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- /* 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 <openssl/ssl.h>
-
- #include <assert.h>
- #include <limits.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include <openssl/bytestring.h>
- #include <openssl/digest.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/hmac.h>
- #include <openssl/mem.h>
- #include <openssl/nid.h>
- #include <openssl/rand.h>
- #include <openssl/type_check.h>
-
- #include "internal.h"
- #include "../crypto/internal.h"
-
-
- static int ssl_check_clienthello_tlsext(SSL_HANDSHAKE *hs);
-
- 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 = OPENSSL_malloc(sizeof(uint16_t) * num_extensions);
- if (extension_types == NULL) {
- OPENSSL_PUT_ERROR(SSL, 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;
- }
-
- int ssl_client_hello_init(SSL *ssl, SSL_CLIENT_HELLO *out, const uint8_t *in,
- size_t in_len) {
- OPENSSL_memset(out, 0, sizeof(*out));
- out->ssl = ssl;
- out->client_hello = in;
- out->client_hello_len = in_len;
-
- CBS client_hello, random, session_id;
- CBS_init(&client_hello, out->client_hello, out->client_hello_len);
- if (!CBS_get_u16(&client_hello, &out->version) ||
- !CBS_get_bytes(&client_hello, &random, SSL3_RANDOM_SIZE) ||
- !CBS_get_u8_length_prefixed(&client_hello, &session_id) ||
- CBS_len(&session_id) > SSL_MAX_SSL_SESSION_ID_LENGTH) {
- return 0;
- }
-
- out->random = CBS_data(&random);
- out->random_len = CBS_len(&random);
- out->session_id = CBS_data(&session_id);
- out->session_id_len = CBS_len(&session_id);
-
- /* Skip past DTLS cookie */
- if (SSL_is_dtls(out->ssl)) {
- CBS cookie;
- if (!CBS_get_u8_length_prefixed(&client_hello, &cookie) ||
- CBS_len(&cookie) > DTLS1_COOKIE_LENGTH) {
- return 0;
- }
- }
-
- CBS cipher_suites, compression_methods;
- if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
- CBS_len(&cipher_suites) < 2 || (CBS_len(&cipher_suites) & 1) != 0 ||
- !CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
- CBS_len(&compression_methods) < 1) {
- return 0;
- }
-
- out->cipher_suites = CBS_data(&cipher_suites);
- out->cipher_suites_len = CBS_len(&cipher_suites);
- out->compression_methods = CBS_data(&compression_methods);
- out->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) {
- out->extensions = NULL;
- out->extensions_len = 0;
- return 1;
- }
-
- /* Extract extensions and check it is valid. */
- CBS extensions;
- if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) ||
- !tls1_check_duplicate_extensions(&extensions) ||
- CBS_len(&client_hello) != 0) {
- return 0;
- }
-
- out->extensions = CBS_data(&extensions);
- out->extensions_len = CBS_len(&extensions);
-
- return 1;
- }
-
- int ssl_client_hello_get_extension(const SSL_CLIENT_HELLO *client_hello,
- CBS *out, uint16_t extension_type) {
- CBS extensions;
- CBS_init(&extensions, client_hello->extensions, client_hello->extensions_len);
- while (CBS_len(&extensions) != 0) {
- /* Decode the next extension. */
- uint16_t type;
- CBS extension;
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- return 0;
- }
-
- if (type == extension_type) {
- *out = extension;
- return 1;
- }
- }
-
- return 0;
- }
-
- int SSL_early_callback_ctx_extension_get(const SSL_CLIENT_HELLO *client_hello,
- uint16_t extension_type,
- const uint8_t **out_data,
- size_t *out_len) {
- CBS cbs;
- if (!ssl_client_hello_get_extension(client_hello, &cbs, extension_type)) {
- return 0;
- }
-
- *out_data = CBS_data(&cbs);
- *out_len = CBS_len(&cbs);
- return 1;
- }
-
- static const uint16_t kDefaultGroups[] = {
- SSL_CURVE_X25519,
- SSL_CURVE_SECP256R1,
- SSL_CURVE_SECP384R1,
- };
-
- void tls1_get_grouplist(SSL *ssl, const uint16_t **out_group_ids,
- size_t *out_group_ids_len) {
- *out_group_ids = ssl->supported_group_list;
- *out_group_ids_len = ssl->supported_group_list_len;
- if (!*out_group_ids) {
- *out_group_ids = kDefaultGroups;
- *out_group_ids_len = OPENSSL_ARRAY_SIZE(kDefaultGroups);
- }
- }
-
- int tls1_get_shared_group(SSL_HANDSHAKE *hs, uint16_t *out_group_id) {
- SSL *const ssl = hs->ssl;
- assert(ssl->server);
-
- const uint16_t *groups, *pref, *supp;
- size_t groups_len, pref_len, supp_len;
- tls1_get_grouplist(ssl, &groups, &groups_len);
-
- /* Clients are not required to send a supported_groups extension. In this
- * case, the server is free to pick any group it likes. See RFC 4492,
- * section 4, paragraph 3.
- *
- * However, in the interests of compatibility, we will skip ECDH if the
- * client didn't send an extension because we can't be sure that they'll
- * support our favoured group. Thus we do not special-case an emtpy
- * |peer_supported_group_list|. */
-
- if (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
- pref = groups;
- pref_len = groups_len;
- supp = hs->peer_supported_group_list;
- supp_len = hs->peer_supported_group_list_len;
- } else {
- pref = hs->peer_supported_group_list;
- pref_len = hs->peer_supported_group_list_len;
- supp = groups;
- supp_len = groups_len;
- }
-
- for (size_t i = 0; i < pref_len; i++) {
- for (size_t j = 0; j < supp_len; j++) {
- if (pref[i] == supp[j]) {
- *out_group_id = pref[i];
- return 1;
- }
- }
- }
-
- return 0;
- }
-
- int tls1_set_curves(uint16_t **out_group_ids, size_t *out_group_ids_len,
- const int *curves, size_t ncurves) {
- uint16_t *group_ids;
-
- group_ids = OPENSSL_malloc(ncurves * sizeof(uint16_t));
- if (group_ids == NULL) {
- return 0;
- }
-
- for (size_t i = 0; i < ncurves; i++) {
- if (!ssl_nid_to_group_id(&group_ids[i], curves[i])) {
- OPENSSL_free(group_ids);
- return 0;
- }
- }
-
- OPENSSL_free(*out_group_ids);
- *out_group_ids = group_ids;
- *out_group_ids_len = ncurves;
-
- return 1;
- }
-
- int tls1_set_curves_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
- const char *curves) {
- uint16_t *group_ids = NULL;
- size_t ncurves = 0;
-
- const char *col;
- const char *ptr = curves;
-
- do {
- col = strchr(ptr, ':');
-
- uint16_t group_id;
- if (!ssl_name_to_group_id(&group_id, ptr,
- col ? (size_t)(col - ptr) : strlen(ptr))) {
- goto err;
- }
-
- uint16_t *new_group_ids = OPENSSL_realloc(group_ids,
- (ncurves + 1) * sizeof(uint16_t));
- if (new_group_ids == NULL) {
- goto err;
- }
- group_ids = new_group_ids;
-
- group_ids[ncurves] = group_id;
- ncurves++;
-
- if (col) {
- ptr = col + 1;
- }
- } while (col);
-
- OPENSSL_free(*out_group_ids);
- *out_group_ids = group_ids;
- *out_group_ids_len = ncurves;
-
- return 1;
-
- err:
- OPENSSL_free(group_ids);
- return 0;
- }
-
- int tls1_check_group_id(SSL *ssl, uint16_t group_id) {
- const uint16_t *groups;
- size_t groups_len;
- tls1_get_grouplist(ssl, &groups, &groups_len);
- for (size_t i = 0; i < groups_len; i++) {
- if (groups[i] == group_id) {
- return 1;
- }
- }
-
- return 0;
- }
-
- /* kVerifySignatureAlgorithms is the default list of accepted signature
- * algorithms for verifying.
- *
- * For now, RSA-PSS signature algorithms are not enabled on Android's system
- * BoringSSL. Once the change in Chrome has stuck and the values are finalized,
- * restore them. */
- static const uint16_t kVerifySignatureAlgorithms[] = {
- /* List our preferred algorithms first. */
- SSL_SIGN_ED25519,
- SSL_SIGN_ECDSA_SECP256R1_SHA256,
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA256,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA256,
-
- /* Larger hashes are acceptable. */
- SSL_SIGN_ECDSA_SECP384R1_SHA384,
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA384,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA384,
-
- /* TODO(davidben): Remove this. */
- #if defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_ECDSA_SECP521R1_SHA512,
- #endif
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA512,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA512,
-
- /* For now, SHA-1 is still accepted but least preferable. */
- SSL_SIGN_RSA_PKCS1_SHA1,
-
- };
-
- /* kSignSignatureAlgorithms is the default list of supported signature
- * algorithms for signing.
- *
- * For now, RSA-PSS signature algorithms are not enabled on Android's system
- * BoringSSL. Once the change in Chrome has stuck and the values are finalized,
- * restore them. */
- static const uint16_t kSignSignatureAlgorithms[] = {
- /* List our preferred algorithms first. */
- SSL_SIGN_ED25519,
- SSL_SIGN_ECDSA_SECP256R1_SHA256,
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA256,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA256,
-
- /* If needed, sign larger hashes.
- *
- * TODO(davidben): Determine which of these may be pruned. */
- SSL_SIGN_ECDSA_SECP384R1_SHA384,
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA384,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA384,
-
- SSL_SIGN_ECDSA_SECP521R1_SHA512,
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA512,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA512,
-
- /* If the peer supports nothing else, sign with SHA-1. */
- SSL_SIGN_ECDSA_SHA1,
- SSL_SIGN_RSA_PKCS1_SHA1,
- };
-
- void SSL_CTX_set_ed25519_enabled(SSL_CTX *ctx, int enabled) {
- ctx->ed25519_enabled = !!enabled;
- }
-
- int tls12_add_verify_sigalgs(const SSL *ssl, CBB *out) {
- const uint16_t *sigalgs = kVerifySignatureAlgorithms;
- size_t num_sigalgs = OPENSSL_ARRAY_SIZE(kVerifySignatureAlgorithms);
- if (ssl->ctx->num_verify_sigalgs != 0) {
- sigalgs = ssl->ctx->verify_sigalgs;
- num_sigalgs = ssl->ctx->num_verify_sigalgs;
- }
-
- for (size_t i = 0; i < num_sigalgs; i++) {
- if (sigalgs == kVerifySignatureAlgorithms &&
- sigalgs[i] == SSL_SIGN_ED25519 &&
- !ssl->ctx->ed25519_enabled) {
- continue;
- }
- if (!CBB_add_u16(out, sigalgs[i])) {
- return 0;
- }
- }
-
- return 1;
- }
-
- int tls12_check_peer_sigalg(SSL *ssl, int *out_alert, uint16_t sigalg) {
- const uint16_t *sigalgs = kVerifySignatureAlgorithms;
- size_t num_sigalgs = OPENSSL_ARRAY_SIZE(kVerifySignatureAlgorithms);
- if (ssl->ctx->num_verify_sigalgs != 0) {
- sigalgs = ssl->ctx->verify_sigalgs;
- num_sigalgs = ssl->ctx->num_verify_sigalgs;
- }
-
- for (size_t i = 0; i < num_sigalgs; i++) {
- if (sigalgs == kVerifySignatureAlgorithms &&
- sigalgs[i] == SSL_SIGN_ED25519 &&
- !ssl->ctx->ed25519_enabled) {
- continue;
- }
- if (sigalg == sigalgs[i]) {
- return 1;
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- /* tls_extension represents a TLS extension that is handled internally. The
- * |init| function is called for each handshake, before any other functions of
- * the extension. Then the add and parse callbacks are called as needed.
- *
- * The parse callbacks receive a |CBS| that contains the contents of the
- * extension (i.e. not including the type and length bytes). If an extension is
- * not received then the parse callbacks will be called with a NULL CBS so that
- * they can do any processing needed to handle the absence of an extension.
- *
- * The add callbacks receive a |CBB| to which the extension can be appended but
- * the function is responsible for appending the type and length bytes too.
- *
- * All callbacks return one for success and zero for error. If a parse function
- * returns zero then a fatal alert with value |*out_alert| will be sent. If
- * |*out_alert| isn't set, then a |decode_error| alert will be sent. */
- struct tls_extension {
- uint16_t value;
- void (*init)(SSL_HANDSHAKE *hs);
-
- int (*add_clienthello)(SSL_HANDSHAKE *hs, CBB *out);
- int (*parse_serverhello)(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents);
-
- int (*parse_clienthello)(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents);
- int (*add_serverhello)(SSL_HANDSHAKE *hs, CBB *out);
- };
-
- static int forbid_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents != NULL) {
- /* Servers MUST NOT send this extension. */
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- return 0;
- }
-
- return 1;
- }
-
- static int ignore_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- /* This extension from the client is handled elsewhere. */
- return 1;
- }
-
- static int dont_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- return 1;
- }
-
- /* Server name indication (SNI).
- *
- * https://tools.ietf.org/html/rfc6066#section-3. */
-
- static int ext_sni_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->tlsext_hostname == NULL) {
- return 1;
- }
-
- CBB contents, server_name_list, name;
- if (!CBB_add_u16(out, TLSEXT_TYPE_server_name) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &server_name_list) ||
- !CBB_add_u8(&server_name_list, TLSEXT_NAMETYPE_host_name) ||
- !CBB_add_u16_length_prefixed(&server_name_list, &name) ||
- !CBB_add_bytes(&name, (const uint8_t *)ssl->tlsext_hostname,
- strlen(ssl->tlsext_hostname)) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sni_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- assert(ssl->tlsext_hostname != NULL);
-
- if (ssl->session == NULL) {
- OPENSSL_free(hs->new_session->tlsext_hostname);
- hs->new_session->tlsext_hostname = BUF_strdup(ssl->tlsext_hostname);
- if (!hs->new_session->tlsext_hostname) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
- }
-
- return 1;
- }
-
- static int ext_sni_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS server_name_list, host_name;
- uint8_t name_type;
- if (!CBS_get_u16_length_prefixed(contents, &server_name_list) ||
- !CBS_get_u8(&server_name_list, &name_type) ||
- /* Although the server_name extension was intended to be extensible to
- * new name types and multiple names, OpenSSL 1.0.x had a bug which meant
- * different name types will cause an error. Further, RFC 4366 originally
- * defined syntax inextensibly. RFC 6066 corrected this mistake, but
- * adding new name types is no longer feasible.
- *
- * Act as if the extensibility does not exist to simplify parsing. */
- !CBS_get_u16_length_prefixed(&server_name_list, &host_name) ||
- CBS_len(&server_name_list) != 0 ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- if (name_type != TLSEXT_NAMETYPE_host_name ||
- CBS_len(&host_name) == 0 ||
- CBS_len(&host_name) > TLSEXT_MAXLEN_host_name ||
- CBS_contains_zero_byte(&host_name)) {
- *out_alert = SSL_AD_UNRECOGNIZED_NAME;
- return 0;
- }
-
- /* Copy the hostname as a string. */
- if (!CBS_strdup(&host_name, &hs->hostname)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- hs->should_ack_sni = 1;
- return 1;
- }
-
- static int ext_sni_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (hs->ssl->s3->session_reused ||
- !hs->should_ack_sni) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_server_name) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Renegotiation indication.
- *
- * https://tools.ietf.org/html/rfc5746 */
-
- static int ext_ri_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* Renegotiation indication is not necessary in TLS 1.3. */
- if (min_version >= TLS1_3_VERSION) {
- return 1;
- }
-
- assert(ssl->s3->initial_handshake_complete ==
- (ssl->s3->previous_client_finished_len != 0));
-
- CBB contents, prev_finished;
- if (!CBB_add_u16(out, TLSEXT_TYPE_renegotiate) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &prev_finished) ||
- !CBB_add_bytes(&prev_finished, ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ri_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents != NULL && ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- /* Servers may not switch between omitting the extension and supporting it.
- * See RFC 5746, sections 3.5 and 4.2. */
- if (ssl->s3->initial_handshake_complete &&
- (contents != NULL) != ssl->s3->send_connection_binding) {
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- return 0;
- }
-
- if (contents == NULL) {
- /* Strictly speaking, if we want to avoid an attack we should *always* see
- * RI even on initial ServerHello 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.
- *
- * OpenSSL has |SSL_OP_LEGACY_SERVER_CONNECT| to control this, but in
- * practical terms every client sets it so it's just assumed here. */
- return 1;
- }
-
- const size_t expected_len = ssl->s3->previous_client_finished_len +
- ssl->s3->previous_server_finished_len;
-
- /* Check for logic errors */
- assert(!expected_len || ssl->s3->previous_client_finished_len);
- assert(!expected_len || ssl->s3->previous_server_finished_len);
- assert(ssl->s3->initial_handshake_complete ==
- (ssl->s3->previous_client_finished_len != 0));
- assert(ssl->s3->initial_handshake_complete ==
- (ssl->s3->previous_server_finished_len != 0));
-
- /* Parse out the extension contents. */
- CBS renegotiated_connection;
- if (!CBS_get_u8_length_prefixed(contents, &renegotiated_connection) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_ENCODING_ERR);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- /* Check that the extension matches. */
- if (CBS_len(&renegotiated_connection) != expected_len) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
-
- const uint8_t *d = CBS_data(&renegotiated_connection);
- if (CRYPTO_memcmp(d, ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
- d += ssl->s3->previous_client_finished_len;
-
- if (CRYPTO_memcmp(d, ssl->s3->previous_server_finished,
- ssl->s3->previous_server_finished_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
- ssl->s3->send_connection_binding = 1;
-
- return 1;
- }
-
- static int ext_ri_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- /* Renegotiation isn't supported as a server so this function should never be
- * called after the initial handshake. */
- assert(!ssl->s3->initial_handshake_complete);
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (contents == NULL) {
- return 1;
- }
-
- CBS renegotiated_connection;
- if (!CBS_get_u8_length_prefixed(contents, &renegotiated_connection) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_ENCODING_ERR);
- return 0;
- }
-
- /* Check that the extension matches. We do not support renegotiation as a
- * server, so this must be empty. */
- if (CBS_len(&renegotiated_connection) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
-
- ssl->s3->send_connection_binding = 1;
-
- return 1;
- }
-
- static int ext_ri_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- /* Renegotiation isn't supported as a server so this function should never be
- * called after the initial handshake. */
- assert(!ssl->s3->initial_handshake_complete);
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_renegotiate) ||
- !CBB_add_u16(out, 1 /* length */) ||
- !CBB_add_u8(out, 0 /* empty renegotiation info */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Extended Master Secret.
- *
- * https://tools.ietf.org/html/rfc7627 */
-
- static int ext_ems_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(hs->ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* Extended master secret is not necessary in TLS 1.3. */
- if (min_version >= TLS1_3_VERSION || max_version <= SSL3_VERSION) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ems_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
-
- if (contents != NULL) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION ||
- ssl->version == SSL3_VERSION ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- hs->extended_master_secret = 1;
- }
-
- /* Whether EMS is negotiated may not change on renegotiation. */
- if (ssl->s3->established_session != NULL &&
- hs->extended_master_secret !=
- ssl->s3->established_session->extended_master_secret) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_EMS_MISMATCH);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ems_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- uint16_t version = ssl3_protocol_version(hs->ssl);
- if (version >= TLS1_3_VERSION ||
- version == SSL3_VERSION) {
- return 1;
- }
-
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- hs->extended_master_secret = 1;
- return 1;
- }
-
- static int ext_ems_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->extended_master_secret) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Session tickets.
- *
- * https://tools.ietf.org/html/rfc5077 */
-
- static int ext_ticket_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* TLS 1.3 uses a different ticket extension. */
- if (min_version >= TLS1_3_VERSION ||
- SSL_get_options(ssl) & SSL_OP_NO_TICKET) {
- return 1;
- }
-
- const uint8_t *ticket_data = NULL;
- int ticket_len = 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. */
- uint16_t session_version;
- if (!ssl->s3->initial_handshake_complete &&
- ssl->session != NULL &&
- ssl->session->tlsext_tick != NULL &&
- /* Don't send TLS 1.3 session tickets in the ticket extension. */
- ssl->method->version_from_wire(&session_version,
- ssl->session->ssl_version) &&
- session_version < TLS1_3_VERSION) {
- ticket_data = ssl->session->tlsext_tick;
- ticket_len = ssl->session->tlsext_ticklen;
- }
-
- CBB ticket;
- if (!CBB_add_u16(out, TLSEXT_TYPE_session_ticket) ||
- !CBB_add_u16_length_prefixed(out, &ticket) ||
- !CBB_add_bytes(&ticket, ticket_data, ticket_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ticket_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* If |SSL_OP_NO_TICKET| is set then no extension will have been sent and
- * this function should never be called, even if the server tries to send the
- * extension. */
- assert((SSL_get_options(ssl) & SSL_OP_NO_TICKET) == 0);
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- hs->ticket_expected = 1;
- return 1;
- }
-
- static int ext_ticket_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ticket_expected) {
- return 1;
- }
-
- /* If |SSL_OP_NO_TICKET| is set, |ticket_expected| should never be true. */
- assert((SSL_get_options(hs->ssl) & SSL_OP_NO_TICKET) == 0);
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_session_ticket) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Signature Algorithms.
- *
- * https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1 */
-
- static int ext_sigalgs_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version < TLS1_2_VERSION) {
- return 1;
- }
-
- CBB contents, sigalgs_cbb;
- if (!CBB_add_u16(out, TLSEXT_TYPE_signature_algorithms) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &sigalgs_cbb) ||
- !tls12_add_verify_sigalgs(ssl, &sigalgs_cbb) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sigalgs_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- OPENSSL_free(hs->peer_sigalgs);
- hs->peer_sigalgs = NULL;
- hs->num_peer_sigalgs = 0;
-
- if (contents == NULL) {
- return 1;
- }
-
- CBS supported_signature_algorithms;
- if (!CBS_get_u16_length_prefixed(contents, &supported_signature_algorithms) ||
- CBS_len(contents) != 0 ||
- CBS_len(&supported_signature_algorithms) == 0 ||
- !tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* OCSP Stapling.
- *
- * https://tools.ietf.org/html/rfc6066#section-8 */
-
- static int ext_ocsp_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->ocsp_stapling_enabled) {
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_status_request) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8(&contents, TLSEXT_STATUSTYPE_ocsp) ||
- !CBB_add_u16(&contents, 0 /* empty responder ID list */) ||
- !CBB_add_u16(&contents, 0 /* empty request extensions */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ocsp_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- /* TLS 1.3 OCSP responses are included in the Certificate extensions. */
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* OCSP stapling is forbidden on non-certificate ciphers. */
- if (CBS_len(contents) != 0 ||
- !ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
- return 0;
- }
-
- /* Note this does not check for resumption in TLS 1.2. Sending
- * status_request here does not make sense, but OpenSSL does so and the
- * specification does not say anything. Tolerate it but ignore it. */
-
- hs->certificate_status_expected = 1;
- return 1;
- }
-
- static int ext_ocsp_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- uint8_t status_type;
- if (!CBS_get_u8(contents, &status_type)) {
- return 0;
- }
-
- /* We cannot decide whether OCSP stapling will occur yet because the correct
- * SSL_CTX might not have been selected. */
- hs->ocsp_stapling_requested = status_type == TLSEXT_STATUSTYPE_ocsp;
-
- return 1;
- }
-
- static int ext_ocsp_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION ||
- !hs->ocsp_stapling_requested ||
- ssl->cert->ocsp_response == NULL ||
- ssl->s3->session_reused ||
- !ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
- return 1;
- }
-
- hs->certificate_status_expected = 1;
-
- return CBB_add_u16(out, TLSEXT_TYPE_status_request) &&
- CBB_add_u16(out, 0 /* length */);
- }
-
-
- /* Next protocol negotiation.
- *
- * https://htmlpreview.github.io/?https://github.com/agl/technotes/blob/master/nextprotoneg.html */
-
- static int ext_npn_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->s3->initial_handshake_complete ||
- ssl->ctx->next_proto_select_cb == NULL ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_next_proto_neg) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_npn_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* If any of these are false then we should never have sent the NPN
- * extension in the ClientHello and thus this function should never have been
- * called. */
- assert(!ssl->s3->initial_handshake_complete);
- assert(!SSL_is_dtls(ssl));
- assert(ssl->ctx->next_proto_select_cb != NULL);
-
- if (ssl->s3->alpn_selected != NULL) {
- /* NPN and ALPN may not be negotiated in the same connection. */
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN);
- return 0;
- }
-
- const uint8_t *const orig_contents = CBS_data(contents);
- const size_t orig_len = CBS_len(contents);
-
- while (CBS_len(contents) != 0) {
- CBS proto;
- if (!CBS_get_u8_length_prefixed(contents, &proto) ||
- CBS_len(&proto) == 0) {
- return 0;
- }
- }
-
- uint8_t *selected;
- uint8_t selected_len;
- if (ssl->ctx->next_proto_select_cb(
- ssl, &selected, &selected_len, orig_contents, orig_len,
- ssl->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- OPENSSL_free(ssl->s3->next_proto_negotiated);
- ssl->s3->next_proto_negotiated = BUF_memdup(selected, selected_len);
- if (ssl->s3->next_proto_negotiated == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- ssl->s3->next_proto_negotiated_len = selected_len;
- hs->next_proto_neg_seen = 1;
-
- return 1;
- }
-
- static int ext_npn_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (contents != NULL && CBS_len(contents) != 0) {
- return 0;
- }
-
- if (contents == NULL ||
- ssl->s3->initial_handshake_complete ||
- ssl->ctx->next_protos_advertised_cb == NULL ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- hs->next_proto_neg_seen = 1;
- return 1;
- }
-
- static int ext_npn_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- /* |next_proto_neg_seen| might have been cleared when an ALPN extension was
- * parsed. */
- if (!hs->next_proto_neg_seen) {
- return 1;
- }
-
- const uint8_t *npa;
- unsigned npa_len;
-
- if (ssl->ctx->next_protos_advertised_cb(
- ssl, &npa, &npa_len, ssl->ctx->next_protos_advertised_cb_arg) !=
- SSL_TLSEXT_ERR_OK) {
- hs->next_proto_neg_seen = 0;
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_next_proto_neg) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_bytes(&contents, npa, npa_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Signed certificate timestamps.
- *
- * https://tools.ietf.org/html/rfc6962#section-3.3.1 */
-
- static int ext_sct_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->signed_cert_timestamps_enabled) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_certificate_timestamp) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sct_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- /* TLS 1.3 SCTs are included in the Certificate extensions. */
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* If this is false then we should never have sent the SCT extension in the
- * ClientHello and thus this function should never have been called. */
- assert(ssl->signed_cert_timestamps_enabled);
-
- if (!ssl_is_sct_list_valid(contents)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* Session resumption uses the original session information. The extension
- * should not be sent on resumption, but RFC 6962 did not make it a
- * requirement, so tolerate this.
- *
- * TODO(davidben): Enforce this anyway. */
- if (!ssl->s3->session_reused &&
- !CBS_stow(contents, &hs->new_session->tlsext_signed_cert_timestamp_list,
- &hs->new_session->tlsext_signed_cert_timestamp_list_length)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sct_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- hs->scts_requested = 1;
- return 1;
- }
-
- static int ext_sct_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- /* The extension shouldn't be sent when resuming sessions. */
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION ||
- ssl->s3->session_reused ||
- ssl->cert->signed_cert_timestamp_list == NULL) {
- return 1;
- }
-
- CBB contents;
- return CBB_add_u16(out, TLSEXT_TYPE_certificate_timestamp) &&
- CBB_add_u16_length_prefixed(out, &contents) &&
- CBB_add_bytes(
- &contents,
- CRYPTO_BUFFER_data(ssl->cert->signed_cert_timestamp_list),
- CRYPTO_BUFFER_len(ssl->cert->signed_cert_timestamp_list)) &&
- CBB_flush(out);
- }
-
-
- /* Application-level Protocol Negotiation.
- *
- * https://tools.ietf.org/html/rfc7301 */
-
- static int ext_alpn_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->alpn_client_proto_list == NULL ||
- ssl->s3->initial_handshake_complete) {
- return 1;
- }
-
- CBB contents, proto_list;
- if (!CBB_add_u16(out, TLSEXT_TYPE_application_layer_protocol_negotiation) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &proto_list) ||
- !CBB_add_bytes(&proto_list, ssl->alpn_client_proto_list,
- ssl->alpn_client_proto_list_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_alpn_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- assert(!ssl->s3->initial_handshake_complete);
- assert(ssl->alpn_client_proto_list != NULL);
-
- if (hs->next_proto_neg_seen) {
- /* NPN and ALPN may not be negotiated in the same connection. */
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN);
- return 0;
- }
-
- /* The extension data consists of a ProtocolNameList which must have
- * exactly one ProtocolName. Each of these is length-prefixed. */
- CBS protocol_name_list, protocol_name;
- if (!CBS_get_u16_length_prefixed(contents, &protocol_name_list) ||
- CBS_len(contents) != 0 ||
- !CBS_get_u8_length_prefixed(&protocol_name_list, &protocol_name) ||
- /* Empty protocol names are forbidden. */
- CBS_len(&protocol_name) == 0 ||
- CBS_len(&protocol_name_list) != 0) {
- return 0;
- }
-
- if (!ssl->ctx->allow_unknown_alpn_protos) {
- /* Check that the protocol name is one of the ones we advertised. */
- int protocol_ok = 0;
- CBS client_protocol_name_list, client_protocol_name;
- CBS_init(&client_protocol_name_list, ssl->alpn_client_proto_list,
- ssl->alpn_client_proto_list_len);
- while (CBS_len(&client_protocol_name_list) > 0) {
- if (!CBS_get_u8_length_prefixed(&client_protocol_name_list,
- &client_protocol_name)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- if (CBS_len(&client_protocol_name) == CBS_len(&protocol_name) &&
- OPENSSL_memcmp(CBS_data(&client_protocol_name),
- CBS_data(&protocol_name),
- CBS_len(&protocol_name)) == 0) {
- protocol_ok = 1;
- break;
- }
- }
-
- if (!protocol_ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_ALPN_PROTOCOL);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
- }
-
- if (!CBS_stow(&protocol_name, &ssl->s3->alpn_selected,
- &ssl->s3->alpn_selected_len)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- return 1;
- }
-
- int ssl_negotiate_alpn(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- const SSL_CLIENT_HELLO *client_hello) {
- SSL *const ssl = hs->ssl;
- CBS contents;
- if (ssl->ctx->alpn_select_cb == NULL ||
- !ssl_client_hello_get_extension(
- client_hello, &contents,
- TLSEXT_TYPE_application_layer_protocol_negotiation)) {
- /* Ignore ALPN if not configured or no extension was supplied. */
- return 1;
- }
-
- /* ALPN takes precedence over NPN. */
- hs->next_proto_neg_seen = 0;
-
- CBS protocol_name_list;
- if (!CBS_get_u16_length_prefixed(&contents, &protocol_name_list) ||
- CBS_len(&contents) != 0 ||
- CBS_len(&protocol_name_list) < 2) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* Validate the protocol list. */
- CBS 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) ||
- /* Empty protocol names are forbidden. */
- CBS_len(&protocol_name) == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
- }
-
- const uint8_t *selected;
- uint8_t selected_len;
- if (ssl->ctx->alpn_select_cb(
- ssl, &selected, &selected_len, CBS_data(&protocol_name_list),
- CBS_len(&protocol_name_list),
- ssl->ctx->alpn_select_cb_arg) == SSL_TLSEXT_ERR_OK) {
- OPENSSL_free(ssl->s3->alpn_selected);
- ssl->s3->alpn_selected = BUF_memdup(selected, selected_len);
- if (ssl->s3->alpn_selected == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
- ssl->s3->alpn_selected_len = selected_len;
- }
-
- return 1;
- }
-
- static int ext_alpn_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->s3->alpn_selected == NULL) {
- return 1;
- }
-
- CBB contents, proto_list, proto;
- if (!CBB_add_u16(out, TLSEXT_TYPE_application_layer_protocol_negotiation) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &proto_list) ||
- !CBB_add_u8_length_prefixed(&proto_list, &proto) ||
- !CBB_add_bytes(&proto, ssl->s3->alpn_selected,
- ssl->s3->alpn_selected_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Channel ID.
- *
- * https://tools.ietf.org/html/draft-balfanz-tls-channelid-01 */
-
- static void ext_channel_id_init(SSL_HANDSHAKE *hs) {
- hs->ssl->s3->tlsext_channel_id_valid = 0;
- }
-
- static int ext_channel_id_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->tlsext_channel_id_enabled ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_channel_id_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert, CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- assert(!SSL_is_dtls(ssl));
- assert(ssl->tlsext_channel_id_enabled);
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tlsext_channel_id_valid = 1;
- return 1;
- }
-
- static int ext_channel_id_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert, CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL ||
- !ssl->tlsext_channel_id_enabled ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tlsext_channel_id_valid = 1;
- return 1;
- }
-
- static int ext_channel_id_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->s3->tlsext_channel_id_valid) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Secure Real-time Transport Protocol (SRTP) extension.
- *
- * https://tools.ietf.org/html/rfc5764 */
-
-
- static void ext_srtp_init(SSL_HANDSHAKE *hs) {
- hs->ssl->srtp_profile = NULL;
- }
-
- static int ext_srtp_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
- if (profiles == NULL) {
- return 1;
- }
- const size_t num_profiles = sk_SRTP_PROTECTION_PROFILE_num(profiles);
- if (num_profiles == 0) {
- return 1;
- }
-
- CBB contents, profile_ids;
- if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &profile_ids)) {
- return 0;
- }
-
- for (size_t i = 0; i < num_profiles; i++) {
- if (!CBB_add_u16(&profile_ids,
- sk_SRTP_PROTECTION_PROFILE_value(profiles, i)->id)) {
- return 0;
- }
- }
-
- if (!CBB_add_u8(&contents, 0 /* empty use_mki value */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_srtp_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- /* The extension consists of a u16-prefixed profile ID list containing a
- * single uint16_t profile ID, then followed by a u8-prefixed srtp_mki field.
- *
- * See https://tools.ietf.org/html/rfc5764#section-4.1.1 */
- CBS profile_ids, srtp_mki;
- uint16_t profile_id;
- if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
- !CBS_get_u16(&profile_ids, &profile_id) ||
- CBS_len(&profile_ids) != 0 ||
- !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- return 0;
- }
-
- if (CBS_len(&srtp_mki) != 0) {
- /* Must be no MKI, since we never offer one. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_MKI_VALUE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
-
- /* Check to see if the server gave us something we support (and presumably
- * offered). */
- for (size_t i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(profiles); i++) {
- const SRTP_PROTECTION_PROFILE *profile =
- sk_SRTP_PROTECTION_PROFILE_value(profiles, i);
-
- if (profile->id == profile_id) {
- ssl->srtp_profile = profile;
- return 1;
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- static int ext_srtp_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- CBS profile_ids, srtp_mki;
- if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
- CBS_len(&profile_ids) < 2 ||
- !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- return 0;
- }
- /* Discard the MKI value for now. */
-
- const STACK_OF(SRTP_PROTECTION_PROFILE) *server_profiles =
- SSL_get_srtp_profiles(ssl);
-
- /* Pick the server's most preferred profile. */
- for (size_t i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(server_profiles); i++) {
- const SRTP_PROTECTION_PROFILE *server_profile =
- sk_SRTP_PROTECTION_PROFILE_value(server_profiles, i);
-
- CBS profile_ids_tmp;
- CBS_init(&profile_ids_tmp, CBS_data(&profile_ids), CBS_len(&profile_ids));
-
- while (CBS_len(&profile_ids_tmp) > 0) {
- uint16_t profile_id;
- if (!CBS_get_u16(&profile_ids_tmp, &profile_id)) {
- return 0;
- }
-
- if (server_profile->id == profile_id) {
- ssl->srtp_profile = server_profile;
- return 1;
- }
- }
- }
-
- return 1;
- }
-
- static int ext_srtp_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->srtp_profile == NULL) {
- return 1;
- }
-
- CBB contents, profile_ids;
- if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &profile_ids) ||
- !CBB_add_u16(&profile_ids, ssl->srtp_profile->id) ||
- !CBB_add_u8(&contents, 0 /* empty MKI */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* EC point formats.
- *
- * https://tools.ietf.org/html/rfc4492#section-5.1.2 */
-
- static int ext_ec_point_add_extension(SSL_HANDSHAKE *hs, CBB *out) {
- CBB contents, formats;
- if (!CBB_add_u16(out, TLSEXT_TYPE_ec_point_formats) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &formats) ||
- !CBB_add_u8(&formats, TLSEXT_ECPOINTFORMAT_uncompressed) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ec_point_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(hs->ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* The point format extension is unneccessary in TLS 1.3. */
- if (min_version >= TLS1_3_VERSION) {
- return 1;
- }
-
- return ext_ec_point_add_extension(hs, out);
- }
-
- static int ext_ec_point_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- CBS ec_point_format_list;
- if (!CBS_get_u8_length_prefixed(contents, &ec_point_format_list) ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- /* Per RFC 4492, section 5.1.2, implementations MUST support the uncompressed
- * point format. */
- if (OPENSSL_memchr(CBS_data(&ec_point_format_list),
- TLSEXT_ECPOINTFORMAT_uncompressed,
- CBS_len(&ec_point_format_list)) == NULL) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ec_point_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (ssl3_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- return ext_ec_point_parse_serverhello(hs, out_alert, contents);
- }
-
- static int ext_ec_point_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- const uint32_t alg_k = hs->new_cipher->algorithm_mkey;
- const uint32_t alg_a = hs->new_cipher->algorithm_auth;
- const int using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA);
-
- if (!using_ecc) {
- return 1;
- }
-
- return ext_ec_point_add_extension(hs, out);
- }
-
-
- /* Pre Shared Key
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-18#section-4.2.6 */
-
- static size_t ext_pre_shared_key_clienthello_length(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- uint16_t session_version;
- if (max_version < TLS1_3_VERSION || ssl->session == NULL ||
- !ssl->method->version_from_wire(&session_version,
- ssl->session->ssl_version) ||
- session_version < TLS1_3_VERSION) {
- return 0;
- }
-
- const EVP_MD *digest = SSL_SESSION_get_digest(ssl->session, ssl);
- if (digest == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- size_t binder_len = EVP_MD_size(digest);
- return 15 + ssl->session->tlsext_ticklen + binder_len;
- }
-
- static int ext_pre_shared_key_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- uint16_t session_version;
- if (max_version < TLS1_3_VERSION || ssl->session == NULL ||
- !ssl->method->version_from_wire(&session_version,
- ssl->session->ssl_version) ||
- session_version < TLS1_3_VERSION) {
- return 1;
- }
-
- struct OPENSSL_timeval now;
- ssl_get_current_time(ssl, &now);
- uint32_t ticket_age = 1000 * (now.tv_sec - ssl->session->time);
- uint32_t obfuscated_ticket_age = ticket_age + ssl->session->ticket_age_add;
-
- /* Fill in a placeholder zero binder of the appropriate length. It will be
- * computed and filled in later after length prefixes are computed. */
- uint8_t zero_binder[EVP_MAX_MD_SIZE] = {0};
-
- const EVP_MD *digest = SSL_SESSION_get_digest(ssl->session, ssl);
- if (digest == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- size_t binder_len = EVP_MD_size(digest);
-
- CBB contents, identity, ticket, binders, binder;
- if (!CBB_add_u16(out, TLSEXT_TYPE_pre_shared_key) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &identity) ||
- !CBB_add_u16_length_prefixed(&identity, &ticket) ||
- !CBB_add_bytes(&ticket, ssl->session->tlsext_tick,
- ssl->session->tlsext_ticklen) ||
- !CBB_add_u32(&identity, obfuscated_ticket_age) ||
- !CBB_add_u16_length_prefixed(&contents, &binders) ||
- !CBB_add_u8_length_prefixed(&binders, &binder) ||
- !CBB_add_bytes(&binder, zero_binder, binder_len)) {
- return 0;
- }
-
- hs->needs_psk_binder = 1;
- return CBB_flush(out);
- }
-
- int ssl_ext_pre_shared_key_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- uint16_t psk_id;
- if (!CBS_get_u16(contents, &psk_id) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* We only advertise one PSK identity, so the only legal index is zero. */
- if (psk_id != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND);
- *out_alert = SSL_AD_UNKNOWN_PSK_IDENTITY;
- return 0;
- }
-
- return 1;
- }
-
- int ssl_ext_pre_shared_key_parse_clienthello(
- SSL_HANDSHAKE *hs, CBS *out_ticket, CBS *out_binders,
- uint32_t *out_obfuscated_ticket_age, uint8_t *out_alert, CBS *contents) {
- /* We only process the first PSK identity since we don't support pure PSK. */
- CBS identities, binders;
- if (!CBS_get_u16_length_prefixed(contents, &identities) ||
- !CBS_get_u16_length_prefixed(&identities, out_ticket) ||
- !CBS_get_u32(&identities, out_obfuscated_ticket_age) ||
- !CBS_get_u16_length_prefixed(contents, &binders) ||
- CBS_len(&binders) == 0 ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- *out_binders = binders;
-
- /* Check the syntax of the remaining identities, but do not process them. */
- size_t num_identities = 1;
- while (CBS_len(&identities) != 0) {
- CBS unused_ticket;
- uint32_t unused_obfuscated_ticket_age;
- if (!CBS_get_u16_length_prefixed(&identities, &unused_ticket) ||
- !CBS_get_u32(&identities, &unused_obfuscated_ticket_age)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- num_identities++;
- }
-
- /* Check the syntax of the binders. The value will be checked later if
- * resuming. */
- size_t num_binders = 0;
- while (CBS_len(&binders) != 0) {
- CBS binder;
- if (!CBS_get_u8_length_prefixed(&binders, &binder)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- num_binders++;
- }
-
- if (num_identities != num_binders) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_BINDER_COUNT_MISMATCH);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- int ssl_ext_pre_shared_key_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ssl->s3->session_reused) {
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_pre_shared_key) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- /* We only consider the first identity for resumption */
- !CBB_add_u16(&contents, 0) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Pre-Shared Key Exchange Modes
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-18#section-4.2.7 */
-
- static int ext_psk_key_exchange_modes_add_clienthello(SSL_HANDSHAKE *hs,
- CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version < TLS1_3_VERSION) {
- return 1;
- }
-
- CBB contents, ke_modes;
- if (!CBB_add_u16(out, TLSEXT_TYPE_psk_key_exchange_modes) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &ke_modes) ||
- !CBB_add_u8(&ke_modes, SSL_PSK_DHE_KE)) {
- return 0;
- }
-
- return CBB_flush(out);
- }
-
- static int ext_psk_key_exchange_modes_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS ke_modes;
- if (!CBS_get_u8_length_prefixed(contents, &ke_modes) ||
- CBS_len(&ke_modes) == 0 ||
- CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* We only support tickets with PSK_DHE_KE. */
- hs->accept_psk_mode = OPENSSL_memchr(CBS_data(&ke_modes), SSL_PSK_DHE_KE,
- CBS_len(&ke_modes)) != NULL;
-
- return 1;
- }
-
-
- /* Early Data Indication
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-18#section-4.2.8 */
-
- static int ext_early_data_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t session_version;
- if (ssl->session == NULL ||
- !ssl->method->version_from_wire(&session_version,
- ssl->session->ssl_version) ||
- session_version < TLS1_3_VERSION ||
- ssl->session->ticket_max_early_data == 0 ||
- hs->received_hello_retry_request ||
- !ssl->cert->enable_early_data) {
- return 1;
- }
-
- hs->early_data_offered = 1;
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_early_data) ||
- !CBB_add_u16(out, 0) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_early_data_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert, CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- if (!ssl->s3->session_reused) {
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- return 0;
- }
-
- ssl->early_data_accepted = 1;
- return 1;
- }
-
- static int ext_early_data_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert, CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL ||
- ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- hs->early_data_offered = 1;
- return 1;
- }
-
- static int ext_early_data_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ssl->early_data_accepted) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_early_data) ||
- !CBB_add_u16(out, 0) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Key Share
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-16#section-4.2.5 */
-
- static int ext_key_share_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version < TLS1_3_VERSION) {
- return 1;
- }
-
- CBB contents, kse_bytes;
- if (!CBB_add_u16(out, TLSEXT_TYPE_key_share) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &kse_bytes)) {
- return 0;
- }
-
- uint16_t group_id = hs->retry_group;
- if (hs->received_hello_retry_request) {
- /* We received a HelloRetryRequest without a new curve, so there is no new
- * share to append. Leave |ecdh_ctx| as-is. */
- if (group_id == 0 &&
- !CBB_add_bytes(&kse_bytes, hs->key_share_bytes,
- hs->key_share_bytes_len)) {
- return 0;
- }
- OPENSSL_free(hs->key_share_bytes);
- hs->key_share_bytes = NULL;
- hs->key_share_bytes_len = 0;
- if (group_id == 0) {
- return CBB_flush(out);
- }
- } else {
- /* Add a fake group. See draft-davidben-tls-grease-01. */
- if (ssl->ctx->grease_enabled &&
- (!CBB_add_u16(&kse_bytes,
- ssl_get_grease_value(ssl, ssl_grease_group)) ||
- !CBB_add_u16(&kse_bytes, 1 /* length */) ||
- !CBB_add_u8(&kse_bytes, 0 /* one byte key share */))) {
- return 0;
- }
-
- /* Predict the most preferred group. */
- const uint16_t *groups;
- size_t groups_len;
- tls1_get_grouplist(ssl, &groups, &groups_len);
- if (groups_len == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_GROUPS_SPECIFIED);
- return 0;
- }
-
- group_id = groups[0];
- }
-
- CBB key_exchange;
- if (!CBB_add_u16(&kse_bytes, group_id) ||
- !CBB_add_u16_length_prefixed(&kse_bytes, &key_exchange) ||
- !SSL_ECDH_CTX_init(&hs->ecdh_ctx, group_id) ||
- !SSL_ECDH_CTX_offer(&hs->ecdh_ctx, &key_exchange) ||
- !CBB_flush(&kse_bytes)) {
- return 0;
- }
-
- if (!hs->received_hello_retry_request) {
- /* Save the contents of the extension to repeat it in the second
- * ClientHello. */
- hs->key_share_bytes_len = CBB_len(&kse_bytes);
- hs->key_share_bytes = BUF_memdup(CBB_data(&kse_bytes), CBB_len(&kse_bytes));
- if (hs->key_share_bytes == NULL) {
- return 0;
- }
- }
-
- return CBB_flush(out);
- }
-
- int ssl_ext_key_share_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t **out_secret,
- size_t *out_secret_len,
- uint8_t *out_alert, CBS *contents) {
- CBS peer_key;
- uint16_t group_id;
- if (!CBS_get_u16(contents, &group_id) ||
- !CBS_get_u16_length_prefixed(contents, &peer_key) ||
- CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- if (SSL_ECDH_CTX_get_id(&hs->ecdh_ctx) != group_id) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
- return 0;
- }
-
- if (!SSL_ECDH_CTX_finish(&hs->ecdh_ctx, out_secret, out_secret_len, out_alert,
- CBS_data(&peer_key), CBS_len(&peer_key))) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- hs->new_session->group_id = group_id;
- SSL_ECDH_CTX_cleanup(&hs->ecdh_ctx);
- return 1;
- }
-
- int ssl_ext_key_share_parse_clienthello(SSL_HANDSHAKE *hs, int *out_found,
- uint8_t **out_secret,
- size_t *out_secret_len,
- uint8_t *out_alert, CBS *contents) {
- uint16_t group_id;
- CBS key_shares;
- if (!tls1_get_shared_group(hs, &group_id)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_GROUP);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
-
- if (!CBS_get_u16_length_prefixed(contents, &key_shares) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- return 0;
- }
-
- /* Find the corresponding key share. */
- int found = 0;
- CBS peer_key;
- while (CBS_len(&key_shares) > 0) {
- uint16_t id;
- CBS peer_key_tmp;
- if (!CBS_get_u16(&key_shares, &id) ||
- !CBS_get_u16_length_prefixed(&key_shares, &peer_key_tmp)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- return 0;
- }
-
- if (id == group_id) {
- if (found) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_KEY_SHARE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- found = 1;
- peer_key = peer_key_tmp;
- /* Continue parsing the structure to keep peers honest. */
- }
- }
-
- if (!found) {
- *out_found = 0;
- *out_secret = NULL;
- *out_secret_len = 0;
- return 1;
- }
-
- /* Compute the DH secret. */
- uint8_t *secret = NULL;
- size_t secret_len;
- SSL_ECDH_CTX group;
- OPENSSL_memset(&group, 0, sizeof(SSL_ECDH_CTX));
- CBB public_key;
- if (!CBB_init(&public_key, 32) ||
- !SSL_ECDH_CTX_init(&group, group_id) ||
- !SSL_ECDH_CTX_accept(&group, &public_key, &secret, &secret_len, out_alert,
- CBS_data(&peer_key), CBS_len(&peer_key)) ||
- !CBB_finish(&public_key, &hs->ecdh_public_key,
- &hs->ecdh_public_key_len)) {
- OPENSSL_free(secret);
- SSL_ECDH_CTX_cleanup(&group);
- CBB_cleanup(&public_key);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- SSL_ECDH_CTX_cleanup(&group);
-
- *out_secret = secret;
- *out_secret_len = secret_len;
- *out_found = 1;
- return 1;
- }
-
- int ssl_ext_key_share_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- uint16_t group_id;
- CBB kse_bytes, public_key;
- if (!tls1_get_shared_group(hs, &group_id) ||
- !CBB_add_u16(out, TLSEXT_TYPE_key_share) ||
- !CBB_add_u16_length_prefixed(out, &kse_bytes) ||
- !CBB_add_u16(&kse_bytes, group_id) ||
- !CBB_add_u16_length_prefixed(&kse_bytes, &public_key) ||
- !CBB_add_bytes(&public_key, hs->ecdh_public_key,
- hs->ecdh_public_key_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- OPENSSL_free(hs->ecdh_public_key);
- hs->ecdh_public_key = NULL;
- hs->ecdh_public_key_len = 0;
-
- hs->new_session->group_id = group_id;
- return 1;
- }
-
-
- /* Supported Versions
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-16#section-4.2.1 */
-
- static int ext_supported_versions_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version <= TLS1_2_VERSION) {
- return 1;
- }
-
- CBB contents, versions;
- if (!CBB_add_u16(out, TLSEXT_TYPE_supported_versions) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &versions)) {
- return 0;
- }
-
- /* Add a fake version. See draft-davidben-tls-grease-01. */
- if (ssl->ctx->grease_enabled &&
- !CBB_add_u16(&versions, ssl_get_grease_value(ssl, ssl_grease_version))) {
- return 0;
- }
-
- for (uint16_t version = max_version; version >= min_version; version--) {
- if (!CBB_add_u16(&versions, ssl->method->version_to_wire(version))) {
- return 0;
- }
- }
-
- if (!CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Cookie
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-16#section-4.2.2 */
-
- static int ext_cookie_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- if (hs->cookie == NULL) {
- return 1;
- }
-
- CBB contents, cookie;
- if (!CBB_add_u16(out, TLSEXT_TYPE_cookie) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &cookie) ||
- !CBB_add_bytes(&cookie, hs->cookie, hs->cookie_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- /* The cookie is no longer needed in memory. */
- OPENSSL_free(hs->cookie);
- hs->cookie = NULL;
- hs->cookie_len = 0;
- return 1;
- }
-
-
- /* Negotiated Groups
- *
- * https://tools.ietf.org/html/rfc4492#section-5.1.2
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-16#section-4.2.4 */
-
- static int ext_supported_groups_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- CBB contents, groups_bytes;
- if (!CBB_add_u16(out, TLSEXT_TYPE_supported_groups) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &groups_bytes)) {
- return 0;
- }
-
- /* Add a fake group. See draft-davidben-tls-grease-01. */
- if (ssl->ctx->grease_enabled &&
- !CBB_add_u16(&groups_bytes,
- ssl_get_grease_value(ssl, ssl_grease_group))) {
- return 0;
- }
-
- const uint16_t *groups;
- size_t groups_len;
- tls1_get_grouplist(ssl, &groups, &groups_len);
-
- for (size_t i = 0; i < groups_len; i++) {
- if (!CBB_add_u16(&groups_bytes, groups[i])) {
- return 0;
- }
- }
-
- return CBB_flush(out);
- }
-
- static int ext_supported_groups_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- /* This extension is not expected to be echoed by servers in TLS 1.2, but some
- * BigIP servers send it nonetheless, so do not enforce this. */
- return 1;
- }
-
- static int ext_supported_groups_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS supported_group_list;
- if (!CBS_get_u16_length_prefixed(contents, &supported_group_list) ||
- CBS_len(&supported_group_list) == 0 ||
- (CBS_len(&supported_group_list) & 1) != 0 ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- hs->peer_supported_group_list =
- OPENSSL_malloc(CBS_len(&supported_group_list));
- if (hs->peer_supported_group_list == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- const size_t num_groups = CBS_len(&supported_group_list) / 2;
- for (size_t i = 0; i < num_groups; i++) {
- if (!CBS_get_u16(&supported_group_list,
- &hs->peer_supported_group_list[i])) {
- goto err;
- }
- }
-
- assert(CBS_len(&supported_group_list) == 0);
- hs->peer_supported_group_list_len = num_groups;
-
- return 1;
-
- err:
- OPENSSL_free(hs->peer_supported_group_list);
- hs->peer_supported_group_list = NULL;
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- static int ext_supported_groups_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- /* Servers don't echo this extension. */
- return 1;
- }
-
-
- /* kExtensions contains all the supported extensions. */
- static const struct tls_extension kExtensions[] = {
- {
- TLSEXT_TYPE_renegotiate,
- NULL,
- ext_ri_add_clienthello,
- ext_ri_parse_serverhello,
- ext_ri_parse_clienthello,
- ext_ri_add_serverhello,
- },
- {
- TLSEXT_TYPE_server_name,
- NULL,
- ext_sni_add_clienthello,
- ext_sni_parse_serverhello,
- ext_sni_parse_clienthello,
- ext_sni_add_serverhello,
- },
- {
- TLSEXT_TYPE_extended_master_secret,
- NULL,
- ext_ems_add_clienthello,
- ext_ems_parse_serverhello,
- ext_ems_parse_clienthello,
- ext_ems_add_serverhello,
- },
- {
- TLSEXT_TYPE_session_ticket,
- NULL,
- ext_ticket_add_clienthello,
- ext_ticket_parse_serverhello,
- /* Ticket extension client parsing is handled in ssl_session.c */
- ignore_parse_clienthello,
- ext_ticket_add_serverhello,
- },
- {
- TLSEXT_TYPE_signature_algorithms,
- NULL,
- ext_sigalgs_add_clienthello,
- forbid_parse_serverhello,
- ext_sigalgs_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_status_request,
- NULL,
- ext_ocsp_add_clienthello,
- ext_ocsp_parse_serverhello,
- ext_ocsp_parse_clienthello,
- ext_ocsp_add_serverhello,
- },
- {
- TLSEXT_TYPE_next_proto_neg,
- NULL,
- ext_npn_add_clienthello,
- ext_npn_parse_serverhello,
- ext_npn_parse_clienthello,
- ext_npn_add_serverhello,
- },
- {
- TLSEXT_TYPE_certificate_timestamp,
- NULL,
- ext_sct_add_clienthello,
- ext_sct_parse_serverhello,
- ext_sct_parse_clienthello,
- ext_sct_add_serverhello,
- },
- {
- TLSEXT_TYPE_application_layer_protocol_negotiation,
- NULL,
- ext_alpn_add_clienthello,
- ext_alpn_parse_serverhello,
- /* ALPN is negotiated late in |ssl_negotiate_alpn|. */
- ignore_parse_clienthello,
- ext_alpn_add_serverhello,
- },
- {
- TLSEXT_TYPE_channel_id,
- ext_channel_id_init,
- ext_channel_id_add_clienthello,
- ext_channel_id_parse_serverhello,
- ext_channel_id_parse_clienthello,
- ext_channel_id_add_serverhello,
- },
- {
- TLSEXT_TYPE_srtp,
- ext_srtp_init,
- ext_srtp_add_clienthello,
- ext_srtp_parse_serverhello,
- ext_srtp_parse_clienthello,
- ext_srtp_add_serverhello,
- },
- {
- TLSEXT_TYPE_ec_point_formats,
- NULL,
- ext_ec_point_add_clienthello,
- ext_ec_point_parse_serverhello,
- ext_ec_point_parse_clienthello,
- ext_ec_point_add_serverhello,
- },
- {
- TLSEXT_TYPE_key_share,
- NULL,
- ext_key_share_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_psk_key_exchange_modes,
- NULL,
- ext_psk_key_exchange_modes_add_clienthello,
- forbid_parse_serverhello,
- ext_psk_key_exchange_modes_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_early_data,
- NULL,
- ext_early_data_add_clienthello,
- ext_early_data_parse_serverhello,
- ext_early_data_parse_clienthello,
- ext_early_data_add_serverhello,
- },
- {
- TLSEXT_TYPE_supported_versions,
- NULL,
- ext_supported_versions_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_cookie,
- NULL,
- ext_cookie_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- /* The final extension must be non-empty. WebSphere Application Server 7.0 is
- * intolerant to the last extension being zero-length. See
- * https://crbug.com/363583. */
- {
- TLSEXT_TYPE_supported_groups,
- NULL,
- ext_supported_groups_add_clienthello,
- ext_supported_groups_parse_serverhello,
- ext_supported_groups_parse_clienthello,
- ext_supported_groups_add_serverhello,
- },
- };
-
- #define kNumExtensions (sizeof(kExtensions) / sizeof(struct tls_extension))
-
- OPENSSL_COMPILE_ASSERT(kNumExtensions <=
- sizeof(((SSL_HANDSHAKE *)NULL)->extensions.sent) * 8,
- too_many_extensions_for_sent_bitset);
- OPENSSL_COMPILE_ASSERT(
- kNumExtensions <= sizeof(((SSL_HANDSHAKE *)NULL)->extensions.received) * 8,
- too_many_extensions_for_received_bitset);
-
- static const struct tls_extension *tls_extension_find(uint32_t *out_index,
- uint16_t value) {
- unsigned i;
- for (i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].value == value) {
- *out_index = i;
- return &kExtensions[i];
- }
- }
-
- return NULL;
- }
-
- int SSL_extension_supported(unsigned extension_value) {
- uint32_t index;
- return extension_value == TLSEXT_TYPE_padding ||
- tls_extension_find(&index, extension_value) != NULL;
- }
-
- int ssl_add_clienthello_tlsext(SSL_HANDSHAKE *hs, CBB *out, size_t header_len) {
- SSL *const ssl = hs->ssl;
- /* Don't add extensions for SSLv3 unless doing secure renegotiation. */
- if (hs->client_version == SSL3_VERSION &&
- !ssl->s3->send_connection_binding) {
- return 1;
- }
-
- CBB extensions;
- if (!CBB_add_u16_length_prefixed(out, &extensions)) {
- goto err;
- }
-
- hs->extensions.sent = 0;
- hs->custom_extensions.sent = 0;
-
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].init != NULL) {
- kExtensions[i].init(hs);
- }
- }
-
- uint16_t grease_ext1 = 0;
- if (ssl->ctx->grease_enabled) {
- /* Add a fake empty extension. See draft-davidben-tls-grease-01. */
- grease_ext1 = ssl_get_grease_value(ssl, ssl_grease_extension1);
- if (!CBB_add_u16(&extensions, grease_ext1) ||
- !CBB_add_u16(&extensions, 0 /* zero length */)) {
- goto err;
- }
- }
-
- for (size_t i = 0; i < kNumExtensions; i++) {
- const size_t len_before = CBB_len(&extensions);
- if (!kExtensions[i].add_clienthello(hs, &extensions)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_ADDING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)kExtensions[i].value);
- goto err;
- }
-
- if (CBB_len(&extensions) != len_before) {
- hs->extensions.sent |= (1u << i);
- }
- }
-
- if (!custom_ext_add_clienthello(hs, &extensions)) {
- goto err;
- }
-
- if (ssl->ctx->grease_enabled) {
- /* Add a fake non-empty extension. See draft-davidben-tls-grease-01. */
- uint16_t grease_ext2 = ssl_get_grease_value(ssl, ssl_grease_extension2);
-
- /* The two fake extensions must not have the same value. GREASE values are
- * of the form 0x1a1a, 0x2a2a, 0x3a3a, etc., so XOR to generate a different
- * one. */
- if (grease_ext1 == grease_ext2) {
- grease_ext2 ^= 0x1010;
- }
-
- if (!CBB_add_u16(&extensions, grease_ext2) ||
- !CBB_add_u16(&extensions, 1 /* one byte length */) ||
- !CBB_add_u8(&extensions, 0 /* single zero byte as contents */)) {
- goto err;
- }
- }
-
- if (!SSL_is_dtls(ssl)) {
- size_t psk_extension_len = ext_pre_shared_key_clienthello_length(hs);
- header_len += 2 + CBB_len(&extensions) + psk_extension_len;
- if (header_len > 0xff && header_len < 0x200) {
- /* Add padding to workaround bugs in F5 terminators. See RFC 7685.
- *
- * NB: because this code works out the length of all existing extensions
- * it MUST always appear last. */
- size_t padding_len = 0x200 - header_len;
- /* Extensions take at least four bytes to encode. Always include at least
- * one byte of data if including the extension. WebSphere Application
- * Server 7.0 is intolerant to the last extension being zero-length. See
- * https://crbug.com/363583. */
- if (padding_len >= 4 + 1) {
- padding_len -= 4;
- } else {
- padding_len = 1;
- }
-
- uint8_t *padding_bytes;
- if (!CBB_add_u16(&extensions, TLSEXT_TYPE_padding) ||
- !CBB_add_u16(&extensions, padding_len) ||
- !CBB_add_space(&extensions, &padding_bytes, padding_len)) {
- goto err;
- }
-
- OPENSSL_memset(padding_bytes, 0, padding_len);
- }
- }
-
- /* The PSK extension must be last, including after the padding. */
- if (!ext_pre_shared_key_add_clienthello(hs, &extensions)) {
- goto err;
- }
-
- /* Discard empty extensions blocks. */
- if (CBB_len(&extensions) == 0) {
- CBB_discard_child(out);
- }
-
- return CBB_flush(out);
-
- err:
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- int ssl_add_serverhello_tlsext(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- CBB extensions;
- if (!CBB_add_u16_length_prefixed(out, &extensions)) {
- goto err;
- }
-
- for (unsigned i = 0; i < kNumExtensions; i++) {
- if (!(hs->extensions.received & (1u << i))) {
- /* Don't send extensions that were not received. */
- continue;
- }
-
- if (!kExtensions[i].add_serverhello(hs, &extensions)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_ADDING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)kExtensions[i].value);
- goto err;
- }
- }
-
- if (!custom_ext_add_serverhello(hs, &extensions)) {
- goto err;
- }
-
- /* Discard empty extensions blocks before TLS 1.3. */
- if (ssl3_protocol_version(ssl) < TLS1_3_VERSION &&
- CBB_len(&extensions) == 0) {
- CBB_discard_child(out);
- }
-
- return CBB_flush(out);
-
- err:
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- static int ssl_scan_clienthello_tlsext(SSL_HANDSHAKE *hs,
- const SSL_CLIENT_HELLO *client_hello,
- int *out_alert) {
- SSL *const ssl = hs->ssl;
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].init != NULL) {
- kExtensions[i].init(hs);
- }
- }
-
- hs->extensions.received = 0;
- hs->custom_extensions.received = 0;
-
- CBS extensions;
- CBS_init(&extensions, client_hello->extensions, client_hello->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)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* RFC 5746 made the existence of extensions in SSL 3.0 somewhat
- * ambiguous. Ignore all but the renegotiation_info extension. */
- if (ssl->version == SSL3_VERSION && type != TLSEXT_TYPE_renegotiate) {
- continue;
- }
-
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
-
- if (ext == NULL) {
- if (!custom_ext_parse_clienthello(hs, out_alert, type, &extension)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- return 0;
- }
- continue;
- }
-
- hs->extensions.received |= (1u << ext_index);
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!ext->parse_clienthello(hs, &alert, &extension)) {
- *out_alert = alert;
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)type);
- return 0;
- }
- }
-
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (hs->extensions.received & (1u << i)) {
- continue;
- }
-
- CBS *contents = NULL, fake_contents;
- static const uint8_t kFakeRenegotiateExtension[] = {0};
- if (kExtensions[i].value == TLSEXT_TYPE_renegotiate &&
- ssl_client_cipher_list_contains_cipher(client_hello,
- SSL3_CK_SCSV & 0xffff)) {
- /* The renegotiation SCSV was received so pretend that we received a
- * renegotiation extension. */
- CBS_init(&fake_contents, kFakeRenegotiateExtension,
- sizeof(kFakeRenegotiateExtension));
- contents = &fake_contents;
- hs->extensions.received |= (1u << i);
- }
-
- /* Extension wasn't observed so call the callback with a NULL
- * parameter. */
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!kExtensions[i].parse_clienthello(hs, &alert, contents)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)kExtensions[i].value);
- *out_alert = alert;
- return 0;
- }
- }
-
- return 1;
- }
-
- int ssl_parse_clienthello_tlsext(SSL_HANDSHAKE *hs,
- const SSL_CLIENT_HELLO *client_hello) {
- SSL *const ssl = hs->ssl;
- int alert = SSL_AD_DECODE_ERROR;
- if (ssl_scan_clienthello_tlsext(hs, client_hello, &alert) <= 0) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return 0;
- }
-
- if (ssl_check_clienthello_tlsext(hs) <= 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_TLSEXT);
- return 0;
- }
-
- return 1;
- }
-
- static int ssl_scan_serverhello_tlsext(SSL_HANDSHAKE *hs, CBS *cbs,
- int *out_alert) {
- SSL *const ssl = hs->ssl;
- /* Before TLS 1.3, ServerHello extensions blocks may be omitted if empty. */
- if (CBS_len(cbs) == 0 && ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- return 1;
- }
-
- /* Decode the extensions block and check it is valid. */
- CBS extensions;
- if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
- !tls1_check_duplicate_extensions(&extensions)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- uint32_t received = 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;
- }
-
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
-
- if (ext == NULL) {
- if (!custom_ext_parse_serverhello(hs, out_alert, type, &extension)) {
- return 0;
- }
- continue;
- }
-
- OPENSSL_COMPILE_ASSERT(kNumExtensions <= sizeof(hs->extensions.sent) * 8,
- too_many_bits);
-
- if (!(hs->extensions.sent & (1u << ext_index)) &&
- type != TLSEXT_TYPE_renegotiate) {
- /* If the extension was never sent then it is illegal, except for the
- * renegotiation extension which, in SSL 3.0, is signaled via SCSV. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- ERR_add_error_dataf("extension :%u", (unsigned)type);
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- return 0;
- }
-
- received |= (1u << ext_index);
-
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!ext->parse_serverhello(hs, &alert, &extension)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)type);
- *out_alert = alert;
- return 0;
- }
- }
-
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (!(received & (1u << i))) {
- /* Extension wasn't observed so call the callback with a NULL
- * parameter. */
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!kExtensions[i].parse_serverhello(hs, &alert, NULL)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)kExtensions[i].value);
- *out_alert = alert;
- return 0;
- }
- }
- }
-
- return 1;
- }
-
- static int ssl_check_clienthello_tlsext(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- int ret = SSL_TLSEXT_ERR_NOACK;
- int al = SSL_AD_UNRECOGNIZED_NAME;
-
- if (ssl->ctx->tlsext_servername_callback != 0) {
- ret = ssl->ctx->tlsext_servername_callback(ssl, &al,
- ssl->ctx->tlsext_servername_arg);
- } else if (ssl->session_ctx->tlsext_servername_callback != 0) {
- ret = ssl->session_ctx->tlsext_servername_callback(
- ssl, &al, ssl->session_ctx->tlsext_servername_arg);
- }
-
- switch (ret) {
- case SSL_TLSEXT_ERR_ALERT_FATAL:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
- return -1;
-
- case SSL_TLSEXT_ERR_NOACK:
- hs->should_ack_sni = 0;
- return 1;
-
- default:
- return 1;
- }
- }
-
- int ssl_parse_serverhello_tlsext(SSL_HANDSHAKE *hs, CBS *cbs) {
- SSL *const ssl = hs->ssl;
- int alert = SSL_AD_DECODE_ERROR;
- if (ssl_scan_serverhello_tlsext(hs, cbs, &alert) <= 0) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return 0;
- }
-
- return 1;
- }
-
- static enum ssl_ticket_aead_result_t
- ssl_decrypt_ticket_with_cipher_ctx(SSL *ssl, uint8_t **out, size_t *out_len,
- int *out_renew_ticket, const uint8_t *ticket,
- size_t ticket_len) {
- enum ssl_ticket_aead_result_t ret = ssl_ticket_aead_ignore_ticket;
- const SSL_CTX *const ssl_ctx = ssl->session_ctx;
- uint8_t *plaintext = NULL;
-
- HMAC_CTX hmac_ctx;
- HMAC_CTX_init(&hmac_ctx);
- EVP_CIPHER_CTX cipher_ctx;
- EVP_CIPHER_CTX_init(&cipher_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 (ticket_len < SSL_TICKET_KEY_NAME_LEN + EVP_MAX_IV_LENGTH) {
- goto out;
- }
- const uint8_t *iv = ticket + SSL_TICKET_KEY_NAME_LEN;
-
- if (ssl_ctx->tlsext_ticket_key_cb != NULL) {
- int cb_ret = ssl_ctx->tlsext_ticket_key_cb(
- ssl, (uint8_t *)ticket /* name */, (uint8_t *)iv, &cipher_ctx,
- &hmac_ctx, 0 /* decrypt */);
- if (cb_ret < 0) {
- ret = ssl_ticket_aead_error;
- goto out;
- } else if (cb_ret == 0) {
- goto out;
- } else if (cb_ret == 2) {
- *out_renew_ticket = 1;
- }
- } else {
- /* Check the key name matches. */
- if (OPENSSL_memcmp(ticket, ssl_ctx->tlsext_tick_key_name,
- SSL_TICKET_KEY_NAME_LEN) != 0) {
- goto out;
- }
- if (!HMAC_Init_ex(&hmac_ctx, ssl_ctx->tlsext_tick_hmac_key,
- sizeof(ssl_ctx->tlsext_tick_hmac_key), tlsext_tick_md(),
- NULL) ||
- !EVP_DecryptInit_ex(&cipher_ctx, EVP_aes_128_cbc(), NULL,
- ssl_ctx->tlsext_tick_aes_key, iv)) {
- ret = ssl_ticket_aead_error;
- goto out;
- }
- }
- size_t iv_len = EVP_CIPHER_CTX_iv_length(&cipher_ctx);
-
- /* Check the MAC at the end of the ticket. */
- uint8_t mac[EVP_MAX_MD_SIZE];
- size_t mac_len = HMAC_size(&hmac_ctx);
- if (ticket_len < SSL_TICKET_KEY_NAME_LEN + iv_len + 1 + mac_len) {
- /* The ticket must be large enough for key name, IV, data, and MAC. */
- goto out;
- }
- HMAC_Update(&hmac_ctx, ticket, ticket_len - mac_len);
- HMAC_Final(&hmac_ctx, mac, NULL);
- int mac_ok =
- CRYPTO_memcmp(mac, ticket + (ticket_len - mac_len), mac_len) == 0;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- mac_ok = 1;
- #endif
- if (!mac_ok) {
- goto out;
- }
-
- /* Decrypt the session data. */
- const uint8_t *ciphertext = ticket + SSL_TICKET_KEY_NAME_LEN + iv_len;
- size_t ciphertext_len = ticket_len - SSL_TICKET_KEY_NAME_LEN - iv_len -
- mac_len;
- plaintext = OPENSSL_malloc(ciphertext_len);
- if (plaintext == NULL) {
- ret = ssl_ticket_aead_error;
- goto out;
- }
- size_t plaintext_len;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- OPENSSL_memcpy(plaintext, ciphertext, ciphertext_len);
- plaintext_len = ciphertext_len;
- #else
- if (ciphertext_len >= INT_MAX) {
- goto out;
- }
- int len1, len2;
- if (!EVP_DecryptUpdate(&cipher_ctx, plaintext, &len1, ciphertext,
- (int)ciphertext_len) ||
- !EVP_DecryptFinal_ex(&cipher_ctx, plaintext + len1, &len2)) {
- ERR_clear_error();
- goto out;
- }
- plaintext_len = (size_t)(len1) + len2;
- #endif
-
- *out = plaintext;
- plaintext = NULL;
- *out_len = plaintext_len;
- ret = ssl_ticket_aead_success;
-
- out:
- OPENSSL_free(plaintext);
- HMAC_CTX_cleanup(&hmac_ctx);
- EVP_CIPHER_CTX_cleanup(&cipher_ctx);
- return ret;
- }
-
- static enum ssl_ticket_aead_result_t ssl_decrypt_ticket_with_method(
- SSL *ssl, uint8_t **out, size_t *out_len, int *out_renew_ticket,
- const uint8_t *ticket, size_t ticket_len) {
- uint8_t *plaintext = OPENSSL_malloc(ticket_len);
- if (plaintext == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- return ssl_ticket_aead_error;
- }
-
- size_t plaintext_len;
- const enum ssl_ticket_aead_result_t result =
- ssl->session_ctx->ticket_aead_method->open(
- ssl, plaintext, &plaintext_len, ticket_len, ticket, ticket_len);
-
- if (result == ssl_ticket_aead_success) {
- *out = plaintext;
- plaintext = NULL;
- *out_len = plaintext_len;
- }
-
- OPENSSL_free(plaintext);
- return result;
- }
-
- enum ssl_ticket_aead_result_t ssl_process_ticket(
- SSL *ssl, SSL_SESSION **out_session, int *out_renew_ticket,
- const uint8_t *ticket, size_t ticket_len, const uint8_t *session_id,
- size_t session_id_len) {
- *out_renew_ticket = 0;
- *out_session = NULL;
-
- if ((SSL_get_options(ssl) & SSL_OP_NO_TICKET) ||
- session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
- return ssl_ticket_aead_ignore_ticket;
- }
-
- uint8_t *plaintext = NULL;
- size_t plaintext_len;
- enum ssl_ticket_aead_result_t result;
- if (ssl->session_ctx->ticket_aead_method != NULL) {
- result = ssl_decrypt_ticket_with_method(
- ssl, &plaintext, &plaintext_len, out_renew_ticket, ticket, ticket_len);
- } else {
- result = ssl_decrypt_ticket_with_cipher_ctx(
- ssl, &plaintext, &plaintext_len, out_renew_ticket, ticket, ticket_len);
- }
-
- if (result != ssl_ticket_aead_success) {
- return result;
- }
-
- /* Decode the session. */
- SSL_SESSION *session =
- SSL_SESSION_from_bytes(plaintext, plaintext_len, ssl->ctx);
- OPENSSL_free(plaintext);
-
- if (session == NULL) {
- ERR_clear_error(); /* Don't leave an error on the queue. */
- return ssl_ticket_aead_ignore_ticket;
- }
-
- /* Copy the client's session ID into the new session, to denote the ticket has
- * been accepted. */
- OPENSSL_memcpy(session->session_id, session_id, session_id_len);
- session->session_id_length = session_id_len;
-
- *out_session = session;
- return ssl_ticket_aead_success;
- }
-
- int tls1_parse_peer_sigalgs(SSL_HANDSHAKE *hs, const CBS *in_sigalgs) {
- /* Extension ignored for inappropriate versions */
- if (ssl3_protocol_version(hs->ssl) < TLS1_2_VERSION) {
- return 1;
- }
-
- OPENSSL_free(hs->peer_sigalgs);
- hs->peer_sigalgs = NULL;
- hs->num_peer_sigalgs = 0;
-
- size_t num_sigalgs = CBS_len(in_sigalgs);
- if (num_sigalgs % 2 != 0) {
- return 0;
- }
- num_sigalgs /= 2;
-
- /* supported_signature_algorithms in the certificate request is
- * allowed to be empty. */
- if (num_sigalgs == 0) {
- return 1;
- }
-
- /* This multiplication doesn't overflow because sizeof(uint16_t) is two
- * and we just divided |num_sigalgs| by two. */
- hs->peer_sigalgs = OPENSSL_malloc(num_sigalgs * sizeof(uint16_t));
- if (hs->peer_sigalgs == NULL) {
- return 0;
- }
- hs->num_peer_sigalgs = num_sigalgs;
-
- CBS sigalgs;
- CBS_init(&sigalgs, CBS_data(in_sigalgs), CBS_len(in_sigalgs));
- for (size_t i = 0; i < num_sigalgs; i++) {
- if (!CBS_get_u16(&sigalgs, &hs->peer_sigalgs[i])) {
- return 0;
- }
- }
-
- return 1;
- }
-
- int tls1_choose_signature_algorithm(SSL_HANDSHAKE *hs, uint16_t *out) {
- SSL *const ssl = hs->ssl;
- CERT *cert = ssl->cert;
-
- /* Before TLS 1.2, the signature algorithm isn't negotiated as part of the
- * handshake. It is fixed at MD5-SHA1 for RSA and SHA1 for ECDSA. */
- if (ssl3_protocol_version(ssl) < TLS1_2_VERSION) {
- switch (EVP_PKEY_id(hs->local_pubkey)) {
- case EVP_PKEY_RSA:
- *out = SSL_SIGN_RSA_PKCS1_MD5_SHA1;
- return 1;
- case EVP_PKEY_EC:
- *out = SSL_SIGN_ECDSA_SHA1;
- return 1;
- default:
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return 0;
- }
- }
-
- const uint16_t *sigalgs = cert->sigalgs;
- size_t num_sigalgs = cert->num_sigalgs;
- if (sigalgs == NULL) {
- sigalgs = kSignSignatureAlgorithms;
- num_sigalgs = OPENSSL_ARRAY_SIZE(kSignSignatureAlgorithms);
- }
-
- const uint16_t *peer_sigalgs = hs->peer_sigalgs;
- size_t num_peer_sigalgs = hs->num_peer_sigalgs;
- if (num_peer_sigalgs == 0 && ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- /* If the client didn't specify any signature_algorithms extension then
- * we can assume that it supports SHA1. See
- * http://tools.ietf.org/html/rfc5246#section-7.4.1.4.1 */
- static const uint16_t kDefaultPeerAlgorithms[] = {SSL_SIGN_RSA_PKCS1_SHA1,
- SSL_SIGN_ECDSA_SHA1};
- peer_sigalgs = kDefaultPeerAlgorithms;
- num_peer_sigalgs = OPENSSL_ARRAY_SIZE(kDefaultPeerAlgorithms);
- }
-
- for (size_t i = 0; i < num_sigalgs; i++) {
- uint16_t sigalg = sigalgs[i];
- /* SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal value and should never be
- * negotiated. */
- if (sigalg == SSL_SIGN_RSA_PKCS1_MD5_SHA1 ||
- !ssl_private_key_supports_signature_algorithm(hs, sigalgs[i])) {
- continue;
- }
-
- for (size_t j = 0; j < num_peer_sigalgs; j++) {
- if (sigalg == peer_sigalgs[j]) {
- *out = sigalg;
- return 1;
- }
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return 0;
- }
-
- int tls1_verify_channel_id(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- int ret = 0;
- uint16_t extension_type;
- CBS extension, channel_id;
-
- /* A Channel ID handshake message is structured to contain multiple
- * extensions, but the only one that can be present is Channel ID. */
- CBS_init(&channel_id, ssl->init_msg, ssl->init_num);
- if (!CBS_get_u16(&channel_id, &extension_type) ||
- !CBS_get_u16_length_prefixed(&channel_id, &extension) ||
- CBS_len(&channel_id) != 0 ||
- extension_type != TLSEXT_TYPE_channel_id ||
- CBS_len(&extension) != TLSEXT_CHANNEL_ID_SIZE) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
- return 0;
- }
-
- EC_GROUP *p256 = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
- if (!p256) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_P256_SUPPORT);
- return 0;
- }
-
- EC_KEY *key = NULL;
- EC_POINT *point = NULL;
- BIGNUM x, y;
- ECDSA_SIG sig;
- BN_init(&x);
- BN_init(&y);
- sig.r = BN_new();
- sig.s = BN_new();
- if (sig.r == NULL || sig.s == NULL) {
- goto err;
- }
-
- const uint8_t *p = CBS_data(&extension);
- if (BN_bin2bn(p + 0, 32, &x) == NULL ||
- BN_bin2bn(p + 32, 32, &y) == NULL ||
- BN_bin2bn(p + 64, 32, sig.r) == NULL ||
- BN_bin2bn(p + 96, 32, sig.s) == NULL) {
- goto err;
- }
-
- point = EC_POINT_new(p256);
- if (point == NULL ||
- !EC_POINT_set_affine_coordinates_GFp(p256, point, &x, &y, NULL)) {
- goto err;
- }
-
- key = EC_KEY_new();
- if (key == NULL ||
- !EC_KEY_set_group(key, p256) ||
- !EC_KEY_set_public_key(key, point)) {
- goto err;
- }
-
- uint8_t digest[EVP_MAX_MD_SIZE];
- size_t digest_len;
- if (!tls1_channel_id_hash(hs, digest, &digest_len)) {
- goto err;
- }
-
- int sig_ok = ECDSA_do_verify(digest, digest_len, &sig, key);
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- sig_ok = 1;
- #endif
- if (!sig_ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_SIGNATURE_INVALID);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
- ssl->s3->tlsext_channel_id_valid = 0;
- goto err;
- }
-
- OPENSSL_memcpy(ssl->s3->tlsext_channel_id, p, 64);
- ret = 1;
-
- err:
- BN_free(&x);
- BN_free(&y);
- BN_free(sig.r);
- BN_free(sig.s);
- EC_KEY_free(key);
- EC_POINT_free(point);
- EC_GROUP_free(p256);
- return ret;
- }
-
- int tls1_write_channel_id(SSL_HANDSHAKE *hs, CBB *cbb) {
- SSL *const ssl = hs->ssl;
- uint8_t digest[EVP_MAX_MD_SIZE];
- size_t digest_len;
- if (!tls1_channel_id_hash(hs, digest, &digest_len)) {
- return 0;
- }
-
- EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(ssl->tlsext_channel_id_private);
- if (ec_key == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- int ret = 0;
- BIGNUM *x = BN_new();
- BIGNUM *y = BN_new();
- ECDSA_SIG *sig = NULL;
- if (x == NULL || y == NULL ||
- !EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(ec_key),
- EC_KEY_get0_public_key(ec_key),
- x, y, NULL)) {
- goto err;
- }
-
- sig = ECDSA_do_sign(digest, digest_len, ec_key);
- if (sig == NULL) {
- goto err;
- }
-
- CBB child;
- if (!CBB_add_u16(cbb, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16_length_prefixed(cbb, &child) ||
- !BN_bn2cbb_padded(&child, 32, x) ||
- !BN_bn2cbb_padded(&child, 32, y) ||
- !BN_bn2cbb_padded(&child, 32, sig->r) ||
- !BN_bn2cbb_padded(&child, 32, sig->s) ||
- !CBB_flush(cbb)) {
- goto err;
- }
-
- ret = 1;
-
- err:
- BN_free(x);
- BN_free(y);
- ECDSA_SIG_free(sig);
- return ret;
- }
-
- int tls1_channel_id_hash(SSL_HANDSHAKE *hs, uint8_t *out, size_t *out_len) {
- SSL *const ssl = hs->ssl;
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- uint8_t *msg;
- size_t msg_len;
- if (!tls13_get_cert_verify_signature_input(hs, &msg, &msg_len,
- ssl_cert_verify_channel_id)) {
- return 0;
- }
- SHA256(msg, msg_len, out);
- *out_len = SHA256_DIGEST_LENGTH;
- OPENSSL_free(msg);
- return 1;
- }
-
- SHA256_CTX ctx;
-
- SHA256_Init(&ctx);
- static const char kClientIDMagic[] = "TLS Channel ID signature";
- SHA256_Update(&ctx, kClientIDMagic, sizeof(kClientIDMagic));
-
- if (ssl->session != NULL) {
- static const char kResumptionMagic[] = "Resumption";
- SHA256_Update(&ctx, kResumptionMagic, sizeof(kResumptionMagic));
- if (ssl->session->original_handshake_hash_len == 0) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
- SHA256_Update(&ctx, ssl->session->original_handshake_hash,
- ssl->session->original_handshake_hash_len);
- }
-
- uint8_t hs_hash[EVP_MAX_MD_SIZE];
- size_t hs_hash_len;
- if (!SSL_TRANSCRIPT_get_hash(&hs->transcript, hs_hash, &hs_hash_len)) {
- return 0;
- }
- SHA256_Update(&ctx, hs_hash, (size_t)hs_hash_len);
- SHA256_Final(out, &ctx);
- *out_len = SHA256_DIGEST_LENGTH;
- return 1;
- }
-
- /* tls1_record_handshake_hashes_for_channel_id records the current handshake
- * hashes in |hs->new_session| so that Channel ID resumptions can sign that
- * data. */
- int tls1_record_handshake_hashes_for_channel_id(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- /* 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 (ssl->session != NULL) {
- return -1;
- }
-
- OPENSSL_COMPILE_ASSERT(
- sizeof(hs->new_session->original_handshake_hash) == EVP_MAX_MD_SIZE,
- original_handshake_hash_is_too_small);
-
- size_t digest_len;
- if (!SSL_TRANSCRIPT_get_hash(&hs->transcript,
- hs->new_session->original_handshake_hash,
- &digest_len)) {
- return -1;
- }
-
- OPENSSL_COMPILE_ASSERT(EVP_MAX_MD_SIZE <= 0xff, max_md_size_is_too_large);
- hs->new_session->original_handshake_hash_len = (uint8_t)digest_len;
-
- return 1;
- }
-
- int ssl_do_channel_id_callback(SSL *ssl) {
- if (ssl->tlsext_channel_id_private != NULL ||
- ssl->ctx->channel_id_cb == NULL) {
- return 1;
- }
-
- EVP_PKEY *key = NULL;
- ssl->ctx->channel_id_cb(ssl, &key);
- if (key == NULL) {
- /* The caller should try again later. */
- return 1;
- }
-
- int ret = SSL_set1_tls_channel_id(ssl, key);
- EVP_PKEY_free(key);
- return ret;
- }
-
- int ssl_is_sct_list_valid(const CBS *contents) {
- /* Shallow parse the SCT list for sanity. By the RFC
- * (https://tools.ietf.org/html/rfc6962#section-3.3) neither the list nor any
- * of the SCTs may be empty. */
- CBS copy = *contents;
- CBS sct_list;
- if (!CBS_get_u16_length_prefixed(©, &sct_list) ||
- CBS_len(©) != 0 ||
- CBS_len(&sct_list) == 0) {
- return 0;
- }
-
- while (CBS_len(&sct_list) > 0) {
- CBS sct;
- if (!CBS_get_u16_length_prefixed(&sct_list, &sct) ||
- CBS_len(&sct) == 0) {
- return 0;
- }
- }
-
- return 1;
- }
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