pineapple-src/externals/libressl/ssl/tls13_client.c

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/* $OpenBSD: tls13_client.c,v 1.94 2022/02/03 16:33:12 jsing Exp $ */
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/*
* Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <openssl/ssl3.h>
#include "bytestring.h"
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#include "ssl_locl.h"
#include "ssl_sigalgs.h"
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#include "ssl_tlsext.h"
#include "tls13_handshake.h"
#include "tls13_internal.h"
int
tls13_client_init(struct tls13_ctx *ctx)
{
const uint16_t *groups;
size_t groups_len;
SSL *s = ctx->ssl;
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if (!ssl_supported_tls_version_range(s, &ctx->hs->our_min_tls_version,
&ctx->hs->our_max_tls_version)) {
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SSLerror(s, SSL_R_NO_PROTOCOLS_AVAILABLE);
return 0;
}
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s->version = ctx->hs->our_max_tls_version;
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tls13_record_layer_set_retry_after_phh(ctx->rl,
(s->internal->mode & SSL_MODE_AUTO_RETRY) != 0);
if (!ssl_get_new_session(s, 0)) /* XXX */
return 0;
if (!tls1_transcript_init(s))
return 0;
/* Generate a key share using our preferred group. */
tls1_get_group_list(s, 0, &groups, &groups_len);
if (groups_len < 1)
return 0;
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if ((ctx->hs->key_share = tls_key_share_new(groups[0])) == NULL)
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return 0;
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if (!tls_key_share_generate(ctx->hs->key_share))
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return 0;
arc4random_buf(s->s3->client_random, SSL3_RANDOM_SIZE);
/*
* The legacy session identifier should either be set to an
* unpredictable 32-byte value or zero length... a non-zero length
* legacy session identifier triggers compatibility mode (see RFC 8446
* Appendix D.4). In the pre-TLSv1.3 case a zero length value is used.
*/
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if (ctx->middlebox_compat &&
ctx->hs->our_max_tls_version >= TLS1_3_VERSION) {
arc4random_buf(ctx->hs->tls13.legacy_session_id,
sizeof(ctx->hs->tls13.legacy_session_id));
ctx->hs->tls13.legacy_session_id_len =
sizeof(ctx->hs->tls13.legacy_session_id);
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}
return 1;
}
int
tls13_client_connect(struct tls13_ctx *ctx)
{
if (ctx->mode != TLS13_HS_CLIENT)
return TLS13_IO_FAILURE;
return tls13_handshake_perform(ctx);
}
static int
tls13_client_hello_build(struct tls13_ctx *ctx, CBB *cbb)
{
CBB cipher_suites, compression_methods, session_id;
uint16_t client_version;
SSL *s = ctx->ssl;
/* Legacy client version is capped at TLS 1.2. */
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if (!ssl_max_legacy_version(s, &client_version))
goto err;
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if (!CBB_add_u16(cbb, client_version))
goto err;
if (!CBB_add_bytes(cbb, s->s3->client_random, SSL3_RANDOM_SIZE))
goto err;
if (!CBB_add_u8_length_prefixed(cbb, &session_id))
goto err;
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if (!CBB_add_bytes(&session_id, ctx->hs->tls13.legacy_session_id,
ctx->hs->tls13.legacy_session_id_len))
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goto err;
if (!CBB_add_u16_length_prefixed(cbb, &cipher_suites))
goto err;
if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &cipher_suites)) {
SSLerror(s, SSL_R_NO_CIPHERS_AVAILABLE);
goto err;
}
if (!CBB_add_u8_length_prefixed(cbb, &compression_methods))
goto err;
if (!CBB_add_u8(&compression_methods, 0))
goto err;
if (!tlsext_client_build(s, SSL_TLSEXT_MSG_CH, cbb))
goto err;
if (!CBB_flush(cbb))
goto err;
return 1;
err:
return 0;
}
int
tls13_client_hello_send(struct tls13_ctx *ctx, CBB *cbb)
{
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if (ctx->hs->our_min_tls_version < TLS1_2_VERSION)
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tls13_record_layer_set_legacy_version(ctx->rl, TLS1_VERSION);
/* We may receive a pre-TLSv1.3 alert in response to the client hello. */
tls13_record_layer_allow_legacy_alerts(ctx->rl, 1);
if (!tls13_client_hello_build(ctx, cbb))
return 0;
return 1;
}
int
tls13_client_hello_sent(struct tls13_ctx *ctx)
{
tls13_record_layer_allow_ccs(ctx->rl, 1);
tls1_transcript_freeze(ctx->ssl);
if (ctx->middlebox_compat)
ctx->send_dummy_ccs = 1;
return 1;
}
static int
tls13_server_hello_is_legacy(CBS *cbs)
{
CBS extensions_block, extensions, extension_data;
uint16_t selected_version = 0;
uint16_t type;
CBS_dup(cbs, &extensions_block);
if (!CBS_get_u16_length_prefixed(&extensions_block, &extensions))
return 1;
while (CBS_len(&extensions) > 0) {
if (!CBS_get_u16(&extensions, &type))
return 1;
if (!CBS_get_u16_length_prefixed(&extensions, &extension_data))
return 1;
if (type != TLSEXT_TYPE_supported_versions)
continue;
if (!CBS_get_u16(&extension_data, &selected_version))
return 1;
if (CBS_len(&extension_data) != 0)
return 1;
}
return (selected_version < TLS1_3_VERSION);
}
static int
tls13_server_hello_is_retry(CBS *cbs)
{
CBS server_hello, server_random;
uint16_t legacy_version;
CBS_dup(cbs, &server_hello);
if (!CBS_get_u16(&server_hello, &legacy_version))
return 0;
if (!CBS_get_bytes(&server_hello, &server_random, SSL3_RANDOM_SIZE))
return 0;
/* See if this is a HelloRetryRequest. */
return CBS_mem_equal(&server_random, tls13_hello_retry_request_hash,
sizeof(tls13_hello_retry_request_hash));
}
static int
tls13_server_hello_process(struct tls13_ctx *ctx, CBS *cbs)
{
CBS server_random, session_id;
uint16_t tlsext_msg_type = SSL_TLSEXT_MSG_SH;
uint16_t cipher_suite, legacy_version;
uint8_t compression_method;
const SSL_CIPHER *cipher;
int alert_desc;
SSL *s = ctx->ssl;
if (!CBS_get_u16(cbs, &legacy_version))
goto err;
if (!CBS_get_bytes(cbs, &server_random, SSL3_RANDOM_SIZE))
goto err;
if (!CBS_get_u8_length_prefixed(cbs, &session_id))
goto err;
if (!CBS_get_u16(cbs, &cipher_suite))
goto err;
if (!CBS_get_u8(cbs, &compression_method))
goto err;
if (tls13_server_hello_is_legacy(cbs)) {
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if (ctx->hs->our_max_tls_version >= TLS1_3_VERSION) {
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/*
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* RFC 8446 section 4.1.3: we must not downgrade if
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* the server random value contains the TLS 1.2 or 1.1
* magical value.
*/
if (!CBS_skip(&server_random, CBS_len(&server_random) -
sizeof(tls13_downgrade_12)))
goto err;
if (CBS_mem_equal(&server_random, tls13_downgrade_12,
sizeof(tls13_downgrade_12)) ||
CBS_mem_equal(&server_random, tls13_downgrade_11,
sizeof(tls13_downgrade_11))) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
}
if (!CBS_skip(cbs, CBS_len(cbs)))
goto err;
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ctx->hs->tls13.use_legacy = 1;
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return 1;
}
/* From here on in we know we are doing TLSv1.3. */
tls13_record_layer_set_legacy_version(ctx->rl, TLS1_2_VERSION);
tls13_record_layer_allow_legacy_alerts(ctx->rl, 0);
/* See if this is a HelloRetryRequest. */
/* XXX - see if we can avoid doing this twice. */
if (CBS_mem_equal(&server_random, tls13_hello_retry_request_hash,
sizeof(tls13_hello_retry_request_hash))) {
tlsext_msg_type = SSL_TLSEXT_MSG_HRR;
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ctx->hs->tls13.hrr = 1;
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}
if (!tlsext_client_parse(s, tlsext_msg_type, cbs, &alert_desc)) {
ctx->alert = alert_desc;
goto err;
}
/*
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* The supported versions extension indicated 0x0304 or greater.
* Ensure that it was 0x0304 and that legacy version is set to 0x0303
* (RFC 8446 section 4.2.1).
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*/
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if (ctx->hs->tls13.server_version != TLS1_3_VERSION ||
legacy_version != TLS1_2_VERSION) {
ctx->alert = TLS13_ALERT_PROTOCOL_VERSION;
goto err;
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}
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ctx->hs->negotiated_tls_version = ctx->hs->tls13.server_version;
ctx->hs->peer_legacy_version = legacy_version;
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/* The session_id must match. */
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if (!CBS_mem_equal(&session_id, ctx->hs->tls13.legacy_session_id,
ctx->hs->tls13.legacy_session_id_len)) {
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ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
/*
* Ensure that the cipher suite is one that we offered in the client
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* hello and that it is a TLSv1.3 cipher suite.
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*/
cipher = ssl3_get_cipher_by_value(cipher_suite);
if (cipher == NULL || !ssl_cipher_in_list(SSL_get_ciphers(s), cipher)) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
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if (cipher->algorithm_ssl != SSL_TLSV1_3) {
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ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
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if (!(ctx->handshake_stage.hs_type & WITHOUT_HRR) && !ctx->hs->tls13.hrr) {
/*
* A ServerHello following a HelloRetryRequest MUST use the same
* cipher suite (RFC 8446 section 4.1.4).
*/
if (ctx->hs->cipher != cipher) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
}
ctx->hs->cipher = cipher;
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if (compression_method != 0) {
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
goto err;
}
return 1;
err:
if (ctx->alert == 0)
ctx->alert = TLS13_ALERT_DECODE_ERROR;
return 0;
}
static int
tls13_client_engage_record_protection(struct tls13_ctx *ctx)
{
struct tls13_secrets *secrets;
struct tls13_secret context;
unsigned char buf[EVP_MAX_MD_SIZE];
uint8_t *shared_key = NULL;
size_t shared_key_len = 0;
size_t hash_len;
SSL *s = ctx->ssl;
int ret = 0;
/* Derive the shared key and engage record protection. */
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if (!tls_key_share_derive(ctx->hs->key_share, &shared_key,
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&shared_key_len))
goto err;
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s->session->cipher = ctx->hs->cipher;
s->session->ssl_version = ctx->hs->tls13.server_version;
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if ((ctx->aead = tls13_cipher_aead(ctx->hs->cipher)) == NULL)
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goto err;
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if ((ctx->hash = tls13_cipher_hash(ctx->hs->cipher)) == NULL)
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goto err;
if ((secrets = tls13_secrets_create(ctx->hash, 0)) == NULL)
goto err;
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ctx->hs->tls13.secrets = secrets;
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/* XXX - pass in hash. */
if (!tls1_transcript_hash_init(s))
goto err;
tls1_transcript_free(s);
if (!tls1_transcript_hash_value(s, buf, sizeof(buf), &hash_len))
goto err;
context.data = buf;
context.len = hash_len;
/* Early secrets. */
if (!tls13_derive_early_secrets(secrets, secrets->zeros.data,
secrets->zeros.len, &context))
goto err;
/* Handshake secrets. */
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if (!tls13_derive_handshake_secrets(ctx->hs->tls13.secrets, shared_key,
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shared_key_len, &context))
goto err;
tls13_record_layer_set_aead(ctx->rl, ctx->aead);
tls13_record_layer_set_hash(ctx->rl, ctx->hash);
if (!tls13_record_layer_set_read_traffic_key(ctx->rl,
&secrets->server_handshake_traffic))
goto err;
if (!tls13_record_layer_set_write_traffic_key(ctx->rl,
&secrets->client_handshake_traffic))
goto err;
ret = 1;
err:
freezero(shared_key, shared_key_len);
return ret;
}
int
tls13_server_hello_retry_request_recv(struct tls13_ctx *ctx, CBS *cbs)
{
/*
* The state machine has no way of knowing if we're going to receive a
* HelloRetryRequest or a ServerHello. As such, we have to handle
* this case here and hand off to the appropriate function.
*/
if (!tls13_server_hello_is_retry(cbs)) {
ctx->handshake_stage.hs_type |= WITHOUT_HRR;
return tls13_server_hello_recv(ctx, cbs);
}
if (!tls13_server_hello_process(ctx, cbs))
return 0;
/*
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* This may have been a TLSv1.2 or earlier ServerHello that just
* happened to have matching server random...
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*/
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if (ctx->hs->tls13.use_legacy)
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return tls13_use_legacy_client(ctx);
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if (!ctx->hs->tls13.hrr)
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return 0;
if (!tls13_synthetic_handshake_message(ctx))
return 0;
if (!tls13_handshake_msg_record(ctx))
return 0;
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ctx->hs->tls13.hrr = 0;
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return 1;
}
int
tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb)
{
/*
* Ensure that the server supported group is one that we listed in our
* supported groups and is not the same as the key share we previously
* offered.
*/
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if (!tls1_check_curve(ctx->ssl, ctx->hs->tls13.server_group))
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return 0; /* XXX alert */
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if (ctx->hs->tls13.server_group == tls_key_share_group(ctx->hs->key_share))
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return 0; /* XXX alert */
/* Switch to new key share. */
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tls_key_share_free(ctx->hs->key_share);
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if ((ctx->hs->key_share =
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tls_key_share_new(ctx->hs->tls13.server_group)) == NULL)
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return 0;
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if (!tls_key_share_generate(ctx->hs->key_share))
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return 0;
if (!tls13_client_hello_build(ctx, cbb))
return 0;
return 1;
}
int
tls13_server_hello_recv(struct tls13_ctx *ctx, CBS *cbs)
{
SSL *s = ctx->ssl;
/*
* We may have received a legacy (pre-TLSv1.3) ServerHello or a TLSv1.3
* ServerHello. HelloRetryRequests have already been handled.
*/
if (!tls13_server_hello_process(ctx, cbs))
return 0;
if (ctx->handshake_stage.hs_type & WITHOUT_HRR) {
tls1_transcript_unfreeze(s);
if (!tls13_handshake_msg_record(ctx))
return 0;
}
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if (ctx->hs->tls13.use_legacy) {
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if (!(ctx->handshake_stage.hs_type & WITHOUT_HRR))
return 0;
return tls13_use_legacy_client(ctx);
}
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if (ctx->hs->tls13.hrr) {
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/* The server has sent two HelloRetryRequests. */
ctx->alert = TLS13_ALERT_ILLEGAL_PARAMETER;
return 0;
}
if (!tls13_client_engage_record_protection(ctx))
return 0;
ctx->handshake_stage.hs_type |= NEGOTIATED;
return 1;
}
int
tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx, CBS *cbs)
{
int alert_desc;
if (!tlsext_client_parse(ctx->ssl, SSL_TLSEXT_MSG_EE, cbs, &alert_desc)) {
ctx->alert = alert_desc;
goto err;
}
return 1;
err:
if (ctx->alert == 0)
ctx->alert = TLS13_ALERT_DECODE_ERROR;
return 0;
}
int
tls13_server_certificate_request_recv(struct tls13_ctx *ctx, CBS *cbs)
{
CBS cert_request_context;
int alert_desc;
/*
* Thanks to poor state design in the RFC, this function can be called
* when we actually have a certificate message instead of a certificate
* request... in that case we call the certificate handler after
* switching state, to avoid advancing state.
*/
if (tls13_handshake_msg_type(ctx->hs_msg) == TLS13_MT_CERTIFICATE) {
ctx->handshake_stage.hs_type |= WITHOUT_CR;
return tls13_server_certificate_recv(ctx, cbs);
}
if (!CBS_get_u8_length_prefixed(cbs, &cert_request_context))
goto err;
if (CBS_len(&cert_request_context) != 0)
goto err;
if (!tlsext_client_parse(ctx->ssl, SSL_TLSEXT_MSG_CR, cbs, &alert_desc)) {
ctx->alert = alert_desc;
goto err;
}
return 1;
err:
if (ctx->alert == 0)
ctx->alert = TLS13_ALERT_DECODE_ERROR;
return 0;
}
int
tls13_server_certificate_recv(struct tls13_ctx *ctx, CBS *cbs)
{
CBS cert_request_context, cert_list, cert_data;
struct stack_st_X509 *certs = NULL;
SSL *s = ctx->ssl;
X509 *cert = NULL;
EVP_PKEY *pkey;
const uint8_t *p;
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int alert_desc, cert_type;
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int ret = 0;
if ((certs = sk_X509_new_null()) == NULL)
goto err;
if (!CBS_get_u8_length_prefixed(cbs, &cert_request_context))
goto err;
if (CBS_len(&cert_request_context) != 0)
goto err;
if (!CBS_get_u24_length_prefixed(cbs, &cert_list))
goto err;
while (CBS_len(&cert_list) > 0) {
if (!CBS_get_u24_length_prefixed(&cert_list, &cert_data))
goto err;
if (!tlsext_client_parse(ctx->ssl, SSL_TLSEXT_MSG_CT,
&cert_list, &alert_desc)) {
ctx->alert = alert_desc;
goto err;
}
p = CBS_data(&cert_data);
if ((cert = d2i_X509(NULL, &p, CBS_len(&cert_data))) == NULL)
goto err;
if (p != CBS_data(&cert_data) + CBS_len(&cert_data))
goto err;
if (!sk_X509_push(certs, cert))
goto err;
cert = NULL;
}
/* A server must always provide a non-empty certificate list. */
if (sk_X509_num(certs) < 1) {
ctx->alert = TLS13_ALERT_DECODE_ERROR;
tls13_set_errorx(ctx, TLS13_ERR_NO_PEER_CERTIFICATE, 0,
"peer failed to provide a certificate", NULL);
goto err;
}
/*
* At this stage we still have no proof of possession. As such, it would
* be preferable to keep the chain and verify once we have successfully
* processed the CertificateVerify message.
*/
if (ssl_verify_cert_chain(s, certs) <= 0 &&
s->verify_mode != SSL_VERIFY_NONE) {
ctx->alert = ssl_verify_alarm_type(s->verify_result);
tls13_set_errorx(ctx, TLS13_ERR_VERIFY_FAILED, 0,
"failed to verify peer certificate", NULL);
goto err;
}
ERR_clear_error();
cert = sk_X509_value(certs, 0);
X509_up_ref(cert);
if ((pkey = X509_get0_pubkey(cert)) == NULL)
goto err;
if (EVP_PKEY_missing_parameters(pkey))
goto err;
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if ((cert_type = ssl_cert_type(pkey)) < 0)
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goto err;
X509_up_ref(cert);
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X509_free(s->session->peer_cert);
s->session->peer_cert = cert;
s->session->peer_cert_type = cert_type;
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s->session->verify_result = s->verify_result;
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sk_X509_pop_free(s->session->cert_chain, X509_free);
s->session->cert_chain = certs;
certs = NULL;
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if (ctx->ocsp_status_recv_cb != NULL &&
!ctx->ocsp_status_recv_cb(ctx))
goto err;
ret = 1;
err:
sk_X509_pop_free(certs, X509_free);
X509_free(cert);
return ret;
}
int
tls13_server_certificate_verify_recv(struct tls13_ctx *ctx, CBS *cbs)
{
const struct ssl_sigalg *sigalg;
uint16_t signature_scheme;
uint8_t *sig_content = NULL;
size_t sig_content_len;
EVP_MD_CTX *mdctx = NULL;
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
X509 *cert;
CBS signature;
CBB cbb;
int ret = 0;
memset(&cbb, 0, sizeof(cbb));
if (!CBS_get_u16(cbs, &signature_scheme))
goto err;
if (!CBS_get_u16_length_prefixed(cbs, &signature))
goto err;
if (!CBB_init(&cbb, 0))
goto err;
if (!CBB_add_bytes(&cbb, tls13_cert_verify_pad,
sizeof(tls13_cert_verify_pad)))
goto err;
if (!CBB_add_bytes(&cbb, tls13_cert_server_verify_context,
strlen(tls13_cert_server_verify_context)))
goto err;
if (!CBB_add_u8(&cbb, 0))
goto err;
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if (!CBB_add_bytes(&cbb, ctx->hs->tls13.transcript_hash,
ctx->hs->tls13.transcript_hash_len))
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goto err;
if (!CBB_finish(&cbb, &sig_content, &sig_content_len))
goto err;
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if ((cert = ctx->ssl->session->peer_cert) == NULL)
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goto err;
if ((pkey = X509_get0_pubkey(cert)) == NULL)
goto err;
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if ((sigalg = ssl_sigalg_for_peer(ctx->ssl, pkey,
signature_scheme)) == NULL)
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goto err;
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ctx->hs->peer_sigalg = sigalg;
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if (CBS_len(&signature) > EVP_PKEY_size(pkey))
goto err;
if ((mdctx = EVP_MD_CTX_new()) == NULL)
goto err;
if (!EVP_DigestVerifyInit(mdctx, &pctx, sigalg->md(), NULL, pkey))
goto err;
if (sigalg->flags & SIGALG_FLAG_RSA_PSS) {
if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING))
goto err;
if (!EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))
goto err;
}
if (!EVP_DigestVerifyUpdate(mdctx, sig_content, sig_content_len)) {
ctx->alert = TLS13_ALERT_DECRYPT_ERROR;
goto err;
}
if (EVP_DigestVerifyFinal(mdctx, CBS_data(&signature),
CBS_len(&signature)) <= 0) {
ctx->alert = TLS13_ALERT_DECRYPT_ERROR;
goto err;
}
ret = 1;
err:
if (!ret && ctx->alert == 0)
ctx->alert = TLS13_ALERT_DECODE_ERROR;
CBB_cleanup(&cbb);
EVP_MD_CTX_free(mdctx);
free(sig_content);
return ret;
}
int
tls13_server_finished_recv(struct tls13_ctx *ctx, CBS *cbs)
{
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struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
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struct tls13_secret context = { .data = "", .len = 0 };
struct tls13_secret finished_key;
uint8_t transcript_hash[EVP_MAX_MD_SIZE];
size_t transcript_hash_len;
uint8_t *verify_data = NULL;
size_t verify_data_len;
uint8_t key[EVP_MAX_MD_SIZE];
HMAC_CTX *hmac_ctx = NULL;
unsigned int hlen;
int ret = 0;
/*
* Verify server finished.
*/
finished_key.data = key;
finished_key.len = EVP_MD_size(ctx->hash);
if (!tls13_hkdf_expand_label(&finished_key, ctx->hash,
&secrets->server_handshake_traffic, "finished",
&context))
goto err;
if ((hmac_ctx = HMAC_CTX_new()) == NULL)
goto err;
if (!HMAC_Init_ex(hmac_ctx, finished_key.data, finished_key.len,
ctx->hash, NULL))
goto err;
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if (!HMAC_Update(hmac_ctx, ctx->hs->tls13.transcript_hash,
ctx->hs->tls13.transcript_hash_len))
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goto err;
verify_data_len = HMAC_size(hmac_ctx);
if ((verify_data = calloc(1, verify_data_len)) == NULL)
goto err;
if (!HMAC_Final(hmac_ctx, verify_data, &hlen))
goto err;
if (hlen != verify_data_len)
goto err;
if (!CBS_mem_equal(cbs, verify_data, verify_data_len)) {
ctx->alert = TLS13_ALERT_DECRYPT_ERROR;
goto err;
}
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if (!CBS_write_bytes(cbs, ctx->hs->peer_finished,
sizeof(ctx->hs->peer_finished),
&ctx->hs->peer_finished_len))
goto err;
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if (!CBS_skip(cbs, verify_data_len))
goto err;
/*
* Derive application traffic keys.
*/
if (!tls1_transcript_hash_value(ctx->ssl, transcript_hash,
sizeof(transcript_hash), &transcript_hash_len))
goto err;
context.data = transcript_hash;
context.len = transcript_hash_len;
if (!tls13_derive_application_secrets(secrets, &context))
goto err;
/*
* Any records following the server finished message must be encrypted
* using the server application traffic keys.
*/
if (!tls13_record_layer_set_read_traffic_key(ctx->rl,
&secrets->server_application_traffic))
goto err;
tls13_record_layer_allow_ccs(ctx->rl, 0);
ret = 1;
err:
HMAC_CTX_free(hmac_ctx);
free(verify_data);
return ret;
}
static int
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tls13_client_check_certificate(struct tls13_ctx *ctx, SSL_CERT_PKEY *cpk,
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int *ok, const struct ssl_sigalg **out_sigalg)
{
const struct ssl_sigalg *sigalg;
SSL *s = ctx->ssl;
*ok = 0;
*out_sigalg = NULL;
if (cpk->x509 == NULL || cpk->privatekey == NULL)
goto done;
if ((sigalg = ssl_sigalg_select(s, cpk->privatekey)) == NULL)
goto done;
*ok = 1;
*out_sigalg = sigalg;
done:
return 1;
}
static int
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tls13_client_select_certificate(struct tls13_ctx *ctx, SSL_CERT_PKEY **out_cpk,
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const struct ssl_sigalg **out_sigalg)
{
SSL *s = ctx->ssl;
const struct ssl_sigalg *sigalg;
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SSL_CERT_PKEY *cpk;
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int cert_ok;
*out_cpk = NULL;
*out_sigalg = NULL;
/*
* XXX - RFC 8446, 4.4.2.3: the server can communicate preferences
* with the certificate_authorities (4.2.4) and oid_filters (4.2.5)
* extensions. We should honor the former and must apply the latter.
*/
cpk = &s->cert->pkeys[SSL_PKEY_ECC];
if (!tls13_client_check_certificate(ctx, cpk, &cert_ok, &sigalg))
return 0;
if (cert_ok)
goto done;
cpk = &s->cert->pkeys[SSL_PKEY_RSA];
if (!tls13_client_check_certificate(ctx, cpk, &cert_ok, &sigalg))
return 0;
if (cert_ok)
goto done;
cpk = NULL;
sigalg = NULL;
done:
*out_cpk = cpk;
*out_sigalg = sigalg;
return 1;
}
int
tls13_client_certificate_send(struct tls13_ctx *ctx, CBB *cbb)
{
SSL *s = ctx->ssl;
CBB cert_request_context, cert_list;
const struct ssl_sigalg *sigalg;
STACK_OF(X509) *chain;
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SSL_CERT_PKEY *cpk;
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X509 *cert;
int i, ret = 0;
if (!tls13_client_select_certificate(ctx, &cpk, &sigalg))
goto err;
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ctx->hs->tls13.cpk = cpk;
ctx->hs->our_sigalg = sigalg;
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if (!CBB_add_u8_length_prefixed(cbb, &cert_request_context))
goto err;
if (!CBB_add_u24_length_prefixed(cbb, &cert_list))
goto err;
/* No certificate selected. */
if (cpk == NULL)
goto done;
if ((chain = cpk->chain) == NULL)
chain = s->ctx->extra_certs;
if (!tls13_cert_add(ctx, &cert_list, cpk->x509, tlsext_client_build))
goto err;
for (i = 0; i < sk_X509_num(chain); i++) {
cert = sk_X509_value(chain, i);
if (!tls13_cert_add(ctx, &cert_list, cert, tlsext_client_build))
goto err;
}
ctx->handshake_stage.hs_type |= WITH_CCV;
done:
if (!CBB_flush(cbb))
goto err;
ret = 1;
err:
return ret;
}
int
tls13_client_certificate_verify_send(struct tls13_ctx *ctx, CBB *cbb)
{
const struct ssl_sigalg *sigalg;
uint8_t *sig = NULL, *sig_content = NULL;
size_t sig_len, sig_content_len;
EVP_MD_CTX *mdctx = NULL;
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
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const SSL_CERT_PKEY *cpk;
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CBB sig_cbb;
int ret = 0;
memset(&sig_cbb, 0, sizeof(sig_cbb));
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if ((cpk = ctx->hs->tls13.cpk) == NULL)
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goto err;
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if ((sigalg = ctx->hs->our_sigalg) == NULL)
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goto err;
pkey = cpk->privatekey;
if (!CBB_init(&sig_cbb, 0))
goto err;
if (!CBB_add_bytes(&sig_cbb, tls13_cert_verify_pad,
sizeof(tls13_cert_verify_pad)))
goto err;
if (!CBB_add_bytes(&sig_cbb, tls13_cert_client_verify_context,
strlen(tls13_cert_client_verify_context)))
goto err;
if (!CBB_add_u8(&sig_cbb, 0))
goto err;
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if (!CBB_add_bytes(&sig_cbb, ctx->hs->tls13.transcript_hash,
ctx->hs->tls13.transcript_hash_len))
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goto err;
if (!CBB_finish(&sig_cbb, &sig_content, &sig_content_len))
goto err;
if ((mdctx = EVP_MD_CTX_new()) == NULL)
goto err;
if (!EVP_DigestSignInit(mdctx, &pctx, sigalg->md(), NULL, pkey))
goto err;
if (sigalg->flags & SIGALG_FLAG_RSA_PSS) {
if (!EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING))
goto err;
if (!EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx, -1))
goto err;
}
if (!EVP_DigestSignUpdate(mdctx, sig_content, sig_content_len))
goto err;
if (EVP_DigestSignFinal(mdctx, NULL, &sig_len) <= 0)
goto err;
if ((sig = calloc(1, sig_len)) == NULL)
goto err;
if (EVP_DigestSignFinal(mdctx, sig, &sig_len) <= 0)
goto err;
if (!CBB_add_u16(cbb, sigalg->value))
goto err;
if (!CBB_add_u16_length_prefixed(cbb, &sig_cbb))
goto err;
if (!CBB_add_bytes(&sig_cbb, sig, sig_len))
goto err;
if (!CBB_flush(cbb))
goto err;
ret = 1;
err:
if (!ret && ctx->alert == 0)
ctx->alert = TLS13_ALERT_INTERNAL_ERROR;
CBB_cleanup(&sig_cbb);
EVP_MD_CTX_free(mdctx);
free(sig_content);
free(sig);
return ret;
}
int
tls13_client_end_of_early_data_send(struct tls13_ctx *ctx, CBB *cbb)
{
return 0;
}
int
tls13_client_finished_send(struct tls13_ctx *ctx, CBB *cbb)
{
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struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
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struct tls13_secret context = { .data = "", .len = 0 };
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struct tls13_secret finished_key = { .data = NULL, .len = 0 };
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uint8_t transcript_hash[EVP_MAX_MD_SIZE];
size_t transcript_hash_len;
uint8_t *verify_data;
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size_t verify_data_len;
2020-12-28 15:15:37 +00:00
unsigned int hlen;
HMAC_CTX *hmac_ctx = NULL;
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CBS cbs;
2020-12-28 15:15:37 +00:00
int ret = 0;
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if (!tls13_secret_init(&finished_key, EVP_MD_size(ctx->hash)))
goto err;
2020-12-28 15:15:37 +00:00
if (!tls13_hkdf_expand_label(&finished_key, ctx->hash,
&secrets->client_handshake_traffic, "finished",
&context))
goto err;
if (!tls1_transcript_hash_value(ctx->ssl, transcript_hash,
sizeof(transcript_hash), &transcript_hash_len))
goto err;
if ((hmac_ctx = HMAC_CTX_new()) == NULL)
goto err;
if (!HMAC_Init_ex(hmac_ctx, finished_key.data, finished_key.len,
ctx->hash, NULL))
goto err;
if (!HMAC_Update(hmac_ctx, transcript_hash, transcript_hash_len))
goto err;
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verify_data_len = HMAC_size(hmac_ctx);
if (!CBB_add_space(cbb, &verify_data, verify_data_len))
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goto err;
if (!HMAC_Final(hmac_ctx, verify_data, &hlen))
goto err;
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if (hlen != verify_data_len)
goto err;
CBS_init(&cbs, verify_data, verify_data_len);
if (!CBS_write_bytes(&cbs, ctx->hs->finished,
sizeof(ctx->hs->finished), &ctx->hs->finished_len))
2020-12-28 15:15:37 +00:00
goto err;
ret = 1;
err:
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tls13_secret_cleanup(&finished_key);
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HMAC_CTX_free(hmac_ctx);
return ret;
}
int
tls13_client_finished_sent(struct tls13_ctx *ctx)
{
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struct tls13_secrets *secrets = ctx->hs->tls13.secrets;
2020-12-28 15:15:37 +00:00
/*
* Any records following the client finished message must be encrypted
* using the client application traffic keys.
*/
return tls13_record_layer_set_write_traffic_key(ctx->rl,
&secrets->client_application_traffic);
}