/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). */ #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" static int tls_decrypt_ticket(SSL *s, const uint8_t *tick, int ticklen, const uint8_t *sess_id, int sesslen, SSL_SESSION **psess); static int ssl_check_clienthello_tlsext(SSL *s); static int ssl_check_serverhello_tlsext(SSL *s); const SSL3_ENC_METHOD TLSv1_enc_data = { tls1_prf, tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_mac, tls1_cert_verify_mac, TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE, TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE, tls1_alert_code, tls1_export_keying_material, 0, }; const SSL3_ENC_METHOD TLSv1_1_enc_data = { tls1_prf, tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_mac, tls1_cert_verify_mac, TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE, TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE, tls1_alert_code, tls1_export_keying_material, SSL_ENC_FLAG_EXPLICIT_IV, }; const SSL3_ENC_METHOD TLSv1_2_enc_data = { tls1_prf, tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_mac, tls1_cert_verify_mac, TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE, TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE, tls1_alert_code, tls1_export_keying_material, SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_SHA256_PRF |SSL_ENC_FLAG_TLS1_2_CIPHERS, }; static int compare_uint16_t(const void *p1, const void *p2) { uint16_t u1 = *((const uint16_t *)p1); uint16_t u2 = *((const uint16_t *)p2); if (u1 < u2) { return -1; } else if (u1 > u2) { return 1; } else { return 0; } } /* 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 does an initial scan over the extensions block to filter those * out. */ static int tls1_check_duplicate_extensions(const CBS *cbs) { CBS extensions = *cbs; size_t num_extensions = 0, i = 0; uint16_t *extension_types = NULL; int ret = 0; /* First pass: count the extensions. */ while (CBS_len(&extensions) > 0) { uint16_t type; CBS extension; if (!CBS_get_u16(&extensions, &type) || !CBS_get_u16_length_prefixed(&extensions, &extension)) { goto done; } num_extensions++; } if (num_extensions == 0) { return 1; } extension_types = (uint16_t *)OPENSSL_malloc(sizeof(uint16_t) * num_extensions); if (extension_types == NULL) { OPENSSL_PUT_ERROR(SSL, tls1_check_duplicate_extensions, ERR_R_MALLOC_FAILURE); goto done; } /* Second pass: gather the extension types. */ extensions = *cbs; for (i = 0; i < num_extensions; i++) { CBS extension; if (!CBS_get_u16(&extensions, &extension_types[i]) || !CBS_get_u16_length_prefixed(&extensions, &extension)) { /* This should not happen. */ goto done; } } assert(CBS_len(&extensions) == 0); /* Sort the extensions and make sure there are no duplicates. */ qsort(extension_types, num_extensions, sizeof(uint16_t), compare_uint16_t); for (i = 1; i < num_extensions; i++) { if (extension_types[i - 1] == extension_types[i]) { goto done; } } ret = 1; done: OPENSSL_free(extension_types); return ret; } char ssl_early_callback_init(struct ssl_early_callback_ctx *ctx) { CBS client_hello, session_id, cipher_suites, compression_methods, extensions; CBS_init(&client_hello, ctx->client_hello, ctx->client_hello_len); if (/* Skip client version. */ !CBS_skip(&client_hello, 2) || /* Skip client nonce. */ !CBS_skip(&client_hello, 32) || /* Extract session_id. */ !CBS_get_u8_length_prefixed(&client_hello, &session_id)) { return 0; } ctx->session_id = CBS_data(&session_id); ctx->session_id_len = CBS_len(&session_id); /* Skip past DTLS cookie */ if (SSL_IS_DTLS(ctx->ssl)) { CBS cookie; if (!CBS_get_u8_length_prefixed(&client_hello, &cookie)) { return 0; } } /* Extract cipher_suites. */ if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) || CBS_len(&cipher_suites) < 2 || (CBS_len(&cipher_suites) & 1) != 0) { return 0; } ctx->cipher_suites = CBS_data(&cipher_suites); ctx->cipher_suites_len = CBS_len(&cipher_suites); /* Extract compression_methods. */ if (!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) || CBS_len(&compression_methods) < 1) { return 0; } ctx->compression_methods = CBS_data(&compression_methods); ctx->compression_methods_len = CBS_len(&compression_methods); /* If the ClientHello ends here then it's valid, but doesn't have any * extensions. (E.g. SSLv3.) */ if (CBS_len(&client_hello) == 0) { ctx->extensions = NULL; ctx->extensions_len = 0; return 1; } /* Extract extensions and check it is valid. */ if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) || !tls1_check_duplicate_extensions(&extensions) || CBS_len(&client_hello) != 0) { return 0; } ctx->extensions = CBS_data(&extensions); ctx->extensions_len = CBS_len(&extensions); return 1; } char SSL_early_callback_ctx_extension_get( const struct ssl_early_callback_ctx *ctx, uint16_t extension_type, const uint8_t **out_data, size_t *out_len) { CBS extensions; CBS_init(&extensions, ctx->extensions, ctx->extensions_len); while (CBS_len(&extensions) != 0) { uint16_t type; CBS extension; /* Decode the next extension. */ if (!CBS_get_u16(&extensions, &type) || !CBS_get_u16_length_prefixed(&extensions, &extension)) { return 0; } if (type == extension_type) { *out_data = CBS_data(&extension); *out_len = CBS_len(&extension); return 1; } } return 0; } struct tls_curve { uint16_t curve_id; int nid; }; /* ECC curves from RFC4492. */ static const struct tls_curve tls_curves[] = { {21, NID_secp224r1}, {23, NID_X9_62_prime256v1}, {24, NID_secp384r1}, {25, NID_secp521r1}, }; static const uint8_t ecformats_default[] = { TLSEXT_ECPOINTFORMAT_uncompressed, }; static const uint16_t eccurves_default[] = { 23, /* X9_62_prime256v1 */ 24, /* secp384r1 */ #if defined(ANDROID) 25, /* secp521r1 */ #endif }; int tls1_ec_curve_id2nid(uint16_t curve_id) { size_t i; for (i = 0; i < sizeof(tls_curves) / sizeof(tls_curves[0]); i++) { if (curve_id == tls_curves[i].curve_id) { return tls_curves[i].nid; } } return NID_undef; } int tls1_ec_nid2curve_id(uint16_t *out_curve_id, int nid) { size_t i; for (i = 0; i < sizeof(tls_curves) / sizeof(tls_curves[0]); i++) { if (nid == tls_curves[i].nid) { *out_curve_id = tls_curves[i].curve_id; return 1; } } return 0; } /* tls1_get_curvelist sets |*out_curve_ids| and |*out_curve_ids_len| to the * list of allowed curve IDs. If |get_peer_curves| is non-zero, return the * peer's curve list. Otherwise, return the preferred list. */ static void tls1_get_curvelist(SSL *s, int get_peer_curves, const uint16_t **out_curve_ids, size_t *out_curve_ids_len) { if (get_peer_curves) { /* Only clients send a curve list, so this function is only called * on the server. */ assert(s->server); *out_curve_ids = s->s3->tmp.peer_ellipticcurvelist; *out_curve_ids_len = s->s3->tmp.peer_ellipticcurvelist_length; return; } *out_curve_ids = s->tlsext_ellipticcurvelist; *out_curve_ids_len = s->tlsext_ellipticcurvelist_length; if (!*out_curve_ids) { *out_curve_ids = eccurves_default; *out_curve_ids_len = sizeof(eccurves_default) / sizeof(eccurves_default[0]); } } int tls1_check_curve(SSL *s, CBS *cbs, uint16_t *out_curve_id) { uint8_t curve_type; uint16_t curve_id; const uint16_t *curves; size_t curves_len, i; /* Only support named curves. */ if (!CBS_get_u8(cbs, &curve_type) || curve_type != NAMED_CURVE_TYPE || !CBS_get_u16(cbs, &curve_id)) { return 0; } tls1_get_curvelist(s, 0, &curves, &curves_len); for (i = 0; i < curves_len; i++) { if (curve_id == curves[i]) { *out_curve_id = curve_id; return 1; } } return 0; } int tls1_get_shared_curve(SSL *s) { const uint16_t *curves, *peer_curves, *pref, *supp; size_t curves_len, peer_curves_len, pref_len, supp_len, i, j; /* Can't do anything on client side */ if (s->server == 0) { return NID_undef; } tls1_get_curvelist(s, 0 /* local curves */, &curves, &curves_len); tls1_get_curvelist(s, 1 /* peer curves */, &peer_curves, &peer_curves_len); if (peer_curves_len == 0) { /* Clients are not required to send a supported_curves extension. In this * case, the server is free to pick any curve it likes. See RFC 4492, * section 4, paragraph 3. */ return (curves_len == 0) ? NID_undef : tls1_ec_curve_id2nid(curves[0]); } if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) { pref = curves; pref_len = curves_len; supp = peer_curves; supp_len = peer_curves_len; } else { pref = peer_curves; pref_len = peer_curves_len; supp = curves; supp_len = curves_len; } for (i = 0; i < pref_len; i++) { for (j = 0; j < supp_len; j++) { if (pref[i] == supp[j]) { return tls1_ec_curve_id2nid(pref[i]); } } } return NID_undef; } int tls1_set_curves(uint16_t **out_curve_ids, size_t *out_curve_ids_len, const int *curves, size_t ncurves) { uint16_t *curve_ids; size_t i; curve_ids = (uint16_t *)OPENSSL_malloc(ncurves * sizeof(uint16_t)); if (curve_ids == NULL) { return 0; } for (i = 0; i < ncurves; i++) { if (!tls1_ec_nid2curve_id(&curve_ids[i], curves[i])) { OPENSSL_free(curve_ids); return 0; } } OPENSSL_free(*out_curve_ids); *out_curve_ids = curve_ids; *out_curve_ids_len = ncurves; return 1; } /* tls1_curve_params_from_ec_key sets |*out_curve_id| and |*out_comp_id| to the * TLS curve ID and point format, respectively, for |ec|. It returns one on * success and zero on failure. */ static int tls1_curve_params_from_ec_key(uint16_t *out_curve_id, uint8_t *out_comp_id, EC_KEY *ec) { int nid; uint16_t id; const EC_GROUP *grp; if (ec == NULL) { return 0; } grp = EC_KEY_get0_group(ec); if (grp == NULL) { return 0; } /* Determine curve ID */ nid = EC_GROUP_get_curve_name(grp); if (!tls1_ec_nid2curve_id(&id, nid)) { return 0; } /* Set the named curve ID. Arbitrary explicit curves are not supported. */ *out_curve_id = id; if (out_comp_id) { if (EC_KEY_get0_public_key(ec) == NULL) { return 0; } if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) { *out_comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime; } else { *out_comp_id = TLSEXT_ECPOINTFORMAT_uncompressed; } } return 1; } /* tls1_check_point_format returns one if |comp_id| is consistent with the * peer's point format preferences. */ static int tls1_check_point_format(SSL *s, uint8_t comp_id) { uint8_t *p = s->s3->tmp.peer_ecpointformatlist; size_t plen = s->s3->tmp.peer_ecpointformatlist_length; size_t i; /* If point formats extension present check it, otherwise everything is * supported (see RFC4492). */ if (p == NULL) { return 1; } for (i = 0; i < plen; i++) { if (comp_id == p[i]) { return 1; } } return 0; } /* tls1_check_curve_id returns one if |curve_id| is consistent with both our * and the peer's curve preferences. Note: if called as the client, only our * preferences are checked; the peer (the server) does not send preferences. */ static int tls1_check_curve_id(SSL *s, uint16_t curve_id) { const uint16_t *curves; size_t curves_len, i, get_peer_curves; /* Check against our list, then the peer's list. */ for (get_peer_curves = 0; get_peer_curves <= 1; get_peer_curves++) { if (get_peer_curves && !s->server) { /* Servers do not present a preference list so, if we are a client, only * check our list. */ continue; } tls1_get_curvelist(s, get_peer_curves, &curves, &curves_len); if (get_peer_curves && curves_len == 0) { /* Clients are not required to send a supported_curves extension. In this * case, the server is free to pick any curve it likes. See RFC 4492, * section 4, paragraph 3. */ continue; } for (i = 0; i < curves_len; i++) { if (curves[i] == curve_id) { break; } } if (i == curves_len) { return 0; } } return 1; } static void tls1_get_formatlist(SSL *s, const uint8_t **pformats, size_t *pformatslen) { /* If we have a custom point format list use it otherwise use default */ if (s->tlsext_ecpointformatlist) { *pformats = s->tlsext_ecpointformatlist; *pformatslen = s->tlsext_ecpointformatlist_length; } else { *pformats = ecformats_default; *pformatslen = sizeof(ecformats_default); } } int tls1_check_ec_cert(SSL *s, X509 *x) { int ret = 0; EVP_PKEY *pkey = X509_get_pubkey(x); uint16_t curve_id; uint8_t comp_id; if (!pkey || pkey->type != EVP_PKEY_EC || !tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec) || !tls1_check_curve_id(s, curve_id) || !tls1_check_point_format(s, comp_id)) { goto done; } ret = 1; done: EVP_PKEY_free(pkey); return ret; } int tls1_check_ec_tmp_key(SSL *s) { if (s->cert->ecdh_nid != NID_undef) { /* If the curve is preconfigured, ECDH is acceptable iff the peer supports * the curve. */ uint16_t curve_id; return tls1_ec_nid2curve_id(&curve_id, s->cert->ecdh_nid) && tls1_check_curve_id(s, curve_id); } if (s->cert->ecdh_tmp_cb != NULL) { /* Assume the callback will provide an acceptable curve. */ return 1; } /* Otherwise, the curve gets selected automatically. ECDH is acceptable iff * there is a shared curve. */ return tls1_get_shared_curve(s) != NID_undef; } /* List of supported signature algorithms and hashes. Should make this * customisable at some point, for now include everything we support. */ #define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa, #define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa, #define tlsext_sigalg(md) tlsext_sigalg_rsa(md) tlsext_sigalg_ecdsa(md) static const uint8_t tls12_sigalgs[] = { tlsext_sigalg(TLSEXT_hash_sha512) tlsext_sigalg(TLSEXT_hash_sha384) tlsext_sigalg(TLSEXT_hash_sha256) tlsext_sigalg(TLSEXT_hash_sha224) tlsext_sigalg(TLSEXT_hash_sha1) }; size_t tls12_get_psigalgs(SSL *s, const uint8_t **psigs) { /* If server use client authentication sigalgs if not NULL */ if (s->server && s->cert->client_sigalgs) { *psigs = s->cert->client_sigalgs; return s->cert->client_sigalgslen; } else if (s->cert->conf_sigalgs) { *psigs = s->cert->conf_sigalgs; return s->cert->conf_sigalgslen; } else { *psigs = tls12_sigalgs; return sizeof(tls12_sigalgs); } } /* tls12_check_peer_sigalg parses a SignatureAndHashAlgorithm out of |cbs|. It * checks it is consistent with |s|'s sent supported signature algorithms and, * if so, writes the relevant digest into |*out_md| and returns 1. Otherwise it * returns 0 and writes an alert into |*out_alert|. */ int tls12_check_peer_sigalg(const EVP_MD **out_md, int *out_alert, SSL *s, CBS *cbs, EVP_PKEY *pkey) { const uint8_t *sent_sigs; size_t sent_sigslen, i; int sigalg = tls12_get_sigid(pkey); uint8_t hash, signature; /* Should never happen */ if (sigalg == -1) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, ERR_R_INTERNAL_ERROR); *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } if (!CBS_get_u8(cbs, &hash) || !CBS_get_u8(cbs, &signature)) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_DECODE_ERROR); *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Check key type is consistent with signature */ if (sigalg != signature) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE); *out_alert = SSL_AD_ILLEGAL_PARAMETER; return 0; } if (pkey->type == EVP_PKEY_EC) { uint16_t curve_id; uint8_t comp_id; /* Check compression and curve matches extensions */ if (!tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } if (s->server && (!tls1_check_curve_id(s, curve_id) || !tls1_check_point_format(s, comp_id))) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_CURVE); *out_alert = SSL_AD_ILLEGAL_PARAMETER; return 0; } } /* Check signature matches a type we sent */ sent_sigslen = tls12_get_psigalgs(s, &sent_sigs); for (i = 0; i < sent_sigslen; i += 2, sent_sigs += 2) { if (hash == sent_sigs[0] && signature == sent_sigs[1]) { break; } } /* Allow fallback to SHA-1. */ if (i == sent_sigslen && hash != TLSEXT_hash_sha1) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE); *out_alert = SSL_AD_ILLEGAL_PARAMETER; return 0; } *out_md = tls12_get_hash(hash); if (*out_md == NULL) { OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_UNKNOWN_DIGEST); *out_alert = SSL_AD_ILLEGAL_PARAMETER; return 0; } return 1; } /* Get a mask of disabled algorithms: an algorithm is disabled if it isn't * supported or doesn't appear in supported signature algorithms. Unlike * ssl_cipher_get_disabled this applies to a specific session and not global * settings. */ void ssl_set_client_disabled(SSL *s) { CERT *c = s->cert; const uint8_t *sigalgs; size_t i, sigalgslen; int have_rsa = 0, have_ecdsa = 0; c->mask_a = 0; c->mask_k = 0; /* Don't allow TLS 1.2 only ciphers if we don't suppport them */ if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s)) { c->mask_ssl = SSL_TLSV1_2; } else { c->mask_ssl = 0; } /* Now go through all signature algorithms seeing if we support any for RSA, * DSA, ECDSA. Do this for all versions not just TLS 1.2. */ sigalgslen = tls12_get_psigalgs(s, &sigalgs); for (i = 0; i < sigalgslen; i += 2, sigalgs += 2) { switch (sigalgs[1]) { case TLSEXT_signature_rsa: have_rsa = 1; break; case TLSEXT_signature_ecdsa: have_ecdsa = 1; break; } } /* Disable auth if we don't include any appropriate signature algorithms. */ if (!have_rsa) { c->mask_a |= SSL_aRSA; } if (!have_ecdsa) { c->mask_a |= SSL_aECDSA; } /* with PSK there must be client callback set */ if (!s->psk_client_callback) { c->mask_a |= SSL_aPSK; c->mask_k |= SSL_kPSK; } } /* header_len is the length of the ClientHello header written so far, used to * compute padding. It does not include the record header. Pass 0 if no padding * is to be done. */ uint8_t *ssl_add_clienthello_tlsext(SSL *s, uint8_t *buf, uint8_t *limit, size_t header_len) { int extdatalen = 0; uint8_t *ret = buf; uint8_t *orig = buf; /* See if we support any ECC ciphersuites */ int using_ecc = 0; if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s)) { size_t i; uint32_t alg_k, alg_a; STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s); for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) { const SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i); alg_k = c->algorithm_mkey; alg_a = c->algorithm_auth; if ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA)) { using_ecc = 1; break; } } } /* don't add extensions for SSLv3 unless doing secure renegotiation */ if (s->client_version == SSL3_VERSION && !s->s3->send_connection_binding) { return orig; } ret += 2; if (ret >= limit) { return NULL; /* should never occur. */ } if (s->tlsext_hostname != NULL) { /* Add TLS extension servername to the Client Hello message */ unsigned long size_str; long lenmax; /* check for enough space. 4 for the servername type and entension length 2 for servernamelist length 1 for the hostname type 2 for hostname length + hostname length */ lenmax = limit - ret - 9; size_str = strlen(s->tlsext_hostname); if (lenmax < 0 || size_str > (unsigned long)lenmax) { return NULL; } /* extension type and length */ s2n(TLSEXT_TYPE_server_name, ret); s2n(size_str + 5, ret); /* length of servername list */ s2n(size_str + 3, ret); /* hostname type, length and hostname */ *(ret++) = (uint8_t)TLSEXT_NAMETYPE_host_name; s2n(size_str, ret); memcpy(ret, s->tlsext_hostname, size_str); ret += size_str; } /* Add RI if renegotiating */ if (s->s3->initial_handshake_complete) { int el; if (!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0)) { OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } if ((limit - ret - 4 - el) < 0) { return NULL; } s2n(TLSEXT_TYPE_renegotiate, ret); s2n(el, ret); if (!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el)) { OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } ret += el; } /* Add extended master secret. */ if (s->version != SSL3_VERSION) { if (limit - ret - 4 < 0) { return NULL; } s2n(TLSEXT_TYPE_extended_master_secret, ret); s2n(0, ret); } if (!(SSL_get_options(s) & SSL_OP_NO_TICKET)) { int ticklen = 0; /* Renegotiation does not participate in session resumption. However, still * advertise the extension to avoid potentially breaking servers which carry * over the state from the previous handshake, such as OpenSSL servers * without upstream's 3c3f0259238594d77264a78944d409f2127642c4. */ if (!s->s3->initial_handshake_complete && s->session != NULL && s->session->tlsext_tick != NULL) { ticklen = s->session->tlsext_ticklen; } /* Check for enough room 2 for extension type, 2 for len rest for * ticket. */ if ((long)(limit - ret - 4 - ticklen) < 0) { return NULL; } s2n(TLSEXT_TYPE_session_ticket, ret); s2n(ticklen, ret); if (ticklen) { memcpy(ret, s->session->tlsext_tick, ticklen); ret += ticklen; } } if (ssl3_version_from_wire(s, s->client_version) >= TLS1_2_VERSION) { size_t salglen; const uint8_t *salg; salglen = tls12_get_psigalgs(s, &salg); if ((size_t)(limit - ret) < salglen + 6) { return NULL; } s2n(TLSEXT_TYPE_signature_algorithms, ret); s2n(salglen + 2, ret); s2n(salglen, ret); memcpy(ret, salg, salglen); ret += salglen; } if (s->ocsp_stapling_enabled) { /* The status_request extension is excessively extensible at every layer. * On the client, only support requesting OCSP responses with an empty * responder_id_list and no extensions. */ if (limit - ret - 4 - 1 - 2 - 2 < 0) { return NULL; } s2n(TLSEXT_TYPE_status_request, ret); s2n(1 + 2 + 2, ret); /* status_type */ *(ret++) = TLSEXT_STATUSTYPE_ocsp; /* responder_id_list - empty */ s2n(0, ret); /* request_extensions - empty */ s2n(0, ret); } if (s->ctx->next_proto_select_cb && !s->s3->initial_handshake_complete && !SSL_IS_DTLS(s)) { /* The client advertises an emtpy extension to indicate its support for * Next Protocol Negotiation */ if (limit - ret - 4 < 0) { return NULL; } s2n(TLSEXT_TYPE_next_proto_neg, ret); s2n(0, ret); } if (s->signed_cert_timestamps_enabled) { /* The client advertises an empty extension to indicate its support for * certificate timestamps. */ if (limit - ret - 4 < 0) { return NULL; } s2n(TLSEXT_TYPE_certificate_timestamp, ret); s2n(0, ret); } if (s->alpn_client_proto_list && !s->s3->initial_handshake_complete) { if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len) { return NULL; } s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret); s2n(2 + s->alpn_client_proto_list_len, ret); s2n(s->alpn_client_proto_list_len, ret); memcpy(ret, s->alpn_client_proto_list, s->alpn_client_proto_list_len); ret += s->alpn_client_proto_list_len; } if (s->tlsext_channel_id_enabled && !SSL_IS_DTLS(s)) { /* The client advertises an emtpy extension to indicate its support for * Channel ID. */ if (limit - ret - 4 < 0) { return NULL; } if (s->ctx->tlsext_channel_id_enabled_new) { s2n(TLSEXT_TYPE_channel_id_new, ret); } else { s2n(TLSEXT_TYPE_channel_id, ret); } s2n(0, ret); } if (SSL_get_srtp_profiles(s)) { int el; ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0); if ((limit - ret - 4 - el) < 0) { return NULL; } s2n(TLSEXT_TYPE_use_srtp, ret); s2n(el, ret); if (!ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) { OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } ret += el; } if (using_ecc) { /* Add TLS extension ECPointFormats to the ClientHello message */ long lenmax; const uint8_t *formats; const uint16_t *curves; size_t formats_len, curves_len, i; tls1_get_formatlist(s, &formats, &formats_len); lenmax = limit - ret - 5; if (lenmax < 0) { return NULL; } if (formats_len > (size_t)lenmax) { return NULL; } if (formats_len > 255) { OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } s2n(TLSEXT_TYPE_ec_point_formats, ret); s2n(formats_len + 1, ret); *(ret++) = (uint8_t)formats_len; memcpy(ret, formats, formats_len); ret += formats_len; /* Add TLS extension EllipticCurves to the ClientHello message */ tls1_get_curvelist(s, 0, &curves, &curves_len); lenmax = limit - ret - 6; if (lenmax < 0) { return NULL; } if (curves_len * 2 > (size_t)lenmax) { return NULL; } if (curves_len * 2 > 65532) { OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } s2n(TLSEXT_TYPE_elliptic_curves, ret); s2n((curves_len * 2) + 2, ret); s2n(curves_len * 2, ret); for (i = 0; i < curves_len; i++) { s2n(curves[i], ret); } } if (header_len > 0) { size_t clienthello_minsize = 0; header_len += ret - orig; if (header_len > 0xff && header_len < 0x200) { /* Add padding to workaround bugs in F5 terminators. See * https://tools.ietf.org/html/draft-agl-tls-padding-03 * * NB: because this code works out the length of all existing extensions * it MUST always appear last. */ clienthello_minsize = 0x200; } if (s->fastradio_padding) { /* Pad the ClientHello record to 1024 bytes to fast forward the radio * into DCH (high data rate) state in 3G networks. Note that when * fastradio_padding is enabled, even if the header_len is less than 255 * bytes, the padding will be applied regardless. This is slightly * different from the TLS padding extension suggested in * https://tools.ietf.org/html/draft-agl-tls-padding-03 */ clienthello_minsize = 0x400; } if (header_len < clienthello_minsize) { size_t padding_len = clienthello_minsize - header_len; /* Extensions take at least four bytes to encode. Always include least * one byte of data if including the extension. WebSphere Application * Server 7.0 is intolerant to the last extension being zero-length. */ if (padding_len >= 4 + 1) { padding_len -= 4; } else { padding_len = 1; } if (limit - ret - 4 - (long)padding_len < 0) { return NULL; } s2n(TLSEXT_TYPE_padding, ret); s2n(padding_len, ret); memset(ret, 0, padding_len); ret += padding_len; } } extdatalen = ret - orig - 2; if (extdatalen == 0) { return orig; } s2n(extdatalen, orig); return ret; } uint8_t *ssl_add_serverhello_tlsext(SSL *s, uint8_t *buf, uint8_t *limit) { int extdatalen = 0; uint8_t *orig = buf; uint8_t *ret = buf; int next_proto_neg_seen; uint32_t alg_k = s->s3->tmp.new_cipher->algorithm_mkey; uint32_t alg_a = s->s3->tmp.new_cipher->algorithm_auth; int using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA); using_ecc = using_ecc && (s->s3->tmp.peer_ecpointformatlist != NULL); /* don't add extensions for SSLv3, unless doing secure renegotiation */ if (s->version == SSL3_VERSION && !s->s3->send_connection_binding) { return orig; } ret += 2; if (ret >= limit) { return NULL; /* should never happen. */ } if (!s->hit && s->should_ack_sni && s->session->tlsext_hostname != NULL) { if ((long)(limit - ret - 4) < 0) { return NULL; } s2n(TLSEXT_TYPE_server_name, ret); s2n(0, ret); } if (s->s3->send_connection_binding) { int el; if (!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0)) { OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } if ((limit - ret - 4 - el) < 0) { return NULL; } s2n(TLSEXT_TYPE_renegotiate, ret); s2n(el, ret); if (!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el)) { OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } ret += el; } if (s->s3->tmp.extended_master_secret) { if ((long)(limit - ret - 4) < 0) { return NULL; } s2n(TLSEXT_TYPE_extended_master_secret, ret); s2n(0, ret); } if (using_ecc) { const uint8_t *plist; size_t plistlen; /* Add TLS extension ECPointFormats to the ServerHello message */ long lenmax; tls1_get_formatlist(s, &plist, &plistlen); lenmax = limit - ret - 5; if (lenmax < 0) { return NULL; } if (plistlen > (size_t)lenmax) { return NULL; } if (plistlen > 255) { OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } s2n(TLSEXT_TYPE_ec_point_formats, ret); s2n(plistlen + 1, ret); *(ret++) = (uint8_t)plistlen; memcpy(ret, plist, plistlen); ret += plistlen; } /* Currently the server should not respond with a SupportedCurves extension */ if (s->tlsext_ticket_expected && !(SSL_get_options(s) & SSL_OP_NO_TICKET)) { if ((long)(limit - ret - 4) < 0) { return NULL; } s2n(TLSEXT_TYPE_session_ticket, ret); s2n(0, ret); } if (s->s3->tmp.certificate_status_expected) { if ((long)(limit - ret - 4) < 0) { return NULL; } s2n(TLSEXT_TYPE_status_request, ret); s2n(0, ret); } if (s->srtp_profile) { int el; ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0); if ((limit - ret - 4 - el) < 0) { return NULL; } s2n(TLSEXT_TYPE_use_srtp, ret); s2n(el, ret); if (!ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) { OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR); return NULL; } ret += el; } next_proto_neg_seen = s->s3->next_proto_neg_seen; s->s3->next_proto_neg_seen = 0; if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb) { const uint8_t *npa; unsigned int npalen; int r; r = s->ctx->next_protos_advertised_cb( s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg); if (r == SSL_TLSEXT_ERR_OK) { if ((long)(limit - ret - 4 - npalen) < 0) { return NULL; } s2n(TLSEXT_TYPE_next_proto_neg, ret); s2n(npalen, ret); memcpy(ret, npa, npalen); ret += npalen; s->s3->next_proto_neg_seen = 1; } } if (s->s3->alpn_selected) { const uint8_t *selected = s->s3->alpn_selected; size_t len = s->s3->alpn_selected_len; if ((long)(limit - ret - 4 - 2 - 1 - len) < 0) { return NULL; } s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret); s2n(3 + len, ret); s2n(1 + len, ret); *ret++ = len; memcpy(ret, selected, len); ret += len; } /* If the client advertised support for Channel ID, and we have it * enabled, then we want to echo it back. */ if (s->s3->tlsext_channel_id_valid) { if (limit - ret - 4 < 0) { return NULL; } if (s->s3->tlsext_channel_id_new) { s2n(TLSEXT_TYPE_channel_id_new, ret); } else { s2n(TLSEXT_TYPE_channel_id, ret); } s2n(0, ret); } extdatalen = ret - orig - 2; if (extdatalen == 0) { return orig; } s2n(extdatalen, orig); return ret; } /* tls1_alpn_handle_client_hello is called to process the ALPN extension in a * ClientHello. * cbs: the contents of the extension, not including the type and length. * out_alert: a pointer to the alert value to send in the event of a zero * return. * * returns: 1 on success. */ static int tls1_alpn_handle_client_hello(SSL *s, CBS *cbs, int *out_alert) { CBS protocol_name_list, protocol_name_list_copy; const uint8_t *selected; uint8_t selected_len; int r; if (s->ctx->alpn_select_cb == NULL) { return 1; } if (!CBS_get_u16_length_prefixed(cbs, &protocol_name_list) || CBS_len(cbs) != 0 || CBS_len(&protocol_name_list) < 2) { goto parse_error; } /* Validate the protocol list. */ protocol_name_list_copy = protocol_name_list; while (CBS_len(&protocol_name_list_copy) > 0) { CBS protocol_name; if (!CBS_get_u8_length_prefixed(&protocol_name_list_copy, &protocol_name)) { goto parse_error; } } r = s->ctx->alpn_select_cb( s, &selected, &selected_len, CBS_data(&protocol_name_list), CBS_len(&protocol_name_list), s->ctx->alpn_select_cb_arg); if (r == SSL_TLSEXT_ERR_OK) { OPENSSL_free(s->s3->alpn_selected); s->s3->alpn_selected = BUF_memdup(selected, selected_len); if (!s->s3->alpn_selected) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } s->s3->alpn_selected_len = selected_len; } return 1; parse_error: *out_alert = SSL_AD_DECODE_ERROR; return 0; } static int ssl_scan_clienthello_tlsext(SSL *s, CBS *cbs, int *out_alert) { int renegotiate_seen = 0; CBS extensions; s->should_ack_sni = 0; s->srtp_profile = NULL; s->s3->next_proto_neg_seen = 0; s->s3->tmp.certificate_status_expected = 0; s->s3->tmp.extended_master_secret = 0; OPENSSL_free(s->s3->alpn_selected); s->s3->alpn_selected = NULL; /* Clear any signature algorithms extension received */ OPENSSL_free(s->cert->peer_sigalgs); s->cert->peer_sigalgs = NULL; s->cert->peer_sigalgslen = 0; /* Clear any shared signature algorithms */ OPENSSL_free(s->cert->shared_sigalgs); s->cert->shared_sigalgs = NULL; s->cert->shared_sigalgslen = 0; /* Clear ECC extensions */ OPENSSL_free(s->s3->tmp.peer_ecpointformatlist); s->s3->tmp.peer_ecpointformatlist = NULL; s->s3->tmp.peer_ecpointformatlist_length = 0; OPENSSL_free(s->s3->tmp.peer_ellipticcurvelist); s->s3->tmp.peer_ellipticcurvelist = NULL; s->s3->tmp.peer_ellipticcurvelist_length = 0; /* There may be no extensions. */ if (CBS_len(cbs) == 0) { goto ri_check; } /* Decode the extensions block and check it is valid. */ if (!CBS_get_u16_length_prefixed(cbs, &extensions) || !tls1_check_duplicate_extensions(&extensions)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } while (CBS_len(&extensions) != 0) { uint16_t type; CBS extension; /* Decode the next extension. */ if (!CBS_get_u16(&extensions, &type) || !CBS_get_u16_length_prefixed(&extensions, &extension)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* The servername extension is treated as follows: - Only the hostname type is supported with a maximum length of 255. - The servername is rejected if too long or if it contains zeros, in which case an fatal alert is generated. - The servername field is maintained together with the session cache. - When a session is resumed, the servername call back invoked in order to allow the application to position itself to the right context. - The servername is acknowledged if it is new for a session or when it is identical to a previously used for the same session. Applications can control the behaviour. They can at any time set a 'desirable' servername for a new SSL object. This can be the case for example with HTTPS when a Host: header field is received and a renegotiation is requested. In this case, a possible servername presented in the new client hello is only acknowledged if it matches the value of the Host: field. - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION if they provide for changing an explicit servername context for the session, i.e. when the session has been established with a servername extension. - On session reconnect, the servername extension may be absent. */ if (type == TLSEXT_TYPE_server_name) { CBS server_name_list; char have_seen_host_name = 0; if (!CBS_get_u16_length_prefixed(&extension, &server_name_list) || CBS_len(&server_name_list) < 1 || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Decode each ServerName in the extension. */ while (CBS_len(&server_name_list) > 0) { uint8_t name_type; CBS host_name; /* Decode the NameType. */ if (!CBS_get_u8(&server_name_list, &name_type)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Only host_name is supported. */ if (name_type != TLSEXT_NAMETYPE_host_name) { continue; } if (have_seen_host_name) { /* The ServerNameList MUST NOT contain more than one name of the same * name_type. */ *out_alert = SSL_AD_DECODE_ERROR; return 0; } have_seen_host_name = 1; if (!CBS_get_u16_length_prefixed(&server_name_list, &host_name) || CBS_len(&host_name) < 1) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (CBS_len(&host_name) > TLSEXT_MAXLEN_host_name || CBS_contains_zero_byte(&host_name)) { *out_alert = SSL_AD_UNRECOGNIZED_NAME; return 0; } if (!s->hit) { assert(s->session->tlsext_hostname == NULL); if (s->session->tlsext_hostname) { /* This should be impossible. */ *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Copy the hostname as a string. */ if (!CBS_strdup(&host_name, &s->session->tlsext_hostname)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } s->should_ack_sni = 1; } } } else if (type == TLSEXT_TYPE_ec_point_formats) { CBS ec_point_format_list; if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!CBS_stow(&ec_point_format_list, &s->s3->tmp.peer_ecpointformatlist, &s->s3->tmp.peer_ecpointformatlist_length)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } } else if (type == TLSEXT_TYPE_elliptic_curves) { CBS elliptic_curve_list; size_t i, num_curves; if (!CBS_get_u16_length_prefixed(&extension, &elliptic_curve_list) || CBS_len(&elliptic_curve_list) == 0 || (CBS_len(&elliptic_curve_list) & 1) != 0 || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } OPENSSL_free(s->s3->tmp.peer_ellipticcurvelist); s->s3->tmp.peer_ellipticcurvelist_length = 0; s->s3->tmp.peer_ellipticcurvelist = (uint16_t *)OPENSSL_malloc(CBS_len(&elliptic_curve_list)); if (s->s3->tmp.peer_ellipticcurvelist == NULL) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } num_curves = CBS_len(&elliptic_curve_list) / 2; for (i = 0; i < num_curves; i++) { if (!CBS_get_u16(&elliptic_curve_list, &s->s3->tmp.peer_ellipticcurvelist[i])) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } } if (CBS_len(&elliptic_curve_list) != 0) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } s->s3->tmp.peer_ellipticcurvelist_length = num_curves; } else if (type == TLSEXT_TYPE_renegotiate) { if (!ssl_parse_clienthello_renegotiate_ext(s, &extension, out_alert)) { return 0; } renegotiate_seen = 1; } else if (type == TLSEXT_TYPE_signature_algorithms) { CBS supported_signature_algorithms; if (!CBS_get_u16_length_prefixed(&extension, &supported_signature_algorithms) || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Ensure the signature algorithms are non-empty. It contains a list of * SignatureAndHashAlgorithms which are two bytes each. */ if (CBS_len(&supported_signature_algorithms) == 0 || (CBS_len(&supported_signature_algorithms) % 2) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!tls1_process_sigalgs(s, &supported_signature_algorithms)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* If sigalgs received and no shared algorithms fatal error. */ if (s->cert->peer_sigalgs && !s->cert->shared_sigalgs) { OPENSSL_PUT_ERROR(SSL, ssl_scan_clienthello_tlsext, SSL_R_NO_SHARED_SIGATURE_ALGORITHMS); *out_alert = SSL_AD_ILLEGAL_PARAMETER; return 0; } } else if (type == TLSEXT_TYPE_next_proto_neg && !s->s3->initial_handshake_complete && s->s3->alpn_selected == NULL && !SSL_IS_DTLS(s)) { /* The extension must be empty. */ if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->next_proto_neg_seen = 1; } else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation && s->ctx->alpn_select_cb && !s->s3->initial_handshake_complete) { if (!tls1_alpn_handle_client_hello(s, &extension, out_alert)) { return 0; } /* ALPN takes precedence over NPN. */ s->s3->next_proto_neg_seen = 0; } else if (type == TLSEXT_TYPE_channel_id && s->tlsext_channel_id_enabled && !SSL_IS_DTLS(s)) { /* The extension must be empty. */ if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tlsext_channel_id_valid = 1; } else if (type == TLSEXT_TYPE_channel_id_new && s->tlsext_channel_id_enabled && !SSL_IS_DTLS(s)) { /* The extension must be empty. */ if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tlsext_channel_id_valid = 1; s->s3->tlsext_channel_id_new = 1; } else if (type == TLSEXT_TYPE_use_srtp) { if (!ssl_parse_clienthello_use_srtp_ext(s, &extension, out_alert)) { return 0; } } else if (type == TLSEXT_TYPE_extended_master_secret && s->version != SSL3_VERSION) { if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tmp.extended_master_secret = 1; } } ri_check: /* Need RI if renegotiating */ if (!renegotiate_seen && s->s3->initial_handshake_complete && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) { *out_alert = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, ssl_scan_clienthello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); return 0; } return 1; } int ssl_parse_clienthello_tlsext(SSL *s, CBS *cbs) { int alert = -1; if (ssl_scan_clienthello_tlsext(s, cbs, &alert) <= 0) { ssl3_send_alert(s, SSL3_AL_FATAL, alert); return 0; } if (ssl_check_clienthello_tlsext(s) <= 0) { OPENSSL_PUT_ERROR(SSL, ssl_parse_clienthello_tlsext, SSL_R_CLIENTHELLO_TLSEXT); return 0; } return 1; } /* ssl_next_proto_validate validates a Next Protocol Negotiation block. No * elements of zero length are allowed and the set of elements must exactly * fill the length of the block. */ static char ssl_next_proto_validate(const CBS *cbs) { CBS copy = *cbs; while (CBS_len(©) != 0) { CBS proto; if (!CBS_get_u8_length_prefixed(©, &proto) || CBS_len(&proto) == 0) { return 0; } } return 1; } static int ssl_scan_serverhello_tlsext(SSL *s, CBS *cbs, int *out_alert) { int tlsext_servername = 0; int renegotiate_seen = 0; CBS extensions; /* TODO(davidben): Move all of these to some per-handshake state that gets * systematically reset on a new handshake; perhaps allocate it fresh each * time so it's not even kept around post-handshake. */ s->s3->next_proto_neg_seen = 0; s->tlsext_ticket_expected = 0; s->s3->tmp.certificate_status_expected = 0; s->s3->tmp.extended_master_secret = 0; s->srtp_profile = NULL; OPENSSL_free(s->s3->alpn_selected); s->s3->alpn_selected = NULL; /* Clear ECC extensions */ OPENSSL_free(s->s3->tmp.peer_ecpointformatlist); s->s3->tmp.peer_ecpointformatlist = NULL; s->s3->tmp.peer_ecpointformatlist_length = 0; /* There may be no extensions. */ if (CBS_len(cbs) == 0) { goto ri_check; } /* Decode the extensions block and check it is valid. */ if (!CBS_get_u16_length_prefixed(cbs, &extensions) || !tls1_check_duplicate_extensions(&extensions)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } while (CBS_len(&extensions) != 0) { uint16_t type; CBS extension; /* Decode the next extension. */ if (!CBS_get_u16(&extensions, &type) || !CBS_get_u16_length_prefixed(&extensions, &extension)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (type == TLSEXT_TYPE_server_name) { /* The extension must be empty. */ if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* We must have sent it in ClientHello. */ if (s->tlsext_hostname == NULL) { *out_alert = SSL_AD_UNSUPPORTED_EXTENSION; return 0; } tlsext_servername = 1; } else if (type == TLSEXT_TYPE_ec_point_formats) { CBS ec_point_format_list; if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!CBS_stow(&ec_point_format_list, &s->s3->tmp.peer_ecpointformatlist, &s->s3->tmp.peer_ecpointformatlist_length)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } } else if (type == TLSEXT_TYPE_session_ticket) { if ((SSL_get_options(s) & SSL_OP_NO_TICKET) || CBS_len(&extension) > 0) { *out_alert = SSL_AD_UNSUPPORTED_EXTENSION; return 0; } s->tlsext_ticket_expected = 1; } else if (type == TLSEXT_TYPE_status_request) { /* The extension MUST be empty and may only sent if we've requested a * status request message. */ if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!s->ocsp_stapling_enabled) { *out_alert = SSL_AD_UNSUPPORTED_EXTENSION; return 0; } /* Set a flag to expect a CertificateStatus message */ s->s3->tmp.certificate_status_expected = 1; } else if (type == TLSEXT_TYPE_next_proto_neg && !s->s3->initial_handshake_complete && !SSL_IS_DTLS(s)) { uint8_t *selected; uint8_t selected_len; /* We must have requested it. */ if (s->ctx->next_proto_select_cb == NULL) { *out_alert = SSL_AD_UNSUPPORTED_EXTENSION; return 0; } /* The data must be valid. */ if (!ssl_next_proto_validate(&extension)) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (s->ctx->next_proto_select_cb( s, &selected, &selected_len, CBS_data(&extension), CBS_len(&extension), s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } s->next_proto_negotiated = BUF_memdup(selected, selected_len); if (s->next_proto_negotiated == NULL) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } s->next_proto_negotiated_len = selected_len; s->s3->next_proto_neg_seen = 1; } else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation && !s->s3->initial_handshake_complete) { CBS protocol_name_list, protocol_name; /* We must have requested it. */ if (s->alpn_client_proto_list == NULL) { *out_alert = SSL_AD_UNSUPPORTED_EXTENSION; return 0; } /* The extension data consists of a ProtocolNameList which must have * exactly one ProtocolName. Each of these is length-prefixed. */ if (!CBS_get_u16_length_prefixed(&extension, &protocol_name_list) || CBS_len(&extension) != 0 || !CBS_get_u8_length_prefixed(&protocol_name_list, &protocol_name) || CBS_len(&protocol_name_list) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!CBS_stow(&protocol_name, &s->s3->alpn_selected, &s->s3->alpn_selected_len)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } } else if (type == TLSEXT_TYPE_channel_id && !SSL_IS_DTLS(s)) { if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tlsext_channel_id_valid = 1; } else if (type == TLSEXT_TYPE_channel_id_new && !SSL_IS_DTLS(s)) { if (CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tlsext_channel_id_valid = 1; s->s3->tlsext_channel_id_new = 1; } else if (type == TLSEXT_TYPE_certificate_timestamp) { if (CBS_len(&extension) == 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } /* Session resumption uses the original session information. */ if (!s->hit && !CBS_stow(&extension, &s->session->tlsext_signed_cert_timestamp_list, &s->session->tlsext_signed_cert_timestamp_list_length)) { *out_alert = SSL_AD_INTERNAL_ERROR; return 0; } } else if (type == TLSEXT_TYPE_renegotiate) { if (!ssl_parse_serverhello_renegotiate_ext(s, &extension, out_alert)) { return 0; } renegotiate_seen = 1; } else if (type == TLSEXT_TYPE_use_srtp) { if (!ssl_parse_serverhello_use_srtp_ext(s, &extension, out_alert)) { return 0; } } else if (type == TLSEXT_TYPE_extended_master_secret) { if (/* It is invalid for the server to select EMS and SSLv3. */ s->version == SSL3_VERSION || CBS_len(&extension) != 0) { *out_alert = SSL_AD_DECODE_ERROR; return 0; } s->s3->tmp.extended_master_secret = 1; } } if (!s->hit && tlsext_servername == 1 && s->tlsext_hostname) { if (s->session->tlsext_hostname == NULL) { s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname); if (!s->session->tlsext_hostname) { *out_alert = SSL_AD_UNRECOGNIZED_NAME; return 0; } } else { *out_alert = SSL_AD_DECODE_ERROR; return 0; } } ri_check: /* Determine if we need to see RI. Strictly speaking if we want to avoid an * attack we should *always* see RI even on initial server hello because the * client doesn't see any renegotiation during an attack. However this would * mean we could not connect to any server which doesn't support RI so for * the immediate future tolerate RI absence on initial connect only. */ if (!renegotiate_seen && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT) && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) { *out_alert = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, ssl_scan_serverhello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); return 0; } return 1; } int ssl_prepare_clienthello_tlsext(SSL *s) { return 1; } int ssl_prepare_serverhello_tlsext(SSL *s) { return 1; } static int ssl_check_clienthello_tlsext(SSL *s) { int ret = SSL_TLSEXT_ERR_NOACK; int al = SSL_AD_UNRECOGNIZED_NAME; /* The handling of the ECPointFormats extension is done elsewhere, namely in * ssl3_choose_cipher in s3_lib.c. */ if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) { ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg); } else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0) { ret = s->initial_ctx->tlsext_servername_callback( s, &al, s->initial_ctx->tlsext_servername_arg); } switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: ssl3_send_alert(s, SSL3_AL_FATAL, al); return -1; case SSL_TLSEXT_ERR_ALERT_WARNING: ssl3_send_alert(s, SSL3_AL_WARNING, al); return 1; case SSL_TLSEXT_ERR_NOACK: s->should_ack_sni = 0; return 1; default: return 1; } } static int ssl_check_serverhello_tlsext(SSL *s) { int ret = SSL_TLSEXT_ERR_NOACK; int al = SSL_AD_UNRECOGNIZED_NAME; /* 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. */ uint32_t alg_k = s->s3->tmp.new_cipher->algorithm_mkey; uint32_t alg_a = s->s3->tmp.new_cipher->algorithm_auth; if (((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA)) && !tls1_check_point_format(s, TLSEXT_ECPOINTFORMAT_uncompressed)) { OPENSSL_PUT_ERROR(SSL, ssl_check_serverhello_tlsext, SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST); return -1; } ret = SSL_TLSEXT_ERR_OK; if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) { ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg); } else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0) { ret = s->initial_ctx->tlsext_servername_callback( s, &al, s->initial_ctx->tlsext_servername_arg); } switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: ssl3_send_alert(s, SSL3_AL_FATAL, al); return -1; case SSL_TLSEXT_ERR_ALERT_WARNING: ssl3_send_alert(s, SSL3_AL_WARNING, al); return 1; default: return 1; } } int ssl_parse_serverhello_tlsext(SSL *s, CBS *cbs) { int alert = -1; if (s->version < SSL3_VERSION) { return 1; } if (ssl_scan_serverhello_tlsext(s, cbs, &alert) <= 0) { ssl3_send_alert(s, SSL3_AL_FATAL, alert); return 0; } if (ssl_check_serverhello_tlsext(s) <= 0) { OPENSSL_PUT_ERROR(SSL, ssl_parse_serverhello_tlsext, SSL_R_SERVERHELLO_TLSEXT); return 0; } return 1; } /* Since the server cache lookup is done early on in the processing of the * ClientHello, and other operations depend on the result, we need to handle * any TLS session ticket extension at the same time. * * ctx: contains the early callback context, which is the result of a * shallow parse of the ClientHello. * ret: (output) on return, if a ticket was decrypted, then this is set to * point to the resulting session. * * Returns: * -1: fatal error, either from parsing or decrypting the ticket. * 0: no ticket was found (or was ignored, based on settings). * 1: a zero length extension was found, indicating that the client supports * session tickets but doesn't currently have one to offer. * 2: a ticket was offered but couldn't be decrypted because of a non-fatal * error. * 3: a ticket was successfully decrypted and *ret was set. * * Side effects: * Sets s->tlsext_ticket_expected to 1 if the server will have to issue * a new session ticket to the client because the client indicated support * but the client either doesn't have a session ticket or we couldn't use * the one it gave us, or if s->ctx->tlsext_ticket_key_cb asked to renew * the client's ticket. Otherwise, s->tlsext_ticket_expected is set to 0. */ int tls1_process_ticket(SSL *s, const struct ssl_early_callback_ctx *ctx, SSL_SESSION **ret) { *ret = NULL; s->tlsext_ticket_expected = 0; const uint8_t *data; size_t len; int r; /* If tickets disabled behave as if no ticket present to permit stateful * resumption. */ if ((SSL_get_options(s) & SSL_OP_NO_TICKET) || (s->version <= SSL3_VERSION && !ctx->extensions) || !SSL_early_callback_ctx_extension_get(ctx, TLSEXT_TYPE_session_ticket, &data, &len)) { return 0; } if (len == 0) { /* The client will accept a ticket but doesn't currently have one. */ s->tlsext_ticket_expected = 1; return 1; } r = tls_decrypt_ticket(s, data, len, ctx->session_id, ctx->session_id_len, ret); switch (r) { case 2: /* ticket couldn't be decrypted */ s->tlsext_ticket_expected = 1; return 2; case 3: /* ticket was decrypted */ return r; case 4: /* ticket decrypted but need to renew */ s->tlsext_ticket_expected = 1; return 3; default: /* fatal error */ return -1; } } /* tls_decrypt_ticket attempts to decrypt a session ticket. * * etick: points to the body of the session ticket extension. * eticklen: the length of the session tickets extenion. * sess_id: points at the session ID. * sesslen: the length of the session ID. * psess: (output) on return, if a ticket was decrypted, then this is set to * point to the resulting session. * * Returns: * -1: fatal error, either from parsing or decrypting the ticket. * 2: the ticket couldn't be decrypted. * 3: a ticket was successfully decrypted and *psess was set. * 4: same as 3, but the ticket needs to be renewed. */ static int tls_decrypt_ticket(SSL *s, const uint8_t *etick, int eticklen, const uint8_t *sess_id, int sesslen, SSL_SESSION **psess) { SSL_SESSION *sess; uint8_t *sdec; const uint8_t *p; int slen, mlen, renew_ticket = 0; uint8_t tick_hmac[EVP_MAX_MD_SIZE]; HMAC_CTX hctx; EVP_CIPHER_CTX ctx; SSL_CTX *tctx = s->initial_ctx; /* Ensure there is room for the key name and the largest IV * |tlsext_ticket_key_cb| may try to consume. The real limit may be lower, but * the maximum IV length should be well under the minimum size for the * session material and HMAC. */ if (eticklen < 16 + EVP_MAX_IV_LENGTH) { return 2; } /* Initialize session ticket encryption and HMAC contexts */ HMAC_CTX_init(&hctx); EVP_CIPHER_CTX_init(&ctx); if (tctx->tlsext_ticket_key_cb) { uint8_t *nctick = (uint8_t *)etick; int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16, &ctx, &hctx, 0 /* decrypt */); if (rv < 0) { return -1; } if (rv == 0) { return 2; } if (rv == 2) { renew_ticket = 1; } } else { /* Check key name matches */ if (memcmp(etick, tctx->tlsext_tick_key_name, 16)) { return 2; } if (!HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16, tlsext_tick_md(), NULL) || !EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, tctx->tlsext_tick_aes_key, etick + 16)) { HMAC_CTX_cleanup(&hctx); EVP_CIPHER_CTX_cleanup(&ctx); return -1; } } /* First, check the MAC. The MAC is at the end of the ticket. */ mlen = HMAC_size(&hctx); if ((size_t) eticklen < 16 + EVP_CIPHER_CTX_iv_length(&ctx) + 1 + mlen) { /* The ticket must be large enough for key name, IV, data, and MAC. */ HMAC_CTX_cleanup(&hctx); EVP_CIPHER_CTX_cleanup(&ctx); return 2; } eticklen -= mlen; /* Check HMAC of encrypted ticket */ HMAC_Update(&hctx, etick, eticklen); HMAC_Final(&hctx, tick_hmac, NULL); HMAC_CTX_cleanup(&hctx); if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) { EVP_CIPHER_CTX_cleanup(&ctx); return 2; } /* Attempt to decrypt session data */ /* Move p after IV to start of encrypted ticket, update length */ p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx); eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx); sdec = OPENSSL_malloc(eticklen); if (!sdec) { EVP_CIPHER_CTX_cleanup(&ctx); return -1; } EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen); if (EVP_DecryptFinal_ex(&ctx, sdec + slen, &mlen) <= 0) { EVP_CIPHER_CTX_cleanup(&ctx); OPENSSL_free(sdec); return 2; } slen += mlen; EVP_CIPHER_CTX_cleanup(&ctx); p = sdec; sess = d2i_SSL_SESSION(NULL, &p, slen); OPENSSL_free(sdec); if (sess) { /* The session ID, if non-empty, is used by some clients to detect that the * ticket has been accepted. So we copy it to the session structure. If it * is empty set length to zero as required by standard. */ if (sesslen) { memcpy(sess->session_id, sess_id, sesslen); } sess->session_id_length = sesslen; *psess = sess; if (renew_ticket) { return 4; } return 3; } ERR_clear_error(); /* For session parse failure, indicate that we need to send a new ticket. */ return 2; } /* Tables to translate from NIDs to TLS v1.2 ids */ typedef struct { int nid; int id; } tls12_lookup; static const tls12_lookup tls12_md[] = {{NID_md5, TLSEXT_hash_md5}, {NID_sha1, TLSEXT_hash_sha1}, {NID_sha224, TLSEXT_hash_sha224}, {NID_sha256, TLSEXT_hash_sha256}, {NID_sha384, TLSEXT_hash_sha384}, {NID_sha512, TLSEXT_hash_sha512}}; static const tls12_lookup tls12_sig[] = {{EVP_PKEY_RSA, TLSEXT_signature_rsa}, {EVP_PKEY_EC, TLSEXT_signature_ecdsa}}; static int tls12_find_id(int nid, const tls12_lookup *table, size_t tlen) { size_t i; for (i = 0; i < tlen; i++) { if (table[i].nid == nid) { return table[i].id; } } return -1; } static int tls12_find_nid(int id, const tls12_lookup *table, size_t tlen) { size_t i; for (i = 0; i < tlen; i++) { if (table[i].id == id) { return table[i].nid; } } return NID_undef; } int tls12_get_sigandhash(uint8_t *p, const EVP_PKEY *pk, const EVP_MD *md) { int sig_id, md_id; if (!md) { return 0; } md_id = tls12_find_id(EVP_MD_type(md), tls12_md, sizeof(tls12_md) / sizeof(tls12_lookup)); if (md_id == -1) { return 0; } sig_id = tls12_get_sigid(pk); if (sig_id == -1) { return 0; } p[0] = (uint8_t)md_id; p[1] = (uint8_t)sig_id; return 1; } int tls12_get_sigid(const EVP_PKEY *pk) { return tls12_find_id(pk->type, tls12_sig, sizeof(tls12_sig) / sizeof(tls12_lookup)); } const EVP_MD *tls12_get_hash(uint8_t hash_alg) { switch (hash_alg) { case TLSEXT_hash_md5: return EVP_md5(); case TLSEXT_hash_sha1: return EVP_sha1(); case TLSEXT_hash_sha224: return EVP_sha224(); case TLSEXT_hash_sha256: return EVP_sha256(); case TLSEXT_hash_sha384: return EVP_sha384(); case TLSEXT_hash_sha512: return EVP_sha512(); default: return NULL; } } /* tls12_get_pkey_type returns the EVP_PKEY type corresponding to TLS signature * algorithm |sig_alg|. It returns -1 if the type is unknown. */ static int tls12_get_pkey_type(uint8_t sig_alg) { switch (sig_alg) { case TLSEXT_signature_rsa: return EVP_PKEY_RSA; case TLSEXT_signature_ecdsa: return EVP_PKEY_EC; default: return -1; } } /* Convert TLS 1.2 signature algorithm extension values into NIDs */ static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid, int *psignhash_nid, const uint8_t *data) { int sign_nid = 0, hash_nid = 0; if (!phash_nid && !psign_nid && !psignhash_nid) { return; } if (phash_nid || psignhash_nid) { hash_nid = tls12_find_nid(data[0], tls12_md, sizeof(tls12_md) / sizeof(tls12_lookup)); if (phash_nid) { *phash_nid = hash_nid; } } if (psign_nid || psignhash_nid) { sign_nid = tls12_find_nid(data[1], tls12_sig, sizeof(tls12_sig) / sizeof(tls12_lookup)); if (psign_nid) { *psign_nid = sign_nid; } } if (psignhash_nid) { if (sign_nid && hash_nid) { OBJ_find_sigid_by_algs(psignhash_nid, hash_nid, sign_nid); } else { *psignhash_nid = NID_undef; } } } /* Given preference and allowed sigalgs set shared sigalgs */ static int tls12_do_shared_sigalgs(TLS_SIGALGS *shsig, const uint8_t *pref, size_t preflen, const uint8_t *allow, size_t allowlen) { const uint8_t *ptmp, *atmp; size_t i, j, nmatch = 0; for (i = 0, ptmp = pref; i < preflen; i += 2, ptmp += 2) { /* Skip disabled hashes or signature algorithms */ if (tls12_get_hash(ptmp[0]) == NULL || tls12_get_pkey_type(ptmp[1]) == -1) { continue; } for (j = 0, atmp = allow; j < allowlen; j += 2, atmp += 2) { if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1]) { nmatch++; if (shsig) { shsig->rhash = ptmp[0]; shsig->rsign = ptmp[1]; tls1_lookup_sigalg(&shsig->hash_nid, &shsig->sign_nid, &shsig->signandhash_nid, ptmp); shsig++; } break; } } } return nmatch; } /* Set shared signature algorithms for SSL structures */ static int tls1_set_shared_sigalgs(SSL *s) { const uint8_t *pref, *allow, *conf; size_t preflen, allowlen, conflen; size_t nmatch; TLS_SIGALGS *salgs = NULL; CERT *c = s->cert; OPENSSL_free(c->shared_sigalgs); c->shared_sigalgs = NULL; c->shared_sigalgslen = 0; /* If client use client signature algorithms if not NULL */ if (!s->server && c->client_sigalgs) { conf = c->client_sigalgs; conflen = c->client_sigalgslen; } else if (c->conf_sigalgs) { conf = c->conf_sigalgs; conflen = c->conf_sigalgslen; } else { conflen = tls12_get_psigalgs(s, &conf); } if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) { pref = conf; preflen = conflen; allow = c->peer_sigalgs; allowlen = c->peer_sigalgslen; } else { allow = conf; allowlen = conflen; pref = c->peer_sigalgs; preflen = c->peer_sigalgslen; } nmatch = tls12_do_shared_sigalgs(NULL, pref, preflen, allow, allowlen); if (!nmatch) { return 1; } salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS)); if (!salgs) { return 0; } nmatch = tls12_do_shared_sigalgs(salgs, pref, preflen, allow, allowlen); c->shared_sigalgs = salgs; c->shared_sigalgslen = nmatch; return 1; } /* Set preferred digest for each key type */ int tls1_process_sigalgs(SSL *s, const CBS *sigalgs) { CERT *c = s->cert; /* Extension ignored for inappropriate versions */ if (!SSL_USE_SIGALGS(s)) { return 1; } if (CBS_len(sigalgs) % 2 != 0 || !CBS_stow(sigalgs, &c->peer_sigalgs, &c->peer_sigalgslen) || !tls1_set_shared_sigalgs(s)) { return 0; } return 1; } const EVP_MD *tls1_choose_signing_digest(SSL *s, EVP_PKEY *pkey) { CERT *c = s->cert; int type = EVP_PKEY_id(pkey); size_t i; /* Select the first shared digest supported by our key. */ for (i = 0; i < c->shared_sigalgslen; i++) { const EVP_MD *md = tls12_get_hash(c->shared_sigalgs[i].rhash); if (md == NULL || tls12_get_pkey_type(c->shared_sigalgs[i].rsign) != type || !EVP_PKEY_supports_digest(pkey, md)) { continue; } return md; } /* If no suitable digest may be found, default to SHA-1. */ return EVP_sha1(); } int SSL_get_sigalgs(SSL *s, int idx, int *psign, int *phash, int *psignhash, uint8_t *rsig, uint8_t *rhash) { const uint8_t *psig = s->cert->peer_sigalgs; if (psig == NULL) { return 0; } if (idx >= 0) { idx <<= 1; if (idx >= (int)s->cert->peer_sigalgslen) { return 0; } psig += idx; if (rhash) { *rhash = psig[0]; } if (rsig) { *rsig = psig[1]; } tls1_lookup_sigalg(phash, psign, psignhash, psig); } return s->cert->peer_sigalgslen / 2; } int SSL_get_shared_sigalgs(SSL *s, int idx, int *psign, int *phash, int *psignhash, uint8_t *rsig, uint8_t *rhash) { TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs; if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen) { return 0; } shsigalgs += idx; if (phash) { *phash = shsigalgs->hash_nid; } if (psign) { *psign = shsigalgs->sign_nid; } if (psignhash) { *psignhash = shsigalgs->signandhash_nid; } if (rsig) { *rsig = shsigalgs->rsign; } if (rhash) { *rhash = shsigalgs->rhash; } return s->cert->shared_sigalgslen; } /* tls1_channel_id_hash calculates the signed data for a Channel ID on the * given SSL connection and writes it to |md|. */ int tls1_channel_id_hash(EVP_MD_CTX *md, SSL *s) { EVP_MD_CTX ctx; uint8_t temp_digest[EVP_MAX_MD_SIZE]; unsigned temp_digest_len; int i; static const char kClientIDMagic[] = "TLS Channel ID signature"; if (s->s3->handshake_buffer && !ssl3_digest_cached_records(s, free_handshake_buffer)) { return 0; } EVP_DigestUpdate(md, kClientIDMagic, sizeof(kClientIDMagic)); if (s->hit && s->s3->tlsext_channel_id_new) { static const char kResumptionMagic[] = "Resumption"; EVP_DigestUpdate(md, kResumptionMagic, sizeof(kResumptionMagic)); if (s->session->original_handshake_hash_len == 0) { return 0; } EVP_DigestUpdate(md, s->session->original_handshake_hash, s->session->original_handshake_hash_len); } EVP_MD_CTX_init(&ctx); for (i = 0; i < SSL_MAX_DIGEST; i++) { if (s->s3->handshake_dgst[i] == NULL) { continue; } if (!EVP_MD_CTX_copy_ex(&ctx, s->s3->handshake_dgst[i])) { EVP_MD_CTX_cleanup(&ctx); return 0; } EVP_DigestFinal_ex(&ctx, temp_digest, &temp_digest_len); EVP_DigestUpdate(md, temp_digest, temp_digest_len); } EVP_MD_CTX_cleanup(&ctx); return 1; } /* tls1_record_handshake_hashes_for_channel_id records the current handshake * hashes in |s->session| so that Channel ID resumptions can sign that data. */ int tls1_record_handshake_hashes_for_channel_id(SSL *s) { int digest_len; /* This function should never be called for a resumed session because the * handshake hashes that we wish to record are for the original, full * handshake. */ if (s->hit) { return -1; } /* It only makes sense to call this function if Channel IDs have been * negotiated. */ if (!s->s3->tlsext_channel_id_new) { return -1; } digest_len = tls1_handshake_digest(s, s->session->original_handshake_hash, sizeof(s->session->original_handshake_hash)); if (digest_len < 0) { return -1; } s->session->original_handshake_hash_len = digest_len; return 1; } int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client) { uint8_t *sigalgs, *sptr; int rhash, rsign; size_t i; if (salglen & 1) { return 0; } sigalgs = OPENSSL_malloc(salglen); if (sigalgs == NULL) { return 0; } for (i = 0, sptr = sigalgs; i < salglen; i += 2) { rhash = tls12_find_id(*psig_nids++, tls12_md, sizeof(tls12_md) / sizeof(tls12_lookup)); rsign = tls12_find_id(*psig_nids++, tls12_sig, sizeof(tls12_sig) / sizeof(tls12_lookup)); if (rhash == -1 || rsign == -1) { goto err; } *sptr++ = rhash; *sptr++ = rsign; } if (client) { OPENSSL_free(c->client_sigalgs); c->client_sigalgs = sigalgs; c->client_sigalgslen = salglen; } else { OPENSSL_free(c->conf_sigalgs); c->conf_sigalgs = sigalgs; c->conf_sigalgslen = salglen; } return 1; err: OPENSSL_free(sigalgs); return 0; }