|
- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.]
- */
- /* ====================================================================
- * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@openssl.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
- *
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
- *
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com). */
-
- #include <openssl/ssl.h>
-
- #include <assert.h>
- #include <limits.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include <openssl/bytestring.h>
- #include <openssl/digest.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/hmac.h>
- #include <openssl/mem.h>
- #include <openssl/nid.h>
- #include <openssl/rand.h>
- #include <openssl/type_check.h>
-
- #include "internal.h"
- #include "../crypto/internal.h"
-
-
- static int ssl_check_clienthello_tlsext(SSL *ssl);
- static int ssl_check_serverhello_tlsext(SSL *ssl);
-
- static int compare_uint16_t(const void *p1, const void *p2) {
- uint16_t u1 = *((const uint16_t *)p1);
- uint16_t u2 = *((const uint16_t *)p2);
- if (u1 < u2) {
- return -1;
- } else if (u1 > u2) {
- return 1;
- } else {
- return 0;
- }
- }
-
- /* Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
- * more than one extension of the same type in a ClientHello or ServerHello.
- * This function does an initial scan over the extensions block to filter those
- * out. */
- static int tls1_check_duplicate_extensions(const CBS *cbs) {
- CBS extensions = *cbs;
- size_t num_extensions = 0, i = 0;
- uint16_t *extension_types = NULL;
- int ret = 0;
-
- /* First pass: count the extensions. */
- while (CBS_len(&extensions) > 0) {
- uint16_t type;
- CBS extension;
-
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- goto done;
- }
-
- num_extensions++;
- }
-
- if (num_extensions == 0) {
- return 1;
- }
-
- extension_types = OPENSSL_malloc(sizeof(uint16_t) * num_extensions);
- if (extension_types == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto done;
- }
-
- /* Second pass: gather the extension types. */
- extensions = *cbs;
- for (i = 0; i < num_extensions; i++) {
- CBS extension;
-
- if (!CBS_get_u16(&extensions, &extension_types[i]) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- /* This should not happen. */
- goto done;
- }
- }
- assert(CBS_len(&extensions) == 0);
-
- /* Sort the extensions and make sure there are no duplicates. */
- qsort(extension_types, num_extensions, sizeof(uint16_t), compare_uint16_t);
- for (i = 1; i < num_extensions; i++) {
- if (extension_types[i - 1] == extension_types[i]) {
- goto done;
- }
- }
-
- ret = 1;
-
- done:
- OPENSSL_free(extension_types);
- return ret;
- }
-
- int ssl_early_callback_init(SSL *ssl, struct ssl_early_callback_ctx *ctx,
- const uint8_t *in, size_t in_len) {
- memset(ctx, 0, sizeof(*ctx));
- ctx->ssl = ssl;
- ctx->client_hello = in;
- ctx->client_hello_len = in_len;
-
- CBS client_hello, random, session_id;
- CBS_init(&client_hello, ctx->client_hello, ctx->client_hello_len);
- if (!CBS_get_u16(&client_hello, &ctx->version) ||
- !CBS_get_bytes(&client_hello, &random, SSL3_RANDOM_SIZE) ||
- !CBS_get_u8_length_prefixed(&client_hello, &session_id) ||
- CBS_len(&session_id) > SSL_MAX_SSL_SESSION_ID_LENGTH) {
- return 0;
- }
-
- ctx->random = CBS_data(&random);
- ctx->random_len = CBS_len(&random);
- ctx->session_id = CBS_data(&session_id);
- ctx->session_id_len = CBS_len(&session_id);
-
- /* Skip past DTLS cookie */
- if (SSL_is_dtls(ctx->ssl)) {
- CBS cookie;
- if (!CBS_get_u8_length_prefixed(&client_hello, &cookie) ||
- CBS_len(&cookie) > DTLS1_COOKIE_LENGTH) {
- return 0;
- }
- }
-
- CBS cipher_suites, compression_methods;
- if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
- CBS_len(&cipher_suites) < 2 || (CBS_len(&cipher_suites) & 1) != 0 ||
- !CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
- CBS_len(&compression_methods) < 1) {
- return 0;
- }
-
- ctx->cipher_suites = CBS_data(&cipher_suites);
- ctx->cipher_suites_len = CBS_len(&cipher_suites);
- ctx->compression_methods = CBS_data(&compression_methods);
- ctx->compression_methods_len = CBS_len(&compression_methods);
-
- /* If the ClientHello ends here then it's valid, but doesn't have any
- * extensions. (E.g. SSLv3.) */
- if (CBS_len(&client_hello) == 0) {
- ctx->extensions = NULL;
- ctx->extensions_len = 0;
- return 1;
- }
-
- /* Extract extensions and check it is valid. */
- CBS extensions;
- if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) ||
- !tls1_check_duplicate_extensions(&extensions) ||
- CBS_len(&client_hello) != 0) {
- return 0;
- }
-
- ctx->extensions = CBS_data(&extensions);
- ctx->extensions_len = CBS_len(&extensions);
-
- return 1;
- }
-
- int ssl_early_callback_get_extension(const struct ssl_early_callback_ctx *ctx,
- CBS *out, uint16_t extension_type) {
- CBS extensions;
- CBS_init(&extensions, ctx->extensions, ctx->extensions_len);
- while (CBS_len(&extensions) != 0) {
- /* Decode the next extension. */
- uint16_t type;
- CBS extension;
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- return 0;
- }
-
- if (type == extension_type) {
- *out = extension;
- return 1;
- }
- }
-
- return 0;
- }
-
- int SSL_early_callback_ctx_extension_get(
- const struct ssl_early_callback_ctx *ctx, uint16_t extension_type,
- const uint8_t **out_data, size_t *out_len) {
- CBS cbs;
- if (!ssl_early_callback_get_extension(ctx, &cbs, extension_type)) {
- return 0;
- }
-
- *out_data = CBS_data(&cbs);
- *out_len = CBS_len(&cbs);
- return 1;
- }
-
- static const uint16_t kDefaultGroups[] = {
- SSL_CURVE_X25519,
- SSL_CURVE_SECP256R1,
- SSL_CURVE_SECP384R1,
- #if defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_CURVE_SECP521R1,
- #endif
- };
-
- void tls1_get_grouplist(SSL *ssl, int get_peer_groups,
- const uint16_t **out_group_ids,
- size_t *out_group_ids_len) {
- if (get_peer_groups) {
- /* Only clients send a supported group list, so this function is only
- * called on the server. */
- assert(ssl->server);
- *out_group_ids = ssl->s3->tmp.peer_supported_group_list;
- *out_group_ids_len = ssl->s3->tmp.peer_supported_group_list_len;
- return;
- }
-
- *out_group_ids = ssl->supported_group_list;
- *out_group_ids_len = ssl->supported_group_list_len;
- if (!*out_group_ids) {
- *out_group_ids = kDefaultGroups;
- *out_group_ids_len = OPENSSL_ARRAY_SIZE(kDefaultGroups);
- }
- }
-
- int tls1_get_shared_group(SSL *ssl, uint16_t *out_group_id) {
- const uint16_t *groups, *peer_groups, *pref, *supp;
- size_t groups_len, peer_groups_len, pref_len, supp_len, i, j;
-
- /* Can't do anything on client side */
- if (ssl->server == 0) {
- return 0;
- }
-
- tls1_get_grouplist(ssl, 0 /* local groups */, &groups, &groups_len);
- tls1_get_grouplist(ssl, 1 /* peer groups */, &peer_groups, &peer_groups_len);
-
- if (peer_groups_len == 0) {
- /* 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. */
- return 0;
- }
-
- if (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
- pref = groups;
- pref_len = groups_len;
- supp = peer_groups;
- supp_len = peer_groups_len;
- } else {
- pref = peer_groups;
- pref_len = peer_groups_len;
- supp = groups;
- supp_len = groups_len;
- }
-
- for (i = 0; i < pref_len; i++) {
- for (j = 0; j < supp_len; j++) {
- if (pref[i] == supp[j]) {
- *out_group_id = pref[i];
- return 1;
- }
- }
- }
-
- return 0;
- }
-
- int tls1_set_curves(uint16_t **out_group_ids, size_t *out_group_ids_len,
- const int *curves, size_t ncurves) {
- uint16_t *group_ids;
- size_t i;
-
- group_ids = OPENSSL_malloc(ncurves * sizeof(uint16_t));
- if (group_ids == NULL) {
- return 0;
- }
-
- for (i = 0; i < ncurves; i++) {
- if (!ssl_nid_to_group_id(&group_ids[i], curves[i])) {
- OPENSSL_free(group_ids);
- return 0;
- }
- }
-
- OPENSSL_free(*out_group_ids);
- *out_group_ids = group_ids;
- *out_group_ids_len = ncurves;
-
- return 1;
- }
-
- /* tls1_curve_params_from_ec_key sets |*out_group_id| and |*out_comp_id| to the
- * TLS group ID and point format, respectively, for |ec|. It returns one on
- * success and zero on failure. */
- static int tls1_curve_params_from_ec_key(uint16_t *out_group_id,
- uint8_t *out_comp_id, EC_KEY *ec) {
- int nid;
- uint16_t id;
- const EC_GROUP *grp;
-
- if (ec == NULL) {
- return 0;
- }
-
- grp = EC_KEY_get0_group(ec);
- if (grp == NULL) {
- return 0;
- }
-
- /* Determine group ID */
- nid = EC_GROUP_get_curve_name(grp);
- if (!ssl_nid_to_group_id(&id, nid)) {
- return 0;
- }
-
- /* Set the named group ID. Arbitrary explicit groups are not supported. */
- *out_group_id = id;
-
- if (out_comp_id) {
- if (EC_KEY_get0_public_key(ec) == NULL) {
- return 0;
- }
- if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) {
- *out_comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
- } else {
- *out_comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
- }
- }
-
- return 1;
- }
-
- /* tls1_check_group_id returns one if |group_id| is consistent with both our
- * and the peer's group preferences. Note: if called as the client, only our
- * preferences are checked; the peer (the server) does not send preferences. */
- int tls1_check_group_id(SSL *ssl, uint16_t group_id) {
- const uint16_t *groups;
- size_t groups_len, i, get_peer_groups;
-
- /* Check against our list, then the peer's list. */
- for (get_peer_groups = 0; get_peer_groups <= 1; get_peer_groups++) {
- if (get_peer_groups && !ssl->server) {
- /* Servers do not present a preference list so, if we are a client, only
- * check our list. */
- continue;
- }
-
- tls1_get_grouplist(ssl, get_peer_groups, &groups, &groups_len);
- if (get_peer_groups && groups_len == 0) {
- /* 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. */
- continue;
- }
- for (i = 0; i < groups_len; i++) {
- if (groups[i] == group_id) {
- break;
- }
- }
-
- if (i == groups_len) {
- return 0;
- }
- }
-
- return 1;
- }
-
- int tls1_check_ec_cert(SSL *ssl, X509 *x) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- /* In TLS 1.3, the ECDSA curve is negotiated via signature algorithms. */
- return 1;
- }
-
- EVP_PKEY *pkey = X509_get_pubkey(x);
- if (pkey == NULL) {
- return 0;
- }
-
- int ret = 0;
- uint16_t group_id;
- uint8_t comp_id;
- EC_KEY *ec_key = EVP_PKEY_get0_EC_KEY(pkey);
- if (ec_key == NULL ||
- !tls1_curve_params_from_ec_key(&group_id, &comp_id, ec_key) ||
- !tls1_check_group_id(ssl, group_id) ||
- comp_id != TLSEXT_ECPOINTFORMAT_uncompressed) {
- goto done;
- }
-
- ret = 1;
-
- done:
- EVP_PKEY_free(pkey);
- return ret;
- }
-
- /* List of supported signature algorithms and hashes. Should make this
- * customisable at some point, for now include everything we support. */
-
- static const uint16_t kDefaultSignatureAlgorithms[] = {
- /* For now, do not ship RSA-PSS signature algorithms on Android's system
- * BoringSSL. Once TLS 1.3 is finalized and the change in Chrome has stuck,
- * restore them. */
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA512,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA512,
- SSL_SIGN_ECDSA_SECP521R1_SHA512,
-
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA384,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA384,
- SSL_SIGN_ECDSA_SECP384R1_SHA384,
-
- #if !defined(BORINGSSL_ANDROID_SYSTEM)
- SSL_SIGN_RSA_PSS_SHA256,
- #endif
- SSL_SIGN_RSA_PKCS1_SHA256,
- SSL_SIGN_ECDSA_SECP256R1_SHA256,
-
- SSL_SIGN_RSA_PKCS1_SHA1,
- SSL_SIGN_ECDSA_SHA1,
- };
-
- size_t tls12_get_psigalgs(SSL *ssl, const uint16_t **psigs) {
- *psigs = kDefaultSignatureAlgorithms;
- return OPENSSL_ARRAY_SIZE(kDefaultSignatureAlgorithms);
- }
-
- int tls12_check_peer_sigalg(SSL *ssl, int *out_alert, uint16_t sigalg) {
- const uint16_t *sent_sigs;
- size_t sent_sigslen, i;
-
- /* Check signature matches a type we sent */
- sent_sigslen = tls12_get_psigalgs(ssl, &sent_sigs);
- for (i = 0; i < sent_sigslen; i++) {
- if (sigalg == sent_sigs[i]) {
- break;
- }
- }
-
- if (i == sent_sigslen) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SIGNATURE_TYPE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- /* Get a mask of disabled algorithms: an algorithm is disabled if it isn't
- * supported or doesn't appear in supported signature algorithms. Unlike
- * ssl_cipher_get_disabled this applies to a specific session and not global
- * settings. */
- void ssl_set_client_disabled(SSL *ssl) {
- CERT *c = ssl->cert;
- int have_rsa = 0, have_ecdsa = 0;
- c->mask_a = 0;
- c->mask_k = 0;
-
- /* Now go through all signature algorithms seeing if we support any for RSA,
- * DSA, ECDSA. Do this for all versions not just TLS 1.2. */
- const uint16_t *sigalgs;
- size_t num_sigalgs = tls12_get_psigalgs(ssl, &sigalgs);
- for (size_t i = 0; i < num_sigalgs; i++) {
- switch (sigalgs[i]) {
- case SSL_SIGN_RSA_PSS_SHA512:
- case SSL_SIGN_RSA_PSS_SHA384:
- case SSL_SIGN_RSA_PSS_SHA256:
- case SSL_SIGN_RSA_PKCS1_SHA512:
- case SSL_SIGN_RSA_PKCS1_SHA384:
- case SSL_SIGN_RSA_PKCS1_SHA256:
- case SSL_SIGN_RSA_PKCS1_SHA1:
- have_rsa = 1;
- break;
-
- case SSL_SIGN_ECDSA_SECP521R1_SHA512:
- case SSL_SIGN_ECDSA_SECP384R1_SHA384:
- case SSL_SIGN_ECDSA_SECP256R1_SHA256:
- case SSL_SIGN_ECDSA_SHA1:
- have_ecdsa = 1;
- break;
- }
- }
-
- /* Disable auth if we don't include any appropriate signature algorithms. */
- if (!have_rsa) {
- c->mask_a |= SSL_aRSA;
- }
- if (!have_ecdsa) {
- c->mask_a |= SSL_aECDSA;
- }
-
- /* with PSK there must be client callback set */
- if (!ssl->psk_client_callback) {
- c->mask_a |= SSL_aPSK;
- c->mask_k |= SSL_kPSK;
- }
- }
-
- /* tls_extension represents a TLS extension that is handled internally. The
- * |init| function is called for each handshake, before any other functions of
- * the extension. Then the add and parse callbacks are called as needed.
- *
- * The parse callbacks receive a |CBS| that contains the contents of the
- * extension (i.e. not including the type and length bytes). If an extension is
- * not received then the parse callbacks will be called with a NULL CBS so that
- * they can do any processing needed to handle the absence of an extension.
- *
- * The add callbacks receive a |CBB| to which the extension can be appended but
- * the function is responsible for appending the type and length bytes too.
- *
- * All callbacks return one for success and zero for error. If a parse function
- * returns zero then a fatal alert with value |*out_alert| will be sent. If
- * |*out_alert| isn't set, then a |decode_error| alert will be sent. */
- struct tls_extension {
- uint16_t value;
- void (*init)(SSL *ssl);
-
- int (*add_clienthello)(SSL *ssl, CBB *out);
- int (*parse_serverhello)(SSL *ssl, uint8_t *out_alert, CBS *contents);
-
- int (*parse_clienthello)(SSL *ssl, uint8_t *out_alert, CBS *contents);
- int (*add_serverhello)(SSL *ssl, CBB *out);
- };
-
- static int forbid_parse_serverhello(SSL *ssl, uint8_t *out_alert, CBS *contents) {
- if (contents != NULL) {
- /* Servers MUST NOT send this extension. */
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- return 0;
- }
-
- return 1;
- }
-
- static int ignore_parse_clienthello(SSL *ssl, uint8_t *out_alert, CBS *contents) {
- /* This extension from the client is handled elsewhere. */
- return 1;
- }
-
- static int dont_add_serverhello(SSL *ssl, CBB *out) {
- return 1;
- }
-
- /* Server name indication (SNI).
- *
- * https://tools.ietf.org/html/rfc6066#section-3. */
-
- static void ext_sni_init(SSL *ssl) {
- ssl->s3->tmp.should_ack_sni = 0;
- }
-
- static int ext_sni_add_clienthello(SSL *ssl, CBB *out) {
- if (ssl->tlsext_hostname == NULL) {
- return 1;
- }
-
- CBB contents, server_name_list, name;
- if (!CBB_add_u16(out, TLSEXT_TYPE_server_name) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &server_name_list) ||
- !CBB_add_u8(&server_name_list, TLSEXT_NAMETYPE_host_name) ||
- !CBB_add_u16_length_prefixed(&server_name_list, &name) ||
- !CBB_add_bytes(&name, (const uint8_t *)ssl->tlsext_hostname,
- strlen(ssl->tlsext_hostname)) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sni_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- assert(ssl->tlsext_hostname != NULL);
-
- if (ssl->session == NULL) {
- assert(ssl->s3->new_session->tlsext_hostname == NULL);
- ssl->s3->new_session->tlsext_hostname = BUF_strdup(ssl->tlsext_hostname);
- if (!ssl->s3->new_session->tlsext_hostname) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
- }
-
- return 1;
- }
-
- static int ext_sni_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS server_name_list, host_name;
- uint8_t name_type;
- if (!CBS_get_u16_length_prefixed(contents, &server_name_list) ||
- !CBS_get_u8(&server_name_list, &name_type) ||
- /* Although the server_name extension was intended to be extensible to
- * new name types and multiple names, OpenSSL 1.0.x had a bug which meant
- * different name types will cause an error. Further, RFC 4366 originally
- * defined syntax inextensibly. RFC 6066 corrected this mistake, but
- * adding new name types is no longer feasible.
- *
- * Act as if the extensibility does not exist to simplify parsing. */
- !CBS_get_u16_length_prefixed(&server_name_list, &host_name) ||
- CBS_len(&server_name_list) != 0 ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- if (name_type != TLSEXT_NAMETYPE_host_name ||
- CBS_len(&host_name) == 0 ||
- CBS_len(&host_name) > TLSEXT_MAXLEN_host_name ||
- CBS_contains_zero_byte(&host_name)) {
- *out_alert = SSL_AD_UNRECOGNIZED_NAME;
- return 0;
- }
-
- /* TODO(davidben): SNI should be resolved before resumption. We have the
- * early callback as a replacement, but we should fix the current callback
- * and avoid the need for |SSL_CTX_set_session_id_context|. */
- if (ssl->session == NULL) {
- assert(ssl->s3->new_session->tlsext_hostname == NULL);
-
- /* Copy the hostname as a string. */
- if (!CBS_strdup(&host_name, &ssl->s3->new_session->tlsext_hostname)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- ssl->s3->tmp.should_ack_sni = 1;
- }
-
- return 1;
- }
-
- static int ext_sni_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl->session != NULL ||
- !ssl->s3->tmp.should_ack_sni ||
- ssl->s3->new_session->tlsext_hostname == NULL) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_server_name) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Renegotiation indication.
- *
- * https://tools.ietf.org/html/rfc5746 */
-
- static int ext_ri_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* Renegotiation indication is not necessary in TLS 1.3. */
- if (min_version >= TLS1_3_VERSION) {
- return 1;
- }
-
- CBB contents, prev_finished;
- if (!CBB_add_u16(out, TLSEXT_TYPE_renegotiate) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &prev_finished) ||
- !CBB_add_bytes(&prev_finished, ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ri_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents != NULL && ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* Servers may not switch between omitting the extension and supporting it.
- * See RFC 5746, sections 3.5 and 4.2. */
- if (ssl->s3->initial_handshake_complete &&
- (contents != NULL) != ssl->s3->send_connection_binding) {
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- return 0;
- }
-
- if (contents == NULL) {
- /* Strictly speaking, if we want to avoid an attack we should *always* see
- * RI even on initial ServerHello because the client doesn't see any
- * renegotiation during an attack. However this would mean we could not
- * connect to any server which doesn't support RI.
- *
- * OpenSSL has |SSL_OP_LEGACY_SERVER_CONNECT| to control this, but in
- * practical terms every client sets it so it's just assumed here. */
- return 1;
- }
-
- const size_t expected_len = ssl->s3->previous_client_finished_len +
- ssl->s3->previous_server_finished_len;
-
- /* Check for logic errors */
- assert(!expected_len || ssl->s3->previous_client_finished_len);
- assert(!expected_len || ssl->s3->previous_server_finished_len);
-
- /* Parse out the extension contents. */
- CBS renegotiated_connection;
- if (!CBS_get_u8_length_prefixed(contents, &renegotiated_connection) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_ENCODING_ERR);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- /* Check that the extension matches. */
- if (CBS_len(&renegotiated_connection) != expected_len) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
-
- const uint8_t *d = CBS_data(&renegotiated_connection);
- if (CRYPTO_memcmp(d, ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
- d += ssl->s3->previous_client_finished_len;
-
- if (CRYPTO_memcmp(d, ssl->s3->previous_server_finished,
- ssl->s3->previous_server_finished_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
- ssl->s3->send_connection_binding = 1;
-
- return 1;
- }
-
- static int ext_ri_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- /* Renegotiation isn't supported as a server so this function should never be
- * called after the initial handshake. */
- assert(!ssl->s3->initial_handshake_complete);
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (contents == NULL) {
- return 1;
- }
-
- CBS renegotiated_connection;
- if (!CBS_get_u8_length_prefixed(contents, &renegotiated_connection) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_ENCODING_ERR);
- return 0;
- }
-
- /* Check that the extension matches */
- if (!CBS_mem_equal(&renegotiated_connection,
- ssl->s3->previous_client_finished,
- ssl->s3->previous_client_finished_len)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_MISMATCH);
- *out_alert = SSL_AD_HANDSHAKE_FAILURE;
- return 0;
- }
-
- ssl->s3->send_connection_binding = 1;
-
- return 1;
- }
-
- static int ext_ri_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- 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_add_bytes(&prev_finished, ssl->s3->previous_server_finished,
- ssl->s3->previous_server_finished_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Extended Master Secret.
- *
- * https://tools.ietf.org/html/rfc7627 */
-
- static int ext_ems_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* Extended master secret is not necessary in TLS 1.3. */
- if (min_version >= TLS1_3_VERSION || max_version <= SSL3_VERSION) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ems_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- /* Whether EMS is negotiated may not change on renegotation. */
- if (ssl->s3->initial_handshake_complete) {
- if ((contents != NULL) != ssl->s3->tmp.extended_master_secret) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_RENEGOTIATION_EMS_MISMATCH);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION ||
- ssl->version == SSL3_VERSION) {
- return 0;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tmp.extended_master_secret = 1;
- return 1;
- }
-
- static int ext_ems_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION ||
- ssl->version == SSL3_VERSION) {
- return 1;
- }
-
- if (contents == NULL) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tmp.extended_master_secret = 1;
- return 1;
- }
-
- static int ext_ems_add_serverhello(SSL *ssl, CBB *out) {
- if (!ssl->s3->tmp.extended_master_secret) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_extended_master_secret) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Session tickets.
- *
- * https://tools.ietf.org/html/rfc5077 */
-
- static int ext_ticket_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- /* TLS 1.3 uses a different ticket extension. */
- if (min_version >= TLS1_3_VERSION ||
- SSL_get_options(ssl) & SSL_OP_NO_TICKET) {
- return 1;
- }
-
- const uint8_t *ticket_data = NULL;
- int ticket_len = 0;
-
- /* Renegotiation does not participate in session resumption. However, still
- * advertise the extension to avoid potentially breaking servers which carry
- * over the state from the previous handshake, such as OpenSSL servers
- * without upstream's 3c3f0259238594d77264a78944d409f2127642c4. */
- if (!ssl->s3->initial_handshake_complete &&
- ssl->session != NULL &&
- ssl->session->tlsext_tick != NULL &&
- /* Don't send TLS 1.3 session tickets in the ticket extension. */
- ssl->method->version_from_wire(ssl->session->ssl_version) <
- TLS1_3_VERSION) {
- ticket_data = ssl->session->tlsext_tick;
- ticket_len = ssl->session->tlsext_ticklen;
- }
-
- CBB ticket;
- if (!CBB_add_u16(out, TLSEXT_TYPE_session_ticket) ||
- !CBB_add_u16_length_prefixed(out, &ticket) ||
- !CBB_add_bytes(&ticket, ticket_data, ticket_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ticket_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- ssl->tlsext_ticket_expected = 0;
-
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* If |SSL_OP_NO_TICKET| is set then no extension will have been sent and
- * this function should never be called, even if the server tries to send the
- * extension. */
- assert((SSL_get_options(ssl) & SSL_OP_NO_TICKET) == 0);
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->tlsext_ticket_expected = 1;
- return 1;
- }
-
- static int ext_ticket_add_serverhello(SSL *ssl, CBB *out) {
- if (!ssl->tlsext_ticket_expected) {
- return 1;
- }
-
- /* If |SSL_OP_NO_TICKET| is set, |tlsext_ticket_expected| should never be
- * true. */
- assert((SSL_get_options(ssl) & SSL_OP_NO_TICKET) == 0);
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_session_ticket) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Signature Algorithms.
- *
- * https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1 */
-
- static int ext_sigalgs_add_clienthello(SSL *ssl, CBB *out) {
- if (ssl->method->version_from_wire(ssl->client_version) < TLS1_2_VERSION) {
- return 1;
- }
-
- const uint16_t *sigalgs;
- const size_t num_sigalgs = tls12_get_psigalgs(ssl, &sigalgs);
-
- 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)) {
- return 0;
- }
-
- for (size_t i = 0; i < num_sigalgs; i++) {
- if (!CBB_add_u16(&sigalgs_cbb, sigalgs[i])) {
- return 0;
- }
- }
-
- if (!CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sigalgs_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- OPENSSL_free(ssl->s3->hs->peer_sigalgs);
- ssl->s3->hs->peer_sigalgs = NULL;
- ssl->s3->hs->num_peer_sigalgs = 0;
-
- if (contents == NULL) {
- return 1;
- }
-
- CBS supported_signature_algorithms;
- if (!CBS_get_u16_length_prefixed(contents, &supported_signature_algorithms) ||
- CBS_len(contents) != 0 ||
- CBS_len(&supported_signature_algorithms) == 0 ||
- !tls1_parse_peer_sigalgs(ssl, &supported_signature_algorithms)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* OCSP Stapling.
- *
- * https://tools.ietf.org/html/rfc6066#section-8 */
-
- static void ext_ocsp_init(SSL *ssl) {
- ssl->s3->tmp.certificate_status_expected = 0;
- ssl->tlsext_status_type = -1;
- }
-
- static int ext_ocsp_add_clienthello(SSL *ssl, CBB *out) {
- if (!ssl->ocsp_stapling_enabled) {
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_status_request) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8(&contents, TLSEXT_STATUSTYPE_ocsp) ||
- !CBB_add_u16(&contents, 0 /* empty responder ID list */) ||
- !CBB_add_u16(&contents, 0 /* empty request extensions */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- ssl->tlsext_status_type = TLSEXT_STATUSTYPE_ocsp;
- return 1;
- }
-
- static int ext_ocsp_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- /* OCSP stapling is forbidden on a non-certificate cipher. */
- if (!ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
- return 0;
- }
-
- if (ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tmp.certificate_status_expected = 1;
- return 1;
- }
-
- uint8_t status_type;
- CBS ocsp_response;
- if (!CBS_get_u8(contents, &status_type) ||
- status_type != TLSEXT_STATUSTYPE_ocsp ||
- !CBS_get_u24_length_prefixed(contents, &ocsp_response) ||
- CBS_len(&ocsp_response) == 0 ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- if (!CBS_stow(&ocsp_response, &ssl->s3->new_session->ocsp_response,
- &ssl->s3->new_session->ocsp_response_length)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ocsp_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- uint8_t status_type;
- if (!CBS_get_u8(contents, &status_type)) {
- return 0;
- }
-
- /* We cannot decide whether OCSP stapling will occur yet because the correct
- * SSL_CTX might not have been selected. */
- ssl->s3->tmp.ocsp_stapling_requested = status_type == TLSEXT_STATUSTYPE_ocsp;
-
- return 1;
- }
-
- static int ext_ocsp_add_serverhello(SSL *ssl, CBB *out) {
- if (!ssl->s3->tmp.ocsp_stapling_requested ||
- ssl->ctx->ocsp_response_length == 0 ||
- !ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- /* The extension shouldn't be sent when resuming sessions. */
- if (ssl->session != NULL) {
- return 1;
- }
-
- ssl->s3->tmp.certificate_status_expected = 1;
-
- return CBB_add_u16(out, TLSEXT_TYPE_status_request) &&
- CBB_add_u16(out, 0 /* length */);
- }
-
- CBB body, ocsp_response;
- return CBB_add_u16(out, TLSEXT_TYPE_status_request) &&
- CBB_add_u16_length_prefixed(out, &body) &&
- CBB_add_u8(&body, TLSEXT_STATUSTYPE_ocsp) &&
- CBB_add_u24_length_prefixed(&body, &ocsp_response) &&
- CBB_add_bytes(&ocsp_response, ssl->ctx->ocsp_response,
- ssl->ctx->ocsp_response_length) &&
- CBB_flush(out);
- }
-
-
- /* Next protocol negotiation.
- *
- * https://htmlpreview.github.io/?https://github.com/agl/technotes/blob/master/nextprotoneg.html */
-
- static void ext_npn_init(SSL *ssl) {
- ssl->s3->next_proto_neg_seen = 0;
- }
-
- static int ext_npn_add_clienthello(SSL *ssl, CBB *out) {
- if (ssl->s3->initial_handshake_complete ||
- ssl->ctx->next_proto_select_cb == NULL ||
- (ssl->options & SSL_OP_DISABLE_NPN) ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_next_proto_neg) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_npn_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- /* If any of these are false then we should never have sent the NPN
- * extension in the ClientHello and thus this function should never have been
- * called. */
- assert(!ssl->s3->initial_handshake_complete);
- assert(!SSL_is_dtls(ssl));
- assert(ssl->ctx->next_proto_select_cb != NULL);
- assert(!(ssl->options & SSL_OP_DISABLE_NPN));
-
- if (ssl->s3->alpn_selected != NULL) {
- /* NPN and ALPN may not be negotiated in the same connection. */
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN);
- return 0;
- }
-
- const uint8_t *const orig_contents = CBS_data(contents);
- const size_t orig_len = CBS_len(contents);
-
- while (CBS_len(contents) != 0) {
- CBS proto;
- if (!CBS_get_u8_length_prefixed(contents, &proto) ||
- CBS_len(&proto) == 0) {
- return 0;
- }
- }
-
- uint8_t *selected;
- uint8_t selected_len;
- if (ssl->ctx->next_proto_select_cb(
- ssl, &selected, &selected_len, orig_contents, orig_len,
- ssl->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- OPENSSL_free(ssl->s3->next_proto_negotiated);
- ssl->s3->next_proto_negotiated = BUF_memdup(selected, selected_len);
- if (ssl->s3->next_proto_negotiated == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- ssl->s3->next_proto_negotiated_len = selected_len;
- ssl->s3->next_proto_neg_seen = 1;
-
- return 1;
- }
-
- static int ext_npn_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (contents != NULL && CBS_len(contents) != 0) {
- return 0;
- }
-
- if (contents == NULL ||
- ssl->s3->initial_handshake_complete ||
- /* If the ALPN extension is seen before NPN, ignore it. (If ALPN is seen
- * afterwards, parsing the ALPN extension will clear
- * |next_proto_neg_seen|. */
- ssl->s3->alpn_selected != NULL ||
- ssl->ctx->next_protos_advertised_cb == NULL ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- ssl->s3->next_proto_neg_seen = 1;
- return 1;
- }
-
- static int ext_npn_add_serverhello(SSL *ssl, CBB *out) {
- /* |next_proto_neg_seen| might have been cleared when an ALPN extension was
- * parsed. */
- if (!ssl->s3->next_proto_neg_seen) {
- return 1;
- }
-
- const uint8_t *npa;
- unsigned npa_len;
-
- if (ssl->ctx->next_protos_advertised_cb(
- ssl, &npa, &npa_len, ssl->ctx->next_protos_advertised_cb_arg) !=
- SSL_TLSEXT_ERR_OK) {
- ssl->s3->next_proto_neg_seen = 0;
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_next_proto_neg) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_bytes(&contents, npa, npa_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Signed certificate timestamps.
- *
- * https://tools.ietf.org/html/rfc6962#section-3.3.1 */
-
- static int ext_sct_add_clienthello(SSL *ssl, CBB *out) {
- if (!ssl->signed_cert_timestamps_enabled) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_certificate_timestamp) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sct_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- /* If this is false then we should never have sent the SCT extension in the
- * ClientHello and thus this function should never have been called. */
- assert(ssl->signed_cert_timestamps_enabled);
-
- if (CBS_len(contents) == 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* Session resumption uses the original session information. */
- if (!ssl->s3->session_reused &&
- !CBS_stow(
- contents,
- &ssl->s3->new_session->tlsext_signed_cert_timestamp_list,
- &ssl->s3->new_session->tlsext_signed_cert_timestamp_list_length)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_sct_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- return contents == NULL || CBS_len(contents) == 0;
- }
-
- static int ext_sct_add_serverhello(SSL *ssl, CBB *out) {
- /* The extension shouldn't be sent when resuming sessions. */
- if (ssl->s3->session_reused ||
- ssl->ctx->signed_cert_timestamp_list_length == 0) {
- return 1;
- }
-
- CBB contents;
- return CBB_add_u16(out, TLSEXT_TYPE_certificate_timestamp) &&
- CBB_add_u16_length_prefixed(out, &contents) &&
- CBB_add_bytes(&contents, ssl->ctx->signed_cert_timestamp_list,
- ssl->ctx->signed_cert_timestamp_list_length) &&
- CBB_flush(out);
- }
-
-
- /* Application-level Protocol Negotiation.
- *
- * https://tools.ietf.org/html/rfc7301 */
-
- static void ext_alpn_init(SSL *ssl) {
- OPENSSL_free(ssl->s3->alpn_selected);
- ssl->s3->alpn_selected = NULL;
- }
-
- static int ext_alpn_add_clienthello(SSL *ssl, CBB *out) {
- if (ssl->alpn_client_proto_list == NULL ||
- ssl->s3->initial_handshake_complete) {
- return 1;
- }
-
- CBB contents, proto_list;
- if (!CBB_add_u16(out, TLSEXT_TYPE_application_layer_protocol_negotiation) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &proto_list) ||
- !CBB_add_bytes(&proto_list, ssl->alpn_client_proto_list,
- ssl->alpn_client_proto_list_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_alpn_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- assert(!ssl->s3->initial_handshake_complete);
- assert(ssl->alpn_client_proto_list != NULL);
-
- if (ssl->s3->next_proto_neg_seen) {
- /* NPN and ALPN may not be negotiated in the same connection. */
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN);
- return 0;
- }
-
- /* The extension data consists of a ProtocolNameList which must have
- * exactly one ProtocolName. Each of these is length-prefixed. */
- CBS protocol_name_list, protocol_name;
- if (!CBS_get_u16_length_prefixed(contents, &protocol_name_list) ||
- CBS_len(contents) != 0 ||
- !CBS_get_u8_length_prefixed(&protocol_name_list, &protocol_name) ||
- /* Empty protocol names are forbidden. */
- CBS_len(&protocol_name) == 0 ||
- CBS_len(&protocol_name_list) != 0) {
- return 0;
- }
-
- /* Check that the protcol name is one of the ones we advertised. */
- int protocol_ok = 0;
- CBS client_protocol_name_list, client_protocol_name;
- CBS_init(&client_protocol_name_list, ssl->alpn_client_proto_list,
- ssl->alpn_client_proto_list_len);
- while (CBS_len(&client_protocol_name_list) > 0) {
- if (!CBS_get_u8_length_prefixed(&client_protocol_name_list,
- &client_protocol_name)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- if (CBS_len(&client_protocol_name) == CBS_len(&protocol_name) &&
- memcmp(CBS_data(&client_protocol_name), CBS_data(&protocol_name),
- CBS_len(&protocol_name)) == 0) {
- protocol_ok = 1;
- break;
- }
- }
-
- if (!protocol_ok) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_ALPN_PROTOCOL);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- if (!CBS_stow(&protocol_name, &ssl->s3->alpn_selected,
- &ssl->s3->alpn_selected_len)) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_alpn_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl->ctx->alpn_select_cb == NULL ||
- ssl->s3->initial_handshake_complete) {
- return 1;
- }
-
- /* ALPN takes precedence over NPN. */
- ssl->s3->next_proto_neg_seen = 0;
-
- CBS protocol_name_list;
- if (!CBS_get_u16_length_prefixed(contents, &protocol_name_list) ||
- CBS_len(contents) != 0 ||
- CBS_len(&protocol_name_list) < 2) {
- return 0;
- }
-
- /* Validate the protocol list. */
- CBS protocol_name_list_copy = protocol_name_list;
- while (CBS_len(&protocol_name_list_copy) > 0) {
- CBS protocol_name;
-
- if (!CBS_get_u8_length_prefixed(&protocol_name_list_copy, &protocol_name) ||
- /* Empty protocol names are forbidden. */
- CBS_len(&protocol_name) == 0) {
- return 0;
- }
- }
-
- const uint8_t *selected;
- uint8_t selected_len;
- if (ssl->ctx->alpn_select_cb(
- ssl, &selected, &selected_len, CBS_data(&protocol_name_list),
- CBS_len(&protocol_name_list),
- ssl->ctx->alpn_select_cb_arg) == SSL_TLSEXT_ERR_OK) {
- OPENSSL_free(ssl->s3->alpn_selected);
- ssl->s3->alpn_selected = BUF_memdup(selected, selected_len);
- if (ssl->s3->alpn_selected == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
- ssl->s3->alpn_selected_len = selected_len;
- }
-
- return 1;
- }
-
- static int ext_alpn_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl->s3->alpn_selected == NULL) {
- return 1;
- }
-
- CBB contents, proto_list, proto;
- if (!CBB_add_u16(out, TLSEXT_TYPE_application_layer_protocol_negotiation) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &proto_list) ||
- !CBB_add_u8_length_prefixed(&proto_list, &proto) ||
- !CBB_add_bytes(&proto, ssl->s3->alpn_selected,
- ssl->s3->alpn_selected_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Channel ID.
- *
- * https://tools.ietf.org/html/draft-balfanz-tls-channelid-01 */
-
- static void ext_channel_id_init(SSL *ssl) {
- ssl->s3->tlsext_channel_id_valid = 0;
- }
-
- static int ext_channel_id_add_clienthello(SSL *ssl, CBB *out) {
- if (!ssl->tlsext_channel_id_enabled ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_channel_id_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- assert(!SSL_is_dtls(ssl));
- assert(ssl->tlsext_channel_id_enabled);
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tlsext_channel_id_valid = 1;
- return 1;
- }
-
- static int ext_channel_id_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL ||
- !ssl->tlsext_channel_id_enabled ||
- SSL_is_dtls(ssl)) {
- return 1;
- }
-
- if (CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tlsext_channel_id_valid = 1;
- return 1;
- }
-
- static int ext_channel_id_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- if (!ssl->s3->tlsext_channel_id_valid) {
- return 1;
- }
-
- if (!CBB_add_u16(out, TLSEXT_TYPE_channel_id) ||
- !CBB_add_u16(out, 0 /* length */)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Secure Real-time Transport Protocol (SRTP) extension.
- *
- * https://tools.ietf.org/html/rfc5764 */
-
-
- static void ext_srtp_init(SSL *ssl) {
- ssl->srtp_profile = NULL;
- }
-
- static int ext_srtp_add_clienthello(SSL *ssl, CBB *out) {
- STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
- if (profiles == NULL) {
- return 1;
- }
- const size_t num_profiles = sk_SRTP_PROTECTION_PROFILE_num(profiles);
- if (num_profiles == 0) {
- return 1;
- }
-
- CBB contents, profile_ids;
- if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &profile_ids)) {
- return 0;
- }
-
- size_t i;
- for (i = 0; i < num_profiles; i++) {
- if (!CBB_add_u16(&profile_ids,
- sk_SRTP_PROTECTION_PROFILE_value(profiles, i)->id)) {
- return 0;
- }
- }
-
- if (!CBB_add_u8(&contents, 0 /* empty use_mki value */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_srtp_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- /* The extension consists of a u16-prefixed profile ID list containing a
- * single uint16_t profile ID, then followed by a u8-prefixed srtp_mki field.
- *
- * See https://tools.ietf.org/html/rfc5764#section-4.1.1 */
- CBS profile_ids, srtp_mki;
- uint16_t profile_id;
- if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
- !CBS_get_u16(&profile_ids, &profile_id) ||
- CBS_len(&profile_ids) != 0 ||
- !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- return 0;
- }
-
- if (CBS_len(&srtp_mki) != 0) {
- /* Must be no MKI, since we never offer one. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_MKI_VALUE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
-
- /* Check to see if the server gave us something we support (and presumably
- * offered). */
- size_t i;
- for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(profiles); i++) {
- const SRTP_PROTECTION_PROFILE *profile =
- sk_SRTP_PROTECTION_PROFILE_value(profiles, i);
-
- if (profile->id == profile_id) {
- ssl->srtp_profile = profile;
- return 1;
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- static int ext_srtp_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS profile_ids, srtp_mki;
- if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
- CBS_len(&profile_ids) < 2 ||
- !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
- CBS_len(contents) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- return 0;
- }
- /* Discard the MKI value for now. */
-
- const STACK_OF(SRTP_PROTECTION_PROFILE) *server_profiles =
- SSL_get_srtp_profiles(ssl);
-
- /* Pick the server's most preferred profile. */
- size_t i;
- for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(server_profiles); i++) {
- const SRTP_PROTECTION_PROFILE *server_profile =
- sk_SRTP_PROTECTION_PROFILE_value(server_profiles, i);
-
- CBS profile_ids_tmp;
- CBS_init(&profile_ids_tmp, CBS_data(&profile_ids), CBS_len(&profile_ids));
-
- while (CBS_len(&profile_ids_tmp) > 0) {
- uint16_t profile_id;
- if (!CBS_get_u16(&profile_ids_tmp, &profile_id)) {
- return 0;
- }
-
- if (server_profile->id == profile_id) {
- ssl->srtp_profile = server_profile;
- return 1;
- }
- }
- }
-
- return 1;
- }
-
- static int ext_srtp_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl->srtp_profile == NULL) {
- return 1;
- }
-
- CBB contents, profile_ids;
- if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &profile_ids) ||
- !CBB_add_u16(&profile_ids, ssl->srtp_profile->id) ||
- !CBB_add_u8(&contents, 0 /* empty MKI */) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* EC point formats.
- *
- * https://tools.ietf.org/html/rfc4492#section-5.1.2 */
-
- static int ssl_any_ec_cipher_suites_enabled(const SSL *ssl) {
- if (ssl->version < TLS1_VERSION && !SSL_is_dtls(ssl)) {
- return 0;
- }
-
- const STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(ssl);
-
- size_t i;
- for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) {
- const SSL_CIPHER *cipher = sk_SSL_CIPHER_value(cipher_stack, i);
-
- const uint32_t alg_k = cipher->algorithm_mkey;
- const uint32_t alg_a = cipher->algorithm_auth;
- if ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA)) {
- return 1;
- }
- }
-
- return 0;
- }
-
- static int ext_ec_point_add_extension(SSL *ssl, CBB *out) {
- CBB contents, formats;
- if (!CBB_add_u16(out, TLSEXT_TYPE_ec_point_formats) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u8_length_prefixed(&contents, &formats) ||
- !CBB_add_u8(&formats, TLSEXT_ECPOINTFORMAT_uncompressed) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ec_point_add_clienthello(SSL *ssl, CBB *out) {
- if (!ssl_any_ec_cipher_suites_enabled(ssl)) {
- return 1;
- }
-
- return ext_ec_point_add_extension(ssl, out);
- }
-
- static int ext_ec_point_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 0;
- }
-
- CBS ec_point_format_list;
- if (!CBS_get_u8_length_prefixed(contents, &ec_point_format_list) ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- /* Per RFC 4492, section 5.1.2, implementations MUST support the uncompressed
- * point format. */
- if (memchr(CBS_data(&ec_point_format_list), TLSEXT_ECPOINTFORMAT_uncompressed,
- CBS_len(&ec_point_format_list)) == NULL) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- return 1;
- }
-
- static int ext_ec_point_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- return ext_ec_point_parse_serverhello(ssl, out_alert, contents);
- }
-
- static int ext_ec_point_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
- return 1;
- }
-
- const uint32_t alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
- const uint32_t alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
- const int using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA);
-
- if (!using_ecc) {
- return 1;
- }
-
- return ext_ec_point_add_extension(ssl, out);
- }
-
-
- /* Draft Version Extension */
-
- static int ext_draft_version_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version) ||
- max_version < TLS1_3_VERSION) {
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_draft_version) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16(&contents, TLS1_3_DRAFT_VERSION)) {
- return 0;
- }
-
- return CBB_flush(out);
- }
-
-
- /* Pre Shared Key
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-14 */
-
- static int ext_pre_shared_key_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version < TLS1_3_VERSION || ssl->session == NULL ||
- ssl->method->version_from_wire(ssl->session->ssl_version) <
- TLS1_3_VERSION) {
- return 1;
- }
-
- CBB contents, identities, identity;
- if (!CBB_add_u16(out, TLSEXT_TYPE_pre_shared_key) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &identities) ||
- !CBB_add_u16_length_prefixed(&identities, &identity) ||
- !CBB_add_bytes(&identity, ssl->session->tlsext_tick,
- ssl->session->tlsext_ticklen)) {
- return 0;
- }
-
- return CBB_flush(out);
- }
-
- int ssl_ext_pre_shared_key_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- uint16_t psk_id;
- if (!CBS_get_u16(contents, &psk_id) ||
- CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- if (psk_id != 0) {
- *out_alert = SSL_AD_UNKNOWN_PSK_IDENTITY;
- return 0;
- }
-
- return 1;
- }
-
- int ssl_ext_pre_shared_key_parse_clienthello(SSL *ssl,
- SSL_SESSION **out_session,
- uint8_t *out_alert,
- CBS *contents) {
- CBS identities, identity;
- if (!CBS_get_u16_length_prefixed(contents, &identities) ||
- !CBS_get_u16_length_prefixed(&identities, &identity) ||
- CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* TLS 1.3 session tickets are renewed separately as part of the
- * NewSessionTicket. */
- int renew;
- return tls_process_ticket(ssl, out_session, &renew, CBS_data(&identity),
- CBS_len(&identity), NULL, 0);
- }
-
- int ssl_ext_pre_shared_key_add_serverhello(SSL *ssl, CBB *out) {
- if (!ssl->s3->session_reused) {
- return 1;
- }
-
- CBB contents;
- if (!CBB_add_u16(out, TLSEXT_TYPE_pre_shared_key) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- /* We only consider the first identity for resumption */
- !CBB_add_u16(&contents, 0) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Key Share
- *
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-12 */
-
- static int ext_key_share_add_clienthello(SSL *ssl, CBB *out) {
- uint16_t min_version, max_version;
- if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
- return 0;
- }
-
- if (max_version < TLS1_3_VERSION || !ssl_any_ec_cipher_suites_enabled(ssl)) {
- return 1;
- }
-
- CBB contents, kse_bytes;
- if (!CBB_add_u16(out, TLSEXT_TYPE_key_share) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &kse_bytes)) {
- return 0;
- }
-
- const uint16_t *groups;
- size_t groups_len;
- if (ssl->s3->hs->retry_group) {
- /* Append the new key share to the old list. */
- if (!CBB_add_bytes(&kse_bytes, ssl->s3->hs->key_share_bytes,
- ssl->s3->hs->key_share_bytes_len)) {
- return 0;
- }
- OPENSSL_free(ssl->s3->hs->key_share_bytes);
- ssl->s3->hs->key_share_bytes = NULL;
-
- groups = &ssl->s3->hs->retry_group;
- groups_len = 1;
- } else {
- tls1_get_grouplist(ssl, 0 /* local groups */, &groups, &groups_len);
- /* Only send the top two preferred key shares. */
- if (groups_len > 2) {
- groups_len = 2;
- }
- }
-
- ssl->s3->hs->groups = OPENSSL_malloc(groups_len * sizeof(SSL_ECDH_CTX));
- if (ssl->s3->hs->groups == NULL) {
- return 0;
- }
- memset(ssl->s3->hs->groups, 0, groups_len * sizeof(SSL_ECDH_CTX));
- ssl->s3->hs->groups_len = groups_len;
-
- for (size_t i = 0; i < groups_len; i++) {
- if (!CBB_add_u16(&kse_bytes, groups[i])) {
- return 0;
- }
-
- CBB key_exchange;
- if (!CBB_add_u16_length_prefixed(&kse_bytes, &key_exchange) ||
- !SSL_ECDH_CTX_init(&ssl->s3->hs->groups[i], groups[i]) ||
- !SSL_ECDH_CTX_offer(&ssl->s3->hs->groups[i], &key_exchange) ||
- !CBB_flush(&kse_bytes)) {
- return 0;
- }
- }
-
- if (!ssl->s3->hs->retry_group) {
- /* Save the contents of the extension to repeat it in the second
- * ClientHello. */
- ssl->s3->hs->key_share_bytes_len = CBB_len(&kse_bytes);
- ssl->s3->hs->key_share_bytes = BUF_memdup(CBB_data(&kse_bytes),
- CBB_len(&kse_bytes));
- if (ssl->s3->hs->key_share_bytes == NULL) {
- return 0;
- }
- }
-
- return CBB_flush(out);
- }
-
- int ssl_ext_key_share_parse_serverhello(SSL *ssl, uint8_t **out_secret,
- size_t *out_secret_len,
- uint8_t *out_alert, CBS *contents) {
- CBS peer_key;
- uint16_t group_id;
- if (!CBS_get_u16(contents, &group_id) ||
- !CBS_get_u16_length_prefixed(contents, &peer_key) ||
- CBS_len(contents) != 0) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- SSL_ECDH_CTX *group_ctx = NULL;
- for (size_t i = 0; i < ssl->s3->hs->groups_len; i++) {
- if (SSL_ECDH_CTX_get_id(&ssl->s3->hs->groups[i]) == group_id) {
- group_ctx = &ssl->s3->hs->groups[i];
- break;
- }
- }
-
- if (group_ctx == NULL) {
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
- return 0;
- }
-
- if (!SSL_ECDH_CTX_finish(group_ctx, out_secret, out_secret_len, out_alert,
- CBS_data(&peer_key), CBS_len(&peer_key))) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- ssl->s3->new_session->key_exchange_info = group_id;
- ssl_handshake_clear_groups(ssl->s3->hs);
- return 1;
- }
-
- int ssl_ext_key_share_parse_clienthello(SSL *ssl, int *out_found,
- uint8_t **out_secret,
- size_t *out_secret_len,
- uint8_t *out_alert, CBS *contents) {
- uint16_t group_id;
- CBS key_shares;
- if (!tls1_get_shared_group(ssl, &group_id) ||
- !CBS_get_u16_length_prefixed(contents, &key_shares) ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- *out_found = 0;
- while (CBS_len(&key_shares) > 0) {
- uint16_t id;
- CBS peer_key;
- if (!CBS_get_u16(&key_shares, &id) ||
- !CBS_get_u16_length_prefixed(&key_shares, &peer_key)) {
- return 0;
- }
-
- if (id != group_id || *out_found) {
- continue;
- }
-
- SSL_ECDH_CTX group;
- memset(&group, 0, sizeof(SSL_ECDH_CTX));
- CBB public_key;
- if (!CBB_init(&public_key, 0) ||
- !SSL_ECDH_CTX_init(&group, group_id) ||
- !SSL_ECDH_CTX_accept(&group, &public_key, out_secret, out_secret_len,
- out_alert, CBS_data(&peer_key),
- CBS_len(&peer_key)) ||
- !CBB_finish(&public_key, &ssl->s3->hs->public_key,
- &ssl->s3->hs->public_key_len)) {
- SSL_ECDH_CTX_cleanup(&group);
- CBB_cleanup(&public_key);
- return 0;
- }
- SSL_ECDH_CTX_cleanup(&group);
-
- *out_found = 1;
- }
-
- return 1;
- }
-
- int ssl_ext_key_share_add_serverhello(SSL *ssl, CBB *out) {
- if (ssl->s3->tmp.new_cipher->algorithm_mkey != SSL_kECDHE) {
- return 1;
- }
-
- uint16_t group_id;
- CBB kse_bytes, public_key;
- if (!tls1_get_shared_group(ssl, &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, ssl->s3->hs->public_key,
- ssl->s3->hs->public_key_len) ||
- !CBB_flush(out)) {
- return 0;
- }
-
- ssl->s3->new_session->key_exchange_info = group_id;
- return 1;
- }
-
-
- /* Negotiated Groups
- *
- * https://tools.ietf.org/html/rfc4492#section-5.1.2
- * https://tools.ietf.org/html/draft-ietf-tls-tls13-12#section-6.3.2.2 */
-
- static void ext_supported_groups_init(SSL *ssl) {
- OPENSSL_free(ssl->s3->tmp.peer_supported_group_list);
- ssl->s3->tmp.peer_supported_group_list = NULL;
- ssl->s3->tmp.peer_supported_group_list_len = 0;
- }
-
- static int ext_supported_groups_add_clienthello(SSL *ssl, CBB *out) {
- if (!ssl_any_ec_cipher_suites_enabled(ssl)) {
- return 1;
- }
-
- CBB contents, groups_bytes;
- if (!CBB_add_u16(out, TLSEXT_TYPE_supported_groups) ||
- !CBB_add_u16_length_prefixed(out, &contents) ||
- !CBB_add_u16_length_prefixed(&contents, &groups_bytes)) {
- return 0;
- }
-
- const uint16_t *groups;
- size_t groups_len;
- tls1_get_grouplist(ssl, 0, &groups, &groups_len);
-
- size_t i;
- for (i = 0; i < groups_len; i++) {
- if (!CBB_add_u16(&groups_bytes, groups[i])) {
- return 0;
- }
- }
-
- return CBB_flush(out);
- }
-
- static int ext_supported_groups_parse_serverhello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- /* This extension is not expected to be echoed by servers in TLS 1.2, but some
- * BigIP servers send it nonetheless, so do not enforce this. */
- return 1;
- }
-
- static int ext_supported_groups_parse_clienthello(SSL *ssl, uint8_t *out_alert,
- CBS *contents) {
- if (contents == NULL) {
- return 1;
- }
-
- CBS supported_group_list;
- if (!CBS_get_u16_length_prefixed(contents, &supported_group_list) ||
- CBS_len(&supported_group_list) == 0 ||
- (CBS_len(&supported_group_list) & 1) != 0 ||
- CBS_len(contents) != 0) {
- return 0;
- }
-
- ssl->s3->tmp.peer_supported_group_list = OPENSSL_malloc(
- CBS_len(&supported_group_list));
- if (ssl->s3->tmp.peer_supported_group_list == NULL) {
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- const size_t num_groups = CBS_len(&supported_group_list) / 2;
- size_t i;
- for (i = 0; i < num_groups; i++) {
- if (!CBS_get_u16(&supported_group_list,
- &ssl->s3->tmp.peer_supported_group_list[i])) {
- goto err;
- }
- }
-
- assert(CBS_len(&supported_group_list) == 0);
- ssl->s3->tmp.peer_supported_group_list_len = num_groups;
-
- return 1;
-
- err:
- OPENSSL_free(ssl->s3->tmp.peer_supported_group_list);
- ssl->s3->tmp.peer_supported_group_list = NULL;
- *out_alert = SSL_AD_INTERNAL_ERROR;
- return 0;
- }
-
- static int ext_supported_groups_add_serverhello(SSL *ssl, CBB *out) {
- /* Servers don't echo this extension. */
- return 1;
- }
-
-
- /* kExtensions contains all the supported extensions. */
- static const struct tls_extension kExtensions[] = {
- {
- TLSEXT_TYPE_renegotiate,
- NULL,
- ext_ri_add_clienthello,
- ext_ri_parse_serverhello,
- ext_ri_parse_clienthello,
- ext_ri_add_serverhello,
- },
- {
- TLSEXT_TYPE_server_name,
- ext_sni_init,
- ext_sni_add_clienthello,
- ext_sni_parse_serverhello,
- ext_sni_parse_clienthello,
- ext_sni_add_serverhello,
- },
- {
- TLSEXT_TYPE_extended_master_secret,
- NULL,
- ext_ems_add_clienthello,
- ext_ems_parse_serverhello,
- ext_ems_parse_clienthello,
- ext_ems_add_serverhello,
- },
- {
- TLSEXT_TYPE_session_ticket,
- NULL,
- ext_ticket_add_clienthello,
- ext_ticket_parse_serverhello,
- /* Ticket extension client parsing is handled in ssl_session.c */
- ignore_parse_clienthello,
- ext_ticket_add_serverhello,
- },
- {
- TLSEXT_TYPE_signature_algorithms,
- NULL,
- ext_sigalgs_add_clienthello,
- forbid_parse_serverhello,
- ext_sigalgs_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_status_request,
- ext_ocsp_init,
- ext_ocsp_add_clienthello,
- ext_ocsp_parse_serverhello,
- ext_ocsp_parse_clienthello,
- ext_ocsp_add_serverhello,
- },
- {
- TLSEXT_TYPE_next_proto_neg,
- ext_npn_init,
- ext_npn_add_clienthello,
- ext_npn_parse_serverhello,
- ext_npn_parse_clienthello,
- ext_npn_add_serverhello,
- },
- {
- TLSEXT_TYPE_certificate_timestamp,
- NULL,
- ext_sct_add_clienthello,
- ext_sct_parse_serverhello,
- ext_sct_parse_clienthello,
- ext_sct_add_serverhello,
- },
- {
- TLSEXT_TYPE_application_layer_protocol_negotiation,
- ext_alpn_init,
- ext_alpn_add_clienthello,
- ext_alpn_parse_serverhello,
- ext_alpn_parse_clienthello,
- ext_alpn_add_serverhello,
- },
- {
- TLSEXT_TYPE_channel_id,
- ext_channel_id_init,
- ext_channel_id_add_clienthello,
- ext_channel_id_parse_serverhello,
- ext_channel_id_parse_clienthello,
- ext_channel_id_add_serverhello,
- },
- {
- TLSEXT_TYPE_srtp,
- ext_srtp_init,
- ext_srtp_add_clienthello,
- ext_srtp_parse_serverhello,
- ext_srtp_parse_clienthello,
- ext_srtp_add_serverhello,
- },
- {
- TLSEXT_TYPE_ec_point_formats,
- NULL,
- ext_ec_point_add_clienthello,
- ext_ec_point_parse_serverhello,
- ext_ec_point_parse_clienthello,
- ext_ec_point_add_serverhello,
- },
- {
- TLSEXT_TYPE_draft_version,
- NULL,
- ext_draft_version_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_key_share,
- NULL,
- ext_key_share_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- {
- TLSEXT_TYPE_pre_shared_key,
- NULL,
- ext_pre_shared_key_add_clienthello,
- forbid_parse_serverhello,
- ignore_parse_clienthello,
- dont_add_serverhello,
- },
- /* The final extension must be non-empty. WebSphere Application Server 7.0 is
- * intolerant to the last extension being zero-length. See
- * https://crbug.com/363583. */
- {
- TLSEXT_TYPE_supported_groups,
- ext_supported_groups_init,
- ext_supported_groups_add_clienthello,
- ext_supported_groups_parse_serverhello,
- ext_supported_groups_parse_clienthello,
- ext_supported_groups_add_serverhello,
- },
- };
-
- #define kNumExtensions (sizeof(kExtensions) / sizeof(struct tls_extension))
-
- OPENSSL_COMPILE_ASSERT(kNumExtensions <=
- sizeof(((SSL *)NULL)->s3->tmp.extensions.sent) * 8,
- too_many_extensions_for_sent_bitset);
- OPENSSL_COMPILE_ASSERT(kNumExtensions <=
- sizeof(((SSL *)NULL)->s3->tmp.extensions.received) *
- 8,
- too_many_extensions_for_received_bitset);
-
- static const struct tls_extension *tls_extension_find(uint32_t *out_index,
- uint16_t value) {
- unsigned i;
- for (i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].value == value) {
- *out_index = i;
- return &kExtensions[i];
- }
- }
-
- return NULL;
- }
-
- int SSL_extension_supported(unsigned extension_value) {
- uint32_t index;
- return extension_value == TLSEXT_TYPE_padding ||
- tls_extension_find(&index, extension_value) != NULL;
- }
-
- int ssl_add_clienthello_tlsext(SSL *ssl, CBB *out, size_t header_len) {
- /* don't add extensions for SSLv3 unless doing secure renegotiation */
- if (ssl->client_version == SSL3_VERSION &&
- !ssl->s3->send_connection_binding) {
- return 1;
- }
-
- CBB extensions;
- if (!CBB_add_u16_length_prefixed(out, &extensions)) {
- goto err;
- }
-
- ssl->s3->tmp.extensions.sent = 0;
- ssl->s3->tmp.custom_extensions.sent = 0;
-
- size_t i;
- for (i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].init != NULL) {
- kExtensions[i].init(ssl);
- }
- }
-
- for (i = 0; i < kNumExtensions; i++) {
- const size_t len_before = CBB_len(&extensions);
- if (!kExtensions[i].add_clienthello(ssl, &extensions)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_ADDING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)kExtensions[i].value);
- goto err;
- }
-
- if (CBB_len(&extensions) != len_before) {
- ssl->s3->tmp.extensions.sent |= (1u << i);
- }
- }
-
- if (!custom_ext_add_clienthello(ssl, &extensions)) {
- goto err;
- }
-
- if (!SSL_is_dtls(ssl)) {
- header_len += 2 + CBB_len(&extensions);
- if (header_len > 0xff && header_len < 0x200) {
- /* Add padding to workaround bugs in F5 terminators. See RFC 7685.
- *
- * NB: because this code works out the length of all existing extensions
- * it MUST always appear last. */
- size_t padding_len = 0x200 - header_len;
- /* Extensions take at least four bytes to encode. Always include at least
- * one byte of data if including the extension. WebSphere Application
- * Server 7.0 is intolerant to the last extension being zero-length. See
- * https://crbug.com/363583. */
- if (padding_len >= 4 + 1) {
- padding_len -= 4;
- } else {
- padding_len = 1;
- }
-
- uint8_t *padding_bytes;
- if (!CBB_add_u16(&extensions, TLSEXT_TYPE_padding) ||
- !CBB_add_u16(&extensions, padding_len) ||
- !CBB_add_space(&extensions, &padding_bytes, padding_len)) {
- goto err;
- }
-
- memset(padding_bytes, 0, padding_len);
- }
- }
-
- /* Discard empty extensions blocks. */
- if (CBB_len(&extensions) == 0) {
- CBB_discard_child(out);
- }
-
- return CBB_flush(out);
-
- err:
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- int ssl_add_serverhello_tlsext(SSL *ssl, CBB *out) {
- CBB extensions;
- if (!CBB_add_u16_length_prefixed(out, &extensions)) {
- goto err;
- }
-
- unsigned i;
- for (i = 0; i < kNumExtensions; i++) {
- if (!(ssl->s3->tmp.extensions.received & (1u << i))) {
- /* Don't send extensions that were not received. */
- continue;
- }
-
- if (!kExtensions[i].add_serverhello(ssl, &extensions)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_ADDING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)kExtensions[i].value);
- goto err;
- }
- }
-
- if (!custom_ext_add_serverhello(ssl, &extensions)) {
- goto err;
- }
-
- /* Discard empty extensions blocks before TLS 1.3. */
- if (ssl3_protocol_version(ssl) < TLS1_3_VERSION &&
- CBB_len(&extensions) == 0) {
- CBB_discard_child(out);
- }
-
- return CBB_flush(out);
-
- err:
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- static int ssl_scan_clienthello_tlsext(
- SSL *ssl, const struct ssl_early_callback_ctx *client_hello,
- int *out_alert) {
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (kExtensions[i].init != NULL) {
- kExtensions[i].init(ssl);
- }
- }
-
- ssl->s3->tmp.extensions.received = 0;
- ssl->s3->tmp.custom_extensions.received = 0;
-
- CBS extensions;
- CBS_init(&extensions, client_hello->extensions, client_hello->extensions_len);
- while (CBS_len(&extensions) != 0) {
- uint16_t type;
- CBS extension;
-
- /* Decode the next extension. */
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* RFC 5746 made the existence of extensions in SSL 3.0 somewhat
- * ambiguous. Ignore all but the renegotiation_info extension. */
- if (ssl->version == SSL3_VERSION && type != TLSEXT_TYPE_renegotiate) {
- continue;
- }
-
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
-
- if (ext == NULL) {
- if (!custom_ext_parse_clienthello(ssl, out_alert, type, &extension)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- return 0;
- }
- continue;
- }
-
- ssl->s3->tmp.extensions.received |= (1u << ext_index);
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!ext->parse_clienthello(ssl, &alert, &extension)) {
- *out_alert = alert;
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)type);
- return 0;
- }
- }
-
- for (size_t i = 0; i < kNumExtensions; i++) {
- if (ssl->s3->tmp.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;
- ssl->s3->tmp.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(ssl, &alert, contents)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)kExtensions[i].value);
- *out_alert = alert;
- return 0;
- }
- }
-
- return 1;
- }
-
- int ssl_parse_clienthello_tlsext(
- SSL *ssl, const struct ssl_early_callback_ctx *client_hello) {
- int alert = -1;
- if (ssl_scan_clienthello_tlsext(ssl, client_hello, &alert) <= 0) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return 0;
- }
-
- if (ssl_check_clienthello_tlsext(ssl) <= 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_TLSEXT);
- return 0;
- }
-
- return 1;
- }
-
- OPENSSL_COMPILE_ASSERT(kNumExtensions <= sizeof(uint32_t) * 8, too_many_bits);
-
- static int ssl_scan_serverhello_tlsext(SSL *ssl, CBS *cbs, int *out_alert) {
- /* Before TLS 1.3, ServerHello extensions blocks may be omitted if empty. */
- if (CBS_len(cbs) == 0 && ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- return 1;
- }
-
- /* Decode the extensions block and check it is valid. */
- CBS extensions;
- if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
- !tls1_check_duplicate_extensions(&extensions)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- uint32_t received = 0;
- while (CBS_len(&extensions) != 0) {
- uint16_t type;
- CBS extension;
-
- /* Decode the next extension. */
- if (!CBS_get_u16(&extensions, &type) ||
- !CBS_get_u16_length_prefixed(&extensions, &extension)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- unsigned ext_index;
- const struct tls_extension *const ext =
- tls_extension_find(&ext_index, type);
-
- if (ext == NULL) {
- if (!custom_ext_parse_serverhello(ssl, out_alert, type, &extension)) {
- return 0;
- }
- continue;
- }
-
- if (!(ssl->s3->tmp.extensions.sent & (1u << ext_index)) &&
- type != TLSEXT_TYPE_renegotiate) {
- /* If the extension was never sent then it is illegal, except for the
- * renegotiation extension which, in SSL 3.0, is signaled via SCSV. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
- ERR_add_error_dataf("extension :%u", (unsigned)type);
- *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
- return 0;
- }
-
- received |= (1u << ext_index);
-
- uint8_t alert = SSL_AD_DECODE_ERROR;
- if (!ext->parse_serverhello(ssl, &alert, &extension)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_PARSING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)type);
- *out_alert = alert;
- return 0;
- }
- }
-
- size_t i;
- for (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(ssl, &alert, NULL)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_EXTENSION);
- ERR_add_error_dataf("extension: %u", (unsigned)kExtensions[i].value);
- *out_alert = alert;
- return 0;
- }
- }
- }
-
- return 1;
- }
-
- static int ssl_check_clienthello_tlsext(SSL *ssl) {
- int ret = SSL_TLSEXT_ERR_NOACK;
- int al = SSL_AD_UNRECOGNIZED_NAME;
-
- if (ssl->ctx->tlsext_servername_callback != 0) {
- ret = ssl->ctx->tlsext_servername_callback(ssl, &al,
- ssl->ctx->tlsext_servername_arg);
- } else if (ssl->initial_ctx->tlsext_servername_callback != 0) {
- ret = ssl->initial_ctx->tlsext_servername_callback(
- ssl, &al, ssl->initial_ctx->tlsext_servername_arg);
- }
-
- switch (ret) {
- case SSL_TLSEXT_ERR_ALERT_FATAL:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
- return -1;
-
- case SSL_TLSEXT_ERR_ALERT_WARNING:
- ssl3_send_alert(ssl, SSL3_AL_WARNING, al);
- return 1;
-
- case SSL_TLSEXT_ERR_NOACK:
- ssl->s3->tmp.should_ack_sni = 0;
- return 1;
-
- default:
- return 1;
- }
- }
-
- static int ssl_check_serverhello_tlsext(SSL *ssl) {
- int ret = SSL_TLSEXT_ERR_OK;
- int al = SSL_AD_UNRECOGNIZED_NAME;
-
- if (ssl->ctx->tlsext_servername_callback != 0) {
- ret = ssl->ctx->tlsext_servername_callback(ssl, &al,
- ssl->ctx->tlsext_servername_arg);
- } else if (ssl->initial_ctx->tlsext_servername_callback != 0) {
- ret = ssl->initial_ctx->tlsext_servername_callback(
- ssl, &al, ssl->initial_ctx->tlsext_servername_arg);
- }
-
- switch (ret) {
- case SSL_TLSEXT_ERR_ALERT_FATAL:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
- return -1;
-
- case SSL_TLSEXT_ERR_ALERT_WARNING:
- ssl3_send_alert(ssl, SSL3_AL_WARNING, al);
- return 1;
-
- default:
- return 1;
- }
- }
-
- int ssl_parse_serverhello_tlsext(SSL *ssl, CBS *cbs) {
- int alert = -1;
- if (ssl_scan_serverhello_tlsext(ssl, cbs, &alert) <= 0) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return 0;
- }
-
- if (ssl_check_serverhello_tlsext(ssl) <= 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SERVERHELLO_TLSEXT);
- return 0;
- }
-
- return 1;
- }
-
- int tls_process_ticket(SSL *ssl, SSL_SESSION **out_session,
- int *out_renew_ticket, const uint8_t *ticket,
- size_t ticket_len, const uint8_t *session_id,
- size_t session_id_len) {
- int ret = 1; /* Most errors are non-fatal. */
- SSL_CTX *ssl_ctx = ssl->initial_ctx;
- uint8_t *plaintext = NULL;
-
- HMAC_CTX hmac_ctx;
- HMAC_CTX_init(&hmac_ctx);
- EVP_CIPHER_CTX cipher_ctx;
- EVP_CIPHER_CTX_init(&cipher_ctx);
-
- *out_renew_ticket = 0;
- *out_session = NULL;
-
- if (SSL_get_options(ssl) & SSL_OP_NO_TICKET) {
- goto done;
- }
-
- if (session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
- goto done;
- }
-
- /* Ensure there is room for the key name and the largest IV
- * |tlsext_ticket_key_cb| may try to consume. The real limit may be lower, but
- * the maximum IV length should be well under the minimum size for the
- * session material and HMAC. */
- if (ticket_len < SSL_TICKET_KEY_NAME_LEN + EVP_MAX_IV_LENGTH) {
- goto done;
- }
- const uint8_t *iv = ticket + SSL_TICKET_KEY_NAME_LEN;
-
- if (ssl_ctx->tlsext_ticket_key_cb != NULL) {
- int cb_ret = ssl_ctx->tlsext_ticket_key_cb(
- ssl, (uint8_t *)ticket /* name */, (uint8_t *)iv, &cipher_ctx,
- &hmac_ctx, 0 /* decrypt */);
- if (cb_ret < 0) {
- ret = 0;
- goto done;
- }
- if (cb_ret == 0) {
- goto done;
- }
- if (cb_ret == 2) {
- *out_renew_ticket = 1;
- }
- } else {
- /* Check the key name matches. */
- if (memcmp(ticket, ssl_ctx->tlsext_tick_key_name,
- SSL_TICKET_KEY_NAME_LEN) != 0) {
- goto done;
- }
- if (!HMAC_Init_ex(&hmac_ctx, ssl_ctx->tlsext_tick_hmac_key,
- sizeof(ssl_ctx->tlsext_tick_hmac_key), tlsext_tick_md(),
- NULL) ||
- !EVP_DecryptInit_ex(&cipher_ctx, EVP_aes_128_cbc(), NULL,
- ssl_ctx->tlsext_tick_aes_key, iv)) {
- ret = 0;
- goto done;
- }
- }
- size_t iv_len = EVP_CIPHER_CTX_iv_length(&cipher_ctx);
-
- /* Check the MAC at the end of the ticket. */
- uint8_t mac[EVP_MAX_MD_SIZE];
- size_t mac_len = HMAC_size(&hmac_ctx);
- if (ticket_len < SSL_TICKET_KEY_NAME_LEN + iv_len + 1 + mac_len) {
- /* The ticket must be large enough for key name, IV, data, and MAC. */
- goto done;
- }
- HMAC_Update(&hmac_ctx, ticket, ticket_len - mac_len);
- HMAC_Final(&hmac_ctx, mac, NULL);
- if (CRYPTO_memcmp(mac, ticket + (ticket_len - mac_len), mac_len) != 0) {
- goto done;
- }
-
- /* Decrypt the session data. */
- const uint8_t *ciphertext = ticket + SSL_TICKET_KEY_NAME_LEN + iv_len;
- size_t ciphertext_len = ticket_len - SSL_TICKET_KEY_NAME_LEN - iv_len -
- mac_len;
- plaintext = OPENSSL_malloc(ciphertext_len);
- if (plaintext == NULL) {
- ret = 0;
- goto done;
- }
- if (ciphertext_len >= INT_MAX) {
- goto done;
- }
- int len1, len2;
- if (!EVP_DecryptUpdate(&cipher_ctx, plaintext, &len1, ciphertext,
- (int)ciphertext_len) ||
- !EVP_DecryptFinal_ex(&cipher_ctx, plaintext + len1, &len2)) {
- ERR_clear_error(); /* Don't leave an error on the queue. */
- goto done;
- }
-
- /* Decode the session. */
- SSL_SESSION *session = SSL_SESSION_from_bytes(plaintext, len1 + len2);
- if (session == NULL) {
- ERR_clear_error(); /* Don't leave an error on the queue. */
- goto done;
- }
-
- /* Copy the client's session ID into the new session, to denote the ticket has
- * been accepted. */
- memcpy(session->session_id, session_id, session_id_len);
- session->session_id_length = session_id_len;
-
- if (!ssl_session_is_context_valid(ssl, session) ||
- !ssl_session_is_time_valid(ssl, session)) {
- SSL_SESSION_free(session);
- session = NULL;
- }
-
- *out_session = session;
-
- done:
- OPENSSL_free(plaintext);
- HMAC_CTX_cleanup(&hmac_ctx);
- EVP_CIPHER_CTX_cleanup(&cipher_ctx);
- return ret;
- }
-
- int tls1_parse_peer_sigalgs(SSL *ssl, const CBS *in_sigalgs) {
- /* Extension ignored for inappropriate versions */
- if (ssl3_protocol_version(ssl) < TLS1_2_VERSION) {
- return 1;
- }
-
- SSL_HANDSHAKE *hs = ssl->s3->hs;
- OPENSSL_free(hs->peer_sigalgs);
- hs->peer_sigalgs = NULL;
- hs->num_peer_sigalgs = 0;
-
- size_t num_sigalgs = CBS_len(in_sigalgs);
- if (num_sigalgs % 2 != 0) {
- return 0;
- }
- num_sigalgs /= 2;
-
- /* supported_signature_algorithms in the certificate request is
- * allowed to be empty. */
- if (num_sigalgs == 0) {
- return 1;
- }
-
- /* This multiplication doesn't overflow because sizeof(uint16_t) is two
- * and we just divided |num_sigalgs| by two. */
- hs->peer_sigalgs = OPENSSL_malloc(num_sigalgs * sizeof(uint16_t));
- if (hs->peer_sigalgs == NULL) {
- return 0;
- }
- hs->num_peer_sigalgs = num_sigalgs;
-
- CBS sigalgs;
- CBS_init(&sigalgs, CBS_data(in_sigalgs), CBS_len(in_sigalgs));
- for (size_t i = 0; i < num_sigalgs; i++) {
- if (!CBS_get_u16(&sigalgs, &hs->peer_sigalgs[i])) {
- return 0;
- }
- }
-
- return 1;
- }
-
- int tls1_choose_signature_algorithm(SSL *ssl, uint16_t *out) {
- CERT *cert = ssl->cert;
- SSL_HANDSHAKE *hs = ssl->s3->hs;
-
- /* Before TLS 1.2, the signature algorithm isn't negotiated as part of the
- * handshake. It is fixed at MD5-SHA1 for RSA and SHA1 for ECDSA. */
- if (ssl3_protocol_version(ssl) < TLS1_2_VERSION) {
- int type = ssl_private_key_type(ssl);
- if (type == NID_rsaEncryption) {
- *out = SSL_SIGN_RSA_PKCS1_MD5_SHA1;
- return 1;
- }
- if (ssl_is_ecdsa_key_type(type)) {
- *out = SSL_SIGN_ECDSA_SHA1;
- return 1;
- }
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return 0;
- }
-
- const uint16_t *sigalgs;
- size_t num_sigalgs = tls12_get_psigalgs(ssl, &sigalgs);
- if (cert->sigalgs != NULL) {
- sigalgs = cert->sigalgs;
- num_sigalgs = cert->num_sigalgs;
- }
-
- const uint16_t *peer_sigalgs = hs->peer_sigalgs;
- size_t num_peer_sigalgs = hs->num_peer_sigalgs;
- if (num_peer_sigalgs == 0 && ssl3_protocol_version(ssl) < TLS1_3_VERSION) {
- /* If the client didn't specify any signature_algorithms extension then
- * we can assume that it supports SHA1. See
- * http://tools.ietf.org/html/rfc5246#section-7.4.1.4.1 */
- static const uint16_t kDefaultPeerAlgorithms[] = {SSL_SIGN_RSA_PKCS1_SHA1,
- SSL_SIGN_ECDSA_SHA1};
- peer_sigalgs = kDefaultPeerAlgorithms;
- num_peer_sigalgs = OPENSSL_ARRAY_SIZE(kDefaultPeerAlgorithms);
- }
-
- for (size_t i = 0; i < num_sigalgs; i++) {
- uint16_t sigalg = sigalgs[i];
- /* SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal value and should never be
- * negotiated. */
- if (sigalg == SSL_SIGN_RSA_PKCS1_MD5_SHA1 ||
- !ssl_private_key_supports_signature_algorithm(ssl, sigalgs[i])) {
- continue;
- }
-
- for (size_t j = 0; j < num_peer_sigalgs; j++) {
- if (sigalg == peer_sigalgs[j]) {
- *out = sigalg;
- return 1;
- }
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS);
- return 0;
- }
-
- int tls1_channel_id_hash(SSL *ssl, uint8_t *out, size_t *out_len) {
- int ret = 0;
- EVP_MD_CTX ctx;
-
- EVP_MD_CTX_init(&ctx);
- if (!EVP_DigestInit_ex(&ctx, EVP_sha256(), NULL)) {
- goto err;
- }
-
- static const char kClientIDMagic[] = "TLS Channel ID signature";
- EVP_DigestUpdate(&ctx, kClientIDMagic, sizeof(kClientIDMagic));
-
- if (ssl->session != NULL) {
- static const char kResumptionMagic[] = "Resumption";
- EVP_DigestUpdate(&ctx, kResumptionMagic, sizeof(kResumptionMagic));
- if (ssl->session->original_handshake_hash_len == 0) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- EVP_DigestUpdate(&ctx, ssl->session->original_handshake_hash,
- ssl->session->original_handshake_hash_len);
- }
-
- uint8_t handshake_hash[EVP_MAX_MD_SIZE];
- int handshake_hash_len = tls1_handshake_digest(ssl, handshake_hash,
- sizeof(handshake_hash));
- if (handshake_hash_len < 0) {
- goto err;
- }
- EVP_DigestUpdate(&ctx, handshake_hash, (size_t)handshake_hash_len);
- unsigned len_u;
- EVP_DigestFinal_ex(&ctx, out, &len_u);
- *out_len = len_u;
-
- ret = 1;
-
- err:
- EVP_MD_CTX_cleanup(&ctx);
- return ret;
- }
-
- /* tls1_record_handshake_hashes_for_channel_id records the current handshake
- * hashes in |ssl->s3->new_session| so that Channel ID resumptions can sign that
- * data. */
- int tls1_record_handshake_hashes_for_channel_id(SSL *ssl) {
- int digest_len;
- /* This function should never be called for a resumed session because the
- * handshake hashes that we wish to record are for the original, full
- * handshake. */
- if (ssl->session != NULL) {
- return -1;
- }
-
- digest_len =
- tls1_handshake_digest(
- ssl, ssl->s3->new_session->original_handshake_hash,
- sizeof(ssl->s3->new_session->original_handshake_hash));
- if (digest_len < 0) {
- return -1;
- }
-
- ssl->s3->new_session->original_handshake_hash_len = digest_len;
-
- return 1;
- }
|