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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 <utility>
- #include <openssl/bytestring.h>
- #include <openssl/chacha.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 "internal.h"
- #include "../crypto/internal.h"
- BSSL_NAMESPACE_BEGIN
- static bool 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 bool tls1_check_duplicate_extensions(const CBS *cbs) {
- // First pass: count the extensions.
- size_t num_extensions = 0;
- CBS extensions = *cbs;
- while (CBS_len(&extensions) > 0) {
- uint16_t type;
- CBS extension;
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- return false;
- }
- num_extensions++;
- }
- if (num_extensions == 0) {
- return true;
- }
- Array<uint16_t> extension_types;
- if (!extension_types.Init(num_extensions)) {
- return false;
- }
- // Second pass: gather the extension types.
- extensions = *cbs;
- for (size_t i = 0; i < extension_types.size(); i++) {
- CBS extension;
- if (!CBS_get_u16(&extensions, &extension_types[i]) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- // This should not happen.
- return false;
- }
- }
- assert(CBS_len(&extensions) == 0);
- // Sort the extensions and make sure there are no duplicates.
- qsort(extension_types.data(), extension_types.size(), sizeof(uint16_t),
- compare_uint16_t);
- for (size_t i = 1; i < num_extensions; i++) {
- if (extension_types[i - 1] == extension_types[i]) {
- return false;
- }
- }
- return true;
- }
- static bool is_post_quantum_group(uint16_t id) {
- return id == SSL_CURVE_CECPQ2 || id == SSL_CURVE_CECPQ2b;
- }
- bool ssl_client_hello_init(const SSL *ssl, SSL_CLIENT_HELLO *out,
- const SSLMessage &msg) {
- OPENSSL_memset(out, 0, sizeof(*out));
- out->ssl = const_cast<SSL *>(ssl);
- out->client_hello = CBS_data(&msg.body);
- out->client_hello_len = CBS_len(&msg.body);
- 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 false;
- }
- 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 false;
- }
- }
- 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 false;
- }
- 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.
- if (CBS_len(&client_hello) == 0) {
- out->extensions = NULL;
- out->extensions_len = 0;
- return true;
- }
- // 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 false;
- }
- out->extensions = CBS_data(&extensions);
- out->extensions_len = CBS_len(&extensions);
- return true;
- }
- bool 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 false;
- }
- if (type == extension_type) {
- *out = extension;
- return true;
- }
- }
- return false;
- }
- static const uint16_t kDefaultGroups[] = {
- SSL_CURVE_X25519,
- SSL_CURVE_SECP256R1,
- SSL_CURVE_SECP384R1,
- };
- Span<const uint16_t> tls1_get_grouplist(const SSL_HANDSHAKE *hs) {
- if (!hs->config->supported_group_list.empty()) {
- return hs->config->supported_group_list;
- }
- return Span<const uint16_t>(kDefaultGroups);
- }
- bool tls1_get_shared_group(SSL_HANDSHAKE *hs, uint16_t *out_group_id) {
- SSL *const ssl = hs->ssl;
- assert(ssl->server);
- // 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|.
- Span<const uint16_t> groups = tls1_get_grouplist(hs);
- Span<const uint16_t> pref, supp;
- if (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
- pref = groups;
- supp = hs->peer_supported_group_list;
- } else {
- pref = hs->peer_supported_group_list;
- supp = groups;
- }
- for (uint16_t pref_group : pref) {
- for (uint16_t supp_group : supp) {
- if (pref_group == supp_group &&
- // CECPQ2(b) doesn't fit in the u8-length-prefixed ECPoint field in
- // TLS 1.2 and below.
- (ssl_protocol_version(ssl) >= TLS1_3_VERSION ||
- !is_post_quantum_group(pref_group))) {
- *out_group_id = pref_group;
- return true;
- }
- }
- }
- return false;
- }
- bool tls1_set_curves(Array<uint16_t> *out_group_ids, Span<const int> curves) {
- Array<uint16_t> group_ids;
- if (!group_ids.Init(curves.size())) {
- return false;
- }
- for (size_t i = 0; i < curves.size(); i++) {
- if (!ssl_nid_to_group_id(&group_ids[i], curves[i])) {
- return false;
- }
- }
- *out_group_ids = std::move(group_ids);
- return true;
- }
- bool tls1_set_curves_list(Array<uint16_t> *out_group_ids, const char *curves) {
- // Count the number of curves in the list.
- size_t count = 0;
- const char *ptr = curves, *col;
- do {
- col = strchr(ptr, ':');
- count++;
- if (col) {
- ptr = col + 1;
- }
- } while (col);
- Array<uint16_t> group_ids;
- if (!group_ids.Init(count)) {
- return false;
- }
- size_t i = 0;
- ptr = curves;
- do {
- col = strchr(ptr, ':');
- if (!ssl_name_to_group_id(&group_ids[i++], ptr,
- col ? (size_t)(col - ptr) : strlen(ptr))) {
- return false;
- }
- if (col) {
- ptr = col + 1;
- }
- } while (col);
- assert(i == count);
- *out_group_ids = std::move(group_ids);
- return true;
- }
- bool tls1_check_group_id(const SSL_HANDSHAKE *hs, uint16_t group_id) {
- if (is_post_quantum_group(group_id) &&
- ssl_protocol_version(hs->ssl) < TLS1_3_VERSION) {
- // CECPQ2(b) requires TLS 1.3.
- return false;
- }
- for (uint16_t supported : tls1_get_grouplist(hs)) {
- if (supported == group_id) {
- return true;
- }
- }
- return false;
- }
- // 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,
- SSL_SIGN_RSA_PSS_RSAE_SHA256,
- SSL_SIGN_RSA_PKCS1_SHA256,
- // Larger hashes are acceptable.
- SSL_SIGN_ECDSA_SECP384R1_SHA384,
- SSL_SIGN_RSA_PSS_RSAE_SHA384,
- SSL_SIGN_RSA_PKCS1_SHA384,
- SSL_SIGN_RSA_PSS_RSAE_SHA512,
- 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,
- SSL_SIGN_RSA_PSS_RSAE_SHA256,
- SSL_SIGN_RSA_PKCS1_SHA256,
- // If needed, sign larger hashes.
- //
- // TODO(davidben): Determine which of these may be pruned.
- SSL_SIGN_ECDSA_SECP384R1_SHA384,
- SSL_SIGN_RSA_PSS_RSAE_SHA384,
- SSL_SIGN_RSA_PKCS1_SHA384,
- SSL_SIGN_ECDSA_SECP521R1_SHA512,
- SSL_SIGN_RSA_PSS_RSAE_SHA512,
- SSL_SIGN_RSA_PKCS1_SHA512,
- // If the peer supports nothing else, sign with SHA-1.
- SSL_SIGN_ECDSA_SHA1,
- SSL_SIGN_RSA_PKCS1_SHA1,
- };
- struct SSLSignatureAlgorithmList {
- bool Next(uint16_t *out) {
- while (!list.empty()) {
- uint16_t sigalg = list[0];
- list = list.subspan(1);
- if (skip_ed25519 && sigalg == SSL_SIGN_ED25519) {
- continue;
- }
- if (skip_rsa_pss_rsae && SSL_is_signature_algorithm_rsa_pss(sigalg)) {
- continue;
- }
- *out = sigalg;
- return true;
- }
- return false;
- }
- bool operator==(const SSLSignatureAlgorithmList &other) const {
- SSLSignatureAlgorithmList a = *this;
- SSLSignatureAlgorithmList b = other;
- uint16_t a_val, b_val;
- while (a.Next(&a_val)) {
- if (!b.Next(&b_val) ||
- a_val != b_val) {
- return false;
- }
- }
- return !b.Next(&b_val);
- }
- bool operator!=(const SSLSignatureAlgorithmList &other) const {
- return !(*this == other);
- }
- Span<const uint16_t> list;
- bool skip_ed25519 = false;
- bool skip_rsa_pss_rsae = false;
- };
- static SSLSignatureAlgorithmList tls12_get_verify_sigalgs(const SSL *ssl,
- bool for_certs) {
- SSLSignatureAlgorithmList ret;
- if (!ssl->config->verify_sigalgs.empty()) {
- ret.list = ssl->config->verify_sigalgs;
- } else {
- ret.list = kVerifySignatureAlgorithms;
- ret.skip_ed25519 = !ssl->ctx->ed25519_enabled;
- }
- if (for_certs) {
- ret.skip_rsa_pss_rsae = !ssl->ctx->rsa_pss_rsae_certs_enabled;
- }
- return ret;
- }
- bool tls12_add_verify_sigalgs(const SSL *ssl, CBB *out, bool for_certs) {
- SSLSignatureAlgorithmList list = tls12_get_verify_sigalgs(ssl, for_certs);
- uint16_t sigalg;
- while (list.Next(&sigalg)) {
- if (!CBB_add_u16(out, sigalg)) {
- return false;
- }
- }
- return true;
- }
- bool tls12_check_peer_sigalg(const SSL *ssl, uint8_t *out_alert,
- uint16_t sigalg) {
- SSLSignatureAlgorithmList list = tls12_get_verify_sigalgs(ssl, false);
- uint16_t verify_sigalg;
- while (list.Next(&verify_sigalg)) {
- if (verify_sigalg == sigalg) {
- return true;
- }
- }
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- bool tls12_has_different_verify_sigalgs_for_certs(const SSL *ssl) {
- return tls12_get_verify_sigalgs(ssl, true) !=
- tls12_get_verify_sigalgs(ssl, false);
- }
- // 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 true for success and false 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);
- bool (*add_clienthello)(SSL_HANDSHAKE *hs, CBB *out);
- bool (*parse_serverhello)(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents);
- bool (*parse_clienthello)(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents);
- bool (*add_serverhello)(SSL_HANDSHAKE *hs, CBB *out);
- };
- static bool 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 false;
- }
- return true;
- }
- static bool ignore_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- // This extension from the client is handled elsewhere.
- return true;
- }
- static bool dont_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- return true;
- }
- // Server name indication (SNI).
- //
- // https://tools.ietf.org/html/rfc6066#section-3.
- static bool ext_sni_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->hostname == nullptr) {
- return true;
- }
- 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->hostname.get(),
- strlen(ssl->hostname.get())) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_sni_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- // The server may acknowledge SNI with an empty extension. We check the syntax
- // but otherwise ignore this signal.
- return contents == NULL || CBS_len(contents) == 0;
- }
- static bool ext_sni_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- // SNI has already been parsed earlier in the handshake. See |extract_sni|.
- return true;
- }
- static bool ext_sni_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (hs->ssl->s3->session_reused ||
- !hs->should_ack_sni) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_server_name) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- // Renegotiation indication.
- //
- // https://tools.ietf.org/html/rfc5746
- static bool ext_ri_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- // Renegotiation indication is not necessary in TLS 1.3.
- if (hs->min_version >= TLS1_3_VERSION) {
- return true;
- }
- 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 false;
- }
- return true;
- }
- static bool ext_ri_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents != NULL && ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- // 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 false;
- }
- 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 true;
- }
- 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 false;
- }
- // 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 false;
- }
- const uint8_t *d = CBS_data(&renegotiated_connection);
- bool ok = CRYPTO_memcmp(d, ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len) == 0;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- ok = true;
- #endif
- if (!ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return false;
- }
- d += ssl->s3->previous_client_finished_len;
- ok = CRYPTO_memcmp(d, ssl->s3->previous_server_finished,
- ssl->s3->previous_server_finished_len) == 0;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- ok = true;
- #endif
- if (!ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return false;
- }
- ssl->s3->send_connection_binding = true;
- return true;
- }
- static bool 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 (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return true;
- }
- if (contents == NULL) {
- return true;
- }
- 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 false;
- }
- // 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 false;
- }
- ssl->s3->send_connection_binding = true;
- return true;
- }
- static bool 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 (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_renegotiate) ||
- !CBB_add_u16(out, 1 /* length */) ||
- !CBB_add_u8(out, 0 /* empty renegotiation info */)) {
- return false;
- }
- return true;
- }
- // Extended Master Secret.
- //
- // https://tools.ietf.org/html/rfc7627
- static bool ext_ems_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- // Extended master secret is not necessary in TLS 1.3.
- if (hs->min_version >= TLS1_3_VERSION) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- static bool ext_ems_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents != NULL) {
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION ||
- CBS_len(contents) != 0) {
- return false;
- }
- hs->extended_master_secret = true;
- }
- // Whether EMS is negotiated may not change on renegotiation.
- if (ssl->s3->established_session != nullptr &&
- 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 false;
- }
- return true;
- }
- static bool ext_ems_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (ssl_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- return true;
- }
- if (contents == NULL) {
- return true;
- }
- if (CBS_len(contents) != 0) {
- return false;
- }
- hs->extended_master_secret = true;
- return true;
- }
- static bool ext_ems_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->extended_master_secret) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- // Session tickets.
- //
- // https://tools.ietf.org/html/rfc5077
- static bool ext_ticket_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- // TLS 1.3 uses a different ticket extension.
- if (hs->min_version >= TLS1_3_VERSION ||
- SSL_get_options(ssl) & SSL_OP_NO_TICKET) {
- return true;
- }
- Span<const uint8_t> ticket;
- // Renegotiation does not participate in session resumption. However, still
- // advertise the extension to avoid potentially breaking servers which carry
- // over the state from the previous handshake, such as OpenSSL servers
- // without upstream's 3c3f0259238594d77264a78944d409f2127642c4.
- if (!ssl->s3->initial_handshake_complete &&
- ssl->session != nullptr &&
- !ssl->session->ticket.empty() &&
- // Don't send TLS 1.3 session tickets in the ticket extension.
- ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION) {
- ticket = ssl->session->ticket;
- }
- CBB ticket_cbb;
- if (!CBB_add_u16(out, TLSEXT_TYPE_session_ticket) ||
- !CBB_add_u16_length_prefixed(out, &ticket_cbb) ||
- !CBB_add_bytes(&ticket_cbb, ticket.data(), ticket.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_ticket_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return false;
- }
- // 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 false;
- }
- hs->ticket_expected = true;
- return true;
- }
- static bool ext_ticket_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ticket_expected) {
- return true;
- }
- // 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 false;
- }
- return true;
- }
- // Signature Algorithms.
- //
- // https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1
- static bool ext_sigalgs_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (hs->max_version < TLS1_2_VERSION) {
- return true;
- }
- // Prior to TLS 1.3, there was no way to signal different signature algorithm
- // preferences between the online signature and certificates. If we do not
- // send the signature_algorithms_cert extension, use the potentially more
- // restrictive certificate list.
- //
- // TODO(davidben): When TLS 1.3 is finalized, we can likely remove the TLS 1.3
- // check both here and in signature_algorithms_cert. |hs->max_version| is not
- // the negotiated version. Rather the expectation is that any server consuming
- // signature algorithms added in TLS 1.3 will also know to look at
- // signature_algorithms_cert. For now, TLS 1.3 is not quite yet final and it
- // seems prudent to condition this new extension on it.
- bool for_certs = hs->max_version < TLS1_3_VERSION;
- 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, for_certs) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_sigalgs_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- hs->peer_sigalgs.Reset();
- if (contents == NULL) {
- return true;
- }
- CBS supported_signature_algorithms;
- if (!CBS_get_u16_length_prefixed(contents, &supported_signature_algorithms) ||
- CBS_len(contents) != 0 ||
- !tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
- return false;
- }
- return true;
- }
- // Signature Algorithms for Certificates.
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.3
- static bool ext_sigalgs_cert_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- // If this extension is omitted, it defaults to the signature_algorithms
- // extension, so only emit it if the list is different.
- //
- // This extension is also new in TLS 1.3, so omit it if TLS 1.3 is disabled.
- // There is a corresponding version check in |ext_sigalgs_add_clienthello|.
- if (hs->max_version < TLS1_3_VERSION ||
- !tls12_has_different_verify_sigalgs_for_certs(ssl)) {
- return true;
- }
- CBB contents, sigalgs_cbb;
- if (!CBB_add_u16(out, TLSEXT_TYPE_signature_algorithms_cert) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &sigalgs_cbb) ||
- !tls12_add_verify_sigalgs(ssl, &sigalgs_cbb, true /* certs */) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // OCSP Stapling.
- //
- // https://tools.ietf.org/html/rfc6066#section-8
- static bool ext_ocsp_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->config->ocsp_stapling_enabled) {
- return true;
- }
- 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 false;
- }
- return true;
- }
- static bool ext_ocsp_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- // TLS 1.3 OCSP responses are included in the Certificate extensions.
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return false;
- }
- // OCSP stapling is forbidden on non-certificate ciphers.
- if (CBS_len(contents) != 0 ||
- !ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
- return false;
- }
- // 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 = true;
- return true;
- }
- static bool ext_ocsp_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return true;
- }
- uint8_t status_type;
- if (!CBS_get_u8(contents, &status_type)) {
- return false;
- }
- // 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 true;
- }
- static bool ext_ocsp_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION ||
- !hs->ocsp_stapling_requested || hs->config->cert->ocsp_response == NULL ||
- ssl->s3->session_reused ||
- !ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
- return true;
- }
- hs->certificate_status_expected = true;
- 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 bool 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 true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_next_proto_neg) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- static bool ext_npn_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return false;
- }
- // 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.empty()) {
- // 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 false;
- }
- 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 false;
- }
- }
- 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 ||
- !ssl->s3->next_proto_negotiated.CopyFrom(
- MakeConstSpan(selected, selected_len))) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- hs->next_proto_neg_seen = true;
- return true;
- }
- static bool ext_npn_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return true;
- }
- if (contents != NULL && CBS_len(contents) != 0) {
- return false;
- }
- if (contents == NULL ||
- ssl->s3->initial_handshake_complete ||
- ssl->ctx->next_protos_advertised_cb == NULL ||
- SSL_is_dtls(ssl)) {
- return true;
- }
- hs->next_proto_neg_seen = true;
- return true;
- }
- static bool 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 true;
- }
- 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 = false;
- return true;
- }
- 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 false;
- }
- return true;
- }
- // Signed certificate timestamps.
- //
- // https://tools.ietf.org/html/rfc6962#section-3.3.1
- static bool ext_sct_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->config->signed_cert_timestamps_enabled) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_certificate_timestamp) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- static bool ext_sct_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- // TLS 1.3 SCTs are included in the Certificate extensions.
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- // 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(hs->config->signed_cert_timestamps_enabled);
- if (!ssl_is_sct_list_valid(contents)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- // 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) {
- hs->new_session->signed_cert_timestamp_list.reset(
- CRYPTO_BUFFER_new_from_CBS(contents, ssl->ctx->pool));
- if (hs->new_session->signed_cert_timestamp_list == nullptr) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- }
- return true;
- }
- static bool ext_sct_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return true;
- }
- if (CBS_len(contents) != 0) {
- return false;
- }
- hs->scts_requested = true;
- return true;
- }
- static bool ext_sct_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- // The extension shouldn't be sent when resuming sessions.
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION || ssl->s3->session_reused ||
- hs->config->cert->signed_cert_timestamp_list == NULL) {
- return true;
- }
- 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(
- hs->config->cert->signed_cert_timestamp_list.get()),
- CRYPTO_BUFFER_len(
- hs->config->cert->signed_cert_timestamp_list.get())) &&
- CBB_flush(out);
- }
- // Application-level Protocol Negotiation.
- //
- // https://tools.ietf.org/html/rfc7301
- static bool ext_alpn_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (hs->config->alpn_client_proto_list.empty() ||
- ssl->s3->initial_handshake_complete) {
- return true;
- }
- 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, hs->config->alpn_client_proto_list.data(),
- hs->config->alpn_client_proto_list.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_alpn_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- assert(!ssl->s3->initial_handshake_complete);
- assert(!hs->config->alpn_client_proto_list.empty());
- 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 false;
- }
- // 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 false;
- }
- if (!ssl_is_alpn_protocol_allowed(hs, protocol_name)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_ALPN_PROTOCOL);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- if (!ssl->s3->alpn_selected.CopyFrom(protocol_name)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- return true;
- }
- bool ssl_is_alpn_protocol_allowed(const SSL_HANDSHAKE *hs,
- Span<const uint8_t> protocol) {
- if (hs->config->alpn_client_proto_list.empty()) {
- return false;
- }
- if (hs->ssl->ctx->allow_unknown_alpn_protos) {
- return true;
- }
- // Check that the protocol name is one of the ones we advertised.
- CBS client_protocol_name_list =
- MakeConstSpan(hs->config->alpn_client_proto_list),
- client_protocol_name;
- while (CBS_len(&client_protocol_name_list) > 0) {
- if (!CBS_get_u8_length_prefixed(&client_protocol_name_list,
- &client_protocol_name)) {
- return false;
- }
- if (client_protocol_name == protocol) {
- return true;
- }
- }
- return false;
- }
- bool 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 true;
- }
- // ALPN takes precedence over NPN.
- hs->next_proto_neg_seen = false;
- 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 false;
- }
- // 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 false;
- }
- }
- 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) {
- if (selected_len == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_ALPN_PROTOCOL);
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- if (!ssl->s3->alpn_selected.CopyFrom(
- MakeConstSpan(selected, selected_len))) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- }
- return true;
- }
- static bool ext_alpn_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->s3->alpn_selected.empty()) {
- return true;
- }
- 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.data(),
- ssl->s3->alpn_selected.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // Channel ID.
- //
- // https://tools.ietf.org/html/draft-balfanz-tls-channelid-01
- static void ext_channel_id_init(SSL_HANDSHAKE *hs) {
- hs->ssl->s3->channel_id_valid = false;
- }
- static bool ext_channel_id_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!hs->config->channel_id_enabled || SSL_is_dtls(ssl)) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- static bool ext_channel_id_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- assert(!SSL_is_dtls(ssl));
- assert(hs->config->channel_id_enabled);
- if (CBS_len(contents) != 0) {
- return false;
- }
- ssl->s3->channel_id_valid = true;
- return true;
- }
- static bool ext_channel_id_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL || !hs->config->channel_id_enabled || SSL_is_dtls(ssl)) {
- return true;
- }
- if (CBS_len(contents) != 0) {
- return false;
- }
- ssl->s3->channel_id_valid = true;
- return true;
- }
- static bool ext_channel_id_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->s3->channel_id_valid) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return false;
- }
- return true;
- }
- // Secure Real-time Transport Protocol (SRTP) extension.
- //
- // https://tools.ietf.org/html/rfc5764
- static void ext_srtp_init(SSL_HANDSHAKE *hs) {
- hs->ssl->s3->srtp_profile = NULL;
- }
- static bool 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 ||
- sk_SRTP_PROTECTION_PROFILE_num(profiles) == 0) {
- return true;
- }
- 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 false;
- }
- for (const SRTP_PROTECTION_PROFILE *profile : profiles) {
- if (!CBB_add_u16(&profile_ids, profile->id)) {
- return false;
- }
- }
- if (!CBB_add_u8(&contents, 0 /* empty use_mki value */) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_srtp_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- // 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 false;
- }
- 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 false;
- }
- 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 (const SRTP_PROTECTION_PROFILE *profile : profiles) {
- if (profile->id == profile_id) {
- ssl->s3->srtp_profile = profile;
- return true;
- }
- }
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- static bool ext_srtp_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- return true;
- }
- 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 false;
- }
- // 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 (const SRTP_PROTECTION_PROFILE *server_profile : server_profiles) {
- 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 false;
- }
- if (server_profile->id == profile_id) {
- ssl->s3->srtp_profile = server_profile;
- return true;
- }
- }
- }
- return true;
- }
- static bool ext_srtp_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl->s3->srtp_profile == NULL) {
- return true;
- }
- 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->s3->srtp_profile->id) ||
- !CBB_add_u8(&contents, 0 /* empty MKI */) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // EC point formats.
- //
- // https://tools.ietf.org/html/rfc4492#section-5.1.2
- static bool 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 false;
- }
- return true;
- }
- static bool ext_ec_point_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- // The point format extension is unnecessary in TLS 1.3.
- if (hs->min_version >= TLS1_3_VERSION) {
- return true;
- }
- return ext_ec_point_add_extension(hs, out);
- }
- static bool ext_ec_point_parse_serverhello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return true;
- }
- if (ssl_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- return false;
- }
- CBS ec_point_format_list;
- if (!CBS_get_u8_length_prefixed(contents, &ec_point_format_list) ||
- CBS_len(contents) != 0) {
- return false;
- }
- // 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 false;
- }
- return true;
- }
- static bool ext_ec_point_parse_clienthello(SSL_HANDSHAKE *hs, uint8_t *out_alert,
- CBS *contents) {
- if (ssl_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- return true;
- }
- return ext_ec_point_parse_serverhello(hs, out_alert, contents);
- }
- static bool ext_ec_point_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- return true;
- }
- const uint32_t alg_k = hs->new_cipher->algorithm_mkey;
- const uint32_t alg_a = hs->new_cipher->algorithm_auth;
- const bool using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA);
- if (!using_ecc) {
- return true;
- }
- return ext_ec_point_add_extension(hs, out);
- }
- // Pre Shared Key
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.11
- static size_t ext_pre_shared_key_clienthello_length(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- if (hs->max_version < TLS1_3_VERSION || ssl->session == nullptr ||
- ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION) {
- return 0;
- }
- size_t binder_len = EVP_MD_size(ssl_session_get_digest(ssl->session.get()));
- return 15 + ssl->session->ticket.size() + binder_len;
- }
- static bool ext_pre_shared_key_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- hs->needs_psk_binder = false;
- if (hs->max_version < TLS1_3_VERSION || ssl->session == nullptr ||
- ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION) {
- return true;
- }
- // Per RFC 8446 section 4.1.4, skip offering the session if the selected
- // cipher in HelloRetryRequest does not match. This avoids performing the
- // transcript hash transformation for multiple hashes.
- if (hs->received_hello_retry_request &&
- ssl->session->cipher->algorithm_prf != hs->new_cipher->algorithm_prf) {
- return true;
- }
- 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};
- size_t binder_len = EVP_MD_size(ssl_session_get_digest(ssl->session.get()));
- 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->ticket.data(),
- ssl->session->ticket.size()) ||
- !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 false;
- }
- hs->needs_psk_binder = true;
- return CBB_flush(out);
- }
- bool 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 false;
- }
- // 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 false;
- }
- return true;
- }
- bool 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,
- const SSL_CLIENT_HELLO *client_hello, CBS *contents) {
- // Verify that the pre_shared_key extension is the last extension in
- // ClientHello.
- if (CBS_data(contents) + CBS_len(contents) !=
- client_hello->extensions + client_hello->extensions_len) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_PRE_SHARED_KEY_MUST_BE_LAST);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- // 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 false;
- }
- *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 false;
- }
- 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 false;
- }
- 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 false;
- }
- return true;
- }
- bool ssl_ext_pre_shared_key_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ssl->s3->session_reused) {
- return true;
- }
- 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 false;
- }
- return true;
- }
- // Pre-Shared Key Exchange Modes
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.9
- static bool ext_psk_key_exchange_modes_add_clienthello(SSL_HANDSHAKE *hs,
- CBB *out) {
- if (hs->max_version < TLS1_3_VERSION) {
- return true;
- }
- 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 false;
- }
- return CBB_flush(out);
- }
- static bool ext_psk_key_exchange_modes_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return true;
- }
- 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 false;
- }
- // 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 true;
- }
- // Early Data Indication
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.10
- static bool ext_early_data_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- // The second ClientHello never offers early data, and we must have already
- // filled in |early_data_reason| by this point.
- if (hs->received_hello_retry_request) {
- assert(ssl->s3->early_data_reason != ssl_early_data_unknown);
- return true;
- }
- if (!ssl->enable_early_data) {
- ssl->s3->early_data_reason = ssl_early_data_disabled;
- return true;
- }
- if (hs->max_version < TLS1_3_VERSION) {
- // We discard inapplicable sessions, so this is redundant with the session
- // checks below, but we check give a more useful reason.
- ssl->s3->early_data_reason = ssl_early_data_protocol_version;
- return true;
- }
- if (ssl->session == nullptr) {
- ssl->s3->early_data_reason = ssl_early_data_no_session_offered;
- return true;
- }
- if (ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION ||
- ssl->session->ticket_max_early_data == 0) {
- ssl->s3->early_data_reason = ssl_early_data_unsupported_for_session;
- return true;
- }
- // In case ALPN preferences changed since this session was established, avoid
- // reporting a confusing value in |SSL_get0_alpn_selected| and sending early
- // data we know will be rejected.
- if (!ssl->session->early_alpn.empty() &&
- !ssl_is_alpn_protocol_allowed(hs, ssl->session->early_alpn)) {
- ssl->s3->early_data_reason = ssl_early_data_alpn_mismatch;
- return true;
- }
- // |early_data_reason| will be filled in later when the server responds.
- hs->early_data_offered = true;
- if (!CBB_add_u16(out, TLSEXT_TYPE_early_data) ||
- !CBB_add_u16(out, 0) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_early_data_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL) {
- if (hs->early_data_offered && !hs->received_hello_retry_request) {
- ssl->s3->early_data_reason = ssl->s3->session_reused
- ? ssl_early_data_peer_declined
- : ssl_early_data_session_not_resumed;
- } else {
- // We already filled in |early_data_reason| when declining to offer 0-RTT
- // or handling the implicit HelloRetryRequest reject.
- assert(ssl->s3->early_data_reason != ssl_early_data_unknown);
- }
- return true;
- }
- // If we received an HRR, the second ClientHello never offers early data, so
- // the extensions logic will automatically reject early data extensions as
- // unsolicited. This covered by the ServerAcceptsEarlyDataOnHRR test.
- assert(!hs->received_hello_retry_request);
- if (CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- if (!ssl->s3->session_reused) {
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- return false;
- }
- ssl->s3->early_data_reason = ssl_early_data_accepted;
- ssl->s3->early_data_accepted = true;
- return true;
- }
- static bool ext_early_data_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert, CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == NULL ||
- ssl_protocol_version(ssl) < TLS1_3_VERSION) {
- return true;
- }
- if (CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- hs->early_data_offered = true;
- return true;
- }
- static bool ext_early_data_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- if (!hs->ssl->s3->early_data_accepted) {
- return true;
- }
- if (!CBB_add_u16(out, TLSEXT_TYPE_early_data) ||
- !CBB_add_u16(out, 0) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // Key Share
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.8
- static bool ext_key_share_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (hs->max_version < TLS1_3_VERSION) {
- return true;
- }
- 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 false;
- }
- uint16_t group_id = hs->retry_group;
- uint16_t second_group_id = 0;
- if (hs->received_hello_retry_request) {
- // We received a HelloRetryRequest without a new curve, so there is no new
- // share to append. Leave |hs->key_share| as-is.
- if (group_id == 0 &&
- !CBB_add_bytes(&kse_bytes, hs->key_share_bytes.data(),
- hs->key_share_bytes.size())) {
- return false;
- }
- hs->key_share_bytes.Reset();
- 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(hs, ssl_grease_group)) ||
- !CBB_add_u16(&kse_bytes, 1 /* length */) ||
- !CBB_add_u8(&kse_bytes, 0 /* one byte key share */))) {
- return false;
- }
- // Predict the most preferred group.
- Span<const uint16_t> groups = tls1_get_grouplist(hs);
- if (groups.empty()) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_GROUPS_SPECIFIED);
- return false;
- }
- group_id = groups[0];
- if (is_post_quantum_group(group_id) && groups.size() >= 2) {
- // CECPQ2(b) is not sent as the only initial key share. We'll include the
- // 2nd preference group too to avoid round-trips.
- second_group_id = groups[1];
- assert(second_group_id != group_id);
- }
- }
- CBB key_exchange;
- hs->key_shares[0] = SSLKeyShare::Create(group_id);
- if (!hs->key_shares[0] ||
- !CBB_add_u16(&kse_bytes, group_id) ||
- !CBB_add_u16_length_prefixed(&kse_bytes, &key_exchange) ||
- !hs->key_shares[0]->Offer(&key_exchange) ||
- !CBB_flush(&kse_bytes)) {
- return false;
- }
- if (second_group_id != 0) {
- hs->key_shares[1] = SSLKeyShare::Create(second_group_id);
- if (!hs->key_shares[1] ||
- !CBB_add_u16(&kse_bytes, second_group_id) ||
- !CBB_add_u16_length_prefixed(&kse_bytes, &key_exchange) ||
- !hs->key_shares[1]->Offer(&key_exchange) ||
- !CBB_flush(&kse_bytes)) {
- return false;
- }
- }
- // Save the contents of the extension to repeat it in the second
- // ClientHello.
- if (!hs->received_hello_retry_request &&
- !hs->key_share_bytes.CopyFrom(
- MakeConstSpan(CBB_data(&kse_bytes), CBB_len(&kse_bytes)))) {
- return false;
- }
- return CBB_flush(out);
- }
- bool ssl_ext_key_share_parse_serverhello(SSL_HANDSHAKE *hs,
- Array<uint8_t> *out_secret,
- 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) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- SSLKeyShare *key_share = hs->key_shares[0].get();
- if (key_share->GroupID() != group_id) {
- if (!hs->key_shares[1] || hs->key_shares[1]->GroupID() != group_id) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
- return false;
- }
- key_share = hs->key_shares[1].get();
- }
- if (!key_share->Finish(out_secret, out_alert, peer_key)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return false;
- }
- hs->new_session->group_id = group_id;
- hs->key_shares[0].reset();
- hs->key_shares[1].reset();
- return true;
- }
- bool ssl_ext_key_share_parse_clienthello(SSL_HANDSHAKE *hs, bool *out_found,
- Array<uint8_t> *out_secret,
- 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 false;
- }
- if (!CBS_get_u16_length_prefixed(contents, &key_shares) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- return false;
- }
- // Find the corresponding key share.
- CBS peer_key;
- CBS_init(&peer_key, NULL, 0);
- 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) ||
- CBS_len(&peer_key_tmp) == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- return false;
- }
- if (id == group_id) {
- if (CBS_len(&peer_key) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DUPLICATE_KEY_SHARE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- peer_key = peer_key_tmp;
- // Continue parsing the structure to keep peers honest.
- }
- }
- if (CBS_len(&peer_key) == 0) {
- *out_found = false;
- out_secret->Reset();
- return true;
- }
- // Compute the DH secret.
- Array<uint8_t> secret;
- ScopedCBB public_key;
- UniquePtr<SSLKeyShare> key_share = SSLKeyShare::Create(group_id);
- if (!key_share ||
- !CBB_init(public_key.get(), 32) ||
- !key_share->Accept(public_key.get(), &secret, out_alert, peer_key) ||
- !CBBFinishArray(public_key.get(), &hs->ecdh_public_key)) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- *out_secret = std::move(secret);
- *out_found = true;
- return true;
- }
- bool 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.data(),
- hs->ecdh_public_key.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- hs->ecdh_public_key.Reset();
- hs->new_session->group_id = group_id;
- return true;
- }
- // Supported Versions
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.1
- static bool ext_supported_versions_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (hs->max_version <= TLS1_2_VERSION) {
- return true;
- }
- 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 false;
- }
- // Add a fake version. See draft-davidben-tls-grease-01.
- if (ssl->ctx->grease_enabled &&
- !CBB_add_u16(&versions, ssl_get_grease_value(hs, ssl_grease_version))) {
- return false;
- }
- if (!ssl_add_supported_versions(hs, &versions) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // Cookie
- //
- // https://tools.ietf.org/html/rfc8446#section-4.2.2
- static bool ext_cookie_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- if (hs->cookie.empty()) {
- return true;
- }
- 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.data(), hs->cookie.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- // The cookie is no longer needed in memory.
- hs->cookie.Reset();
- return true;
- }
- // Supported Groups
- //
- // https://tools.ietf.org/html/rfc4492#section-5.1.1
- // https://tools.ietf.org/html/rfc8446#section-4.2.7
- static bool 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 false;
- }
- // Add a fake group. See draft-davidben-tls-grease-01.
- if (ssl->ctx->grease_enabled &&
- !CBB_add_u16(&groups_bytes,
- ssl_get_grease_value(hs, ssl_grease_group))) {
- return false;
- }
- for (uint16_t group : tls1_get_grouplist(hs)) {
- if (is_post_quantum_group(group) &&
- hs->max_version < TLS1_3_VERSION) {
- continue;
- }
- if (!CBB_add_u16(&groups_bytes, group)) {
- return false;
- }
- }
- return CBB_flush(out);
- }
- static bool 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 true;
- }
- static bool parse_u16_array(const CBS *cbs, Array<uint16_t> *out) {
- CBS copy = *cbs;
- if ((CBS_len(©) & 1) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
- return false;
- }
- Array<uint16_t> ret;
- if (!ret.Init(CBS_len(©) / 2)) {
- return false;
- }
- for (size_t i = 0; i < ret.size(); i++) {
- if (!CBS_get_u16(©, &ret[i])) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- }
- assert(CBS_len(©) == 0);
- *out = std::move(ret);
- return 1;
- }
- static bool ext_supported_groups_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return true;
- }
- CBS supported_group_list;
- if (!CBS_get_u16_length_prefixed(contents, &supported_group_list) ||
- CBS_len(&supported_group_list) == 0 ||
- CBS_len(contents) != 0 ||
- !parse_u16_array(&supported_group_list, &hs->peer_supported_group_list)) {
- return false;
- }
- return true;
- }
- // Token Binding
- //
- // https://tools.ietf.org/html/draft-ietf-tokbind-negotiation-10
- // The Token Binding version number currently matches the draft number of
- // draft-ietf-tokbind-protocol, and when published as an RFC it will be 0x0100.
- // Since there are no wire changes to the protocol from draft 13 through the
- // current draft (16), this implementation supports all versions in that range.
- static uint16_t kTokenBindingMaxVersion = 16;
- static uint16_t kTokenBindingMinVersion = 13;
- static bool ext_token_binding_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (hs->config->token_binding_params.empty() || SSL_is_dtls(ssl)) {
- return true;
- }
- CBB contents, params;
- if (!CBB_add_u16(out, TLSEXT_TYPE_token_binding) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16(&contents, kTokenBindingMaxVersion) ||
- !CBB_add_u8_length_prefixed(&contents, ¶ms) ||
- !CBB_add_bytes(¶ms, hs->config->token_binding_params.data(),
- hs->config->token_binding_params.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_token_binding_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == nullptr) {
- return true;
- }
- CBS params_list;
- uint16_t version;
- uint8_t param;
- if (!CBS_get_u16(contents, &version) ||
- !CBS_get_u8_length_prefixed(contents, ¶ms_list) ||
- !CBS_get_u8(¶ms_list, ¶m) ||
- CBS_len(¶ms_list) > 0 ||
- CBS_len(contents) > 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- // The server-negotiated version must be less than or equal to our version.
- if (version > kTokenBindingMaxVersion) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- // If the server-selected version is less than what we support, then Token
- // Binding wasn't negotiated (but the extension was parsed successfully).
- if (version < kTokenBindingMinVersion) {
- return true;
- }
- for (uint8_t config_param : hs->config->token_binding_params) {
- if (param == config_param) {
- ssl->s3->negotiated_token_binding_param = param;
- ssl->s3->token_binding_negotiated = true;
- return true;
- }
- }
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return false;
- }
- // select_tb_param looks for the first token binding param in
- // |hs->ssl->token_binding_params| that is also in |params| and puts it in
- // |hs->ssl->negotiated_token_binding_param|. It returns true if a token binding
- // param is found, and false otherwise.
- static bool select_tb_param(SSL_HANDSHAKE *hs,
- Span<const uint8_t> peer_params) {
- for (uint8_t tb_param : hs->config->token_binding_params) {
- for (uint8_t peer_param : peer_params) {
- if (tb_param == peer_param) {
- hs->ssl->s3->negotiated_token_binding_param = tb_param;
- return true;
- }
- }
- }
- return false;
- }
- static bool ext_token_binding_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == nullptr || hs->config->token_binding_params.empty()) {
- return true;
- }
- CBS params;
- uint16_t version;
- if (!CBS_get_u16(contents, &version) ||
- !CBS_get_u8_length_prefixed(contents, ¶ms) ||
- CBS_len(¶ms) == 0 ||
- CBS_len(contents) > 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return false;
- }
- // If the client-selected version is less than what we support, then Token
- // Binding wasn't negotiated (but the extension was parsed successfully).
- if (version < kTokenBindingMinVersion) {
- return true;
- }
- // If the client-selected version is higher than we support, use our max
- // version. Otherwise, use the client's version.
- hs->negotiated_token_binding_version =
- std::min(version, kTokenBindingMaxVersion);
- if (!select_tb_param(hs, params)) {
- return true;
- }
- ssl->s3->token_binding_negotiated = true;
- return true;
- }
- static bool ext_token_binding_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- SSL *const ssl = hs->ssl;
- if (!ssl->s3->token_binding_negotiated) {
- return true;
- }
- CBB contents, params;
- if (!CBB_add_u16(out, TLSEXT_TYPE_token_binding) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16(&contents, hs->negotiated_token_binding_version) ||
- !CBB_add_u8_length_prefixed(&contents, ¶ms) ||
- !CBB_add_u8(¶ms, ssl->s3->negotiated_token_binding_param) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // QUIC Transport Parameters
- static bool ext_quic_transport_params_add_clienthello(SSL_HANDSHAKE *hs,
- CBB *out) {
- if (hs->config->quic_transport_params.empty() ||
- hs->max_version <= TLS1_2_VERSION) {
- return true;
- }
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_quic_transport_parameters) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_bytes(&contents, hs->config->quic_transport_params.data(),
- hs->config->quic_transport_params.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- static bool ext_quic_transport_params_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (contents == nullptr) {
- return true;
- }
- // QUIC requires TLS 1.3.
- if (ssl_protocol_version(ssl) < TLS1_3_VERSION) {
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- return false;
- }
- return ssl->s3->peer_quic_transport_params.CopyFrom(*contents);
- }
- static bool ext_quic_transport_params_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- SSL *const ssl = hs->ssl;
- if (!contents || hs->config->quic_transport_params.empty()) {
- return true;
- }
- // Ignore the extension before TLS 1.3.
- if (ssl_protocol_version(ssl) < TLS1_3_VERSION) {
- return true;
- }
- return ssl->s3->peer_quic_transport_params.CopyFrom(*contents);
- }
- static bool ext_quic_transport_params_add_serverhello(SSL_HANDSHAKE *hs,
- CBB *out) {
- if (hs->config->quic_transport_params.empty()) {
- return true;
- }
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_quic_transport_parameters) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_bytes(&contents, hs->config->quic_transport_params.data(),
- hs->config->quic_transport_params.size()) ||
- !CBB_flush(out)) {
- return false;
- }
- return true;
- }
- // Delegated credentials.
- //
- // https://tools.ietf.org/html/draft-ietf-tls-subcerts
- static bool ext_delegated_credential_add_clienthello(SSL_HANDSHAKE *hs,
- CBB *out) {
- return true;
- }
- static bool ext_delegated_credential_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- assert(TLSEXT_TYPE_delegated_credential == 0xff02);
- // TODO: Check that the extension is empty.
- //
- // As of draft-03, the client sends an empty extension in order indicate
- // support for delegated credentials. This could change, however, since the
- // spec is not yet finalized. This assertion is here to remind us to enforce
- // this check once the extension ID is assigned.
- if (contents == nullptr || ssl_protocol_version(hs->ssl) < TLS1_3_VERSION) {
- // Don't use delegated credentials unless we're negotiating TLS 1.3 or
- // higher.
- return true;
- }
- hs->delegated_credential_requested = true;
- return true;
- }
- // Certificate compression
- static bool cert_compression_add_clienthello(SSL_HANDSHAKE *hs, CBB *out) {
- bool first = true;
- CBB contents, algs;
- for (const auto *alg : hs->ssl->ctx->cert_compression_algs.get()) {
- if (alg->decompress == nullptr) {
- continue;
- }
- if (first && (!CBB_add_u16(out, TLSEXT_TYPE_cert_compression) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &algs))) {
- return false;
- }
- first = false;
- if (!CBB_add_u16(&algs, alg->alg_id)) {
- return false;
- }
- }
- return first || CBB_flush(out);
- }
- static bool cert_compression_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == nullptr) {
- return true;
- }
- // The server may not echo this extension. Any server to client negotiation is
- // advertised in the CertificateRequest message.
- return false;
- }
- static bool cert_compression_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == nullptr) {
- return true;
- }
- const size_t num_algs =
- sk_CertCompressionAlg_num(hs->ssl->ctx->cert_compression_algs.get());
- CBS alg_ids;
- if (!CBS_get_u8_length_prefixed(contents, &alg_ids) ||
- CBS_len(contents) != 0 ||
- CBS_len(&alg_ids) == 0 ||
- CBS_len(&alg_ids) % 2 == 1) {
- return false;
- }
- const size_t num_given_alg_ids = CBS_len(&alg_ids) / 2;
- Array<uint16_t> given_alg_ids;
- if (!given_alg_ids.Init(num_given_alg_ids)) {
- return false;
- }
- size_t best_index = num_algs;
- size_t given_alg_idx = 0;
- while (CBS_len(&alg_ids) > 0) {
- uint16_t alg_id;
- if (!CBS_get_u16(&alg_ids, &alg_id)) {
- return false;
- }
- given_alg_ids[given_alg_idx++] = alg_id;
- for (size_t i = 0; i < num_algs; i++) {
- const auto *alg = sk_CertCompressionAlg_value(
- hs->ssl->ctx->cert_compression_algs.get(), i);
- if (alg->alg_id == alg_id && alg->compress != nullptr) {
- if (i < best_index) {
- best_index = i;
- }
- break;
- }
- }
- }
- qsort(given_alg_ids.data(), given_alg_ids.size(), sizeof(uint16_t),
- compare_uint16_t);
- for (size_t i = 1; i < num_given_alg_ids; i++) {
- if (given_alg_ids[i - 1] == given_alg_ids[i]) {
- return false;
- }
- }
- if (best_index < num_algs &&
- ssl_protocol_version(hs->ssl) >= TLS1_3_VERSION) {
- hs->cert_compression_negotiated = true;
- hs->cert_compression_alg_id =
- sk_CertCompressionAlg_value(hs->ssl->ctx->cert_compression_algs.get(),
- best_index)
- ->alg_id;
- }
- return true;
- }
- static bool cert_compression_add_serverhello(SSL_HANDSHAKE *hs, CBB *out) {
- return true;
- }
- // Post-quantum experiment signal
- //
- // This extension may be used in order to identify a control group for
- // experimenting with post-quantum key exchange algorithms.
- static bool ext_pq_experiment_signal_add_clienthello(SSL_HANDSHAKE *hs,
- CBB *out) {
- if (hs->ssl->ctx->pq_experiment_signal &&
- (!CBB_add_u16(out, TLSEXT_TYPE_pq_experiment_signal) ||
- !CBB_add_u16(out, 0))) {
- return false;
- }
- return true;
- }
- static bool ext_pq_experiment_signal_parse_serverhello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == nullptr) {
- return true;
- }
- if (!hs->ssl->ctx->pq_experiment_signal || CBS_len(contents) != 0) {
- return false;
- }
- hs->ssl->s3->pq_experiment_signal_seen = true;
- return true;
- }
- static bool ext_pq_experiment_signal_parse_clienthello(SSL_HANDSHAKE *hs,
- uint8_t *out_alert,
- CBS *contents) {
- if (contents == nullptr) {
- return true;
- }
- if (CBS_len(contents) != 0) {
- return false;
- }
- if (hs->ssl->ctx->pq_experiment_signal) {
- hs->ssl->s3->pq_experiment_signal_seen = true;
- }
- return true;
- }
- static bool ext_pq_experiment_signal_add_serverhello(SSL_HANDSHAKE *hs,
- CBB *out) {
- if (hs->ssl->s3->pq_experiment_signal_seen &&
- (!CBB_add_u16(out, TLSEXT_TYPE_pq_experiment_signal) ||
- !CBB_add_u16(out, 0))) {
- return false;
- }
- return true;
- }
- // kExtensions contains all the supported extensions.
- static const struct tls_extension kExtensions[] = {
- {
- 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_renegotiate,
- NULL,
- ext_ri_add_clienthello,
- ext_ri_parse_serverhello,
- ext_ri_parse_clienthello,
- ext_ri_add_serverhello,
- },
- {
- TLSEXT_TYPE_supported_groups,
- NULL,
- ext_supported_groups_add_clienthello,
- ext_supported_groups_parse_serverhello,
- ext_supported_groups_parse_clienthello,
- dont_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_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_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_status_request,
- NULL,
- ext_ocsp_add_clienthello,
- ext_ocsp_parse_serverhello,
- ext_ocsp_parse_clienthello,
- ext_ocsp_add_serverhello,
- },
- {
- TLSEXT_TYPE_signature_algorithms,
- NULL,
- ext_sigalgs_add_clienthello,
- forbid_parse_serverhello,
- ext_sigalgs_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_signature_algorithms_cert,
- NULL,
- ext_sigalgs_cert_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_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_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_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,
- },
- {
- TLSEXT_TYPE_quic_transport_parameters,
- NULL,
- ext_quic_transport_params_add_clienthello,
- ext_quic_transport_params_parse_serverhello,
- ext_quic_transport_params_parse_clienthello,
- ext_quic_transport_params_add_serverhello,
- },
- {
- TLSEXT_TYPE_token_binding,
- NULL,
- ext_token_binding_add_clienthello,
- ext_token_binding_parse_serverhello,
- ext_token_binding_parse_clienthello,
- ext_token_binding_add_serverhello,
- },
- {
- TLSEXT_TYPE_cert_compression,
- NULL,
- cert_compression_add_clienthello,
- cert_compression_parse_serverhello,
- cert_compression_parse_clienthello,
- cert_compression_add_serverhello,
- },
- {
- TLSEXT_TYPE_delegated_credential,
- NULL,
- ext_delegated_credential_add_clienthello,
- forbid_parse_serverhello,
- ext_delegated_credential_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_pq_experiment_signal,
- NULL,
- ext_pq_experiment_signal_add_clienthello,
- ext_pq_experiment_signal_parse_serverhello,
- ext_pq_experiment_signal_parse_clienthello,
- ext_pq_experiment_signal_add_serverhello,
- },
- };
- #define kNumExtensions (sizeof(kExtensions) / sizeof(struct tls_extension))
- static_assert(kNumExtensions <=
- sizeof(((SSL_HANDSHAKE *)NULL)->extensions.sent) * 8,
- "too many extensions for sent bitset");
- static_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;
- }
- bool ssl_add_clienthello_tlsext(SSL_HANDSHAKE *hs, CBB *out,
- size_t header_len) {
- SSL *const ssl = hs->ssl;
- CBB extensions;
- if (!CBB_add_u16_length_prefixed(out, &extensions)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- // Note we may send multiple ClientHellos for DTLS HelloVerifyRequest and TLS
- // 1.3 HelloRetryRequest. For the latter, the extensions may change, so it is
- // important to reset this value.
- hs->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(hs, ssl_grease_extension1);
- if (!CBB_add_u16(&extensions, grease_ext1) ||
- !CBB_add_u16(&extensions, 0 /* zero length */)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- }
- bool last_was_empty = false;
- 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);
- return false;
- }
- const size_t bytes_written = CBB_len(&extensions) - len_before;
- if (bytes_written != 0) {
- hs->extensions.sent |= (1u << i);
- }
- // If the difference in lengths is only four bytes then the extension had
- // an empty body.
- last_was_empty = (bytes_written == 4);
- }
- 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(hs, 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 */)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- last_was_empty = false;
- }
- 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;
- size_t padding_len = 0;
- // 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.
- if (last_was_empty && psk_extension_len == 0) {
- padding_len = 1;
- // The addition of the padding extension may push us into the F5 bug.
- header_len += 4 + padding_len;
- }
- // 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 (save for any PSK extension).
- if (header_len > 0xff && header_len < 0x200) {
- // If our calculations already included a padding extension, remove that
- // factor because we're about to change its length.
- if (padding_len != 0) {
- header_len -= 4 + padding_len;
- }
- 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;
- }
- }
- if (padding_len != 0) {
- 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)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- 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)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- // Discard empty extensions blocks.
- if (CBB_len(&extensions) == 0) {
- CBB_discard_child(out);
- }
- return CBB_flush(out);
- }
- bool 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;
- }
- }
- // Discard empty extensions blocks before TLS 1.3.
- if (ssl_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 false;
- }
- static bool ssl_scan_clienthello_tlsext(SSL_HANDSHAKE *hs,
- const SSL_CLIENT_HELLO *client_hello,
- int *out_alert) {
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].init != NULL) {
- kExtensions[i].init(hs);
- }
- }
- hs->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 false;
- }
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
- if (ext == NULL) {
- 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 false;
- }
- }
- 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 false;
- }
- }
- return true;
- }
- bool 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)) {
- ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
- return false;
- }
- if (!ssl_check_clienthello_tlsext(hs)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_TLSEXT);
- return false;
- }
- return true;
- }
- static bool 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 && ssl_protocol_version(ssl) < TLS1_3_VERSION) {
- return true;
- }
- // 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 false;
- }
- 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 false;
- }
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
- if (ext == NULL) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- ERR_add_error_dataf("extension %u", (unsigned)type);
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- return false;
- }
- static_assert(kNumExtensions <= sizeof(hs->extensions.sent) * 8,
- "too many bits");
- if (!(hs->extensions.sent & (1u << ext_index))) {
- // If the extension was never sent then it is illegal.
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- ERR_add_error_dataf("extension :%u", (unsigned)type);
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- return false;
- }
- 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 false;
- }
- }
- 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 false;
- }
- }
- }
- return true;
- }
- static bool ssl_check_clienthello_tlsext(SSL_HANDSHAKE *hs) {
- SSL *const ssl = hs->ssl;
- if (ssl->s3->token_binding_negotiated &&
- !(SSL_get_secure_renegotiation_support(ssl) &&
- SSL_get_extms_support(ssl))) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NEGOTIATED_TB_WITHOUT_EMS_OR_RI);
- ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
- return false;
- }
- int ret = SSL_TLSEXT_ERR_NOACK;
- int al = SSL_AD_UNRECOGNIZED_NAME;
- if (ssl->ctx->servername_callback != 0) {
- ret = ssl->ctx->servername_callback(ssl, &al, ssl->ctx->servername_arg);
- } else if (ssl->session_ctx->servername_callback != 0) {
- ret = ssl->session_ctx->servername_callback(
- ssl, &al, ssl->session_ctx->servername_arg);
- }
- switch (ret) {
- case SSL_TLSEXT_ERR_ALERT_FATAL:
- ssl_send_alert(ssl, SSL3_AL_FATAL, al);
- return false;
- case SSL_TLSEXT_ERR_NOACK:
- hs->should_ack_sni = false;
- return true;
- default:
- return true;
- }
- }
- bool 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)) {
- ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
- return false;
- }
- return true;
- }
- static enum ssl_ticket_aead_result_t decrypt_ticket_with_cipher_ctx(
- Array<uint8_t> *out, EVP_CIPHER_CTX *cipher_ctx, HMAC_CTX *hmac_ctx,
- Span<const uint8_t> ticket) {
- 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.size() < SSL_TICKET_KEY_NAME_LEN + iv_len + 1 + mac_len) {
- // The ticket must be large enough for key name, IV, data, and MAC.
- return ssl_ticket_aead_ignore_ticket;
- }
- // Split the ticket into the ticket and the MAC.
- auto ticket_mac = ticket.subspan(ticket.size() - mac_len);
- ticket = ticket.subspan(0, ticket.size() - mac_len);
- HMAC_Update(hmac_ctx, ticket.data(), ticket.size());
- HMAC_Final(hmac_ctx, mac, NULL);
- assert(mac_len == ticket_mac.size());
- bool mac_ok = CRYPTO_memcmp(mac, ticket_mac.data(), mac_len) == 0;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- mac_ok = true;
- #endif
- if (!mac_ok) {
- return ssl_ticket_aead_ignore_ticket;
- }
- // Decrypt the session data.
- auto ciphertext = ticket.subspan(SSL_TICKET_KEY_NAME_LEN + iv_len);
- Array<uint8_t> plaintext;
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- if (!plaintext.CopyFrom(ciphertext)) {
- return ssl_ticket_aead_error;
- }
- #else
- if (ciphertext.size() >= INT_MAX) {
- return ssl_ticket_aead_ignore_ticket;
- }
- if (!plaintext.Init(ciphertext.size())) {
- return ssl_ticket_aead_error;
- }
- int len1, len2;
- if (!EVP_DecryptUpdate(cipher_ctx, plaintext.data(), &len1, ciphertext.data(),
- (int)ciphertext.size()) ||
- !EVP_DecryptFinal_ex(cipher_ctx, plaintext.data() + len1, &len2)) {
- ERR_clear_error();
- return ssl_ticket_aead_ignore_ticket;
- }
- plaintext.Shrink(static_cast<size_t>(len1) + len2);
- #endif
- *out = std::move(plaintext);
- return ssl_ticket_aead_success;
- }
- static enum ssl_ticket_aead_result_t ssl_decrypt_ticket_with_cb(
- SSL_HANDSHAKE *hs, Array<uint8_t> *out, bool *out_renew_ticket,
- Span<const uint8_t> ticket) {
- assert(ticket.size() >= SSL_TICKET_KEY_NAME_LEN + EVP_MAX_IV_LENGTH);
- ScopedEVP_CIPHER_CTX cipher_ctx;
- ScopedHMAC_CTX hmac_ctx;
- auto name = ticket.subspan(0, SSL_TICKET_KEY_NAME_LEN);
- // The actual IV is shorter, but the length is determined by the callback's
- // chosen cipher. Instead we pass in |EVP_MAX_IV_LENGTH| worth of IV to ensure
- // the callback has enough.
- auto iv = ticket.subspan(SSL_TICKET_KEY_NAME_LEN, EVP_MAX_IV_LENGTH);
- int cb_ret = hs->ssl->session_ctx->ticket_key_cb(
- hs->ssl, const_cast<uint8_t *>(name.data()),
- const_cast<uint8_t *>(iv.data()), cipher_ctx.get(), hmac_ctx.get(),
- 0 /* decrypt */);
- if (cb_ret < 0) {
- return ssl_ticket_aead_error;
- } else if (cb_ret == 0) {
- return ssl_ticket_aead_ignore_ticket;
- } else if (cb_ret == 2) {
- *out_renew_ticket = true;
- } else {
- assert(cb_ret == 1);
- }
- return decrypt_ticket_with_cipher_ctx(out, cipher_ctx.get(), hmac_ctx.get(),
- ticket);
- }
- static enum ssl_ticket_aead_result_t ssl_decrypt_ticket_with_ticket_keys(
- SSL_HANDSHAKE *hs, Array<uint8_t> *out, Span<const uint8_t> ticket) {
- assert(ticket.size() >= SSL_TICKET_KEY_NAME_LEN + EVP_MAX_IV_LENGTH);
- SSL_CTX *ctx = hs->ssl->session_ctx.get();
- // Rotate the ticket key if necessary.
- if (!ssl_ctx_rotate_ticket_encryption_key(ctx)) {
- return ssl_ticket_aead_error;
- }
- const EVP_CIPHER *cipher = EVP_aes_128_cbc();
- auto name = ticket.subspan(0, SSL_TICKET_KEY_NAME_LEN);
- auto iv =
- ticket.subspan(SSL_TICKET_KEY_NAME_LEN, EVP_CIPHER_iv_length(cipher));
- // Pick the matching ticket key and decrypt.
- ScopedEVP_CIPHER_CTX cipher_ctx;
- ScopedHMAC_CTX hmac_ctx;
- {
- MutexReadLock lock(&ctx->lock);
- const TicketKey *key;
- if (ctx->ticket_key_current && name == ctx->ticket_key_current->name) {
- key = ctx->ticket_key_current.get();
- } else if (ctx->ticket_key_prev && name == ctx->ticket_key_prev->name) {
- key = ctx->ticket_key_prev.get();
- } else {
- return ssl_ticket_aead_ignore_ticket;
- }
- if (!HMAC_Init_ex(hmac_ctx.get(), key->hmac_key, sizeof(key->hmac_key),
- tlsext_tick_md(), NULL) ||
- !EVP_DecryptInit_ex(cipher_ctx.get(), cipher, NULL,
- key->aes_key, iv.data())) {
- return ssl_ticket_aead_error;
- }
- }
- return decrypt_ticket_with_cipher_ctx(out, cipher_ctx.get(), hmac_ctx.get(),
- ticket);
- }
- static enum ssl_ticket_aead_result_t ssl_decrypt_ticket_with_method(
- SSL_HANDSHAKE *hs, Array<uint8_t> *out, bool *out_renew_ticket,
- Span<const uint8_t> ticket) {
- Array<uint8_t> plaintext;
- if (!plaintext.Init(ticket.size())) {
- 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 =
- hs->ssl->session_ctx->ticket_aead_method->open(
- hs->ssl, plaintext.data(), &plaintext_len, ticket.size(),
- ticket.data(), ticket.size());
- if (result != ssl_ticket_aead_success) {
- return result;
- }
- plaintext.Shrink(plaintext_len);
- *out = std::move(plaintext);
- return ssl_ticket_aead_success;
- }
- enum ssl_ticket_aead_result_t ssl_process_ticket(
- SSL_HANDSHAKE *hs, UniquePtr<SSL_SESSION> *out_session,
- bool *out_renew_ticket, Span<const uint8_t> ticket,
- Span<const uint8_t> session_id) {
- *out_renew_ticket = false;
- out_session->reset();
- if ((SSL_get_options(hs->ssl) & SSL_OP_NO_TICKET) ||
- session_id.size() > SSL_MAX_SSL_SESSION_ID_LENGTH) {
- return ssl_ticket_aead_ignore_ticket;
- }
- Array<uint8_t> plaintext;
- enum ssl_ticket_aead_result_t result;
- if (hs->ssl->session_ctx->ticket_aead_method != NULL) {
- result = ssl_decrypt_ticket_with_method(hs, &plaintext, out_renew_ticket,
- ticket);
- } else {
- // Ensure there is room for the key name and the largest IV |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.size() < SSL_TICKET_KEY_NAME_LEN + EVP_MAX_IV_LENGTH) {
- return ssl_ticket_aead_ignore_ticket;
- }
- if (hs->ssl->session_ctx->ticket_key_cb != NULL) {
- result =
- ssl_decrypt_ticket_with_cb(hs, &plaintext, out_renew_ticket, ticket);
- } else {
- result = ssl_decrypt_ticket_with_ticket_keys(hs, &plaintext, ticket);
- }
- }
- if (result != ssl_ticket_aead_success) {
- return result;
- }
- // Decode the session.
- UniquePtr<SSL_SESSION> session(SSL_SESSION_from_bytes(
- plaintext.data(), plaintext.size(), hs->ssl->ctx.get()));
- if (!session) {
- 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.data(), session_id.size());
- session->session_id_length = session_id.size();
- *out_session = std::move(session);
- return ssl_ticket_aead_success;
- }
- bool tls1_parse_peer_sigalgs(SSL_HANDSHAKE *hs, const CBS *in_sigalgs) {
- // Extension ignored for inappropriate versions
- if (ssl_protocol_version(hs->ssl) < TLS1_2_VERSION) {
- return true;
- }
- // In all contexts, the signature algorithms list may not be empty. (It may be
- // omitted by clients in TLS 1.2, but then the entire extension is omitted.)
- return CBS_len(in_sigalgs) != 0 &&
- parse_u16_array(in_sigalgs, &hs->peer_sigalgs);
- }
- bool tls1_get_legacy_signature_algorithm(uint16_t *out, const EVP_PKEY *pkey) {
- switch (EVP_PKEY_id(pkey)) {
- case EVP_PKEY_RSA:
- *out = SSL_SIGN_RSA_PKCS1_MD5_SHA1;
- return true;
- case EVP_PKEY_EC:
- *out = SSL_SIGN_ECDSA_SHA1;
- return true;
- default:
- return false;
- }
- }
- bool tls1_choose_signature_algorithm(SSL_HANDSHAKE *hs, uint16_t *out) {
- SSL *const ssl = hs->ssl;
- CERT *cert = hs->config->cert.get();
- DC *dc = cert->dc.get();
- // Before TLS 1.2, the signature algorithm isn't negotiated as part of the
- // handshake.
- if (ssl_protocol_version(ssl) < TLS1_2_VERSION) {
- if (!tls1_get_legacy_signature_algorithm(out, hs->local_pubkey.get())) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return false;
- }
- return true;
- }
- Span<const uint16_t> sigalgs = kSignSignatureAlgorithms;
- if (ssl_signing_with_dc(hs)) {
- sigalgs = MakeConstSpan(&dc->expected_cert_verify_algorithm, 1);
- } else if (!cert->sigalgs.empty()) {
- sigalgs = cert->sigalgs;
- }
- Span<const uint16_t> peer_sigalgs = tls1_get_peer_verify_algorithms(hs);
- for (uint16_t sigalg : sigalgs) {
- // 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, sigalg)) {
- continue;
- }
- for (uint16_t peer_sigalg : peer_sigalgs) {
- if (sigalg == peer_sigalg) {
- *out = sigalg;
- return true;
- }
- }
- }
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return false;
- }
- Span<const uint16_t> tls1_get_peer_verify_algorithms(const SSL_HANDSHAKE *hs) {
- Span<const uint16_t> peer_sigalgs = hs->peer_sigalgs;
- if (peer_sigalgs.empty() && ssl_protocol_version(hs->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;
- }
- return peer_sigalgs;
- }
- bool tls1_verify_channel_id(SSL_HANDSHAKE *hs, const SSLMessage &msg) {
- SSL *const ssl = hs->ssl;
- // A Channel ID handshake message is structured to contain multiple
- // extensions, but the only one that can be present is Channel ID.
- uint16_t extension_type;
- CBS channel_id = msg.body, extension;
- 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);
- ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
- return false;
- }
- UniquePtr<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 false;
- }
- UniquePtr<ECDSA_SIG> sig(ECDSA_SIG_new());
- UniquePtr<BIGNUM> x(BN_new()), y(BN_new());
- if (!sig || !x || !y) {
- return false;
- }
- const uint8_t *p = CBS_data(&extension);
- if (BN_bin2bn(p + 0, 32, x.get()) == NULL ||
- BN_bin2bn(p + 32, 32, y.get()) == NULL ||
- BN_bin2bn(p + 64, 32, sig->r) == NULL ||
- BN_bin2bn(p + 96, 32, sig->s) == NULL) {
- return false;
- }
- UniquePtr<EC_KEY> key(EC_KEY_new());
- UniquePtr<EC_POINT> point(EC_POINT_new(p256.get()));
- if (!key || !point ||
- !EC_POINT_set_affine_coordinates_GFp(p256.get(), point.get(), x.get(),
- y.get(), nullptr) ||
- !EC_KEY_set_group(key.get(), p256.get()) ||
- !EC_KEY_set_public_key(key.get(), point.get())) {
- return false;
- }
- uint8_t digest[EVP_MAX_MD_SIZE];
- size_t digest_len;
- if (!tls1_channel_id_hash(hs, digest, &digest_len)) {
- return false;
- }
- bool sig_ok = ECDSA_do_verify(digest, digest_len, sig.get(), key.get());
- #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
- sig_ok = true;
- ERR_clear_error();
- #endif
- if (!sig_ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_SIGNATURE_INVALID);
- ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
- ssl->s3->channel_id_valid = false;
- return false;
- }
- OPENSSL_memcpy(ssl->s3->channel_id, p, 64);
- return true;
- }
- bool tls1_write_channel_id(SSL_HANDSHAKE *hs, CBB *cbb) {
- uint8_t digest[EVP_MAX_MD_SIZE];
- size_t digest_len;
- if (!tls1_channel_id_hash(hs, digest, &digest_len)) {
- return false;
- }
- EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(hs->config->channel_id_private.get());
- if (ec_key == nullptr) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return false;
- }
- UniquePtr<BIGNUM> x(BN_new()), y(BN_new());
- if (!x || !y ||
- !EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(ec_key),
- EC_KEY_get0_public_key(ec_key),
- x.get(), y.get(), nullptr)) {
- return false;
- }
- UniquePtr<ECDSA_SIG> sig(ECDSA_do_sign(digest, digest_len, ec_key));
- if (!sig) {
- return false;
- }
- CBB child;
- if (!CBB_add_u16(cbb, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16_length_prefixed(cbb, &child) ||
- !BN_bn2cbb_padded(&child, 32, x.get()) ||
- !BN_bn2cbb_padded(&child, 32, y.get()) ||
- !BN_bn2cbb_padded(&child, 32, sig->r) ||
- !BN_bn2cbb_padded(&child, 32, sig->s) ||
- !CBB_flush(cbb)) {
- return false;
- }
- return true;
- }
- bool tls1_channel_id_hash(SSL_HANDSHAKE *hs, uint8_t *out, size_t *out_len) {
- SSL *const ssl = hs->ssl;
- if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
- Array<uint8_t> msg;
- if (!tls13_get_cert_verify_signature_input(hs, &msg,
- ssl_cert_verify_channel_id)) {
- return false;
- }
- SHA256(msg.data(), msg.size(), out);
- *out_len = SHA256_DIGEST_LENGTH;
- return true;
- }
- 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 false;
- }
- 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 (!hs->transcript.GetHash(hs_hash, &hs_hash_len)) {
- return false;
- }
- SHA256_Update(&ctx, hs_hash, (size_t)hs_hash_len);
- SHA256_Final(out, &ctx);
- *out_len = SHA256_DIGEST_LENGTH;
- return true;
- }
- bool 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 false;
- }
- static_assert(
- sizeof(hs->new_session->original_handshake_hash) == EVP_MAX_MD_SIZE,
- "original_handshake_hash is too small");
- size_t digest_len;
- if (!hs->transcript.GetHash(hs->new_session->original_handshake_hash,
- &digest_len)) {
- return false;
- }
- static_assert(EVP_MAX_MD_SIZE <= 0xff,
- "EVP_MAX_MD_SIZE does not fit in uint8_t");
- hs->new_session->original_handshake_hash_len = (uint8_t)digest_len;
- return true;
- }
- bool ssl_do_channel_id_callback(SSL_HANDSHAKE *hs) {
- if (hs->config->channel_id_private != NULL ||
- hs->ssl->ctx->channel_id_cb == NULL) {
- return true;
- }
- EVP_PKEY *key = NULL;
- hs->ssl->ctx->channel_id_cb(hs->ssl, &key);
- if (key == NULL) {
- // The caller should try again later.
- return true;
- }
- UniquePtr<EVP_PKEY> free_key(key);
- return SSL_set1_tls_channel_id(hs->ssl, key);
- }
- bool 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 false;
- }
- while (CBS_len(&sct_list) > 0) {
- CBS sct;
- if (!CBS_get_u16_length_prefixed(&sct_list, &sct) ||
- CBS_len(&sct) == 0) {
- return false;
- }
- }
- return true;
- }
- BSSL_NAMESPACE_END
- using namespace bssl;
- 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;
- }
- void SSL_CTX_set_ed25519_enabled(SSL_CTX *ctx, int enabled) {
- ctx->ed25519_enabled = !!enabled;
- }
- void SSL_CTX_set_rsa_pss_rsae_certs_enabled(SSL_CTX *ctx, int enabled) {
- ctx->rsa_pss_rsae_certs_enabled = !!enabled;
- }
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