diff options
Diffstat (limited to 'tests/fuzztest')
| -rw-r--r-- | tests/fuzztest/SConscript | 50 | ||||
| -rw-r--r-- | tests/fuzztest/alltypes_pointer.options | 3 | ||||
| -rw-r--r-- | tests/fuzztest/alltypes_static.options | 3 | ||||
| -rw-r--r-- | tests/fuzztest/fuzz_syshdr.h | 15 | ||||
| -rw-r--r-- | tests/fuzztest/fuzztest.c | 431 | ||||
| -rw-r--r-- | tests/fuzztest/malloc_wrappers.c | 54 | ||||
| -rw-r--r-- | tests/fuzztest/malloc_wrappers.h | 7 |
7 files changed, 563 insertions, 0 deletions
diff --git a/tests/fuzztest/SConscript b/tests/fuzztest/SConscript new file mode 100644 index 00000000..36b62c56 --- /dev/null +++ b/tests/fuzztest/SConscript @@ -0,0 +1,50 @@ +# Run a fuzz test to verify robustness against corrupted/malicious data. + +Import("env") + +# We need our own pb_decode.o for the malloc support +env = env.Clone() +env.Append(CPPDEFINES = {'PB_ENABLE_MALLOC': 1, + 'PB_SYSTEM_HEADER': '\\"fuzz_syshdr.h\\"'}) +env.Append(CPPPATH = ".") + +if 'SYSHDR' in env: + env.Append(CPPDEFINES = {'PB_OLD_SYSHDR': env['SYSHDR']}) + +# Disable libmudflap, because it will confuse valgrind +# and other memory leak detection tools. +if '-fmudflap' in env["CCFLAGS"]: + env["CCFLAGS"].remove("-fmudflap") + env["LINKFLAGS"].remove("-fmudflap") + env["LIBS"].remove("mudflap") + +strict = env.Clone() +strict.Append(CFLAGS = strict['CORECFLAGS']) +strict.Object("pb_decode_with_malloc.o", "$NANOPB/pb_decode.c") +strict.Object("pb_encode_with_malloc.o", "$NANOPB/pb_encode.c") +strict.Object("pb_common_with_malloc.o", "$NANOPB/pb_common.c") + +# We want both pointer and static versions of the AllTypes message +env.Command("alltypes_static.proto", "#alltypes/alltypes.proto", + lambda target, source, env: + open(str(target[0]), 'w').write("package alltypes_static;\n" + + open(str(source[0])).read())) +env.Command("alltypes_pointer.proto", "#alltypes/alltypes.proto", + lambda target, source, env: + open(str(target[0]), 'w').write("package alltypes_pointer;\n" + + open(str(source[0])).read())) + +p1 = env.NanopbProto(["alltypes_pointer", "alltypes_pointer.options"]) +p2 = env.NanopbProto(["alltypes_static", "alltypes_static.options"]) +fuzz = env.Program(["fuzztest.c", + "alltypes_pointer.pb.c", + "alltypes_static.pb.c", + "pb_encode_with_malloc.o", + "pb_decode_with_malloc.o", + "pb_common_with_malloc.o", + "malloc_wrappers.c"]) +Depends([p1, p2, fuzz], ["fuzz_syshdr.h", "malloc_wrappers.h"]) + +env.RunTest(fuzz) + + diff --git a/tests/fuzztest/alltypes_pointer.options b/tests/fuzztest/alltypes_pointer.options new file mode 100644 index 00000000..52abeb7f --- /dev/null +++ b/tests/fuzztest/alltypes_pointer.options @@ -0,0 +1,3 @@ +# Generate all fields as pointers. +* type:FT_POINTER + diff --git a/tests/fuzztest/alltypes_static.options b/tests/fuzztest/alltypes_static.options new file mode 100644 index 00000000..1c10637c --- /dev/null +++ b/tests/fuzztest/alltypes_static.options @@ -0,0 +1,3 @@ +* max_size:32 +* max_count:8 +*.extensions type:FT_IGNORE diff --git a/tests/fuzztest/fuzz_syshdr.h b/tests/fuzztest/fuzz_syshdr.h new file mode 100644 index 00000000..d295d9ed --- /dev/null +++ b/tests/fuzztest/fuzz_syshdr.h @@ -0,0 +1,15 @@ +/* This is just a wrapper in order to get our own malloc wrappers into nanopb core. */ + +#define pb_realloc(ptr,size) counting_realloc(ptr,size) +#define pb_free(ptr) counting_free(ptr) + +#ifdef PB_OLD_SYSHDR +#include PB_OLD_SYSHDR +#else +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> +#include <string.h> +#endif + +#include <malloc_wrappers.h> diff --git a/tests/fuzztest/fuzztest.c b/tests/fuzztest/fuzztest.c new file mode 100644 index 00000000..996ed450 --- /dev/null +++ b/tests/fuzztest/fuzztest.c @@ -0,0 +1,431 @@ +/* Fuzz testing for the nanopb core. + * Attempts to verify all the properties defined in the security model document. + */ + +#include <pb_decode.h> +#include <pb_encode.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <time.h> +#include "malloc_wrappers.h" +#include "alltypes_static.pb.h" +#include "alltypes_pointer.pb.h" + +static uint64_t random_seed; + +/* Uses xorshift64 here instead of rand() for both speed and + * reproducibility across platforms. */ +static uint32_t rand_word() +{ + random_seed ^= random_seed >> 12; + random_seed ^= random_seed << 25; + random_seed ^= random_seed >> 27; + return random_seed * 2685821657736338717ULL; +} + +/* Get a random integer in range, with approximately flat distribution. */ +static int rand_int(int min, int max) +{ + return rand_word() % (max + 1 - min) + min; +} + +static bool rand_bool() +{ + return rand_word() & 1; +} + +/* Get a random byte, with skewed distribution. + * Important corner cases like 0xFF, 0x00 and 0xFE occur more + * often than other values. */ +static uint8_t rand_byte() +{ + uint32_t w = rand_word(); + uint8_t b = w & 0xFF; + if (w & 0x100000) + b >>= (w >> 8) & 7; + if (w & 0x200000) + b <<= (w >> 12) & 7; + if (w & 0x400000) + b ^= 0xFF; + return b; +} + +/* Get a random length, with skewed distribution. + * Favors the shorter lengths, but always atleast 1. */ +static size_t rand_len(size_t max) +{ + uint32_t w = rand_word(); + size_t s; + if (w & 0x800000) + w &= 3; + else if (w & 0x400000) + w &= 15; + else if (w & 0x200000) + w &= 255; + + s = (w % max); + if (s == 0) + s = 1; + + return s; +} + +/* Fills a buffer with random data with skewed distribution. */ +static void rand_fill(uint8_t *buf, size_t count) +{ + while (count--) + *buf++ = rand_byte(); +} + +/* Fill with random protobuf-like data */ +static size_t rand_fill_protobuf(uint8_t *buf, size_t min_bytes, size_t max_bytes, int min_tag) +{ + pb_ostream_t stream = pb_ostream_from_buffer(buf, max_bytes); + + while(stream.bytes_written < min_bytes) + { + pb_wire_type_t wt = rand_int(0, 3); + if (wt == 3) wt = 5; /* Gap in values */ + + if (!pb_encode_tag(&stream, wt, rand_int(min_tag, min_tag + 512))) + break; + + if (wt == PB_WT_VARINT) + { + uint64_t value; + rand_fill((uint8_t*)&value, sizeof(value)); + pb_encode_varint(&stream, value); + } + else if (wt == PB_WT_64BIT) + { + uint64_t value; + rand_fill((uint8_t*)&value, sizeof(value)); + pb_encode_fixed64(&stream, &value); + } + else if (wt == PB_WT_32BIT) + { + uint32_t value; + rand_fill((uint8_t*)&value, sizeof(value)); + pb_encode_fixed32(&stream, &value); + } + else if (wt == PB_WT_STRING) + { + size_t len; + uint8_t *buf; + + if (min_bytes > stream.bytes_written) + len = rand_len(min_bytes - stream.bytes_written); + else + len = 0; + + buf = malloc(len); + pb_encode_varint(&stream, len); + rand_fill(buf, len); + pb_write(&stream, buf, len); + free(buf); + } + } + + return stream.bytes_written; +} + +/* Given a buffer of data, mess it up a bit */ +static void rand_mess(uint8_t *buf, size_t count) +{ + int m = rand_int(0, 3); + + if (m == 0) + { + /* Replace random substring */ + int s = rand_int(0, count - 1); + int l = rand_len(count - s); + rand_fill(buf + s, l); + } + else if (m == 1) + { + /* Swap random bytes */ + int a = rand_int(0, count - 1); + int b = rand_int(0, count - 1); + int x = buf[a]; + buf[a] = buf[b]; + buf[b] = x; + } + else if (m == 2) + { + /* Duplicate substring */ + int s = rand_int(0, count - 2); + int l = rand_len((count - s) / 2); + memcpy(buf + s + l, buf + s, l); + } + else if (m == 3) + { + /* Add random protobuf noise */ + int s = rand_int(0, count - 1); + int l = rand_len(count - s); + rand_fill_protobuf(buf + s, l, count - s, 1); + } +} + +/* Some default data to put in the message */ +static const alltypes_static_AllTypes initval = alltypes_static_AllTypes_init_default; + +#define BUFSIZE 4096 + +static bool do_static_encode(uint8_t *buffer, size_t *msglen) +{ + pb_ostream_t stream; + bool status; + + /* Allocate a message and fill it with defaults */ + alltypes_static_AllTypes *msg = malloc_with_check(sizeof(alltypes_static_AllTypes)); + memcpy(msg, &initval, sizeof(initval)); + + /* Apply randomness to the data before encoding */ + while (rand_int(0, 7)) + rand_mess((uint8_t*)msg, sizeof(alltypes_static_AllTypes)); + + stream = pb_ostream_from_buffer(buffer, BUFSIZE); + status = pb_encode(&stream, alltypes_static_AllTypes_fields, msg); + assert(stream.bytes_written <= BUFSIZE); + assert(stream.bytes_written <= alltypes_static_AllTypes_size); + + *msglen = stream.bytes_written; + free_with_check(msg); + + return status; +} + +/* Append or prepend protobuf noise */ +static void do_protobuf_noise(uint8_t *buffer, size_t *msglen) +{ + int m = rand_int(0, 2); + size_t max_size = BUFSIZE - 32 - *msglen; + if (m == 1) + { + /* Prepend */ + uint8_t *tmp = malloc_with_check(BUFSIZE); + size_t s = rand_fill_protobuf(tmp, rand_len(max_size), BUFSIZE - *msglen, 512); + memmove(buffer + s, buffer, *msglen); + memcpy(buffer, tmp, s); + free_with_check(tmp); + *msglen += s; + } + else if (m == 2) + { + /* Append */ + size_t s = rand_fill_protobuf(buffer + *msglen, rand_len(max_size), BUFSIZE - *msglen, 512); + *msglen += s; + } +} + +static bool do_static_decode(uint8_t *buffer, size_t msglen, bool assert_success) +{ + pb_istream_t stream; + bool status; + + alltypes_static_AllTypes *msg = malloc_with_check(sizeof(alltypes_static_AllTypes)); + rand_fill((uint8_t*)msg, sizeof(alltypes_static_AllTypes)); + stream = pb_istream_from_buffer(buffer, msglen); + status = pb_decode(&stream, alltypes_static_AllTypes_fields, msg); + + if (!status && assert_success) + { + /* Anything that was successfully encoded, should be decodeable. + * One exception: strings without null terminator are encoded up + * to end of buffer, but refused on decode because the terminator + * would not fit. */ + if (strcmp(stream.errmsg, "string overflow") != 0) + assert(status); + } + + free_with_check(msg); + return status; +} + +static bool do_pointer_decode(uint8_t *buffer, size_t msglen, bool assert_success) +{ + pb_istream_t stream; + bool status; + alltypes_pointer_AllTypes *msg; + + msg = malloc_with_check(sizeof(alltypes_pointer_AllTypes)); + memset(msg, 0, sizeof(alltypes_pointer_AllTypes)); + stream = pb_istream_from_buffer(buffer, msglen); + + assert(get_alloc_count() == 0); + status = pb_decode(&stream, alltypes_pointer_AllTypes_fields, msg); + + if (assert_success) + assert(status); + + pb_release(alltypes_pointer_AllTypes_fields, msg); + assert(get_alloc_count() == 0); + + free_with_check(msg); + + return status; +} + +/* Do a decode -> encode -> decode -> encode roundtrip */ +static void do_static_roundtrip(uint8_t *buffer, size_t msglen) +{ + bool status; + uint8_t *buf2 = malloc_with_check(BUFSIZE); + uint8_t *buf3 = malloc_with_check(BUFSIZE); + size_t msglen2, msglen3; + alltypes_static_AllTypes *msg1 = malloc_with_check(sizeof(alltypes_static_AllTypes)); + alltypes_static_AllTypes *msg2 = malloc_with_check(sizeof(alltypes_static_AllTypes)); + memset(msg1, 0, sizeof(alltypes_static_AllTypes)); + memset(msg2, 0, sizeof(alltypes_static_AllTypes)); + + { + pb_istream_t stream = pb_istream_from_buffer(buffer, msglen); + status = pb_decode(&stream, alltypes_static_AllTypes_fields, msg1); + assert(status); + } + + { + pb_ostream_t stream = pb_ostream_from_buffer(buf2, BUFSIZE); + status = pb_encode(&stream, alltypes_static_AllTypes_fields, msg1); + assert(status); + msglen2 = stream.bytes_written; + } + + { + pb_istream_t stream = pb_istream_from_buffer(buf2, msglen2); + status = pb_decode(&stream, alltypes_static_AllTypes_fields, msg2); + assert(status); + } + + { + pb_ostream_t stream = pb_ostream_from_buffer(buf3, BUFSIZE); + status = pb_encode(&stream, alltypes_static_AllTypes_fields, msg2); + assert(status); + msglen3 = stream.bytes_written; + } + + assert(msglen2 == msglen3); + assert(memcmp(buf2, buf3, msglen2) == 0); + + free_with_check(msg1); + free_with_check(msg2); + free_with_check(buf2); + free_with_check(buf3); +} + +/* Do decode -> encode -> decode -> encode roundtrip */ +static void do_pointer_roundtrip(uint8_t *buffer, size_t msglen) +{ + bool status; + uint8_t *buf2 = malloc_with_check(BUFSIZE); + uint8_t *buf3 = malloc_with_check(BUFSIZE); + size_t msglen2, msglen3; + alltypes_pointer_AllTypes *msg1 = malloc_with_check(sizeof(alltypes_pointer_AllTypes)); + alltypes_pointer_AllTypes *msg2 = malloc_with_check(sizeof(alltypes_pointer_AllTypes)); + memset(msg1, 0, sizeof(alltypes_pointer_AllTypes)); + memset(msg2, 0, sizeof(alltypes_pointer_AllTypes)); + + { + pb_istream_t stream = pb_istream_from_buffer(buffer, msglen); + status = pb_decode(&stream, alltypes_pointer_AllTypes_fields, msg1); + assert(status); + } + + { + pb_ostream_t stream = pb_ostream_from_buffer(buf2, BUFSIZE); + status = pb_encode(&stream, alltypes_pointer_AllTypes_fields, msg1); + assert(status); + msglen2 = stream.bytes_written; + } + + { + pb_istream_t stream = pb_istream_from_buffer(buf2, msglen2); + status = pb_decode(&stream, alltypes_pointer_AllTypes_fields, msg2); + assert(status); + } + + { + pb_ostream_t stream = pb_ostream_from_buffer(buf3, BUFSIZE); + status = pb_encode(&stream, alltypes_pointer_AllTypes_fields, msg2); + assert(status); + msglen3 = stream.bytes_written; + } + + assert(msglen2 == msglen3); + assert(memcmp(buf2, buf3, msglen2) == 0); + + pb_release(alltypes_pointer_AllTypes_fields, msg1); + pb_release(alltypes_pointer_AllTypes_fields, msg2); + free_with_check(msg1); + free_with_check(msg2); + free_with_check(buf2); + free_with_check(buf3); +} + +static void run_iteration() +{ + uint8_t *buffer = malloc_with_check(BUFSIZE); + size_t msglen; + bool status; + + rand_fill(buffer, BUFSIZE); + + if (do_static_encode(buffer, &msglen)) + { + do_protobuf_noise(buffer, &msglen); + + status = do_static_decode(buffer, msglen, true); + + if (status) + do_static_roundtrip(buffer, msglen); + + status = do_pointer_decode(buffer, msglen, true); + + if (status) + do_pointer_roundtrip(buffer, msglen); + + /* Apply randomness to the encoded data */ + while (rand_bool()) + rand_mess(buffer, BUFSIZE); + + /* Apply randomness to encoded data length */ + if (rand_bool()) + msglen = rand_int(0, BUFSIZE); + + status = do_static_decode(buffer, msglen, false); + do_pointer_decode(buffer, msglen, status); + + if (status) + { + do_static_roundtrip(buffer, msglen); + do_pointer_roundtrip(buffer, msglen); + } + } + + free_with_check(buffer); +} + +int main(int argc, char **argv) +{ + int i; + if (argc > 1) + { + random_seed = atol(argv[1]); + } + else + { + random_seed = time(NULL); + } + + fprintf(stderr, "Random seed: %llu\n", (long long unsigned)random_seed); + + for (i = 0; i < 10000; i++) + { + run_iteration(); + } + + return 0; +} + diff --git a/tests/fuzztest/malloc_wrappers.c b/tests/fuzztest/malloc_wrappers.c new file mode 100644 index 00000000..ad69f1ce --- /dev/null +++ b/tests/fuzztest/malloc_wrappers.c @@ -0,0 +1,54 @@ +#include "malloc_wrappers.h" +#include <stdint.h> +#include <assert.h> +#include <string.h> + +static size_t alloc_count = 0; + +/* Allocate memory and place check values before and after. */ +void* malloc_with_check(size_t size) +{ + size_t size32 = (size + 3) / 4 + 3; + uint32_t *buf = malloc(size32 * sizeof(uint32_t)); + buf[0] = size32; + buf[1] = 0xDEADBEEF; + buf[size32 - 1] = 0xBADBAD; + return buf + 2; +} + +/* Free memory allocated with malloc_with_check() and do the checks. */ +void free_with_check(void *mem) +{ + uint32_t *buf = (uint32_t*)mem - 2; + assert(buf[1] == 0xDEADBEEF); + assert(buf[buf[0] - 1] == 0xBADBAD); + free(buf); +} + +/* Track memory usage */ +void* counting_realloc(void *ptr, size_t size) +{ + /* Don't allocate crazy amounts of RAM when fuzzing */ + if (size > 1000000) + return NULL; + + if (!ptr && size) + alloc_count++; + + return realloc(ptr, size); +} + +void counting_free(void *ptr) +{ + if (ptr) + { + assert(alloc_count > 0); + alloc_count--; + free(ptr); + } +} + +size_t get_alloc_count() +{ + return alloc_count; +} diff --git a/tests/fuzztest/malloc_wrappers.h b/tests/fuzztest/malloc_wrappers.h new file mode 100644 index 00000000..7eec7952 --- /dev/null +++ b/tests/fuzztest/malloc_wrappers.h @@ -0,0 +1,7 @@ +#include <stdlib.h> + +void* malloc_with_check(size_t size); +void free_with_check(void *mem); +void* counting_realloc(void *ptr, size_t size); +void counting_free(void *ptr); +size_t get_alloc_count(); |