1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  */
57 /* ====================================================================
58  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in
69  *    the documentation and/or other materials provided with the
70  *    distribution.
71  *
72  * 3. All advertising materials mentioning features or use of this
73  *    software must display the following acknowledgment:
74  *    "This product includes software developed by the OpenSSL Project
75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76  *
77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78  *    endorse or promote products derived from this software without
79  *    prior written permission. For written permission, please contact
80  *    openssl-core@openssl.org.
81  *
82  * 5. Products derived from this software may not be called "OpenSSL"
83  *    nor may "OpenSSL" appear in their names without prior written
84  *    permission of the OpenSSL Project.
85  *
86  * 6. Redistributions of any form whatsoever must retain the following
87  *    acknowledgment:
88  *    "This product includes software developed by the OpenSSL Project
89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90  *
91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102  * OF THE POSSIBILITY OF SUCH DAMAGE.
103  * ====================================================================
104  *
105  * This product includes cryptographic software written by Eric Young
106  * (eay@cryptsoft.com).  This product includes software written by Tim
107  * Hudson (tjh@cryptsoft.com).
108  *
109  */
110 /* ====================================================================
111  * Copyright 2005 Nokia. All rights reserved.
112  *
113  * The portions of the attached software ("Contribution") is developed by
114  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
115  * license.
116  *
117  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
118  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
119  * support (see RFC 4279) to OpenSSL.
120  *
121  * No patent licenses or other rights except those expressly stated in
122  * the OpenSSL open source license shall be deemed granted or received
123  * expressly, by implication, estoppel, or otherwise.
124  *
125  * No assurances are provided by Nokia that the Contribution does not
126  * infringe the patent or other intellectual property rights of any third
127  * party or that the license provides you with all the necessary rights
128  * to make use of the Contribution.
129  *
130  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
131  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
132  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
133  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
134  * OTHERWISE. */
135 
136 #include <openssl/ssl.h>
137 
138 #include <assert.h>
139 #include <string.h>
140 
141 #include <utility>
142 
143 #include <openssl/err.h>
144 #include <openssl/evp.h>
145 #include <openssl/hmac.h>
146 #include <openssl/md5.h>
147 #include <openssl/mem.h>
148 #include <openssl/nid.h>
149 #include <openssl/rand.h>
150 
151 #include "../crypto/fipsmodule/tls/internal.h"
152 #include "../crypto/internal.h"
153 #include "internal.h"
154 
155 
156 namespace bssl {
157 
tls1_prf(const EVP_MD * digest,Span<uint8_t> out,Span<const uint8_t> secret,Span<const char> label,Span<const uint8_t> seed1,Span<const uint8_t> seed2)158 bool tls1_prf(const EVP_MD *digest, Span<uint8_t> out,
159               Span<const uint8_t> secret, Span<const char> label,
160               Span<const uint8_t> seed1, Span<const uint8_t> seed2) {
161   return 1 == CRYPTO_tls1_prf(digest, out.data(), out.size(), secret.data(),
162                               secret.size(), label.data(), label.size(),
163                               seed1.data(), seed1.size(), seed2.data(),
164                               seed2.size());
165 }
166 
ssl3_prf(Span<uint8_t> out,Span<const uint8_t> secret,Span<const char> label,Span<const uint8_t> seed1,Span<const uint8_t> seed2)167 static bool ssl3_prf(Span<uint8_t> out, Span<const uint8_t> secret,
168                      Span<const char> label, Span<const uint8_t> seed1,
169                      Span<const uint8_t> seed2) {
170   ScopedEVP_MD_CTX md5;
171   ScopedEVP_MD_CTX sha1;
172   uint8_t buf[16], smd[SHA_DIGEST_LENGTH];
173   uint8_t c = 'A';
174   size_t k = 0;
175   while (!out.empty()) {
176     k++;
177     if (k > sizeof(buf)) {
178       // bug: 'buf' is too small for this ciphersuite
179       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
180       return false;
181     }
182 
183     for (size_t j = 0; j < k; j++) {
184       buf[j] = c;
185     }
186     c++;
187     if (!EVP_DigestInit_ex(sha1.get(), EVP_sha1(), NULL)) {
188       OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
189       return false;
190     }
191     EVP_DigestUpdate(sha1.get(), buf, k);
192     EVP_DigestUpdate(sha1.get(), secret.data(), secret.size());
193     // |label| is ignored for SSLv3.
194     EVP_DigestUpdate(sha1.get(), seed1.data(), seed1.size());
195     EVP_DigestUpdate(sha1.get(), seed2.data(), seed2.size());
196     EVP_DigestFinal_ex(sha1.get(), smd, NULL);
197 
198     if (!EVP_DigestInit_ex(md5.get(), EVP_md5(), NULL)) {
199       OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
200       return false;
201     }
202     EVP_DigestUpdate(md5.get(), secret.data(), secret.size());
203     EVP_DigestUpdate(md5.get(), smd, SHA_DIGEST_LENGTH);
204     if (out.size() < MD5_DIGEST_LENGTH) {
205       EVP_DigestFinal_ex(md5.get(), smd, NULL);
206       OPENSSL_memcpy(out.data(), smd, out.size());
207       break;
208     }
209     EVP_DigestFinal_ex(md5.get(), out.data(), NULL);
210     out = out.subspan(MD5_DIGEST_LENGTH);
211   }
212 
213   OPENSSL_cleanse(smd, SHA_DIGEST_LENGTH);
214   return true;
215 }
216 
get_key_block_lengths(const SSL * ssl,size_t * out_mac_secret_len,size_t * out_key_len,size_t * out_iv_len,const SSL_CIPHER * cipher)217 static bool get_key_block_lengths(const SSL *ssl, size_t *out_mac_secret_len,
218                                   size_t *out_key_len, size_t *out_iv_len,
219                                   const SSL_CIPHER *cipher) {
220   const EVP_AEAD *aead = NULL;
221   if (!ssl_cipher_get_evp_aead(&aead, out_mac_secret_len, out_iv_len, cipher,
222                                ssl_protocol_version(ssl), SSL_is_dtls(ssl))) {
223     OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
224     return false;
225   }
226 
227   *out_key_len = EVP_AEAD_key_length(aead);
228   if (*out_mac_secret_len > 0) {
229     // For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites) the
230     // key length reported by |EVP_AEAD_key_length| will include the MAC key
231     // bytes and initial implicit IV.
232     if (*out_key_len < *out_mac_secret_len + *out_iv_len) {
233       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
234       return false;
235     }
236     *out_key_len -= *out_mac_secret_len + *out_iv_len;
237   }
238 
239   return true;
240 }
241 
tls1_configure_aead(SSL * ssl,evp_aead_direction_t direction,Array<uint8_t> * key_block_cache,const SSL_CIPHER * cipher,Span<const uint8_t> iv_override)242 int tls1_configure_aead(SSL *ssl, evp_aead_direction_t direction,
243                         Array<uint8_t> *key_block_cache,
244                         const SSL_CIPHER *cipher,
245                         Span<const uint8_t> iv_override) {
246   size_t mac_secret_len, key_len, iv_len;
247   if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &iv_len, cipher)) {
248     return 0;
249   }
250 
251   // Ensure that |key_block_cache| is set up.
252   const size_t key_block_size = 2 * (mac_secret_len + key_len + iv_len);
253   if (key_block_cache->empty()) {
254     if (!key_block_cache->Init(key_block_size) ||
255         !SSL_generate_key_block(ssl, key_block_cache->data(), key_block_size)) {
256       return 0;
257     }
258   }
259   assert(key_block_cache->size() == key_block_size);
260 
261   Span<const uint8_t> key_block = *key_block_cache;
262   Span<const uint8_t> mac_secret, key, iv;
263   if (direction == (ssl->server ? evp_aead_open : evp_aead_seal)) {
264     // Use the client write (server read) keys.
265     mac_secret = key_block.subspan(0, mac_secret_len);
266     key = key_block.subspan(2 * mac_secret_len, key_len);
267     iv = key_block.subspan(2 * mac_secret_len + 2 * key_len, iv_len);
268   } else {
269     // Use the server write (client read) keys.
270     mac_secret = key_block.subspan(mac_secret_len, mac_secret_len);
271     key = key_block.subspan(2 * mac_secret_len + key_len, key_len);
272     iv = key_block.subspan(2 * mac_secret_len + 2 * key_len + iv_len, iv_len);
273   }
274 
275   if (!iv_override.empty()) {
276     if (iv_override.size() != iv_len) {
277       return 0;
278     }
279     iv = iv_override;
280   }
281 
282   UniquePtr<SSLAEADContext> aead_ctx = SSLAEADContext::Create(
283       direction, ssl->version, SSL_is_dtls(ssl), cipher, key, mac_secret, iv);
284   if (!aead_ctx) {
285     return 0;
286   }
287 
288   if (direction == evp_aead_open) {
289     return ssl->method->set_read_state(ssl, std::move(aead_ctx));
290   }
291 
292   return ssl->method->set_write_state(ssl, std::move(aead_ctx));
293 }
294 
tls1_change_cipher_state(SSL_HANDSHAKE * hs,evp_aead_direction_t direction)295 int tls1_change_cipher_state(SSL_HANDSHAKE *hs,
296                              evp_aead_direction_t direction) {
297   return tls1_configure_aead(hs->ssl, direction, &hs->key_block,
298                              hs->new_cipher, {});
299 }
300 
tls1_generate_master_secret(SSL_HANDSHAKE * hs,uint8_t * out,Span<const uint8_t> premaster)301 int tls1_generate_master_secret(SSL_HANDSHAKE *hs, uint8_t *out,
302                                 Span<const uint8_t> premaster) {
303   static const char kMasterSecretLabel[] = "master secret";
304   static const char kExtendedMasterSecretLabel[] = "extended master secret";
305 
306   const SSL *ssl = hs->ssl;
307   auto out_span = MakeSpan(out, SSL3_MASTER_SECRET_SIZE);
308   if (hs->extended_master_secret) {
309     auto label = MakeConstSpan(kExtendedMasterSecretLabel,
310                                sizeof(kExtendedMasterSecretLabel) - 1);
311     uint8_t digests[EVP_MAX_MD_SIZE];
312     size_t digests_len;
313     if (!hs->transcript.GetHash(digests, &digests_len) ||
314         !tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
315                   MakeConstSpan(digests, digests_len), {})) {
316       return 0;
317     }
318   } else {
319     auto label =
320         MakeConstSpan(kMasterSecretLabel, sizeof(kMasterSecretLabel) - 1);
321     if (ssl_protocol_version(ssl) == SSL3_VERSION) {
322       if (!ssl3_prf(out_span, premaster, label, ssl->s3->client_random,
323                     ssl->s3->server_random)) {
324         return 0;
325       }
326     } else {
327       if (!tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
328                     ssl->s3->client_random, ssl->s3->server_random)) {
329         return 0;
330       }
331     }
332   }
333 
334   return SSL3_MASTER_SECRET_SIZE;
335 }
336 
337 }  // namespace bssl
338 
339 using namespace bssl;
340 
SSL_get_key_block_len(const SSL * ssl)341 size_t SSL_get_key_block_len(const SSL *ssl) {
342   size_t mac_secret_len, key_len, fixed_iv_len;
343   if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &fixed_iv_len,
344                              SSL_get_current_cipher(ssl))) {
345     ERR_clear_error();
346     return 0;
347   }
348 
349   return 2 * (mac_secret_len + key_len + fixed_iv_len);
350 }
351 
SSL_generate_key_block(const SSL * ssl,uint8_t * out,size_t out_len)352 int SSL_generate_key_block(const SSL *ssl, uint8_t *out, size_t out_len) {
353   const SSL_SESSION *session = SSL_get_session(ssl);
354   auto out_span = MakeSpan(out, out_len);
355   auto master_key =
356       MakeConstSpan(session->master_key, session->master_key_length);
357   static const char kLabel[] = "key expansion";
358   auto label = MakeConstSpan(kLabel, sizeof(kLabel) - 1);
359 
360   if (ssl_protocol_version(ssl) == SSL3_VERSION) {
361     return ssl3_prf(out_span, master_key, label, ssl->s3->server_random,
362                     ssl->s3->client_random);
363   }
364 
365   const EVP_MD *digest = ssl_session_get_digest(session);
366   return tls1_prf(digest, out_span, master_key, label, ssl->s3->server_random,
367                   ssl->s3->client_random);
368 }
369 
SSL_export_keying_material(SSL * ssl,uint8_t * out,size_t out_len,const char * label,size_t label_len,const uint8_t * context,size_t context_len,int use_context)370 int SSL_export_keying_material(SSL *ssl, uint8_t *out, size_t out_len,
371                                const char *label, size_t label_len,
372                                const uint8_t *context, size_t context_len,
373                                int use_context) {
374   if (!ssl->s3->have_version || ssl->version == SSL3_VERSION) {
375     OPENSSL_PUT_ERROR(SSL, SSL_R_HANDSHAKE_NOT_COMPLETE);
376     return 0;
377   }
378 
379   // Exporters may be used in False Start and server 0-RTT, where the handshake
380   // has progressed enough. Otherwise, they may not be used during a handshake.
381   if (SSL_in_init(ssl) &&
382       !SSL_in_false_start(ssl) &&
383       !(SSL_is_server(ssl) && SSL_in_early_data(ssl))) {
384     OPENSSL_PUT_ERROR(SSL, SSL_R_HANDSHAKE_NOT_COMPLETE);
385     return 0;
386   }
387 
388   if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
389     if (!use_context) {
390       context = nullptr;
391       context_len = 0;
392     }
393     return tls13_export_keying_material(
394         ssl, MakeSpan(out, out_len),
395         MakeConstSpan(ssl->s3->exporter_secret, ssl->s3->exporter_secret_len),
396         MakeConstSpan(label, label_len), MakeConstSpan(context, context_len));
397   }
398 
399   size_t seed_len = 2 * SSL3_RANDOM_SIZE;
400   if (use_context) {
401     if (context_len >= 1u << 16) {
402       OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
403       return 0;
404     }
405     seed_len += 2 + context_len;
406   }
407   Array<uint8_t> seed;
408   if (!seed.Init(seed_len)) {
409     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
410     return 0;
411   }
412 
413   OPENSSL_memcpy(seed.data(), ssl->s3->client_random, SSL3_RANDOM_SIZE);
414   OPENSSL_memcpy(seed.data() + SSL3_RANDOM_SIZE, ssl->s3->server_random,
415                  SSL3_RANDOM_SIZE);
416   if (use_context) {
417     seed[2 * SSL3_RANDOM_SIZE] = static_cast<uint8_t>(context_len >> 8);
418     seed[2 * SSL3_RANDOM_SIZE + 1] = static_cast<uint8_t>(context_len);
419     OPENSSL_memcpy(seed.data() + 2 * SSL3_RANDOM_SIZE + 2, context, context_len);
420   }
421 
422   const SSL_SESSION *session = SSL_get_session(ssl);
423   const EVP_MD *digest = ssl_session_get_digest(session);
424   return tls1_prf(
425       digest, MakeSpan(out, out_len),
426       MakeConstSpan(session->master_key, session->master_key_length),
427       MakeConstSpan(label, label_len), seed, {});
428 }
429 
SSL_export_early_keying_material(SSL * ssl,uint8_t * out,size_t out_len,const char * label,size_t label_len,const uint8_t * context,size_t context_len)430 int SSL_export_early_keying_material(
431     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
432     const uint8_t *context, size_t context_len) {
433   if (!SSL_in_early_data(ssl) &&
434       (!ssl->s3->have_version ||
435        ssl_protocol_version(ssl) < TLS1_3_VERSION)) {
436     OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SSL_VERSION);
437     return 0;
438   }
439 
440   // The early exporter only exists if we accepted early data or offered it as
441   // a client.
442   if (!SSL_in_early_data(ssl) && !SSL_early_data_accepted(ssl)) {
443     OPENSSL_PUT_ERROR(SSL, SSL_R_EARLY_DATA_NOT_IN_USE);
444     return 0;
445   }
446 
447   return tls13_export_keying_material(
448       ssl, MakeSpan(out, out_len),
449       MakeConstSpan(ssl->s3->early_exporter_secret,
450                     ssl->s3->early_exporter_secret_len),
451       MakeConstSpan(label, label_len), MakeConstSpan(context, context_len));
452 }
453