | Used -Connectivity-Wireless-Wifi-3 | WPA2 | Should protect data sniffing. -Connectivity-Wireless-Wifi-4 | PSK | Changing regularly the password. -Connectivity-Wireless-Wifi-5 | Device | Upgraded easily in software or firmware to have the last security update. - -<!-- end-section-config --> - -See [Wifi attacks WEP WPA](https://matthieu.io/dl/wifi-attacks-wep-wpa.pdf) -and [Breaking wep and wpa (Beck and Tews)](https://dl.aircrack-ng.org/breakingwepandwpa.pdf) -for more information. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Bluetooth - -### Attacks - -- **Bluesnarfing** attacks involve an attacker covertly gaining access to your - Bluetooth-enabled device for the purpose of retrieving information, including - addresses, calendar information or even the device's **I**nternational - **M**obile **E**quipment **I**dentity. With the **IMEI**, an attacker could - route your incoming calls to his cell phone. -- **Bluebugging** is a form of Bluetooth attack often caused by a lack of - awareness. Similar to bluesnarfing, bluebugging accesses and uses all phone - features but is limited by the transmitting power of class 2 Bluetooth radios, - normally capping its range at 10-15 meters. -- **Bluejacking** is the sending of unsolicited messages. -- **BLE**: **B**luetooth **L**ow **E**nergy [attacks](https://www.usenix.org/system/files/conference/woot13/woot13-ryan.pdf). -- **DoS**: Drain a device's battery or temporarily paralyze the phone. - -### Recommendations - -- Not allowing Bluetooth pairing attempts without the driver's first manually - placing the vehicle in pairing mode. -- Monitoring. -- Use **BLE** with caution. -- For v2.1 and later devices using **S**ecure **S**imple **P**airing (**SSP**), - avoid using the "Just Works" association model. The device must verify that - an authenticated link key was generated during pairing. - -<!-- section-config --> - -Domain | Tech name | Recommendations ---------------------------------- | ------------- | ------------------------------------------------------------ -Connectivity-Wireless-Bluetooth-1 | BLE | Use with caution. -Connectivity-Wireless-Bluetooth-2 | Bluetooth | Monitoring -Connectivity-Wireless-Bluetooth-3 | SSP | Avoid using the "Just Works" association model. -Connectivity-Wireless-Bluetooth-4 | Visibility | Configured by default as undiscoverable. Except when needed. -Connectivity-Wireless-Bluetooth-5 | Anti-scanning | Used, inter alia, to slow down brute force attacks. - -<!-- end-section-config --> - -See [Low energy and the automotive transformation](http://www.ti.com/lit/wp/sway008/sway008.pdf), -[Gattacking Bluetooth Smart Devices](http://gattack.io/whitepaper.pdf), -[Comprehensive Experimental Analyses of Automotive Attack Surfaces](http://www.autosec.org/pubs/cars-usenixsec2011.pdf) -and [With Low Energy comes Low Security](https://www.usenix.org/system/files/conference/woot13/woot13-ryan.pdf) -for more information. - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## Cellular - -### Attacks - -- **IMSI-Catcher**: Is a telephone eavesdropping device used for intercepting - mobile phone traffic and tracking location data of mobile phone users. - Essentially a "fake" mobile tower acting between the target mobile phone and - the service provider's real towers, it is considered a man-in-the-middle - (**MITM**) attack. - -- Lack of mutual authentication (**GPRS**/**EDGE**) and encryption with **GEA0**. - -- **Fall back** from **UMTS**/**HSPA** to **GPRS**/**EDGE** (Jamming against - **UMTS**/**HSPA**). - -- 4G **DoS** attack. - -### Recommendations - -- Check antenna legitimacy. - -<!-- section-config --> - -Domain | Tech name | Recommendations --------------------------------- | --------- | -------------------------- -Connectivity-Wireless-Cellular-1 | GPRS/EDGE | Avoid -Connectivity-Wireless-Cellular-2 | UMTS/HSPA | Protected against Jamming. - -<!-- end-section-config --> - -See [A practical attack against GPRS/EDGE/UMTS/HSPA mobile data communications](https://media.blackhat.com/bh-dc-11/Perez-Pico/BlackHat_DC_2011_Perez-Pico_Mobile_Attacks-wp.pdf) -for more information. - --------------------------------------------------------------------------------- - -## Radio - -### Attacks - -- Interception of data with low cost material (**SDR** with hijacked DVB-T/DAB - for example). - -### Recommendations - -- Use the **R**adio **D**ata **S**ystem (**RDS**) only to send signals for audio - output and meta concerning radio. - -<!-- section-config --> - -Domain | Tech name | Recommendations ------------------------------ | --------- | -------------------------------------------- -Connectivity-Wireless-Radio-1 | RDS | Only audio output and meta concerning radio. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -<!-- pagebreak --> - -## NFC - -### Attacks - -- **MITM**: Relay and replay attack. - -### Recommendations - -- Should implements protection against relay and replay attacks (Tokens, etc...). -- Disable unneeded and unapproved services and profiles. -- NFC should be use encrypted link (secure channel). A standard key agreement - protocol like Diffie-Hellmann based on RSA or Elliptic Curves could be applied - to establish a shared secret between two devices. -- Automotive NFC device should be certified by NFC forum entity: The NFC Forum - Certification Mark shows that products meet global interoperability standards. -- NFC Modified Miller coding is preferred over NFC Manchester coding. - -<!-- section-config --> - -Domain | Tech name | Recommendations ---------------------------- | --------- | ------------------------------------------------------ -Connectivity-Wireless-NFC-1 | NFC | Protected against relay and replay attacks. -Connectivity-Wireless-NFC-2 | Device | Disable unneeded and unapproved services and profiles. - -<!-- end-section-config --> diff --git a/security-blueprint/part-7/3-Cloud.md b/security-blueprint/part-7/3-Cloud.md deleted file mode 100644 index ec7edea..0000000 --- a/security-blueprint/part-7/3-Cloud.md +++ /dev/null @@ -1,107 +0,0 @@ -# Cloud - -## Download - -- **authentication**: Authentication is the security process that validates the - claimed identity of a device, entity or person, relying on one or more - characteristics bound to that device, entity or person. - -- **Authorization**: Parses the network to allow access to some or all network -functionality by providing rules and allowing access or denying access based -on a subscriber's profile and services purchased. - -<!-- section-config --> - -Domain | Object | Recommendations ----------------------------- | -------------- | -------------------------------------- -Application-Cloud-Download-1 | authentication | Must implement authentication process. -Application-Cloud-Download-2 | Authorization | Must implement Authorization process. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Infrastructure - -- **Deep Packet Inspection**: **DPI** provides techniques to analyze the payload - of each packet, adding an extra layer of security. **DPI** can detect and - neutralize attacks that would be missed by other security mechanisms. - -- A **DoS** protection in order to avoid that the Infrastructure is no more - accessible for a period of time. - -- **Scanning tools** such as **SATS** and **DAST** assessments perform - vulnerability scans on the source code and data flows on web applications. - Many of these scanning tools run different security tests that stress - applications under certain attack scenarios to discover security issues. - -- **IDS & IPS**: **IDS** detect and log inappropriate, incorrect, or anomalous - activity. **IDS** can be located in the telecommunications networks and/or - within the host server or computer. Telecommunications carriers build - intrusion detection capability in all network connections to routers and - servers, as well as offering it as a service to enterprise customers. Once - **IDS** systems have identified an attack, **IPS** ensures that malicious - packets are blocked before they cause any harm to backend systems and - networks. **IDS** typically functions via one or more of three systems: - - 1. Pattern matching. - 2. Anomaly detection. - 3. Protocol behavior. - -<!-- pagebreak --> - -<!-- section-config --> - -Domain | Object | Recommendations ----------------------------------- | ------------- | ---------------------------------------------------------- -Application-Cloud-Infrastructure-1 | Packet | Should implement a DPI. -Application-Cloud-Infrastructure-2 | DoS | Must implement a DoS protection. -Application-Cloud-Infrastructure-3 | Test | Should implement scanning tools like SATS and DAST. -Application-Cloud-Infrastructure-4 | Log | Should implement security tools (IDS and IPS). -Application-Cloud-Infrastructure-5 | App integrity | Applications must be signed by the code signing authority. - -<!-- end-section-config --> - --------------------------------------------------------------------------------- - -## Transport - -For data transport, it is necessary to **encrypt data end-to-end**. To prevent **MITM** attacks, -no third party should be able to interpret transported data. Another aspect -is the data anonymization in order to protect the leakage of private information -on the user or any other third party. - -The use of standards such as **IPSec** provides "_private and secure -communications over IP networks, through the use of cryptographic security -services, is a set of protocols using algorithms to transport secure data over -an IP network._". In addition, **IPSec** operates at the network layer of the -**OSI** model, contrary to previous standards that operate at the application -layer. This makes its application independent and means that users do not need -to configure each application to **IPSec** standards. - -**IPSec** provides the services below : - -- Confidentiality: A service that makes it impossible to interpret data if it is - not the recipient. It is the encryption function that provides this service by - transforming intelligible (unencrypted) data into unintelligible (encrypted) - data. -- Authentication: A service that ensures that a piece of data comes from where - it is supposed to come from. -- Integrity: A service that consists in ensuring that data has not been tampered - with accidentally or fraudulently. -- Replay Protection: A service that prevents attacks by re-sending a valid - intercepted packet to the network for the same authorization. - This service is provided by the presence of a sequence number. -- Key management: Mechanism for negotiating the length of encryption keys - between two **IPSec** elements and exchange of these keys. - -An additional means of protection would be to do the monitoring between users -and the cloud as a **CASB** will provide. - -<!-- section-config --> - -Domain | Object | Recommendations ------------------------------ | ----------------------------------------- | --------------------------------- -Application-Cloud-Transport-1 | Integrity, confidentiality and legitimacy | Should implement IPSec standards. - -<!-- end-section-config --> diff --git a/security-blueprint/part-8/0_Abstract.md b/security-blueprint/part-8/0_Abstract.md deleted file mode 100644 index e438e65..0000000 --- a/security-blueprint/part-8/0_Abstract.md +++ /dev/null @@ -1,76 +0,0 @@ -# Part 8 - Update (**OTA**) - -## Abstract - -Updating applications and firmware is essential for the development of new -features and even more to fix security bugs. -However, if a malicious third party manages to alter the content during -transport, it could -alter the functioning of the system and/or applications. The security of the -updates is therefore a critical point to evaluate in order to guarantee the -integrity, the confidentiality and the legitimacy of the transmitted data. - -## Attack Vectors - -Updates Over The Air are one of the most common points where an attacker -will penetrate. An OTA update mechanism is one of the highest threats in the system. -If an attacker is able to install his own application or firmware on the system, -he can get the same level of access that the original application or firmware had. -From that point, the intruder can get unfettered access to the rest of the system, -which might include making modifications, downloading other pieces of software, -and stealing assets. - -### Man In The Middle (MITM) - -The man-in-the-middle attack is the most classic example of an attack, where an adversary -inserts himself between two communicating entities and grabs whatever is being communicated. -In the case of OTA attacks, the connection in the network may be intercepted: - -* On the internet, before the cloud back-end. -* At the base station, 3G,4G,5G connection to the internet. -* At the receiving antenna, connection to the car. -* Between the receiving antenna and the gateway router (if present), connection within the car. -* Between the gateway router and the target component (IVI, In-Vehicle Infotainment unit). - -There are many ways to mount a MITM attack. For example, proxy tools like Burp Proxy can -be used to intercept web traffic as a man-in-the-middle. Under the guise of being a testing tool, -the proxy server is often used in attack scenarios. It runs on a variety of platforms. - -As another example, false base station attacks are known to be fairly easy to set-up. -The problem is apparently fairly prevalent in countries like China and in the UK. -These fake base stations are sometimes just eavesdropping on the communication, -but others have the potential to do serious harm. - -Defenses against MITM attacks include encrypted and signed data pipes. Furthermore, -architects and developers are also recommended to encrypt and sign the payloads that are -being passed over these pipes, to defend against perusal of the data. - -### Man At The End (MATE) - -The man-at-the-end attack is when an intruder analyzes the end-point of the communication when -software is accessing the data communication. This is a more severe attack type where the attacker can: - -* Steal keys. - * For example, a simple debugging session in running software could reveal a key used in memory. -* Tamper software. - * For example, replacing just one function call in software with a NOP (i.e. no operation) can drastically change the behavior of the program. -* Jam branches of control. - * For example, making a program take one branch of control rather than the intended branch can mean the difference between an authorized and a non-authorized installation. -* Modify important data. - * For example, if the data changed is a key or data leading to a control path, then this attack can be severe. - * In the case of OTA updates, MATE attacks are particularly problematic for the system. One of the consequences of MATE attacks can be installed software that allows installation of any other software. For example, an attacker might install remote access software to control any part of the system. - --------------------------------------------------------------------------------- - -## Acronyms and Abbreviations - -The following table lists the terms utilized within this part of the document. - -Acronyms or Abbreviations | Description -------------------------- | ------------------------------------------------------------------------- -_FOTA_ | **F**irmware **O**ver **T**he **A**ir -_MATE_ | **M**an **A**t **T**he **E**nd -_MITM_ | **M**an **I**n **T**he **M**iddle -_OTA_ | **O**ver **T**he **A**ir -_SOTA_ | **S**oftware **O**ver **T**he **A**ir -_TUF_ | **T**he **U**pdate **F**ramework diff --git a/security-blueprint/part-8/1-FOTA.md b/security-blueprint/part-8/1-FOTA.md deleted file mode 100644 index 3d7f58e..0000000 --- a/security-blueprint/part-8/1-FOTA.md +++ /dev/null @@ -1,41 +0,0 @@ -# Firmware Over The Air - -The firmware update is critical since its alteration back to compromise the -entire system. It is therefore necessary to take appropriate protective measures. - -AGL includes the _meta-updater_ Yocto layer that enables OTA software -updates via [Uptane](https://uptane.github.io), an automotive-specific extension -to [The Update Framework](https://theupdateframework.github.io/). Uptane and TUF -are open standards that define a secure protocol for delivering and verifying -updates even when the servers and network--internet and car-internal--aren't fully trusted. - -_meta-updater_ includes the application [`aktualizr`](https://github.com/advancedtelematic/aktualizr), -developed Advanced Telematic Systems (now part of HERE Technologies) that enables -OTA for an ECU. `aktualizr` combined with Uptane is suitable for updating the -firmware, software, and other packages on even functionally critical ECUs. -`aktualizr` can be enabled with the free, open souce backend -[`ota-community-edition`](https://github.com/advancedtelematic/ota-community-edition). - -This FOTA update mechanism can be enabled through the `agl-sota` feature. - -## Building - -To build an AGL image that uses `aktualizr`, the following can be used. - -``` -source meta-agl/scripts/aglsetup.sh -m <machine> agl-sota <other-features...> -``` - -During the build, _meta-updater_ will use credentials downloaded from `ota-community-edition` -to sign metadata verifying the build as authentic. These signatures are part of the Uptane -framework and are used to verify FOTA updates. - -## Atomic Upgrades with Rollbacks - -`aktualizr`'s primary method of updating firmware is to use `libostree` with binary diffs. -The binary diffs use the least amout of bandwidth, and by it's nature `libostree` stores -current and previous firmware versions on disk or in flash memory to allow for rollbacks. - -`libostree` is a content addressable object store much like `git`. Versions are specified -via SHA2-256. These hashes are signed in the Uptane metadata and are robust against -cryptographic compromise. diff --git a/security-blueprint/part-8/2-SOTA.md b/security-blueprint/part-8/2-SOTA.md deleted file mode 100644 index 57df6fc..0000000 --- a/security-blueprint/part-8/2-SOTA.md +++ /dev/null @@ -1,20 +0,0 @@ -# Software Over The Air - -Software updates in connected vehicles are a very useful feature, which can -deliver significant benefits. If not implemented with security in mind, -software updates can incur serious vulnerabilities. Any software update system -must ensure that not only are the software updates to devices done in a secure way, -but also that the repositories and servers hosting these updates are adequately -protected. As the process of updating software migrates from a Dealership update model -towards an **OTA** update model, securing these processes becomes a high priority. - -**SOTA** is made possible by **AppFw** (See Platform part). It will be possible -to manage in a simple way the packets (i.g. Android like). - -<!-- section-todo --> - -Domain | Improvement -------------- | ----------------- -Update-SOTA-1 | Part to complete. - -<!-- end-section-todo --> diff --git a/security-blueprint/part-9/0_Abstract.md b/security-blueprint/part-9/0_Abstract.md deleted file mode 100644 index 25d3f35..0000000 --- a/security-blueprint/part-9/0_Abstract.md +++ /dev/null @@ -1,62 +0,0 @@ -# Part 9 - Secure development - -In order to save a lot of time in code auditing, developers must follow coding guidelines. - -## Secure build - -### Kernel build - -Tools like: - -- [Code optimisation](https://github.com/jduck/lk-reducer). -- [Kernel Drivers test](https://github.com/ucsb-seclab/dr_checker) with [docs](https://www.usenix.org/system/files/conference/usenixsecurity17/sec17-machiry.pdf). - -<!-- section-todo --> - -Domain | Improvement ------------------------ | ------------ -SecureDev-SecureBuild-1 | Add content. - -<!-- end-section-todo --> - -## App/Widget signatures - -<!-- section-todo --> - -Domain | Improvement ----------------------- | ------------ -SecureDev-Signatures-1 | Add content. - -<!-- end-section-todo --> - -## Code audit - -These tools are used to check the correct implementation of functionalities and -compliance with related good practices. - -- [Continuous Code Quality](https://www.sonarqube.org/). - -<!-- section-todo --> - -Domain | Improvement ---------------------- | ----------------------------------------------------- -SecureDev-CodeAudit-1 | Add CVE analyser. -SecureDev-CodeAudit-2 | [OSSTMM](http://www.isecom.org/mirror/OSSTMM.3.pdf). - -<!-- end-section-todo --> - -### SATS - -- [RATS](https://github.com/andrew-d/rough-auditing-tool-for-security) (Maybe to old). -- [Flaw Finder](https://www.dwheeler.com/flawfinder/). - -- [wiki list](https://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis). - -- [Mathematical approach](https://perso.univ-rennes1.fr/david.lubicz/planches/David_Pichardie.pdf). - -It is necessary to verify that the application code does not use functions that -are depreciated and recognized as unsecured or cause problems. - -### DATS - -- [wiki list](https://en.wikipedia.org/wiki/Dynamic_program_analysis#Example_tools). |
