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boringssl/ssl/t1_enc.c
David Benjamin afbc63fc2f Simplify DTLS epoch rewind. 
SSL_AEAD_CTX ownership is currently too confusing. Instead, rely on the lack of
renego, so the previous epoch always uses the NULL cipher. (Were we to support
DTLS renego, we could keep track of s->d1->last_aead_write_ctx like
s->d1->last_write_sequence, but it isn't worth it.)

Buffered messages also tracked an old s->session, but this is unnecessary. The
s->session NULL check in tls1_enc dates to the OpenSSL initial commit and is
redundant with the aead NULL check.

Change-Id: I9a510468d95934c65bca4979094551c7536980ae
Reviewed-on: https://boringssl-review.googlesource.com/3234
Reviewed-by: Adam Langley <agl@google.com>
2015-02-03 20:34:06 +00:00

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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/* ====================================================================
* Copyright 2005 Nokia. All rights reserved.
*
* The portions of the attached software ("Contribution") is developed by
* Nokia Corporation and is licensed pursuant to the OpenSSL open source
* license.
*
* The Contribution, originally written by Mika Kousa and Pasi Eronen of
* Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
* support (see RFC 4279) to OpenSSL.
*
* No patent licenses or other rights except those expressly stated in
* the OpenSSL open source license shall be deemed granted or received
* expressly, by implication, estoppel, or otherwise.
*
* No assurances are provided by Nokia that the Contribution does not
* infringe the patent or other intellectual property rights of any third
* party or that the license provides you with all the necessary rights
* to make use of the Contribution.
*
* THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
* ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
* SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
* OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
* OTHERWISE. */
#include <stdio.h>
#include <assert.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/rand.h>
#include "ssl_locl.h"
/* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
* section 5. It writes |out_len| bytes to |out|, using |md| as the hash and
* |secret| as the secret. |seed1| through |seed3| are concatenated to form the
* seed parameter. It returns one on success and zero on failure. */
static int tls1_P_hash(uint8_t *out, size_t out_len, const EVP_MD *md,
const uint8_t *secret, size_t secret_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len,
const uint8_t *seed3, size_t seed3_len) {
size_t chunk;
HMAC_CTX ctx, ctx_tmp, ctx_init;
uint8_t A1[EVP_MAX_MD_SIZE];
unsigned A1_len;
int ret = 0;
chunk = EVP_MD_size(md);
HMAC_CTX_init(&ctx);
HMAC_CTX_init(&ctx_tmp);
HMAC_CTX_init(&ctx_init);
if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) ||
!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
(seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) ||
(seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) ||
(seed3_len && !HMAC_Update(&ctx, seed3, seed3_len)) ||
!HMAC_Final(&ctx, A1, &A1_len)) {
goto err;
}
for (;;) {
/* Reinit mac contexts. */
if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
!HMAC_Update(&ctx, A1, A1_len) ||
(out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) ||
(seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) ||
(seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) ||
(seed3_len && !HMAC_Update(&ctx, seed3, seed3_len))) {
goto err;
}
if (out_len > chunk) {
unsigned len;
if (!HMAC_Final(&ctx, out, &len)) {
goto err;
}
assert(len == chunk);
out += len;
out_len -= len;
/* Calculate the next A1 value. */
if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
goto err;
}
} else {
/* Last chunk. */
if (!HMAC_Final(&ctx, A1, &A1_len)) {
goto err;
}
memcpy(out, A1, out_len);
break;
}
}
ret = 1;
err:
HMAC_CTX_cleanup(&ctx);
HMAC_CTX_cleanup(&ctx_tmp);
HMAC_CTX_cleanup(&ctx_init);
OPENSSL_cleanse(A1, sizeof(A1));
return ret;
}
int tls1_prf(SSL *s, uint8_t *out, size_t out_len, const uint8_t *secret,
size_t secret_len, const char *label, size_t label_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len) {
size_t idx, len, count, i;
const uint8_t *S1;
long m;
const EVP_MD *md;
int ret = 0;
uint8_t *tmp;
if (out_len == 0) {
return 1;
}
/* Allocate a temporary buffer. */
tmp = OPENSSL_malloc(out_len);
if (tmp == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_prf, ERR_R_MALLOC_FAILURE);
return 0;
}
/* Count number of digests and partition |secret| evenly. */
count = 0;
for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) {
if ((m << TLS1_PRF_DGST_SHIFT) & ssl_get_algorithm2(s)) {
count++;
}
}
/* TODO(davidben): The only case where count isn't 1 is the old MD5/SHA-1
* combination. The logic around multiple handshake digests can probably be
* simplified. */
assert(count == 1 || count == 2);
len = secret_len / count;
if (count == 1) {
secret_len = 0;
}
S1 = secret;
memset(out, 0, out_len);
for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) {
if ((m << TLS1_PRF_DGST_SHIFT) & ssl_get_algorithm2(s)) {
/* If |count| is 2 and |secret_len| is odd, |secret| is partitioned into
* two halves with an overlapping byte. */
if (!tls1_P_hash(tmp, out_len, md, S1, len + (secret_len & 1),
(const uint8_t *)label, label_len, seed1, seed1_len,
seed2, seed2_len)) {
goto err;
}
S1 += len;
for (i = 0; i < out_len; i++) {
out[i] ^= tmp[i];
}
}
}
ret = 1;
err:
OPENSSL_cleanse(tmp, out_len);
OPENSSL_free(tmp);
return ret;
}
static int tls1_generate_key_block(SSL *s, uint8_t *out, size_t out_len) {
return s->enc_method->prf(s, out, out_len, s->session->master_key,
s->session->master_key_length,
TLS_MD_KEY_EXPANSION_CONST,
TLS_MD_KEY_EXPANSION_CONST_SIZE,
s->s3->server_random, SSL3_RANDOM_SIZE,
s->s3->client_random,
SSL3_RANDOM_SIZE);
}
/* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It
* returns 0 on malloc error. */
static int tls1_aead_ctx_init(SSL_AEAD_CTX **aead_ctx) {
if (*aead_ctx != NULL) {
EVP_AEAD_CTX_cleanup(&(*aead_ctx)->ctx);
} else {
*aead_ctx = (SSL_AEAD_CTX *)OPENSSL_malloc(sizeof(SSL_AEAD_CTX));
if (*aead_ctx == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_aead_ctx_init, ERR_R_MALLOC_FAILURE);
return 0;
}
}
return 1;
}
static int tls1_change_cipher_state_aead(SSL *s, char is_read,
const uint8_t *key, unsigned key_len,
const uint8_t *iv, unsigned iv_len,
const uint8_t *mac_secret,
unsigned mac_secret_len) {
const EVP_AEAD *aead = s->s3->tmp.new_aead;
SSL_AEAD_CTX *aead_ctx;
/* merged_key is used to merge the MAC, cipher, and IV keys for an AEAD which
* simulates pre-AEAD cipher suites. */
uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH];
if (mac_secret_len > 0) {
/* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher
* suites). */
if (mac_secret_len + key_len + iv_len > sizeof(merged_key)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead,
ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(merged_key, mac_secret, mac_secret_len);
memcpy(merged_key + mac_secret_len, key, key_len);
memcpy(merged_key + mac_secret_len + key_len, iv, iv_len);
key = merged_key;
key_len += mac_secret_len;
key_len += iv_len;
}
if (is_read) {
if (!tls1_aead_ctx_init(&s->aead_read_ctx)) {
return 0;
}
aead_ctx = s->aead_read_ctx;
} else {
if (SSL_IS_DTLS(s) && s->aead_write_ctx != NULL) {
/* DTLS renegotiation is unsupported, so a CCS can only switch away from
* the NULL cipher. This simplifies renegotiation. */
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead,
ERR_R_INTERNAL_ERROR);
return 0;
}
if (!tls1_aead_ctx_init(&s->aead_write_ctx)) {
return 0;
}
aead_ctx = s->aead_write_ctx;
}
if (!EVP_AEAD_CTX_init(&aead_ctx->ctx, aead, key, key_len,
EVP_AEAD_DEFAULT_TAG_LENGTH, NULL /* engine */)) {
OPENSSL_free(aead_ctx);
if (is_read) {
s->aead_read_ctx = NULL;
} else {
s->aead_write_ctx = NULL;
}
return 0;
}
if (mac_secret_len == 0) {
/* For a real AEAD, the IV is the fixed part of the nonce. */
if (iv_len > sizeof(aead_ctx->fixed_nonce)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(aead_ctx->fixed_nonce, iv, iv_len);
aead_ctx->fixed_nonce_len = iv_len;
aead_ctx->variable_nonce_included_in_record =
(s->s3->tmp.new_cipher->algorithm2 &
SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_INCLUDED_IN_RECORD) != 0;
aead_ctx->random_variable_nonce = 0;
aead_ctx->omit_length_in_ad = 0;
} else {
aead_ctx->fixed_nonce_len = 0;
aead_ctx->variable_nonce_included_in_record = 1;
aead_ctx->random_variable_nonce = 1;
aead_ctx->omit_length_in_ad = 1;
}
aead_ctx->variable_nonce_len = s->s3->tmp.new_variable_iv_len;
aead_ctx->omit_version_in_ad = (s->version == SSL3_VERSION);
if (aead_ctx->variable_nonce_len + aead_ctx->fixed_nonce_len !=
EVP_AEAD_nonce_length(aead)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
return 0;
}
aead_ctx->tag_len = EVP_AEAD_max_overhead(aead);
return 1;
}
int tls1_change_cipher_state(SSL *s, int which) {
/* is_read is true if we have just read a ChangeCipherSpec message - i.e. we
* need to update the read cipherspec. Otherwise we have just written one. */
const char is_read = (which & SSL3_CC_READ) != 0;
/* use_client_keys is true if we wish to use the keys for the "client write"
* direction. This is the case if we're a client sending a ChangeCipherSpec,
* or a server reading a client's ChangeCipherSpec. */
const char use_client_keys = which == SSL3_CHANGE_CIPHER_CLIENT_WRITE ||
which == SSL3_CHANGE_CIPHER_SERVER_READ;
const uint8_t *client_write_mac_secret, *server_write_mac_secret, *mac_secret;
const uint8_t *client_write_key, *server_write_key, *key;
const uint8_t *client_write_iv, *server_write_iv, *iv;
const EVP_AEAD *aead = s->s3->tmp.new_aead;
size_t key_len, iv_len, mac_secret_len;
const uint8_t *key_data;
/* Reset sequence number to zero. */
if (!SSL_IS_DTLS(s)) {
memset(is_read ? s->s3->read_sequence : s->s3->write_sequence, 0, 8);
}
mac_secret_len = s->s3->tmp.new_mac_secret_len;
iv_len = s->s3->tmp.new_fixed_iv_len;
if (aead == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
return 0;
}
key_len = EVP_AEAD_key_length(aead);
if (mac_secret_len > 0) {
/* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher
* suites) the key length reported by |EVP_AEAD_key_length| will
* include the MAC and IV key bytes. */
if (key_len < mac_secret_len + iv_len) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
return 0;
}
key_len -= mac_secret_len + iv_len;
}
key_data = s->s3->tmp.key_block;
client_write_mac_secret = key_data;
key_data += mac_secret_len;
server_write_mac_secret = key_data;
key_data += mac_secret_len;
client_write_key = key_data;
key_data += key_len;
server_write_key = key_data;
key_data += key_len;
client_write_iv = key_data;
key_data += iv_len;
server_write_iv = key_data;
key_data += iv_len;
if (use_client_keys) {
mac_secret = client_write_mac_secret;
key = client_write_key;
iv = client_write_iv;
} else {
mac_secret = server_write_mac_secret;
key = server_write_key;
iv = server_write_iv;
}
if (key_data - s->s3->tmp.key_block != s->s3->tmp.key_block_length) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
return 0;
}
return tls1_change_cipher_state_aead(s, is_read, key, key_len, iv, iv_len,
mac_secret, mac_secret_len);
}
int tls1_setup_key_block(SSL *s) {
uint8_t *p;
const EVP_AEAD *aead = NULL;
int ret = 0;
size_t mac_secret_len, fixed_iv_len, variable_iv_len, key_len;
size_t key_block_len;
if (s->s3->tmp.key_block_length != 0) {
return 1;
}
if (s->session->cipher == NULL) {
goto cipher_unavailable_err;
}
if (!ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len,
s->session->cipher,
ssl3_version_from_wire(s, s->version))) {
goto cipher_unavailable_err;
}
key_len = EVP_AEAD_key_length(aead);
variable_iv_len = EVP_AEAD_nonce_length(aead);
if (mac_secret_len > 0) {
/* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites) the
* key length reported by |EVP_AEAD_key_length| will include the MAC key
* bytes and initial implicit IV. */
if (key_len < mac_secret_len + fixed_iv_len) {
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR);
return 0;
}
key_len -= mac_secret_len + fixed_iv_len;
} else {
/* The nonce is split into a fixed portion and a variable portion. */
if (variable_iv_len < fixed_iv_len) {
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR);
return 0;
}
variable_iv_len -= fixed_iv_len;
}
assert(mac_secret_len < 256);
assert(fixed_iv_len < 256);
assert(variable_iv_len < 256);
s->s3->tmp.new_aead = aead;
s->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len;
s->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len;
s->s3->tmp.new_variable_iv_len = (uint8_t)variable_iv_len;
key_block_len = key_len + mac_secret_len + fixed_iv_len;
key_block_len *= 2;
ssl3_cleanup_key_block(s);
p = (uint8_t *)OPENSSL_malloc(key_block_len);
if (p == NULL) {
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE);
goto err;
}
s->s3->tmp.key_block_length = key_block_len;
s->s3->tmp.key_block = p;
if (!tls1_generate_key_block(s, p, key_block_len)) {
goto err;
}
if (!SSL_USE_EXPLICIT_IV(s) &&
(s->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0) {
/* enable vulnerability countermeasure for CBC ciphers with known-IV
* problem (http://www.openssl.org/~bodo/tls-cbc.txt). */
s->s3->need_record_splitting = 1;
if (s->session->cipher != NULL &&
s->session->cipher->algorithm_enc == SSL_RC4) {
s->s3->need_record_splitting = 0;
}
}
ret = 1;
err:
return ret;
cipher_unavailable_err:
OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block,
SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
return 0;
}
/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|,
* respectively. It returns one on success and zero on failure. */
int tls1_enc(SSL *s, int send) {
SSL3_RECORD *rec;
const SSL_AEAD_CTX *aead;
if (send) {
rec = &s->s3->wrec;
aead = s->aead_write_ctx;
} else {
rec = &s->s3->rrec;
aead = s->aead_read_ctx;
}
if (aead == NULL) {
/* Handle the initial NULL cipher. */
memmove(rec->data, rec->input, rec->length);
rec->input = rec->data;
return 1;
}
uint8_t ad[13], *seq, *in, *out, nonce[EVP_AEAD_MAX_NONCE_LENGTH];
unsigned nonce_used;
size_t n, ad_len;
seq = send ? s->s3->write_sequence : s->s3->read_sequence;
if (SSL_IS_DTLS(s)) {
uint8_t dtlsseq[9], *p = dtlsseq;
s2n(send ? s->d1->w_epoch : s->d1->r_epoch, p);
memcpy(p, &seq[2], 6);
memcpy(ad, dtlsseq, 8);
} else {
int i;
memcpy(ad, seq, 8);
for (i = 7; i >= 0; i--) {
++seq[i];
if (seq[i] != 0) {
break;
}
}
}
ad[8] = rec->type;
ad_len = 9;
if (!aead->omit_version_in_ad) {
ad[ad_len++] = (uint8_t)(s->version >> 8);
ad[ad_len++] = (uint8_t)(s->version);
}
if (aead->fixed_nonce_len + aead->variable_nonce_len > sizeof(nonce)) {
OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(nonce, aead->fixed_nonce, aead->fixed_nonce_len);
nonce_used = aead->fixed_nonce_len;
if (send) {
size_t len = rec->length;
size_t eivlen = 0;
in = rec->input;
out = rec->data;
uint8_t *variable_nonce = nonce + nonce_used;
if (aead->random_variable_nonce) {
assert(aead->variable_nonce_included_in_record);
if (!RAND_bytes(nonce + nonce_used, aead->variable_nonce_len)) {
return 0;
}
} else {
/* When sending we use the sequence number as the variable part of the
* nonce. */
if (aead->variable_nonce_len != 8) {
OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(nonce + nonce_used, ad, aead->variable_nonce_len);
}
nonce_used += aead->variable_nonce_len;
/* in do_ssl3_write, rec->input is moved forward by variable_nonce_len in
* order to leave space for the variable nonce. Thus we can copy the
* sequence number bytes into place without overwriting any of the
* plaintext. */
if (aead->variable_nonce_included_in_record) {
memcpy(out, variable_nonce, aead->variable_nonce_len);
len -= aead->variable_nonce_len;
eivlen = aead->variable_nonce_len;
}
if (!aead->omit_length_in_ad) {
ad[ad_len++] = len >> 8;
ad[ad_len++] = len & 0xff;
}
if (!EVP_AEAD_CTX_seal(&aead->ctx, out + eivlen, &n, len + aead->tag_len,
nonce, nonce_used, in + eivlen, len, ad, ad_len)) {
return 0;
}
if (aead->variable_nonce_included_in_record) {
n += aead->variable_nonce_len;
}
} else {
/* receive */
size_t len = rec->length;
if (rec->data != rec->input) {
OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
return 0;
}
out = in = rec->input;
if (len < aead->variable_nonce_len) {
return 0;
}
memcpy(nonce + nonce_used,
aead->variable_nonce_included_in_record ? in : ad,
aead->variable_nonce_len);
nonce_used += aead->variable_nonce_len;
if (aead->variable_nonce_included_in_record) {
in += aead->variable_nonce_len;
len -= aead->variable_nonce_len;
out += aead->variable_nonce_len;
}
if (!aead->omit_length_in_ad) {
if (len < aead->tag_len) {
return 0;
}
size_t plaintext_len = len - aead->tag_len;
ad[ad_len++] = plaintext_len >> 8;
ad[ad_len++] = plaintext_len & 0xff;
}
if (!EVP_AEAD_CTX_open(&aead->ctx, out, &n, rec->length, nonce, nonce_used, in,
len, ad, ad_len)) {
return 0;
}
rec->data = rec->input = out;
}
rec->length = n;
return 1;
}
int tls1_cert_verify_mac(SSL *s, int md_nid, uint8_t *out) {
unsigned int ret;
EVP_MD_CTX ctx, *d = NULL;
int i;
if (s->s3->handshake_buffer &&
!ssl3_digest_cached_records(s, free_handshake_buffer)) {
return 0;
}
for (i = 0; i < SSL_MAX_DIGEST; i++) {
if (s->s3->handshake_dgst[i] &&
EVP_MD_CTX_type(s->s3->handshake_dgst[i]) == md_nid) {
d = s->s3->handshake_dgst[i];
break;
}
}
if (!d) {
OPENSSL_PUT_ERROR(SSL, tls1_cert_verify_mac, SSL_R_NO_REQUIRED_DIGEST);
return 0;
}
EVP_MD_CTX_init(&ctx);
EVP_MD_CTX_copy_ex(&ctx, d);
EVP_DigestFinal_ex(&ctx, out, &ret);
EVP_MD_CTX_cleanup(&ctx);
return ret;
}
/* tls1_handshake_digest calculates the current handshake hash and writes it to
* |out|, which has space for |out_len| bytes. It returns the number of bytes
* written or -1 in the event of an error. This function works on a copy of the
* underlying digests so can be called multiple times and prior to the final
* update etc. */
int tls1_handshake_digest(SSL *s, uint8_t *out, size_t out_len) {
const EVP_MD *md;
EVP_MD_CTX ctx;
int err = 0, len = 0;
size_t i;
long mask;
EVP_MD_CTX_init(&ctx);
for (i = 0; ssl_get_handshake_digest(i, &mask, &md); i++) {
size_t hash_size;
unsigned int digest_len;
EVP_MD_CTX *hdgst = s->s3->handshake_dgst[i];
if ((mask & ssl_get_algorithm2(s)) == 0) {
continue;
}
hash_size = EVP_MD_size(md);
if (!hdgst ||
hash_size > out_len ||
!EVP_MD_CTX_copy_ex(&ctx, hdgst) ||
!EVP_DigestFinal_ex(&ctx, out, &digest_len) ||
digest_len != hash_size /* internal error */) {
err = 1;
break;
}
out += digest_len;
out_len -= digest_len;
len += digest_len;
}
EVP_MD_CTX_cleanup(&ctx);
if (err != 0) {
return -1;
}
return len;
}
int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) {
uint8_t buf[2 * EVP_MAX_MD_SIZE];
int err = 0;
int digests_len;
if (s->s3->handshake_buffer &&
!ssl3_digest_cached_records(s, free_handshake_buffer)) {
return 0;
}
digests_len = tls1_handshake_digest(s, buf, sizeof(buf));
if (digests_len < 0) {
err = 1;
digests_len = 0;
}
if (!s->enc_method->prf(s, out, 12, s->session->master_key,
s->session->master_key_length, str, slen, buf,
digests_len, NULL, 0)) {
err = 1;
}
if (err) {
return 0;
} else {
return 12;
}
}
int tls1_generate_master_secret(SSL *s, uint8_t *out, const uint8_t *premaster,
size_t premaster_len) {
if (s->s3->tmp.extended_master_secret) {
uint8_t digests[2 * EVP_MAX_MD_SIZE];
int digests_len;
/* The master secret is based on the handshake hash just after sending the
* ClientKeyExchange. However, we might have a client certificate to send,
* in which case we might need different hashes for the verification and
* thus still need the handshake buffer around. Keeping both a handshake
* buffer *and* running hashes isn't yet supported so, when it comes to
* calculating the Finished hash, we'll have to hash the handshake buffer
* again. */
if (s->s3->handshake_buffer &&
!ssl3_digest_cached_records(s, dont_free_handshake_buffer)) {
return 0;
}
digests_len = tls1_handshake_digest(s, digests, sizeof(digests));
if (digests_len == -1) {
return 0;
}
if (!s->enc_method->prf(s, out, SSL3_MASTER_SECRET_SIZE, premaster,
premaster_len, TLS_MD_EXTENDED_MASTER_SECRET_CONST,
TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests,
digests_len, NULL, 0)) {
return 0;
}
} else {
if (!s->enc_method->prf(s, out, SSL3_MASTER_SECRET_SIZE, premaster,
premaster_len, TLS_MD_MASTER_SECRET_CONST,
TLS_MD_MASTER_SECRET_CONST_SIZE,
s->s3->client_random, SSL3_RANDOM_SIZE,
s->s3->server_random, SSL3_RANDOM_SIZE)) {
return 0;
}
}
return SSL3_MASTER_SECRET_SIZE;
}
int tls1_export_keying_material(SSL *s, uint8_t *out, size_t olen,
const char *label, size_t llen,
const uint8_t *context, size_t contextlen,
int use_context) {
uint8_t *val = NULL;
size_t vallen, currentvalpos;
int ret;
/* construct PRF arguments we construct the PRF argument ourself rather than
* passing separate values into the TLS PRF to ensure that the concatenation
* of values does not create a prohibited label. */
vallen = llen + SSL3_RANDOM_SIZE * 2;
if (use_context) {
vallen += 2 + contextlen;
}
val = OPENSSL_malloc(vallen);
if (val == NULL) {
goto err2;
}
currentvalpos = 0;
memcpy(val + currentvalpos, (uint8_t *)label, llen);
currentvalpos += llen;
memcpy(val + currentvalpos, s->s3->client_random, SSL3_RANDOM_SIZE);
currentvalpos += SSL3_RANDOM_SIZE;
memcpy(val + currentvalpos, s->s3->server_random, SSL3_RANDOM_SIZE);
currentvalpos += SSL3_RANDOM_SIZE;
if (use_context) {
val[currentvalpos] = (contextlen >> 8) & 0xff;
currentvalpos++;
val[currentvalpos] = contextlen & 0xff;
currentvalpos++;
if (contextlen > 0 || context != NULL) {
memcpy(val + currentvalpos, context, contextlen);
}
}
/* disallow prohibited labels note that SSL3_RANDOM_SIZE > max(prohibited
* label len) = 15, so size of val > max(prohibited label len) = 15 and the
* comparisons won't have buffer overflow. */
if (memcmp(val, TLS_MD_CLIENT_FINISH_CONST,
TLS_MD_CLIENT_FINISH_CONST_SIZE) == 0 ||
memcmp(val, TLS_MD_SERVER_FINISH_CONST,
TLS_MD_SERVER_FINISH_CONST_SIZE) == 0 ||
memcmp(val, TLS_MD_MASTER_SECRET_CONST,
TLS_MD_MASTER_SECRET_CONST_SIZE) == 0 ||
memcmp(val, TLS_MD_KEY_EXPANSION_CONST,
TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0) {
goto err1;
}
/* SSL_export_keying_material is not implemented for SSLv3, so passing
* everything through the label parameter works. */
assert(s->version != SSL3_VERSION);
ret = s->enc_method->prf(s, out, olen, s->session->master_key,
s->session->master_key_length, (const char *)val,
vallen, NULL, 0, NULL, 0);
goto out;
err1:
OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material,
SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
ret = 0;
goto out;
err2:
OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material, ERR_R_MALLOC_FAILURE);
ret = 0;
out:
if (val != NULL) {
OPENSSL_free(val);
}
return ret;
}
int tls1_alert_code(int code) {
switch (code) {
case SSL_AD_CLOSE_NOTIFY:
return SSL3_AD_CLOSE_NOTIFY;
case SSL_AD_UNEXPECTED_MESSAGE:
return SSL3_AD_UNEXPECTED_MESSAGE;
case SSL_AD_BAD_RECORD_MAC:
return SSL3_AD_BAD_RECORD_MAC;
case SSL_AD_DECRYPTION_FAILED:
return TLS1_AD_DECRYPTION_FAILED;
case SSL_AD_RECORD_OVERFLOW:
return TLS1_AD_RECORD_OVERFLOW;
case SSL_AD_DECOMPRESSION_FAILURE:
return SSL3_AD_DECOMPRESSION_FAILURE;
case SSL_AD_HANDSHAKE_FAILURE:
return SSL3_AD_HANDSHAKE_FAILURE;
case SSL_AD_NO_CERTIFICATE:
return -1;
case SSL_AD_BAD_CERTIFICATE:
return SSL3_AD_BAD_CERTIFICATE;
case SSL_AD_UNSUPPORTED_CERTIFICATE:
return SSL3_AD_UNSUPPORTED_CERTIFICATE;
case SSL_AD_CERTIFICATE_REVOKED:
return SSL3_AD_CERTIFICATE_REVOKED;
case SSL_AD_CERTIFICATE_EXPIRED:
return SSL3_AD_CERTIFICATE_EXPIRED;
case SSL_AD_CERTIFICATE_UNKNOWN:
return SSL3_AD_CERTIFICATE_UNKNOWN;
case SSL_AD_ILLEGAL_PARAMETER:
return SSL3_AD_ILLEGAL_PARAMETER;
case SSL_AD_UNKNOWN_CA:
return TLS1_AD_UNKNOWN_CA;
case SSL_AD_ACCESS_DENIED:
return TLS1_AD_ACCESS_DENIED;
case SSL_AD_DECODE_ERROR:
return TLS1_AD_DECODE_ERROR;
case SSL_AD_DECRYPT_ERROR:
return TLS1_AD_DECRYPT_ERROR;
case SSL_AD_EXPORT_RESTRICTION:
return TLS1_AD_EXPORT_RESTRICTION;
case SSL_AD_PROTOCOL_VERSION:
return TLS1_AD_PROTOCOL_VERSION;
case SSL_AD_INSUFFICIENT_SECURITY:
return TLS1_AD_INSUFFICIENT_SECURITY;
case SSL_AD_INTERNAL_ERROR:
return TLS1_AD_INTERNAL_ERROR;
case SSL_AD_USER_CANCELLED:
return TLS1_AD_USER_CANCELLED;
case SSL_AD_NO_RENEGOTIATION:
return TLS1_AD_NO_RENEGOTIATION;
case SSL_AD_UNSUPPORTED_EXTENSION:
return TLS1_AD_UNSUPPORTED_EXTENSION;
case SSL_AD_CERTIFICATE_UNOBTAINABLE:
return TLS1_AD_CERTIFICATE_UNOBTAINABLE;
case SSL_AD_UNRECOGNIZED_NAME:
return TLS1_AD_UNRECOGNIZED_NAME;
case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE:
return TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
case SSL_AD_BAD_CERTIFICATE_HASH_VALUE:
return TLS1_AD_BAD_CERTIFICATE_HASH_VALUE;
case SSL_AD_UNKNOWN_PSK_IDENTITY:
return TLS1_AD_UNKNOWN_PSK_IDENTITY;
case SSL_AD_INAPPROPRIATE_FALLBACK:
return SSL3_AD_INAPPROPRIATE_FALLBACK;
default:
return -1;
}
}
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