xref: /aosp_15_r20/external/boringssl/src/ssl/ssl_transcript.cc (revision 8fb009dc861624b67b6cdb62ea21f0f22d0c584b)
1*8fb009dcSAndroid Build Coastguard Worker /* Copyright (C) 1995-1998 Eric Young ([email protected])
2*8fb009dcSAndroid Build Coastguard Worker  * All rights reserved.
3*8fb009dcSAndroid Build Coastguard Worker  *
4*8fb009dcSAndroid Build Coastguard Worker  * This package is an SSL implementation written
5*8fb009dcSAndroid Build Coastguard Worker  * by Eric Young ([email protected]).
6*8fb009dcSAndroid Build Coastguard Worker  * The implementation was written so as to conform with Netscapes SSL.
7*8fb009dcSAndroid Build Coastguard Worker  *
8*8fb009dcSAndroid Build Coastguard Worker  * This library is free for commercial and non-commercial use as long as
9*8fb009dcSAndroid Build Coastguard Worker  * the following conditions are aheared to.  The following conditions
10*8fb009dcSAndroid Build Coastguard Worker  * apply to all code found in this distribution, be it the RC4, RSA,
11*8fb009dcSAndroid Build Coastguard Worker  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12*8fb009dcSAndroid Build Coastguard Worker  * included with this distribution is covered by the same copyright terms
13*8fb009dcSAndroid Build Coastguard Worker  * except that the holder is Tim Hudson ([email protected]).
14*8fb009dcSAndroid Build Coastguard Worker  *
15*8fb009dcSAndroid Build Coastguard Worker  * Copyright remains Eric Young's, and as such any Copyright notices in
16*8fb009dcSAndroid Build Coastguard Worker  * the code are not to be removed.
17*8fb009dcSAndroid Build Coastguard Worker  * If this package is used in a product, Eric Young should be given attribution
18*8fb009dcSAndroid Build Coastguard Worker  * as the author of the parts of the library used.
19*8fb009dcSAndroid Build Coastguard Worker  * This can be in the form of a textual message at program startup or
20*8fb009dcSAndroid Build Coastguard Worker  * in documentation (online or textual) provided with the package.
21*8fb009dcSAndroid Build Coastguard Worker  *
22*8fb009dcSAndroid Build Coastguard Worker  * Redistribution and use in source and binary forms, with or without
23*8fb009dcSAndroid Build Coastguard Worker  * modification, are permitted provided that the following conditions
24*8fb009dcSAndroid Build Coastguard Worker  * are met:
25*8fb009dcSAndroid Build Coastguard Worker  * 1. Redistributions of source code must retain the copyright
26*8fb009dcSAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer.
27*8fb009dcSAndroid Build Coastguard Worker  * 2. Redistributions in binary form must reproduce the above copyright
28*8fb009dcSAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer in the
29*8fb009dcSAndroid Build Coastguard Worker  *    documentation and/or other materials provided with the distribution.
30*8fb009dcSAndroid Build Coastguard Worker  * 3. All advertising materials mentioning features or use of this software
31*8fb009dcSAndroid Build Coastguard Worker  *    must display the following acknowledgement:
32*8fb009dcSAndroid Build Coastguard Worker  *    "This product includes cryptographic software written by
33*8fb009dcSAndroid Build Coastguard Worker  *     Eric Young ([email protected])"
34*8fb009dcSAndroid Build Coastguard Worker  *    The word 'cryptographic' can be left out if the rouines from the library
35*8fb009dcSAndroid Build Coastguard Worker  *    being used are not cryptographic related :-).
36*8fb009dcSAndroid Build Coastguard Worker  * 4. If you include any Windows specific code (or a derivative thereof) from
37*8fb009dcSAndroid Build Coastguard Worker  *    the apps directory (application code) you must include an acknowledgement:
38*8fb009dcSAndroid Build Coastguard Worker  *    "This product includes software written by Tim Hudson ([email protected])"
39*8fb009dcSAndroid Build Coastguard Worker  *
40*8fb009dcSAndroid Build Coastguard Worker  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41*8fb009dcSAndroid Build Coastguard Worker  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42*8fb009dcSAndroid Build Coastguard Worker  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43*8fb009dcSAndroid Build Coastguard Worker  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44*8fb009dcSAndroid Build Coastguard Worker  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45*8fb009dcSAndroid Build Coastguard Worker  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46*8fb009dcSAndroid Build Coastguard Worker  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47*8fb009dcSAndroid Build Coastguard Worker  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48*8fb009dcSAndroid Build Coastguard Worker  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49*8fb009dcSAndroid Build Coastguard Worker  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50*8fb009dcSAndroid Build Coastguard Worker  * SUCH DAMAGE.
51*8fb009dcSAndroid Build Coastguard Worker  *
52*8fb009dcSAndroid Build Coastguard Worker  * The licence and distribution terms for any publically available version or
53*8fb009dcSAndroid Build Coastguard Worker  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54*8fb009dcSAndroid Build Coastguard Worker  * copied and put under another distribution licence
55*8fb009dcSAndroid Build Coastguard Worker  * [including the GNU Public Licence.]
56*8fb009dcSAndroid Build Coastguard Worker  */
57*8fb009dcSAndroid Build Coastguard Worker /* ====================================================================
58*8fb009dcSAndroid Build Coastguard Worker  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
59*8fb009dcSAndroid Build Coastguard Worker  *
60*8fb009dcSAndroid Build Coastguard Worker  * Redistribution and use in source and binary forms, with or without
61*8fb009dcSAndroid Build Coastguard Worker  * modification, are permitted provided that the following conditions
62*8fb009dcSAndroid Build Coastguard Worker  * are met:
63*8fb009dcSAndroid Build Coastguard Worker  *
64*8fb009dcSAndroid Build Coastguard Worker  * 1. Redistributions of source code must retain the above copyright
65*8fb009dcSAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer.
66*8fb009dcSAndroid Build Coastguard Worker  *
67*8fb009dcSAndroid Build Coastguard Worker  * 2. Redistributions in binary form must reproduce the above copyright
68*8fb009dcSAndroid Build Coastguard Worker  *    notice, this list of conditions and the following disclaimer in
69*8fb009dcSAndroid Build Coastguard Worker  *    the documentation and/or other materials provided with the
70*8fb009dcSAndroid Build Coastguard Worker  *    distribution.
71*8fb009dcSAndroid Build Coastguard Worker  *
72*8fb009dcSAndroid Build Coastguard Worker  * 3. All advertising materials mentioning features or use of this
73*8fb009dcSAndroid Build Coastguard Worker  *    software must display the following acknowledgment:
74*8fb009dcSAndroid Build Coastguard Worker  *    "This product includes software developed by the OpenSSL Project
75*8fb009dcSAndroid Build Coastguard Worker  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76*8fb009dcSAndroid Build Coastguard Worker  *
77*8fb009dcSAndroid Build Coastguard Worker  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78*8fb009dcSAndroid Build Coastguard Worker  *    endorse or promote products derived from this software without
79*8fb009dcSAndroid Build Coastguard Worker  *    prior written permission. For written permission, please contact
80*8fb009dcSAndroid Build Coastguard Worker  *    [email protected].
81*8fb009dcSAndroid Build Coastguard Worker  *
82*8fb009dcSAndroid Build Coastguard Worker  * 5. Products derived from this software may not be called "OpenSSL"
83*8fb009dcSAndroid Build Coastguard Worker  *    nor may "OpenSSL" appear in their names without prior written
84*8fb009dcSAndroid Build Coastguard Worker  *    permission of the OpenSSL Project.
85*8fb009dcSAndroid Build Coastguard Worker  *
86*8fb009dcSAndroid Build Coastguard Worker  * 6. Redistributions of any form whatsoever must retain the following
87*8fb009dcSAndroid Build Coastguard Worker  *    acknowledgment:
88*8fb009dcSAndroid Build Coastguard Worker  *    "This product includes software developed by the OpenSSL Project
89*8fb009dcSAndroid Build Coastguard Worker  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90*8fb009dcSAndroid Build Coastguard Worker  *
91*8fb009dcSAndroid Build Coastguard Worker  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92*8fb009dcSAndroid Build Coastguard Worker  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93*8fb009dcSAndroid Build Coastguard Worker  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94*8fb009dcSAndroid Build Coastguard Worker  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95*8fb009dcSAndroid Build Coastguard Worker  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96*8fb009dcSAndroid Build Coastguard Worker  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97*8fb009dcSAndroid Build Coastguard Worker  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98*8fb009dcSAndroid Build Coastguard Worker  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99*8fb009dcSAndroid Build Coastguard Worker  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100*8fb009dcSAndroid Build Coastguard Worker  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101*8fb009dcSAndroid Build Coastguard Worker  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102*8fb009dcSAndroid Build Coastguard Worker  * OF THE POSSIBILITY OF SUCH DAMAGE.
103*8fb009dcSAndroid Build Coastguard Worker  * ====================================================================
104*8fb009dcSAndroid Build Coastguard Worker  *
105*8fb009dcSAndroid Build Coastguard Worker  * This product includes cryptographic software written by Eric Young
106*8fb009dcSAndroid Build Coastguard Worker  * ([email protected]).  This product includes software written by Tim
107*8fb009dcSAndroid Build Coastguard Worker  * Hudson ([email protected]).
108*8fb009dcSAndroid Build Coastguard Worker  *
109*8fb009dcSAndroid Build Coastguard Worker  */
110*8fb009dcSAndroid Build Coastguard Worker /* ====================================================================
111*8fb009dcSAndroid Build Coastguard Worker  * Copyright 2005 Nokia. All rights reserved.
112*8fb009dcSAndroid Build Coastguard Worker  *
113*8fb009dcSAndroid Build Coastguard Worker  * The portions of the attached software ("Contribution") is developed by
114*8fb009dcSAndroid Build Coastguard Worker  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
115*8fb009dcSAndroid Build Coastguard Worker  * license.
116*8fb009dcSAndroid Build Coastguard Worker  *
117*8fb009dcSAndroid Build Coastguard Worker  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
118*8fb009dcSAndroid Build Coastguard Worker  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
119*8fb009dcSAndroid Build Coastguard Worker  * support (see RFC 4279) to OpenSSL.
120*8fb009dcSAndroid Build Coastguard Worker  *
121*8fb009dcSAndroid Build Coastguard Worker  * No patent licenses or other rights except those expressly stated in
122*8fb009dcSAndroid Build Coastguard Worker  * the OpenSSL open source license shall be deemed granted or received
123*8fb009dcSAndroid Build Coastguard Worker  * expressly, by implication, estoppel, or otherwise.
124*8fb009dcSAndroid Build Coastguard Worker  *
125*8fb009dcSAndroid Build Coastguard Worker  * No assurances are provided by Nokia that the Contribution does not
126*8fb009dcSAndroid Build Coastguard Worker  * infringe the patent or other intellectual property rights of any third
127*8fb009dcSAndroid Build Coastguard Worker  * party or that the license provides you with all the necessary rights
128*8fb009dcSAndroid Build Coastguard Worker  * to make use of the Contribution.
129*8fb009dcSAndroid Build Coastguard Worker  *
130*8fb009dcSAndroid Build Coastguard Worker  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
131*8fb009dcSAndroid Build Coastguard Worker  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
132*8fb009dcSAndroid Build Coastguard Worker  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
133*8fb009dcSAndroid Build Coastguard Worker  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
134*8fb009dcSAndroid Build Coastguard Worker  * OTHERWISE. */
135*8fb009dcSAndroid Build Coastguard Worker 
136*8fb009dcSAndroid Build Coastguard Worker #include <openssl/ssl.h>
137*8fb009dcSAndroid Build Coastguard Worker 
138*8fb009dcSAndroid Build Coastguard Worker #include <openssl/buf.h>
139*8fb009dcSAndroid Build Coastguard Worker #include <openssl/digest.h>
140*8fb009dcSAndroid Build Coastguard Worker #include <openssl/err.h>
141*8fb009dcSAndroid Build Coastguard Worker 
142*8fb009dcSAndroid Build Coastguard Worker #include "internal.h"
143*8fb009dcSAndroid Build Coastguard Worker 
144*8fb009dcSAndroid Build Coastguard Worker 
145*8fb009dcSAndroid Build Coastguard Worker BSSL_NAMESPACE_BEGIN
146*8fb009dcSAndroid Build Coastguard Worker 
SSLTranscript()147*8fb009dcSAndroid Build Coastguard Worker SSLTranscript::SSLTranscript() {}
148*8fb009dcSAndroid Build Coastguard Worker 
~SSLTranscript()149*8fb009dcSAndroid Build Coastguard Worker SSLTranscript::~SSLTranscript() {}
150*8fb009dcSAndroid Build Coastguard Worker 
Init()151*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::Init() {
152*8fb009dcSAndroid Build Coastguard Worker   buffer_.reset(BUF_MEM_new());
153*8fb009dcSAndroid Build Coastguard Worker   if (!buffer_) {
154*8fb009dcSAndroid Build Coastguard Worker     return false;
155*8fb009dcSAndroid Build Coastguard Worker   }
156*8fb009dcSAndroid Build Coastguard Worker 
157*8fb009dcSAndroid Build Coastguard Worker   hash_.Reset();
158*8fb009dcSAndroid Build Coastguard Worker   return true;
159*8fb009dcSAndroid Build Coastguard Worker }
160*8fb009dcSAndroid Build Coastguard Worker 
InitHash(uint16_t version,const SSL_CIPHER * cipher)161*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::InitHash(uint16_t version, const SSL_CIPHER *cipher) {
162*8fb009dcSAndroid Build Coastguard Worker   const EVP_MD *md = ssl_get_handshake_digest(version, cipher);
163*8fb009dcSAndroid Build Coastguard Worker   if (Digest() == md) {
164*8fb009dcSAndroid Build Coastguard Worker     // No need to re-hash the buffer.
165*8fb009dcSAndroid Build Coastguard Worker     return true;
166*8fb009dcSAndroid Build Coastguard Worker   }
167*8fb009dcSAndroid Build Coastguard Worker   return EVP_DigestInit_ex(hash_.get(), md, nullptr) &&
168*8fb009dcSAndroid Build Coastguard Worker          EVP_DigestUpdate(hash_.get(), buffer_->data, buffer_->length);
169*8fb009dcSAndroid Build Coastguard Worker }
170*8fb009dcSAndroid Build Coastguard Worker 
FreeBuffer()171*8fb009dcSAndroid Build Coastguard Worker void SSLTranscript::FreeBuffer() {
172*8fb009dcSAndroid Build Coastguard Worker   buffer_.reset();
173*8fb009dcSAndroid Build Coastguard Worker }
174*8fb009dcSAndroid Build Coastguard Worker 
DigestLen() const175*8fb009dcSAndroid Build Coastguard Worker size_t SSLTranscript::DigestLen() const {
176*8fb009dcSAndroid Build Coastguard Worker   return EVP_MD_size(Digest());
177*8fb009dcSAndroid Build Coastguard Worker }
178*8fb009dcSAndroid Build Coastguard Worker 
Digest() const179*8fb009dcSAndroid Build Coastguard Worker const EVP_MD *SSLTranscript::Digest() const {
180*8fb009dcSAndroid Build Coastguard Worker   return EVP_MD_CTX_md(hash_.get());
181*8fb009dcSAndroid Build Coastguard Worker }
182*8fb009dcSAndroid Build Coastguard Worker 
UpdateForHelloRetryRequest()183*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::UpdateForHelloRetryRequest() {
184*8fb009dcSAndroid Build Coastguard Worker   if (buffer_) {
185*8fb009dcSAndroid Build Coastguard Worker     buffer_->length = 0;
186*8fb009dcSAndroid Build Coastguard Worker   }
187*8fb009dcSAndroid Build Coastguard Worker 
188*8fb009dcSAndroid Build Coastguard Worker   uint8_t old_hash[EVP_MAX_MD_SIZE];
189*8fb009dcSAndroid Build Coastguard Worker   size_t hash_len;
190*8fb009dcSAndroid Build Coastguard Worker   if (!GetHash(old_hash, &hash_len)) {
191*8fb009dcSAndroid Build Coastguard Worker     return false;
192*8fb009dcSAndroid Build Coastguard Worker   }
193*8fb009dcSAndroid Build Coastguard Worker   const uint8_t header[4] = {SSL3_MT_MESSAGE_HASH, 0, 0,
194*8fb009dcSAndroid Build Coastguard Worker                              static_cast<uint8_t>(hash_len)};
195*8fb009dcSAndroid Build Coastguard Worker   if (!EVP_DigestInit_ex(hash_.get(), Digest(), nullptr) ||
196*8fb009dcSAndroid Build Coastguard Worker       !Update(header) ||
197*8fb009dcSAndroid Build Coastguard Worker       !Update(MakeConstSpan(old_hash, hash_len))) {
198*8fb009dcSAndroid Build Coastguard Worker     return false;
199*8fb009dcSAndroid Build Coastguard Worker   }
200*8fb009dcSAndroid Build Coastguard Worker   return true;
201*8fb009dcSAndroid Build Coastguard Worker }
202*8fb009dcSAndroid Build Coastguard Worker 
CopyToHashContext(EVP_MD_CTX * ctx,const EVP_MD * digest) const203*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::CopyToHashContext(EVP_MD_CTX *ctx,
204*8fb009dcSAndroid Build Coastguard Worker                                       const EVP_MD *digest) const {
205*8fb009dcSAndroid Build Coastguard Worker   const EVP_MD *transcript_digest = Digest();
206*8fb009dcSAndroid Build Coastguard Worker   if (transcript_digest != nullptr &&
207*8fb009dcSAndroid Build Coastguard Worker       EVP_MD_type(transcript_digest) == EVP_MD_type(digest)) {
208*8fb009dcSAndroid Build Coastguard Worker     return EVP_MD_CTX_copy_ex(ctx, hash_.get());
209*8fb009dcSAndroid Build Coastguard Worker   }
210*8fb009dcSAndroid Build Coastguard Worker 
211*8fb009dcSAndroid Build Coastguard Worker   if (buffer_) {
212*8fb009dcSAndroid Build Coastguard Worker     return EVP_DigestInit_ex(ctx, digest, nullptr) &&
213*8fb009dcSAndroid Build Coastguard Worker            EVP_DigestUpdate(ctx, buffer_->data, buffer_->length);
214*8fb009dcSAndroid Build Coastguard Worker   }
215*8fb009dcSAndroid Build Coastguard Worker 
216*8fb009dcSAndroid Build Coastguard Worker   OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
217*8fb009dcSAndroid Build Coastguard Worker   return false;
218*8fb009dcSAndroid Build Coastguard Worker }
219*8fb009dcSAndroid Build Coastguard Worker 
Update(Span<const uint8_t> in)220*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::Update(Span<const uint8_t> in) {
221*8fb009dcSAndroid Build Coastguard Worker   // Depending on the state of the handshake, either the handshake buffer may be
222*8fb009dcSAndroid Build Coastguard Worker   // active, the rolling hash, or both.
223*8fb009dcSAndroid Build Coastguard Worker   if (buffer_ &&
224*8fb009dcSAndroid Build Coastguard Worker       !BUF_MEM_append(buffer_.get(), in.data(), in.size())) {
225*8fb009dcSAndroid Build Coastguard Worker     return false;
226*8fb009dcSAndroid Build Coastguard Worker   }
227*8fb009dcSAndroid Build Coastguard Worker 
228*8fb009dcSAndroid Build Coastguard Worker   if (EVP_MD_CTX_md(hash_.get()) != NULL) {
229*8fb009dcSAndroid Build Coastguard Worker     EVP_DigestUpdate(hash_.get(), in.data(), in.size());
230*8fb009dcSAndroid Build Coastguard Worker   }
231*8fb009dcSAndroid Build Coastguard Worker 
232*8fb009dcSAndroid Build Coastguard Worker   return true;
233*8fb009dcSAndroid Build Coastguard Worker }
234*8fb009dcSAndroid Build Coastguard Worker 
GetHash(uint8_t * out,size_t * out_len) const235*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::GetHash(uint8_t *out, size_t *out_len) const {
236*8fb009dcSAndroid Build Coastguard Worker   ScopedEVP_MD_CTX ctx;
237*8fb009dcSAndroid Build Coastguard Worker   unsigned len;
238*8fb009dcSAndroid Build Coastguard Worker   if (!EVP_MD_CTX_copy_ex(ctx.get(), hash_.get()) ||
239*8fb009dcSAndroid Build Coastguard Worker       !EVP_DigestFinal_ex(ctx.get(), out, &len)) {
240*8fb009dcSAndroid Build Coastguard Worker     return false;
241*8fb009dcSAndroid Build Coastguard Worker   }
242*8fb009dcSAndroid Build Coastguard Worker   *out_len = len;
243*8fb009dcSAndroid Build Coastguard Worker   return true;
244*8fb009dcSAndroid Build Coastguard Worker }
245*8fb009dcSAndroid Build Coastguard Worker 
GetFinishedMAC(uint8_t * out,size_t * out_len,const SSL_SESSION * session,bool from_server) const246*8fb009dcSAndroid Build Coastguard Worker bool SSLTranscript::GetFinishedMAC(uint8_t *out, size_t *out_len,
247*8fb009dcSAndroid Build Coastguard Worker                                    const SSL_SESSION *session,
248*8fb009dcSAndroid Build Coastguard Worker                                    bool from_server) const {
249*8fb009dcSAndroid Build Coastguard Worker   static const char kClientLabel[] = "client finished";
250*8fb009dcSAndroid Build Coastguard Worker   static const char kServerLabel[] = "server finished";
251*8fb009dcSAndroid Build Coastguard Worker   auto label = from_server
252*8fb009dcSAndroid Build Coastguard Worker                    ? MakeConstSpan(kServerLabel, sizeof(kServerLabel) - 1)
253*8fb009dcSAndroid Build Coastguard Worker                    : MakeConstSpan(kClientLabel, sizeof(kClientLabel) - 1);
254*8fb009dcSAndroid Build Coastguard Worker 
255*8fb009dcSAndroid Build Coastguard Worker   uint8_t digest[EVP_MAX_MD_SIZE];
256*8fb009dcSAndroid Build Coastguard Worker   size_t digest_len;
257*8fb009dcSAndroid Build Coastguard Worker   if (!GetHash(digest, &digest_len)) {
258*8fb009dcSAndroid Build Coastguard Worker     return false;
259*8fb009dcSAndroid Build Coastguard Worker   }
260*8fb009dcSAndroid Build Coastguard Worker 
261*8fb009dcSAndroid Build Coastguard Worker   static const size_t kFinishedLen = 12;
262*8fb009dcSAndroid Build Coastguard Worker   if (!tls1_prf(Digest(), MakeSpan(out, kFinishedLen),
263*8fb009dcSAndroid Build Coastguard Worker                 MakeConstSpan(session->secret, session->secret_length), label,
264*8fb009dcSAndroid Build Coastguard Worker                 MakeConstSpan(digest, digest_len), {})) {
265*8fb009dcSAndroid Build Coastguard Worker     return false;
266*8fb009dcSAndroid Build Coastguard Worker   }
267*8fb009dcSAndroid Build Coastguard Worker 
268*8fb009dcSAndroid Build Coastguard Worker   *out_len = kFinishedLen;
269*8fb009dcSAndroid Build Coastguard Worker   return true;
270*8fb009dcSAndroid Build Coastguard Worker }
271*8fb009dcSAndroid Build Coastguard Worker 
272*8fb009dcSAndroid Build Coastguard Worker BSSL_NAMESPACE_END
273