diff options
Diffstat (limited to 'roms/edk2/CryptoPkg/Library/OpensslLib/openssl/ssl/statem/extensions.c')
| -rw-r--r-- | roms/edk2/CryptoPkg/Library/OpensslLib/openssl/ssl/statem/extensions.c | 1703 |
1 files changed, 1703 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/ssl/statem/extensions.c b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/ssl/statem/extensions.c new file mode 100644 index 000000000..4ef8b417b --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/ssl/statem/extensions.c @@ -0,0 +1,1703 @@ +/* + * Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +#include <string.h> +#include "internal/nelem.h" +#include "internal/cryptlib.h" +#include "../ssl_local.h" +#include "statem_local.h" +#include "internal/cryptlib.h" + +static int final_renegotiate(SSL *s, unsigned int context, int sent); +static int init_server_name(SSL *s, unsigned int context); +static int final_server_name(SSL *s, unsigned int context, int sent); +#ifndef OPENSSL_NO_EC +static int final_ec_pt_formats(SSL *s, unsigned int context, int sent); +#endif +static int init_session_ticket(SSL *s, unsigned int context); +#ifndef OPENSSL_NO_OCSP +static int init_status_request(SSL *s, unsigned int context); +#endif +#ifndef OPENSSL_NO_NEXTPROTONEG +static int init_npn(SSL *s, unsigned int context); +#endif +static int init_alpn(SSL *s, unsigned int context); +static int final_alpn(SSL *s, unsigned int context, int sent); +static int init_sig_algs_cert(SSL *s, unsigned int context); +static int init_sig_algs(SSL *s, unsigned int context); +static int init_certificate_authorities(SSL *s, unsigned int context); +static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt, + unsigned int context, + X509 *x, + size_t chainidx); +static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt, + unsigned int context, X509 *x, + size_t chainidx); +#ifndef OPENSSL_NO_SRP +static int init_srp(SSL *s, unsigned int context); +#endif +static int init_etm(SSL *s, unsigned int context); +static int init_ems(SSL *s, unsigned int context); +static int final_ems(SSL *s, unsigned int context, int sent); +static int init_psk_kex_modes(SSL *s, unsigned int context); +#ifndef OPENSSL_NO_EC +static int final_key_share(SSL *s, unsigned int context, int sent); +#endif +#ifndef OPENSSL_NO_SRTP +static int init_srtp(SSL *s, unsigned int context); +#endif +static int final_sig_algs(SSL *s, unsigned int context, int sent); +static int final_early_data(SSL *s, unsigned int context, int sent); +static int final_maxfragmentlen(SSL *s, unsigned int context, int sent); +static int init_post_handshake_auth(SSL *s, unsigned int context); + +/* Structure to define a built-in extension */ +typedef struct extensions_definition_st { + /* The defined type for the extension */ + unsigned int type; + /* + * The context that this extension applies to, e.g. what messages and + * protocol versions + */ + unsigned int context; + /* + * Initialise extension before parsing. Always called for relevant contexts + * even if extension not present + */ + int (*init)(SSL *s, unsigned int context); + /* Parse extension sent from client to server */ + int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, + size_t chainidx); + /* Parse extension send from server to client */ + int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, + size_t chainidx); + /* Construct extension sent from server to client */ + EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, + X509 *x, size_t chainidx); + /* Construct extension sent from client to server */ + EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, + X509 *x, size_t chainidx); + /* + * Finalise extension after parsing. Always called where an extensions was + * initialised even if the extension was not present. |sent| is set to 1 if + * the extension was seen, or 0 otherwise. + */ + int (*final)(SSL *s, unsigned int context, int sent); +} EXTENSION_DEFINITION; + +/* + * Definitions of all built-in extensions. NOTE: Changes in the number or order + * of these extensions should be mirrored with equivalent changes to the + * indexes ( TLSEXT_IDX_* ) defined in ssl_local.h. + * Each extension has an initialiser, a client and + * server side parser and a finaliser. The initialiser is called (if the + * extension is relevant to the given context) even if we did not see the + * extension in the message that we received. The parser functions are only + * called if we see the extension in the message. The finalisers are always + * called if the initialiser was called. + * There are also server and client side constructor functions which are always + * called during message construction if the extension is relevant for the + * given context. + * The initialisation, parsing, finalisation and construction functions are + * always called in the order defined in this list. Some extensions may depend + * on others having been processed first, so the order of this list is + * significant. + * The extension context is defined by a series of flags which specify which + * messages the extension is relevant to. These flags also specify whether the + * extension is relevant to a particular protocol or protocol version. + * + * TODO(TLS1.3): Make sure we have a test to check the consistency of these + * + * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at + * the end, keep these extensions before signature_algorithm. + */ +#define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL } +static const EXTENSION_DEFINITION ext_defs[] = { + { + TLSEXT_TYPE_renegotiate, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate, + tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate, + final_renegotiate + }, + { + TLSEXT_TYPE_server_name, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + init_server_name, + tls_parse_ctos_server_name, tls_parse_stoc_server_name, + tls_construct_stoc_server_name, tls_construct_ctos_server_name, + final_server_name + }, + { + TLSEXT_TYPE_max_fragment_length, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + NULL, tls_parse_ctos_maxfragmentlen, tls_parse_stoc_maxfragmentlen, + tls_construct_stoc_maxfragmentlen, tls_construct_ctos_maxfragmentlen, + final_maxfragmentlen + }, +#ifndef OPENSSL_NO_SRP + { + TLSEXT_TYPE_srp, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL + }, +#else + INVALID_EXTENSION, +#endif +#ifndef OPENSSL_NO_EC + { + TLSEXT_TYPE_ec_point_formats, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats, + tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats, + final_ec_pt_formats + }, + { + /* + * "supported_groups" is spread across several specifications. + * It was originally specified as "elliptic_curves" in RFC 4492, + * and broadened to include named FFDH groups by RFC 7919. + * Both RFCs 4492 and 7919 do not include a provision for the server + * to indicate to the client the complete list of groups supported + * by the server, with the server instead just indicating the + * selected group for this connection in the ServerKeyExchange + * message. TLS 1.3 adds a scheme for the server to indicate + * to the client its list of supported groups in the + * EncryptedExtensions message, but none of the relevant + * specifications permit sending supported_groups in the ServerHello. + * Nonetheless (possibly due to the close proximity to the + * "ec_point_formats" extension, which is allowed in the ServerHello), + * there are several servers that send this extension in the + * ServerHello anyway. Up to and including the 1.1.0 release, + * we did not check for the presence of nonpermitted extensions, + * so to avoid a regression, we must permit this extension in the + * TLS 1.2 ServerHello as well. + * + * Note that there is no tls_parse_stoc_supported_groups function, + * so we do not perform any additional parsing, validation, or + * processing on the server's group list -- this is just a minimal + * change to preserve compatibility with these misbehaving servers. + */ + TLSEXT_TYPE_supported_groups, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS + | SSL_EXT_TLS1_2_SERVER_HELLO, + NULL, tls_parse_ctos_supported_groups, NULL, + tls_construct_stoc_supported_groups, + tls_construct_ctos_supported_groups, NULL + }, +#else + INVALID_EXTENSION, + INVALID_EXTENSION, +#endif + { + TLSEXT_TYPE_session_ticket, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + init_session_ticket, tls_parse_ctos_session_ticket, + tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket, + tls_construct_ctos_session_ticket, NULL + }, +#ifndef OPENSSL_NO_OCSP + { + TLSEXT_TYPE_status_request, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, + init_status_request, tls_parse_ctos_status_request, + tls_parse_stoc_status_request, tls_construct_stoc_status_request, + tls_construct_ctos_status_request, NULL + }, +#else + INVALID_EXTENSION, +#endif +#ifndef OPENSSL_NO_NEXTPROTONEG + { + TLSEXT_TYPE_next_proto_neg, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn, + tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL + }, +#else + INVALID_EXTENSION, +#endif + { + /* + * Must appear in this list after server_name so that finalisation + * happens after server_name callbacks + */ + TLSEXT_TYPE_application_layer_protocol_negotiation, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn, + tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn + }, +#ifndef OPENSSL_NO_SRTP + { + TLSEXT_TYPE_use_srtp, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY, + init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp, + tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL + }, +#else + INVALID_EXTENSION, +#endif + { + TLSEXT_TYPE_encrypt_then_mac, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm, + tls_construct_stoc_etm, tls_construct_ctos_etm, NULL + }, +#ifndef OPENSSL_NO_CT + { + TLSEXT_TYPE_signed_certificate_timestamp, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, + NULL, + /* + * No server side support for this, but can be provided by a custom + * extension. This is an exception to the rule that custom extensions + * cannot override built in ones. + */ + NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL + }, +#else + INVALID_EXTENSION, +#endif + { + TLSEXT_TYPE_extended_master_secret, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems, + tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems + }, + { + TLSEXT_TYPE_signature_algorithms_cert, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, + init_sig_algs_cert, tls_parse_ctos_sig_algs_cert, + tls_parse_ctos_sig_algs_cert, + /* We do not generate signature_algorithms_cert at present. */ + NULL, NULL, NULL + }, + { + TLSEXT_TYPE_post_handshake_auth, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ONLY, + init_post_handshake_auth, + tls_parse_ctos_post_handshake_auth, NULL, + NULL, tls_construct_ctos_post_handshake_auth, + NULL, + }, + { + TLSEXT_TYPE_signature_algorithms, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, + init_sig_algs, tls_parse_ctos_sig_algs, + tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs, + tls_construct_ctos_sig_algs, final_sig_algs + }, + { + TLSEXT_TYPE_supported_versions, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO + | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY, + NULL, + /* Processed inline as part of version selection */ + NULL, tls_parse_stoc_supported_versions, + tls_construct_stoc_supported_versions, + tls_construct_ctos_supported_versions, NULL + }, + { + TLSEXT_TYPE_psk_kex_modes, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY + | SSL_EXT_TLS1_3_ONLY, + init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL, + tls_construct_ctos_psk_kex_modes, NULL + }, +#ifndef OPENSSL_NO_EC + { + /* + * Must be in this list after supported_groups. We need that to have + * been parsed before we do this one. + */ + TLSEXT_TYPE_key_share, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO + | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY + | SSL_EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share, + tls_construct_stoc_key_share, tls_construct_ctos_key_share, + final_key_share + }, +#endif + { + /* Must be after key_share */ + TLSEXT_TYPE_cookie, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST + | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_cookie, tls_parse_stoc_cookie, + tls_construct_stoc_cookie, tls_construct_ctos_cookie, NULL + }, + { + /* + * Special unsolicited ServerHello extension only used when + * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set. We allow it in a ClientHello but + * ignore it. + */ + TLSEXT_TYPE_cryptopro_bug, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO + | SSL_EXT_TLS1_2_AND_BELOW_ONLY, + NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL + }, + { + TLSEXT_TYPE_early_data, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS + | SSL_EXT_TLS1_3_NEW_SESSION_TICKET | SSL_EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data, + tls_construct_stoc_early_data, tls_construct_ctos_early_data, + final_early_data + }, + { + TLSEXT_TYPE_certificate_authorities, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST + | SSL_EXT_TLS1_3_ONLY, + init_certificate_authorities, + tls_parse_certificate_authorities, tls_parse_certificate_authorities, + tls_construct_certificate_authorities, + tls_construct_certificate_authorities, NULL, + }, + { + /* Must be immediately before pre_shared_key */ + TLSEXT_TYPE_padding, + SSL_EXT_CLIENT_HELLO, + NULL, + /* We send this, but don't read it */ + NULL, NULL, NULL, tls_construct_ctos_padding, NULL + }, + { + /* Required by the TLSv1.3 spec to always be the last extension */ + TLSEXT_TYPE_psk, + SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO + | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk, + tls_construct_ctos_psk, NULL + } +}; + +/* Check whether an extension's context matches the current context */ +static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx) +{ + /* Check we're allowed to use this extension in this context */ + if ((thisctx & extctx) == 0) + return 0; + + if (SSL_IS_DTLS(s)) { + if ((extctx & SSL_EXT_TLS_ONLY) != 0) + return 0; + } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) { + return 0; + } + + return 1; +} + +int tls_validate_all_contexts(SSL *s, unsigned int thisctx, RAW_EXTENSION *exts) +{ + size_t i, num_exts, builtin_num = OSSL_NELEM(ext_defs), offset; + RAW_EXTENSION *thisext; + unsigned int context; + ENDPOINT role = ENDPOINT_BOTH; + + if ((thisctx & SSL_EXT_CLIENT_HELLO) != 0) + role = ENDPOINT_SERVER; + else if ((thisctx & SSL_EXT_TLS1_2_SERVER_HELLO) != 0) + role = ENDPOINT_CLIENT; + + /* Calculate the number of extensions in the extensions list */ + num_exts = builtin_num + s->cert->custext.meths_count; + + for (thisext = exts, i = 0; i < num_exts; i++, thisext++) { + if (!thisext->present) + continue; + + if (i < builtin_num) { + context = ext_defs[i].context; + } else { + custom_ext_method *meth = NULL; + + meth = custom_ext_find(&s->cert->custext, role, thisext->type, + &offset); + if (!ossl_assert(meth != NULL)) + return 0; + context = meth->context; + } + + if (!validate_context(s, context, thisctx)) + return 0; + } + + return 1; +} + +/* + * Verify whether we are allowed to use the extension |type| in the current + * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to + * indicate the extension is not allowed. If returning 1 then |*found| is set to + * the definition for the extension we found. + */ +static int verify_extension(SSL *s, unsigned int context, unsigned int type, + custom_ext_methods *meths, RAW_EXTENSION *rawexlist, + RAW_EXTENSION **found) +{ + size_t i; + size_t builtin_num = OSSL_NELEM(ext_defs); + const EXTENSION_DEFINITION *thisext; + + for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) { + if (type == thisext->type) { + if (!validate_context(s, thisext->context, context)) + return 0; + + *found = &rawexlist[i]; + return 1; + } + } + + /* Check the custom extensions */ + if (meths != NULL) { + size_t offset = 0; + ENDPOINT role = ENDPOINT_BOTH; + custom_ext_method *meth = NULL; + + if ((context & SSL_EXT_CLIENT_HELLO) != 0) + role = ENDPOINT_SERVER; + else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0) + role = ENDPOINT_CLIENT; + + meth = custom_ext_find(meths, role, type, &offset); + if (meth != NULL) { + if (!validate_context(s, meth->context, context)) + return 0; + *found = &rawexlist[offset + builtin_num]; + return 1; + } + } + + /* Unknown extension. We allow it */ + *found = NULL; + return 1; +} + +/* + * Check whether the context defined for an extension |extctx| means whether + * the extension is relevant for the current context |thisctx| or not. Returns + * 1 if the extension is relevant for this context, and 0 otherwise + */ +int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx) +{ + int is_tls13; + + /* + * For HRR we haven't selected the version yet but we know it will be + * TLSv1.3 + */ + if ((thisctx & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) + is_tls13 = 1; + else + is_tls13 = SSL_IS_TLS13(s); + + if ((SSL_IS_DTLS(s) + && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0) + || (s->version == SSL3_VERSION + && (extctx & SSL_EXT_SSL3_ALLOWED) == 0) + /* + * Note that SSL_IS_TLS13() means "TLS 1.3 has been negotiated", + * which is never true when generating the ClientHello. + * However, version negotiation *has* occurred by the time the + * ClientHello extensions are being parsed. + * Be careful to allow TLS 1.3-only extensions when generating + * the ClientHello. + */ + || (is_tls13 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0) + || (!is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0 + && (thisctx & SSL_EXT_CLIENT_HELLO) == 0) + || (s->server && !is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0) + || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0)) + return 0; + return 1; +} + +/* + * Gather a list of all the extensions from the data in |packet]. |context| + * tells us which message this extension is for. The raw extension data is + * stored in |*res| on success. We don't actually process the content of the + * extensions yet, except to check their types. This function also runs the + * initialiser functions for all known extensions if |init| is nonzero (whether + * we have collected them or not). If successful the caller is responsible for + * freeing the contents of |*res|. + * + * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be + * more than one extension of the same type in a ClientHello or ServerHello. + * This function returns 1 if all extensions are unique and we have parsed their + * types, and 0 if the extensions contain duplicates, could not be successfully + * found, or an internal error occurred. We only check duplicates for + * extensions that we know about. We ignore others. + */ +int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, + RAW_EXTENSION **res, size_t *len, int init) +{ + PACKET extensions = *packet; + size_t i = 0; + size_t num_exts; + custom_ext_methods *exts = &s->cert->custext; + RAW_EXTENSION *raw_extensions = NULL; + const EXTENSION_DEFINITION *thisexd; + + *res = NULL; + + /* + * Initialise server side custom extensions. Client side is done during + * construction of extensions for the ClientHello. + */ + if ((context & SSL_EXT_CLIENT_HELLO) != 0) + custom_ext_init(&s->cert->custext); + + num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0); + raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions)); + if (raw_extensions == NULL) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS, + ERR_R_MALLOC_FAILURE); + return 0; + } + + i = 0; + while (PACKET_remaining(&extensions) > 0) { + unsigned int type, idx; + PACKET extension; + RAW_EXTENSION *thisex; + + if (!PACKET_get_net_2(&extensions, &type) || + !PACKET_get_length_prefixed_2(&extensions, &extension)) { + SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS, + SSL_R_BAD_EXTENSION); + goto err; + } + /* + * Verify this extension is allowed. We only check duplicates for + * extensions that we recognise. We also have a special case for the + * PSK extension, which must be the last one in the ClientHello. + */ + if (!verify_extension(s, context, type, exts, raw_extensions, &thisex) + || (thisex != NULL && thisex->present == 1) + || (type == TLSEXT_TYPE_psk + && (context & SSL_EXT_CLIENT_HELLO) != 0 + && PACKET_remaining(&extensions) != 0)) { + SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_COLLECT_EXTENSIONS, + SSL_R_BAD_EXTENSION); + goto err; + } + idx = thisex - raw_extensions; + /*- + * Check that we requested this extension (if appropriate). Requests can + * be sent in the ClientHello and CertificateRequest. Unsolicited + * extensions can be sent in the NewSessionTicket. We only do this for + * the built-in extensions. Custom extensions have a different but + * similar check elsewhere. + * Special cases: + * - The HRR cookie extension is unsolicited + * - The renegotiate extension is unsolicited (the client signals + * support via an SCSV) + * - The signed_certificate_timestamp extension can be provided by a + * custom extension or by the built-in version. We let the extension + * itself handle unsolicited response checks. + */ + if (idx < OSSL_NELEM(ext_defs) + && (context & (SSL_EXT_CLIENT_HELLO + | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST + | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0 + && type != TLSEXT_TYPE_cookie + && type != TLSEXT_TYPE_renegotiate + && type != TLSEXT_TYPE_signed_certificate_timestamp + && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0 +#ifndef OPENSSL_NO_GOST + && !((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0 + && type == TLSEXT_TYPE_cryptopro_bug) +#endif + ) { + SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, + SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION); + goto err; + } + if (thisex != NULL) { + thisex->data = extension; + thisex->present = 1; + thisex->type = type; + thisex->received_order = i++; + if (s->ext.debug_cb) + s->ext.debug_cb(s, !s->server, thisex->type, + PACKET_data(&thisex->data), + PACKET_remaining(&thisex->data), + s->ext.debug_arg); + } + } + + if (init) { + /* + * Initialise all known extensions relevant to this context, + * whether we have found them or not + */ + for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); + i++, thisexd++) { + if (thisexd->init != NULL && (thisexd->context & context) != 0 + && extension_is_relevant(s, thisexd->context, context) + && !thisexd->init(s, context)) { + /* SSLfatal() already called */ + goto err; + } + } + } + + *res = raw_extensions; + if (len != NULL) + *len = num_exts; + return 1; + + err: + OPENSSL_free(raw_extensions); + return 0; +} + +/* + * Runs the parser for a given extension with index |idx|. |exts| contains the + * list of all parsed extensions previously collected by + * tls_collect_extensions(). The parser is only run if it is applicable for the + * given |context| and the parser has not already been run. If this is for a + * Certificate message, then we also provide the parser with the relevant + * Certificate |x| and its position in the |chainidx| with 0 being the first + * Certificate. Returns 1 on success or 0 on failure. If an extension is not + * present this counted as success. + */ +int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context, + RAW_EXTENSION *exts, X509 *x, size_t chainidx) +{ + RAW_EXTENSION *currext = &exts[idx]; + int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, + size_t chainidx) = NULL; + + /* Skip if the extension is not present */ + if (!currext->present) + return 1; + + /* Skip if we've already parsed this extension */ + if (currext->parsed) + return 1; + + currext->parsed = 1; + + if (idx < OSSL_NELEM(ext_defs)) { + /* We are handling a built-in extension */ + const EXTENSION_DEFINITION *extdef = &ext_defs[idx]; + + /* Check if extension is defined for our protocol. If not, skip */ + if (!extension_is_relevant(s, extdef->context, context)) + return 1; + + parser = s->server ? extdef->parse_ctos : extdef->parse_stoc; + + if (parser != NULL) + return parser(s, &currext->data, context, x, chainidx); + + /* + * If the parser is NULL we fall through to the custom extension + * processing + */ + } + + /* Parse custom extensions */ + return custom_ext_parse(s, context, currext->type, + PACKET_data(&currext->data), + PACKET_remaining(&currext->data), + x, chainidx); +} + +/* + * Parse all remaining extensions that have not yet been parsed. Also calls the + * finalisation for all extensions at the end if |fin| is nonzero, whether we + * collected them or not. Returns 1 for success or 0 for failure. If we are + * working on a Certificate message then we also pass the Certificate |x| and + * its position in the |chainidx|, with 0 being the first certificate. + */ +int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x, + size_t chainidx, int fin) +{ + size_t i, numexts = OSSL_NELEM(ext_defs); + const EXTENSION_DEFINITION *thisexd; + + /* Calculate the number of extensions in the extensions list */ + numexts += s->cert->custext.meths_count; + + /* Parse each extension in turn */ + for (i = 0; i < numexts; i++) { + if (!tls_parse_extension(s, i, context, exts, x, chainidx)) { + /* SSLfatal() already called */ + return 0; + } + } + + if (fin) { + /* + * Finalise all known extensions relevant to this context, + * whether we have found them or not + */ + for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); + i++, thisexd++) { + if (thisexd->final != NULL && (thisexd->context & context) != 0 + && !thisexd->final(s, context, exts[i].present)) { + /* SSLfatal() already called */ + return 0; + } + } + } + + return 1; +} + +int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx, + int max_version) +{ + /* Skip if not relevant for our context */ + if ((extctx & thisctx) == 0) + return 0; + + /* Check if this extension is defined for our protocol. If not, skip */ + if (!extension_is_relevant(s, extctx, thisctx) + || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0 + && (thisctx & SSL_EXT_CLIENT_HELLO) != 0 + && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))) + return 0; + + return 1; +} + +/* + * Construct all the extensions relevant to the current |context| and write + * them to |pkt|. If this is an extension for a Certificate in a Certificate + * message, then |x| will be set to the Certificate we are handling, and + * |chainidx| will indicate the position in the chainidx we are processing (with + * 0 being the first in the chain). Returns 1 on success or 0 on failure. On a + * failure construction stops at the first extension to fail to construct. + */ +int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, + X509 *x, size_t chainidx) +{ + size_t i; + int min_version, max_version = 0, reason; + const EXTENSION_DEFINITION *thisexd; + + if (!WPACKET_start_sub_packet_u16(pkt) + /* + * If extensions are of zero length then we don't even add the + * extensions length bytes to a ClientHello/ServerHello + * (for non-TLSv1.3). + */ + || ((context & + (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0 + && !WPACKET_set_flags(pkt, + WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, + ERR_R_INTERNAL_ERROR); + return 0; + } + + if ((context & SSL_EXT_CLIENT_HELLO) != 0) { + reason = ssl_get_min_max_version(s, &min_version, &max_version, NULL); + if (reason != 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, + reason); + return 0; + } + } + + /* Add custom extensions first */ + if ((context & SSL_EXT_CLIENT_HELLO) != 0) { + /* On the server side with initialise during ClientHello parsing */ + custom_ext_init(&s->cert->custext); + } + if (!custom_ext_add(s, context, pkt, x, chainidx, max_version)) { + /* SSLfatal() already called */ + return 0; + } + + for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) { + EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context, + X509 *x, size_t chainidx); + EXT_RETURN ret; + + /* Skip if not relevant for our context */ + if (!should_add_extension(s, thisexd->context, context, max_version)) + continue; + + construct = s->server ? thisexd->construct_stoc + : thisexd->construct_ctos; + + if (construct == NULL) + continue; + + ret = construct(s, pkt, context, x, chainidx); + if (ret == EXT_RETURN_FAIL) { + /* SSLfatal() already called */ + return 0; + } + if (ret == EXT_RETURN_SENT + && (context & (SSL_EXT_CLIENT_HELLO + | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST + | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0) + s->ext.extflags[i] |= SSL_EXT_FLAG_SENT; + } + + if (!WPACKET_close(pkt)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, + ERR_R_INTERNAL_ERROR); + return 0; + } + + return 1; +} + +/* + * Built in extension finalisation and initialisation functions. All initialise + * or finalise the associated extension type for the given |context|. For + * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0 + * otherwise. These functions return 1 on success or 0 on failure. + */ + +static int final_renegotiate(SSL *s, unsigned int context, int sent) +{ + if (!s->server) { + /* + * Check if we can connect to a server that doesn't support safe + * renegotiation + */ + if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT) + && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) + && !sent) { + SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE, + SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); + return 0; + } + + return 1; + } + + /* Need RI if renegotiating */ + if (s->renegotiate + && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) + && !sent) { + SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE, + SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); + return 0; + } + + + return 1; +} + +static int init_server_name(SSL *s, unsigned int context) +{ + if (s->server) { + s->servername_done = 0; + + OPENSSL_free(s->ext.hostname); + s->ext.hostname = NULL; + } + + return 1; +} + +static int final_server_name(SSL *s, unsigned int context, int sent) +{ + int ret = SSL_TLSEXT_ERR_NOACK; + int altmp = SSL_AD_UNRECOGNIZED_NAME; + int was_ticket = (SSL_get_options(s) & SSL_OP_NO_TICKET) == 0; + + if (!ossl_assert(s->ctx != NULL) || !ossl_assert(s->session_ctx != NULL)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, + ERR_R_INTERNAL_ERROR); + return 0; + } + + if (s->ctx->ext.servername_cb != NULL) + ret = s->ctx->ext.servername_cb(s, &altmp, + s->ctx->ext.servername_arg); + else if (s->session_ctx->ext.servername_cb != NULL) + ret = s->session_ctx->ext.servername_cb(s, &altmp, + s->session_ctx->ext.servername_arg); + + /* + * For servers, propagate the SNI hostname from the temporary + * storage in the SSL to the persistent SSL_SESSION, now that we + * know we accepted it. + * Clients make this copy when parsing the server's response to + * the extension, which is when they find out that the negotiation + * was successful. + */ + if (s->server) { + if (sent && ret == SSL_TLSEXT_ERR_OK && !s->hit) { + /* Only store the hostname in the session if we accepted it. */ + OPENSSL_free(s->session->ext.hostname); + s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname); + if (s->session->ext.hostname == NULL && s->ext.hostname != NULL) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, + ERR_R_INTERNAL_ERROR); + } + } + } + + /* + * If we switched contexts (whether here or in the client_hello callback), + * move the sess_accept increment from the session_ctx to the new + * context, to avoid the confusing situation of having sess_accept_good + * exceed sess_accept (zero) for the new context. + */ + if (SSL_IS_FIRST_HANDSHAKE(s) && s->ctx != s->session_ctx) { + tsan_counter(&s->ctx->stats.sess_accept); + tsan_decr(&s->session_ctx->stats.sess_accept); + } + + /* + * If we're expecting to send a ticket, and tickets were previously enabled, + * and now tickets are disabled, then turn off expected ticket. + * Also, if this is not a resumption, create a new session ID + */ + if (ret == SSL_TLSEXT_ERR_OK && s->ext.ticket_expected + && was_ticket && (SSL_get_options(s) & SSL_OP_NO_TICKET) != 0) { + s->ext.ticket_expected = 0; + if (!s->hit) { + SSL_SESSION* ss = SSL_get_session(s); + + if (ss != NULL) { + OPENSSL_free(ss->ext.tick); + ss->ext.tick = NULL; + ss->ext.ticklen = 0; + ss->ext.tick_lifetime_hint = 0; + ss->ext.tick_age_add = 0; + if (!ssl_generate_session_id(s, ss)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, + ERR_R_INTERNAL_ERROR); + return 0; + } + } else { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, + ERR_R_INTERNAL_ERROR); + return 0; + } + } + } + + switch (ret) { + case SSL_TLSEXT_ERR_ALERT_FATAL: + SSLfatal(s, altmp, SSL_F_FINAL_SERVER_NAME, SSL_R_CALLBACK_FAILED); + return 0; + + case SSL_TLSEXT_ERR_ALERT_WARNING: + /* TLSv1.3 doesn't have warning alerts so we suppress this */ + if (!SSL_IS_TLS13(s)) + ssl3_send_alert(s, SSL3_AL_WARNING, altmp); + s->servername_done = 0; + return 1; + + case SSL_TLSEXT_ERR_NOACK: + s->servername_done = 0; + return 1; + + default: + return 1; + } +} + +#ifndef OPENSSL_NO_EC +static int final_ec_pt_formats(SSL *s, unsigned int context, int sent) +{ + unsigned long alg_k, alg_a; + + if (s->server) + return 1; + + alg_k = s->s3->tmp.new_cipher->algorithm_mkey; + alg_a = s->s3->tmp.new_cipher->algorithm_auth; + + /* + * If we are client and using an elliptic curve cryptography cipher + * suite, then if server returns an EC point formats lists extension it + * must contain uncompressed. + */ + if (s->ext.ecpointformats != NULL + && s->ext.ecpointformats_len > 0 + && s->ext.peer_ecpointformats != NULL + && s->ext.peer_ecpointformats_len > 0 + && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) { + /* we are using an ECC cipher */ + size_t i; + unsigned char *list = s->ext.peer_ecpointformats; + + for (i = 0; i < s->ext.peer_ecpointformats_len; i++) { + if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed) + break; + } + if (i == s->ext.peer_ecpointformats_len) { + SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EC_PT_FORMATS, + SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST); + return 0; + } + } + + return 1; +} +#endif + +static int init_session_ticket(SSL *s, unsigned int context) +{ + if (!s->server) + s->ext.ticket_expected = 0; + + return 1; +} + +#ifndef OPENSSL_NO_OCSP +static int init_status_request(SSL *s, unsigned int context) +{ + if (s->server) { + s->ext.status_type = TLSEXT_STATUSTYPE_nothing; + } else { + /* + * Ensure we get sensible values passed to tlsext_status_cb in the event + * that we don't receive a status message + */ + OPENSSL_free(s->ext.ocsp.resp); + s->ext.ocsp.resp = NULL; + s->ext.ocsp.resp_len = 0; + } + + return 1; +} +#endif + +#ifndef OPENSSL_NO_NEXTPROTONEG +static int init_npn(SSL *s, unsigned int context) +{ + s->s3->npn_seen = 0; + + return 1; +} +#endif + +static int init_alpn(SSL *s, unsigned int context) +{ + OPENSSL_free(s->s3->alpn_selected); + s->s3->alpn_selected = NULL; + s->s3->alpn_selected_len = 0; + if (s->server) { + OPENSSL_free(s->s3->alpn_proposed); + s->s3->alpn_proposed = NULL; + s->s3->alpn_proposed_len = 0; + } + return 1; +} + +static int final_alpn(SSL *s, unsigned int context, int sent) +{ + if (!s->server && !sent && s->session->ext.alpn_selected != NULL) + s->ext.early_data_ok = 0; + + if (!s->server || !SSL_IS_TLS13(s)) + return 1; + + /* + * Call alpn_select callback if needed. Has to be done after SNI and + * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3 + * we also have to do this before we decide whether to accept early_data. + * In TLSv1.3 we've already negotiated our cipher so we do this call now. + * For < TLSv1.3 we defer it until after cipher negotiation. + * + * On failure SSLfatal() already called. + */ + return tls_handle_alpn(s); +} + +static int init_sig_algs(SSL *s, unsigned int context) +{ + /* Clear any signature algorithms extension received */ + OPENSSL_free(s->s3->tmp.peer_sigalgs); + s->s3->tmp.peer_sigalgs = NULL; + + return 1; +} + +static int init_sig_algs_cert(SSL *s, unsigned int context) +{ + /* Clear any signature algorithms extension received */ + OPENSSL_free(s->s3->tmp.peer_cert_sigalgs); + s->s3->tmp.peer_cert_sigalgs = NULL; + + return 1; +} + +#ifndef OPENSSL_NO_SRP +static int init_srp(SSL *s, unsigned int context) +{ + OPENSSL_free(s->srp_ctx.login); + s->srp_ctx.login = NULL; + + return 1; +} +#endif + +static int init_etm(SSL *s, unsigned int context) +{ + s->ext.use_etm = 0; + + return 1; +} + +static int init_ems(SSL *s, unsigned int context) +{ + if (!s->server) + s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS; + + return 1; +} + +static int final_ems(SSL *s, unsigned int context, int sent) +{ + if (!s->server && s->hit) { + /* + * Check extended master secret extension is consistent with + * original session. + */ + if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) != + !(s->session->flags & SSL_SESS_FLAG_EXTMS)) { + SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_EMS, + SSL_R_INCONSISTENT_EXTMS); + return 0; + } + } + + return 1; +} + +static int init_certificate_authorities(SSL *s, unsigned int context) +{ + sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free); + s->s3->tmp.peer_ca_names = NULL; + return 1; +} + +static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt, + unsigned int context, + X509 *x, + size_t chainidx) +{ + const STACK_OF(X509_NAME) *ca_sk = get_ca_names(s); + + if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0) + return EXT_RETURN_NOT_SENT; + + if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities) + || !WPACKET_start_sub_packet_u16(pkt)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, + SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES, + ERR_R_INTERNAL_ERROR); + return EXT_RETURN_FAIL; + } + + if (!construct_ca_names(s, ca_sk, pkt)) { + /* SSLfatal() already called */ + return EXT_RETURN_FAIL; + } + + if (!WPACKET_close(pkt)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, + SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES, + ERR_R_INTERNAL_ERROR); + return EXT_RETURN_FAIL; + } + + return EXT_RETURN_SENT; +} + +static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt, + unsigned int context, X509 *x, + size_t chainidx) +{ + if (!parse_ca_names(s, pkt)) + return 0; + if (PACKET_remaining(pkt) != 0) { + SSLfatal(s, SSL_AD_DECODE_ERROR, + SSL_F_TLS_PARSE_CERTIFICATE_AUTHORITIES, SSL_R_BAD_EXTENSION); + return 0; + } + return 1; +} + +#ifndef OPENSSL_NO_SRTP +static int init_srtp(SSL *s, unsigned int context) +{ + if (s->server) + s->srtp_profile = NULL; + + return 1; +} +#endif + +static int final_sig_algs(SSL *s, unsigned int context, int sent) +{ + if (!sent && SSL_IS_TLS13(s) && !s->hit) { + SSLfatal(s, TLS13_AD_MISSING_EXTENSION, SSL_F_FINAL_SIG_ALGS, + SSL_R_MISSING_SIGALGS_EXTENSION); + return 0; + } + + return 1; +} + +#ifndef OPENSSL_NO_EC +static int final_key_share(SSL *s, unsigned int context, int sent) +{ + if (!SSL_IS_TLS13(s)) + return 1; + + /* Nothing to do for key_share in an HRR */ + if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) + return 1; + + /* + * If + * we are a client + * AND + * we have no key_share + * AND + * (we are not resuming + * OR the kex_mode doesn't allow non key_share resumes) + * THEN + * fail; + */ + if (!s->server + && !sent + && (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) { + /* Nothing left we can do - just fail */ + SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_KEY_SHARE, + SSL_R_NO_SUITABLE_KEY_SHARE); + return 0; + } + /* + * IF + * we are a server + * THEN + * IF + * we have a suitable key_share + * THEN + * IF + * we are stateless AND we have no cookie + * THEN + * send a HelloRetryRequest + * ELSE + * IF + * we didn't already send a HelloRetryRequest + * AND + * the client sent a key_share extension + * AND + * (we are not resuming + * OR the kex_mode allows key_share resumes) + * AND + * a shared group exists + * THEN + * send a HelloRetryRequest + * ELSE IF + * we are not resuming + * OR + * the kex_mode doesn't allow non key_share resumes + * THEN + * fail + * ELSE IF + * we are stateless AND we have no cookie + * THEN + * send a HelloRetryRequest + */ + if (s->server) { + if (s->s3->peer_tmp != NULL) { + /* We have a suitable key_share */ + if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0 + && !s->ext.cookieok) { + if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) { + /* + * If we are stateless then we wouldn't know about any + * previously sent HRR - so how can this be anything other + * than 0? + */ + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, + ERR_R_INTERNAL_ERROR); + return 0; + } + s->hello_retry_request = SSL_HRR_PENDING; + return 1; + } + } else { + /* No suitable key_share */ + if (s->hello_retry_request == SSL_HRR_NONE && sent + && (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE) + != 0)) { + const uint16_t *pgroups, *clntgroups; + size_t num_groups, clnt_num_groups, i; + unsigned int group_id = 0; + + /* Check if a shared group exists */ + + /* Get the clients list of supported groups. */ + tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups); + tls1_get_supported_groups(s, &pgroups, &num_groups); + + /* + * Find the first group we allow that is also in client's list + */ + for (i = 0; i < num_groups; i++) { + group_id = pgroups[i]; + + if (check_in_list(s, group_id, clntgroups, clnt_num_groups, + 1)) + break; + } + + if (i < num_groups) { + /* A shared group exists so send a HelloRetryRequest */ + s->s3->group_id = group_id; + s->hello_retry_request = SSL_HRR_PENDING; + return 1; + } + } + if (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) { + /* Nothing left we can do - just fail */ + SSLfatal(s, sent ? SSL_AD_HANDSHAKE_FAILURE + : SSL_AD_MISSING_EXTENSION, + SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE); + return 0; + } + + if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0 + && !s->ext.cookieok) { + if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) { + /* + * If we are stateless then we wouldn't know about any + * previously sent HRR - so how can this be anything other + * than 0? + */ + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, + ERR_R_INTERNAL_ERROR); + return 0; + } + s->hello_retry_request = SSL_HRR_PENDING; + return 1; + } + } + + /* + * We have a key_share so don't send any more HelloRetryRequest + * messages + */ + if (s->hello_retry_request == SSL_HRR_PENDING) + s->hello_retry_request = SSL_HRR_COMPLETE; + } else { + /* + * For a client side resumption with no key_share we need to generate + * the handshake secret (otherwise this is done during key_share + * processing). + */ + if (!sent && !tls13_generate_handshake_secret(s, NULL, 0)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, + ERR_R_INTERNAL_ERROR); + return 0; + } + } + + return 1; +} +#endif + +static int init_psk_kex_modes(SSL *s, unsigned int context) +{ + s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE; + return 1; +} + +int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart, + size_t binderoffset, const unsigned char *binderin, + unsigned char *binderout, SSL_SESSION *sess, int sign, + int external) +{ + EVP_PKEY *mackey = NULL; + EVP_MD_CTX *mctx = NULL; + unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE]; + unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE]; + unsigned char *early_secret; +#ifdef CHARSET_EBCDIC + static const unsigned char resumption_label[] = { 0x72, 0x65, 0x73, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 }; + static const unsigned char external_label[] = { 0x65, 0x78, 0x74, 0x20, 0x62, 0x69, 0x6E, 0x64, 0x65, 0x72, 0x00 }; +#else + static const unsigned char resumption_label[] = "res binder"; + static const unsigned char external_label[] = "ext binder"; +#endif + const unsigned char *label; + size_t bindersize, labelsize, hashsize; + int hashsizei = EVP_MD_size(md); + int ret = -1; + int usepskfored = 0; + + /* Ensure cast to size_t is safe */ + if (!ossl_assert(hashsizei >= 0)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + hashsize = (size_t)hashsizei; + + if (external + && s->early_data_state == SSL_EARLY_DATA_CONNECTING + && s->session->ext.max_early_data == 0 + && sess->ext.max_early_data > 0) + usepskfored = 1; + + if (external) { + label = external_label; + labelsize = sizeof(external_label) - 1; + } else { + label = resumption_label; + labelsize = sizeof(resumption_label) - 1; + } + + /* + * Generate the early_secret. On the server side we've selected a PSK to + * resume with (internal or external) so we always do this. On the client + * side we do this for a non-external (i.e. resumption) PSK or external PSK + * that will be used for early_data so that it is in place for sending early + * data. For client side external PSK not being used for early_data we + * generate it but store it away for later use. + */ + if (s->server || !external || usepskfored) + early_secret = (unsigned char *)s->early_secret; + else + early_secret = (unsigned char *)sess->early_secret; + + if (!tls13_generate_secret(s, md, NULL, sess->master_key, + sess->master_key_length, early_secret)) { + /* SSLfatal() already called */ + goto err; + } + + /* + * Create the handshake hash for the binder key...the messages so far are + * empty! + */ + mctx = EVP_MD_CTX_new(); + if (mctx == NULL + || EVP_DigestInit_ex(mctx, md, NULL) <= 0 + || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + + /* Generate the binder key */ + if (!tls13_hkdf_expand(s, md, early_secret, label, labelsize, hash, + hashsize, binderkey, hashsize, 1)) { + /* SSLfatal() already called */ + goto err; + } + + /* Generate the finished key */ + if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) { + /* SSLfatal() already called */ + goto err; + } + + if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + + /* + * Get a hash of the ClientHello up to the start of the binders. If we are + * following a HelloRetryRequest then this includes the hash of the first + * ClientHello and the HelloRetryRequest itself. + */ + if (s->hello_retry_request == SSL_HRR_PENDING) { + size_t hdatalen; + long hdatalen_l; + void *hdata; + + hdatalen = hdatalen_l = + BIO_get_mem_data(s->s3->handshake_buffer, &hdata); + if (hdatalen_l <= 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + SSL_R_BAD_HANDSHAKE_LENGTH); + goto err; + } + + /* + * For servers the handshake buffer data will include the second + * ClientHello - which we don't want - so we need to take that bit off. + */ + if (s->server) { + PACKET hashprefix, msg; + + /* Find how many bytes are left after the first two messages */ + if (!PACKET_buf_init(&hashprefix, hdata, hdatalen) + || !PACKET_forward(&hashprefix, 1) + || !PACKET_get_length_prefixed_3(&hashprefix, &msg) + || !PACKET_forward(&hashprefix, 1) + || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + hdatalen -= PACKET_remaining(&hashprefix); + } + + if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + } + + if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0 + || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + + mackey = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finishedkey, + hashsize); + if (mackey == NULL) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + + if (!sign) + binderout = tmpbinder; + + bindersize = hashsize; + if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0 + || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0 + || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0 + || bindersize != hashsize) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, + ERR_R_INTERNAL_ERROR); + goto err; + } + + if (sign) { + ret = 1; + } else { + /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */ + ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0); + if (!ret) + SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PSK_DO_BINDER, + SSL_R_BINDER_DOES_NOT_VERIFY); + } + + err: + OPENSSL_cleanse(binderkey, sizeof(binderkey)); + OPENSSL_cleanse(finishedkey, sizeof(finishedkey)); + EVP_PKEY_free(mackey); + EVP_MD_CTX_free(mctx); + + return ret; +} + +static int final_early_data(SSL *s, unsigned int context, int sent) +{ + if (!sent) + return 1; + + if (!s->server) { + if (context == SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS + && sent + && !s->ext.early_data_ok) { + /* + * If we get here then the server accepted our early_data but we + * later realised that it shouldn't have done (e.g. inconsistent + * ALPN) + */ + SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EARLY_DATA, + SSL_R_BAD_EARLY_DATA); + return 0; + } + + return 1; + } + + if (s->max_early_data == 0 + || !s->hit + || s->early_data_state != SSL_EARLY_DATA_ACCEPTING + || !s->ext.early_data_ok + || s->hello_retry_request != SSL_HRR_NONE + || (s->allow_early_data_cb != NULL + && !s->allow_early_data_cb(s, + s->allow_early_data_cb_data))) { + s->ext.early_data = SSL_EARLY_DATA_REJECTED; + } else { + s->ext.early_data = SSL_EARLY_DATA_ACCEPTED; + + if (!tls13_change_cipher_state(s, + SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) { + /* SSLfatal() already called */ + return 0; + } + } + + return 1; +} + +static int final_maxfragmentlen(SSL *s, unsigned int context, int sent) +{ + /* + * Session resumption on server-side with MFL extension active + * BUT MFL extension packet was not resent (i.e. sent == 0) + */ + if (s->server && s->hit && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) + && !sent ) { + SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_MAXFRAGMENTLEN, + SSL_R_BAD_EXTENSION); + return 0; + } + + /* Current SSL buffer is lower than requested MFL */ + if (s->session && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) + && s->max_send_fragment < GET_MAX_FRAGMENT_LENGTH(s->session)) + /* trigger a larger buffer reallocation */ + if (!ssl3_setup_buffers(s)) { + /* SSLfatal() already called */ + return 0; + } + + return 1; +} + +static int init_post_handshake_auth(SSL *s, unsigned int context) +{ + s->post_handshake_auth = SSL_PHA_NONE; + + return 1; +} |