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258f8721 MC |
1 | /* ssl/record/ssl3_record.c */ |
2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | |
3 | * All rights reserved. | |
4 | * | |
5 | * This package is an SSL implementation written | |
6 | * by Eric Young (eay@cryptsoft.com). | |
7 | * The implementation was written so as to conform with Netscapes SSL. | |
8 | * | |
9 | * This library is free for commercial and non-commercial use as long as | |
10 | * the following conditions are aheared to. The following conditions | |
11 | * apply to all code found in this distribution, be it the RC4, RSA, | |
12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
13 | * included with this distribution is covered by the same copyright terms | |
14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
15 | * | |
16 | * Copyright remains Eric Young's, and as such any Copyright notices in | |
17 | * the code are not to be removed. | |
18 | * If this package is used in a product, Eric Young should be given attribution | |
19 | * as the author of the parts of the library used. | |
20 | * This can be in the form of a textual message at program startup or | |
21 | * in documentation (online or textual) provided with the package. | |
22 | * | |
23 | * Redistribution and use in source and binary forms, with or without | |
24 | * modification, are permitted provided that the following conditions | |
25 | * are met: | |
26 | * 1. Redistributions of source code must retain the copyright | |
27 | * notice, this list of conditions and the following disclaimer. | |
28 | * 2. Redistributions in binary form must reproduce the above copyright | |
29 | * notice, this list of conditions and the following disclaimer in the | |
30 | * documentation and/or other materials provided with the distribution. | |
31 | * 3. All advertising materials mentioning features or use of this software | |
32 | * must display the following acknowledgement: | |
33 | * "This product includes cryptographic software written by | |
34 | * Eric Young (eay@cryptsoft.com)" | |
35 | * The word 'cryptographic' can be left out if the rouines from the library | |
36 | * being used are not cryptographic related :-). | |
37 | * 4. If you include any Windows specific code (or a derivative thereof) from | |
38 | * the apps directory (application code) you must include an acknowledgement: | |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
40 | * | |
41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | |
42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
51 | * SUCH DAMAGE. | |
52 | * | |
53 | * The licence and distribution terms for any publically available version or | |
54 | * derivative of this code cannot be changed. i.e. this code cannot simply be | |
55 | * copied and put under another distribution licence | |
56 | * [including the GNU Public Licence.] | |
57 | */ | |
58 | /* ==================================================================== | |
59 | * Copyright (c) 1998-2015 The OpenSSL Project. All rights reserved. | |
60 | * | |
61 | * Redistribution and use in source and binary forms, with or without | |
62 | * modification, are permitted provided that the following conditions | |
63 | * are met: | |
64 | * | |
65 | * 1. Redistributions of source code must retain the above copyright | |
66 | * notice, this list of conditions and the following disclaimer. | |
67 | * | |
68 | * 2. Redistributions in binary form must reproduce the above copyright | |
69 | * notice, this list of conditions and the following disclaimer in | |
70 | * the documentation and/or other materials provided with the | |
71 | * distribution. | |
72 | * | |
73 | * 3. All advertising materials mentioning features or use of this | |
74 | * software must display the following acknowledgment: | |
75 | * "This product includes software developed by the OpenSSL Project | |
76 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | |
77 | * | |
78 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
79 | * endorse or promote products derived from this software without | |
80 | * prior written permission. For written permission, please contact | |
81 | * openssl-core@openssl.org. | |
82 | * | |
83 | * 5. Products derived from this software may not be called "OpenSSL" | |
84 | * nor may "OpenSSL" appear in their names without prior written | |
85 | * permission of the OpenSSL Project. | |
86 | * | |
87 | * 6. Redistributions of any form whatsoever must retain the following | |
88 | * acknowledgment: | |
89 | * "This product includes software developed by the OpenSSL Project | |
90 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | |
91 | * | |
92 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
93 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
94 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
95 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
96 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
97 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
98 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
99 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
100 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
101 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
102 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
103 | * OF THE POSSIBILITY OF SUCH DAMAGE. | |
104 | * ==================================================================== | |
105 | * | |
106 | * This product includes cryptographic software written by Eric Young | |
107 | * (eay@cryptsoft.com). This product includes software written by Tim | |
108 | * Hudson (tjh@cryptsoft.com). | |
109 | * | |
110 | */ | |
111 | ||
112 | #include "../ssl_locl.h" | |
68570797 | 113 | #include "internal/constant_time_locl.h" |
02a36fda | 114 | #include <openssl/rand.h> |
c99c4c11 | 115 | #include "record_locl.h" |
02a36fda MC |
116 | |
117 | static const unsigned char ssl3_pad_1[48] = { | |
118 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
119 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
120 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
121 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
122 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
123 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36 | |
124 | }; | |
125 | ||
126 | static const unsigned char ssl3_pad_2[48] = { | |
127 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
128 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
129 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
130 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
131 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
132 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c | |
133 | }; | |
258f8721 MC |
134 | |
135 | void SSL3_RECORD_clear(SSL3_RECORD *r) | |
136 | { | |
137 | memset(r->seq_num, 0, sizeof(r->seq_num)); | |
138 | } | |
139 | ||
140 | void SSL3_RECORD_release(SSL3_RECORD *r) | |
141 | { | |
b548a1f1 | 142 | OPENSSL_free(r->comp); |
258f8721 MC |
143 | r->comp = NULL; |
144 | } | |
145 | ||
bd2e3a95 | 146 | int SSL3_RECORD_setup(SSL3_RECORD *r) |
258f8721 MC |
147 | { |
148 | if (r->comp == NULL) | |
bd2e3a95 MC |
149 | r->comp = (unsigned char *) |
150 | OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH); | |
258f8721 MC |
151 | if (r->comp == NULL) |
152 | return 0; | |
153 | return 1; | |
154 | } | |
155 | ||
156 | void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num) | |
157 | { | |
e5bf62f7 | 158 | memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE); |
258f8721 | 159 | } |
fe589e61 MC |
160 | |
161 | /* | |
162 | * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that | |
163 | * will be processed per call to ssl3_get_record. Without this limit an | |
164 | * attacker could send empty records at a faster rate than we can process and | |
165 | * cause ssl3_get_record to loop forever. | |
166 | */ | |
167 | #define MAX_EMPTY_RECORDS 32 | |
168 | ||
32ec4153 | 169 | #define SSL2_RT_HEADER_LENGTH 2 |
fe589e61 MC |
170 | /*- |
171 | * Call this to get a new input record. | |
172 | * It will return <= 0 if more data is needed, normally due to an error | |
173 | * or non-blocking IO. | |
174 | * When it finishes, one packet has been decoded and can be found in | |
175 | * ssl->s3->rrec.type - is the type of record | |
176 | * ssl->s3->rrec.data, - data | |
177 | * ssl->s3->rrec.length, - number of bytes | |
178 | */ | |
179 | /* used only by ssl3_read_bytes */ | |
180 | int ssl3_get_record(SSL *s) | |
181 | { | |
182 | int ssl_major, ssl_minor, al; | |
183 | int enc_err, n, i, ret = -1; | |
184 | SSL3_RECORD *rr; | |
185 | SSL_SESSION *sess; | |
186 | unsigned char *p; | |
187 | unsigned char md[EVP_MAX_MD_SIZE]; | |
188 | short version; | |
189 | unsigned mac_size; | |
190 | size_t extra; | |
191 | unsigned empty_record_count = 0; | |
192 | ||
193 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
194 | sess = s->session; | |
195 | ||
196 | if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) | |
197 | extra = SSL3_RT_MAX_EXTRA; | |
198 | else | |
199 | extra = 0; | |
200 | if (extra && !s->s3->init_extra) { | |
201 | /* | |
202 | * An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER set after | |
203 | * ssl3_setup_buffers() was done | |
204 | */ | |
205 | SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR); | |
206 | return -1; | |
207 | } | |
208 | ||
209 | again: | |
210 | /* check if we have the header */ | |
295c3f41 | 211 | if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || |
7a7048af | 212 | (RECORD_LAYER_get_packet_length(&s->rlayer) < SSL3_RT_HEADER_LENGTH)) { |
fe589e61 | 213 | n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, |
88c23039 | 214 | SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0); |
fe589e61 MC |
215 | if (n <= 0) |
216 | return (n); /* error or non-blocking */ | |
295c3f41 | 217 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); |
fe589e61 | 218 | |
7a7048af | 219 | p = RECORD_LAYER_get_packet(&s->rlayer); |
fe589e61 | 220 | |
32ec4153 MC |
221 | /* |
222 | * Check whether this is a regular record or an SSLv2 style record. The | |
d45ba43d MC |
223 | * latter is only used in an initial ClientHello for old clients. We |
224 | * check s->read_hash and s->enc_read_ctx to ensure this does not apply | |
225 | * during renegotiation | |
32ec4153 MC |
226 | */ |
227 | if (s->first_packet && s->server && !s->read_hash && !s->enc_read_ctx | |
228 | && (p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) { | |
229 | /* SSLv2 style record */ | |
32ec4153 MC |
230 | rr->type = SSL3_RT_HANDSHAKE; |
231 | rr->rec_version = SSL2_VERSION; | |
232 | ||
233 | rr->length = ((p[0] & 0x7f) << 8) | p[1]; | |
234 | ||
235 | if (rr->length > SSL3_BUFFER_get_len(&s->rlayer.rbuf) | |
236 | - SSL2_RT_HEADER_LENGTH) { | |
237 | al = SSL_AD_RECORD_OVERFLOW; | |
238 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG); | |
fe589e61 MC |
239 | goto f_err; |
240 | } | |
fe589e61 | 241 | |
32ec4153 MC |
242 | if (rr->length < MIN_SSL2_RECORD_LEN) { |
243 | al = SSL_AD_HANDSHAKE_FAILURE; | |
244 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
245 | goto f_err; | |
246 | } | |
247 | } else { | |
248 | /* SSLv3+ style record */ | |
249 | if (s->msg_callback) | |
250 | s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, | |
251 | s->msg_callback_arg); | |
252 | ||
253 | /* Pull apart the header into the SSL3_RECORD */ | |
254 | rr->type = *(p++); | |
255 | ssl_major = *(p++); | |
256 | ssl_minor = *(p++); | |
257 | version = (ssl_major << 8) | ssl_minor; | |
258 | rr->rec_version = version; | |
259 | n2s(p, rr->length); | |
fe589e61 | 260 | |
32ec4153 | 261 | /* Lets check version */ |
d45ba43d MC |
262 | if (!s->first_packet && version != s->version) { |
263 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER); | |
264 | if ((s->version & 0xFF00) == (version & 0xFF00) | |
265 | && !s->enc_write_ctx && !s->write_hash) | |
266 | /* | |
267 | * Send back error using their minor version number :-) | |
268 | */ | |
269 | s->version = (unsigned short)version; | |
270 | al = SSL_AD_PROTOCOL_VERSION; | |
271 | goto f_err; | |
32ec4153 MC |
272 | } |
273 | ||
274 | if ((version >> 8) != SSL3_VERSION_MAJOR) { | |
275 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER); | |
276 | goto err; | |
277 | } | |
278 | ||
279 | if (rr->length > | |
280 | SSL3_BUFFER_get_len(&s->rlayer.rbuf) | |
281 | - SSL3_RT_HEADER_LENGTH) { | |
282 | al = SSL_AD_RECORD_OVERFLOW; | |
283 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG); | |
284 | goto f_err; | |
285 | } | |
fe589e61 MC |
286 | } |
287 | ||
295c3f41 | 288 | /* now s->rlayer.rstate == SSL_ST_READ_BODY */ |
fe589e61 MC |
289 | } |
290 | ||
32ec4153 MC |
291 | /* |
292 | * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data. | |
293 | * Calculate how much more data we need to read for the rest of the record | |
294 | */ | |
295 | if (rr->rec_version == SSL2_VERSION) { | |
296 | i = rr->length + SSL2_RT_HEADER_LENGTH - SSL3_RT_HEADER_LENGTH; | |
297 | } else { | |
fe589e61 | 298 | i = rr->length; |
32ec4153 MC |
299 | } |
300 | if (i > 0) { | |
301 | /* now s->packet_length == SSL3_RT_HEADER_LENGTH */ | |
302 | ||
fe589e61 MC |
303 | n = ssl3_read_n(s, i, i, 1); |
304 | if (n <= 0) | |
305 | return (n); /* error or non-blocking io */ | |
fe589e61 MC |
306 | } |
307 | ||
295c3f41 MC |
308 | /* set state for later operations */ |
309 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); | |
fe589e61 MC |
310 | |
311 | /* | |
32ec4153 MC |
312 | * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length, |
313 | * or s->packet_length == SSL2_RT_HEADER_LENGTH + rr->length | |
fe589e61 MC |
314 | * and we have that many bytes in s->packet |
315 | */ | |
32ec4153 MC |
316 | if(rr->rec_version == SSL2_VERSION) { |
317 | rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]); | |
318 | } else { | |
319 | rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]); | |
320 | } | |
fe589e61 MC |
321 | |
322 | /* | |
323 | * ok, we can now read from 's->packet' data into 'rr' rr->input points | |
324 | * at rr->length bytes, which need to be copied into rr->data by either | |
325 | * the decryption or by the decompression When the data is 'copied' into | |
326 | * the rr->data buffer, rr->input will be pointed at the new buffer | |
327 | */ | |
328 | ||
329 | /* | |
330 | * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length | |
331 | * bytes of encrypted compressed stuff. | |
332 | */ | |
333 | ||
334 | /* check is not needed I believe */ | |
335 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH + extra) { | |
336 | al = SSL_AD_RECORD_OVERFLOW; | |
337 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); | |
338 | goto f_err; | |
339 | } | |
340 | ||
341 | /* decrypt in place in 'rr->input' */ | |
342 | rr->data = rr->input; | |
343 | rr->orig_len = rr->length; | |
344 | /* | |
345 | * If in encrypt-then-mac mode calculate mac from encrypted record. All | |
346 | * the details below are public so no timing details can leak. | |
347 | */ | |
348 | if (SSL_USE_ETM(s) && s->read_hash) { | |
349 | unsigned char *mac; | |
350 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
351 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
352 | if (rr->length < mac_size) { | |
353 | al = SSL_AD_DECODE_ERROR; | |
354 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
355 | goto f_err; | |
356 | } | |
357 | rr->length -= mac_size; | |
358 | mac = rr->data + rr->length; | |
359 | i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); | |
360 | if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) { | |
361 | al = SSL_AD_BAD_RECORD_MAC; | |
362 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
363 | SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); | |
364 | goto f_err; | |
365 | } | |
366 | } | |
367 | ||
368 | enc_err = s->method->ssl3_enc->enc(s, 0); | |
369 | /*- | |
370 | * enc_err is: | |
371 | * 0: (in non-constant time) if the record is publically invalid. | |
372 | * 1: if the padding is valid | |
373 | * -1: if the padding is invalid | |
374 | */ | |
375 | if (enc_err == 0) { | |
376 | al = SSL_AD_DECRYPTION_FAILED; | |
377 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); | |
378 | goto f_err; | |
379 | } | |
380 | #ifdef TLS_DEBUG | |
381 | printf("dec %d\n", rr->length); | |
382 | { | |
383 | unsigned int z; | |
384 | for (z = 0; z < rr->length; z++) | |
385 | printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); | |
386 | } | |
387 | printf("\n"); | |
388 | #endif | |
389 | ||
390 | /* r->length is now the compressed data plus mac */ | |
391 | if ((sess != NULL) && | |
392 | (s->enc_read_ctx != NULL) && | |
393 | (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) { | |
394 | /* s->read_hash != NULL => mac_size != -1 */ | |
395 | unsigned char *mac = NULL; | |
396 | unsigned char mac_tmp[EVP_MAX_MD_SIZE]; | |
397 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
398 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
399 | ||
400 | /* | |
401 | * orig_len is the length of the record before any padding was | |
402 | * removed. This is public information, as is the MAC in use, | |
403 | * therefore we can safely process the record in a different amount | |
404 | * of time if it's too short to possibly contain a MAC. | |
405 | */ | |
406 | if (rr->orig_len < mac_size || | |
407 | /* CBC records must have a padding length byte too. */ | |
408 | (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
409 | rr->orig_len < mac_size + 1)) { | |
410 | al = SSL_AD_DECODE_ERROR; | |
411 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
412 | goto f_err; | |
413 | } | |
414 | ||
415 | if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { | |
416 | /* | |
417 | * We update the length so that the TLS header bytes can be | |
418 | * constructed correctly but we need to extract the MAC in | |
419 | * constant time from within the record, without leaking the | |
420 | * contents of the padding bytes. | |
421 | */ | |
422 | mac = mac_tmp; | |
423 | ssl3_cbc_copy_mac(mac_tmp, rr, mac_size); | |
424 | rr->length -= mac_size; | |
425 | } else { | |
426 | /* | |
427 | * In this case there's no padding, so |rec->orig_len| equals | |
428 | * |rec->length| and we checked that there's enough bytes for | |
429 | * |mac_size| above. | |
430 | */ | |
431 | rr->length -= mac_size; | |
432 | mac = &rr->data[rr->length]; | |
433 | } | |
434 | ||
435 | i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); | |
436 | if (i < 0 || mac == NULL | |
437 | || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) | |
438 | enc_err = -1; | |
439 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra + mac_size) | |
440 | enc_err = -1; | |
441 | } | |
442 | ||
443 | if (enc_err < 0) { | |
444 | /* | |
445 | * A separate 'decryption_failed' alert was introduced with TLS 1.0, | |
446 | * SSL 3.0 only has 'bad_record_mac'. But unless a decryption | |
447 | * failure is directly visible from the ciphertext anyway, we should | |
448 | * not reveal which kind of error occurred -- this might become | |
449 | * visible to an attacker (e.g. via a logfile) | |
450 | */ | |
451 | al = SSL_AD_BAD_RECORD_MAC; | |
452 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
453 | SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); | |
454 | goto f_err; | |
455 | } | |
456 | ||
457 | /* r->length is now just compressed */ | |
458 | if (s->expand != NULL) { | |
459 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra) { | |
460 | al = SSL_AD_RECORD_OVERFLOW; | |
461 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG); | |
462 | goto f_err; | |
463 | } | |
464 | if (!ssl3_do_uncompress(s)) { | |
465 | al = SSL_AD_DECOMPRESSION_FAILURE; | |
466 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION); | |
467 | goto f_err; | |
468 | } | |
469 | } | |
470 | ||
471 | if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH + extra) { | |
472 | al = SSL_AD_RECORD_OVERFLOW; | |
473 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); | |
474 | goto f_err; | |
475 | } | |
476 | ||
477 | rr->off = 0; | |
478 | /*- | |
479 | * So at this point the following is true | |
480 | * ssl->s3->rrec.type is the type of record | |
481 | * ssl->s3->rrec.length == number of bytes in record | |
482 | * ssl->s3->rrec.off == offset to first valid byte | |
483 | * ssl->s3->rrec.data == where to take bytes from, increment | |
484 | * after use :-). | |
485 | */ | |
486 | ||
487 | /* we have pulled in a full packet so zero things */ | |
7a7048af | 488 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
489 | |
490 | /* just read a 0 length packet */ | |
491 | if (rr->length == 0) { | |
492 | empty_record_count++; | |
493 | if (empty_record_count > MAX_EMPTY_RECORDS) { | |
494 | al = SSL_AD_UNEXPECTED_MESSAGE; | |
495 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL); | |
496 | goto f_err; | |
497 | } | |
498 | goto again; | |
499 | } | |
500 | ||
501 | return (1); | |
502 | ||
503 | f_err: | |
504 | ssl3_send_alert(s, SSL3_AL_FATAL, al); | |
505 | err: | |
506 | return (ret); | |
507 | } | |
508 | ||
509 | int ssl3_do_uncompress(SSL *ssl) | |
510 | { | |
511 | #ifndef OPENSSL_NO_COMP | |
512 | int i; | |
513 | SSL3_RECORD *rr; | |
514 | ||
515 | rr = RECORD_LAYER_get_rrec(&ssl->rlayer); | |
516 | i = COMP_expand_block(ssl->expand, rr->comp, | |
517 | SSL3_RT_MAX_PLAIN_LENGTH, rr->data, | |
518 | (int)rr->length); | |
519 | if (i < 0) | |
520 | return (0); | |
521 | else | |
522 | rr->length = i; | |
523 | rr->data = rr->comp; | |
524 | #endif | |
525 | return (1); | |
526 | } | |
527 | ||
528 | int ssl3_do_compress(SSL *ssl) | |
529 | { | |
530 | #ifndef OPENSSL_NO_COMP | |
531 | int i; | |
532 | SSL3_RECORD *wr; | |
533 | ||
534 | wr = RECORD_LAYER_get_wrec(&ssl->rlayer); | |
535 | i = COMP_compress_block(ssl->compress, wr->data, | |
536 | SSL3_RT_MAX_COMPRESSED_LENGTH, | |
537 | wr->input, (int)wr->length); | |
538 | if (i < 0) | |
539 | return (0); | |
540 | else | |
541 | wr->length = i; | |
542 | ||
543 | wr->input = wr->data; | |
544 | #endif | |
545 | return (1); | |
546 | } | |
547 | ||
02a36fda MC |
548 | /*- |
549 | * ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. | |
550 | * | |
551 | * Returns: | |
552 | * 0: (in non-constant time) if the record is publically invalid (i.e. too | |
553 | * short etc). | |
554 | * 1: if the record's padding is valid / the encryption was successful. | |
555 | * -1: if the record's padding is invalid or, if sending, an internal error | |
556 | * occurred. | |
557 | */ | |
558 | int ssl3_enc(SSL *s, int send) | |
559 | { | |
560 | SSL3_RECORD *rec; | |
561 | EVP_CIPHER_CTX *ds; | |
562 | unsigned long l; | |
563 | int bs, i, mac_size = 0; | |
564 | const EVP_CIPHER *enc; | |
565 | ||
566 | if (send) { | |
567 | ds = s->enc_write_ctx; | |
568 | rec = RECORD_LAYER_get_wrec(&s->rlayer); | |
569 | if (s->enc_write_ctx == NULL) | |
570 | enc = NULL; | |
571 | else | |
572 | enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx); | |
573 | } else { | |
574 | ds = s->enc_read_ctx; | |
575 | rec = RECORD_LAYER_get_rrec(&s->rlayer); | |
576 | if (s->enc_read_ctx == NULL) | |
577 | enc = NULL; | |
578 | else | |
579 | enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx); | |
580 | } | |
581 | ||
582 | if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { | |
583 | memmove(rec->data, rec->input, rec->length); | |
584 | rec->input = rec->data; | |
585 | } else { | |
586 | l = rec->length; | |
587 | bs = EVP_CIPHER_block_size(ds->cipher); | |
588 | ||
589 | /* COMPRESS */ | |
590 | ||
591 | if ((bs != 1) && send) { | |
592 | i = bs - ((int)l % bs); | |
593 | ||
594 | /* we need to add 'i-1' padding bytes */ | |
595 | l += i; | |
596 | /* | |
597 | * the last of these zero bytes will be overwritten with the | |
598 | * padding length. | |
599 | */ | |
600 | memset(&rec->input[rec->length], 0, i); | |
601 | rec->length += i; | |
602 | rec->input[l - 1] = (i - 1); | |
603 | } | |
604 | ||
605 | if (!send) { | |
606 | if (l == 0 || l % bs != 0) | |
607 | return 0; | |
608 | /* otherwise, rec->length >= bs */ | |
609 | } | |
610 | ||
611 | if (EVP_Cipher(ds, rec->data, rec->input, l) < 1) | |
612 | return -1; | |
613 | ||
614 | if (EVP_MD_CTX_md(s->read_hash) != NULL) | |
615 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
616 | if ((bs != 1) && !send) | |
617 | return ssl3_cbc_remove_padding(s, rec, bs, mac_size); | |
618 | } | |
619 | return (1); | |
620 | } | |
621 | ||
622 | /*- | |
623 | * tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively. | |
624 | * | |
625 | * Returns: | |
626 | * 0: (in non-constant time) if the record is publically invalid (i.e. too | |
627 | * short etc). | |
628 | * 1: if the record's padding is valid / the encryption was successful. | |
629 | * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, | |
630 | * an internal error occurred. | |
631 | */ | |
632 | int tls1_enc(SSL *s, int send) | |
633 | { | |
634 | SSL3_RECORD *rec; | |
635 | EVP_CIPHER_CTX *ds; | |
636 | unsigned long l; | |
637 | int bs, i, j, k, pad = 0, ret, mac_size = 0; | |
638 | const EVP_CIPHER *enc; | |
639 | ||
640 | if (send) { | |
641 | if (EVP_MD_CTX_md(s->write_hash)) { | |
642 | int n = EVP_MD_CTX_size(s->write_hash); | |
643 | OPENSSL_assert(n >= 0); | |
644 | } | |
645 | ds = s->enc_write_ctx; | |
646 | rec = RECORD_LAYER_get_wrec(&s->rlayer); | |
647 | if (s->enc_write_ctx == NULL) | |
648 | enc = NULL; | |
649 | else { | |
650 | int ivlen; | |
651 | enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx); | |
652 | /* For TLSv1.1 and later explicit IV */ | |
653 | if (SSL_USE_EXPLICIT_IV(s) | |
654 | && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE) | |
655 | ivlen = EVP_CIPHER_iv_length(enc); | |
656 | else | |
657 | ivlen = 0; | |
658 | if (ivlen > 1) { | |
659 | if (rec->data != rec->input) | |
660 | /* | |
661 | * we can't write into the input stream: Can this ever | |
662 | * happen?? (steve) | |
663 | */ | |
664 | fprintf(stderr, | |
665 | "%s:%d: rec->data != rec->input\n", | |
666 | __FILE__, __LINE__); | |
667 | else if (RAND_bytes(rec->input, ivlen) <= 0) | |
668 | return -1; | |
669 | } | |
670 | } | |
671 | } else { | |
672 | if (EVP_MD_CTX_md(s->read_hash)) { | |
673 | int n = EVP_MD_CTX_size(s->read_hash); | |
674 | OPENSSL_assert(n >= 0); | |
675 | } | |
676 | ds = s->enc_read_ctx; | |
677 | rec = RECORD_LAYER_get_rrec(&s->rlayer); | |
678 | if (s->enc_read_ctx == NULL) | |
679 | enc = NULL; | |
680 | else | |
681 | enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx); | |
682 | } | |
683 | ||
02a36fda MC |
684 | if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { |
685 | memmove(rec->data, rec->input, rec->length); | |
686 | rec->input = rec->data; | |
687 | ret = 1; | |
688 | } else { | |
689 | l = rec->length; | |
690 | bs = EVP_CIPHER_block_size(ds->cipher); | |
691 | ||
692 | if (EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) { | |
c8269881 | 693 | unsigned char buf[EVP_AEAD_TLS1_AAD_LEN], *seq; |
02a36fda | 694 | |
de07f311 MC |
695 | seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer) |
696 | : RECORD_LAYER_get_read_sequence(&s->rlayer); | |
02a36fda MC |
697 | |
698 | if (SSL_IS_DTLS(s)) { | |
699 | unsigned char dtlsseq[9], *p = dtlsseq; | |
700 | ||
78a39fe7 MC |
701 | s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) : |
702 | DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p); | |
02a36fda MC |
703 | memcpy(p, &seq[2], 6); |
704 | memcpy(buf, dtlsseq, 8); | |
705 | } else { | |
706 | memcpy(buf, seq, 8); | |
707 | for (i = 7; i >= 0; i--) { /* increment */ | |
708 | ++seq[i]; | |
709 | if (seq[i] != 0) | |
710 | break; | |
711 | } | |
712 | } | |
713 | ||
714 | buf[8] = rec->type; | |
715 | buf[9] = (unsigned char)(s->version >> 8); | |
716 | buf[10] = (unsigned char)(s->version); | |
717 | buf[11] = rec->length >> 8; | |
718 | buf[12] = rec->length & 0xff; | |
c8269881 MC |
719 | pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD, |
720 | EVP_AEAD_TLS1_AAD_LEN, buf); | |
721 | if (pad <= 0) | |
722 | return -1; | |
02a36fda MC |
723 | if (send) { |
724 | l += pad; | |
725 | rec->length += pad; | |
726 | } | |
727 | } else if ((bs != 1) && send) { | |
728 | i = bs - ((int)l % bs); | |
729 | ||
730 | /* Add weird padding of upto 256 bytes */ | |
731 | ||
732 | /* we need to add 'i' padding bytes of value j */ | |
733 | j = i - 1; | |
734 | if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) { | |
735 | if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) | |
736 | j++; | |
737 | } | |
738 | for (k = (int)l; k < (int)(l + i); k++) | |
739 | rec->input[k] = j; | |
740 | l += i; | |
741 | rec->length += i; | |
742 | } | |
02a36fda MC |
743 | |
744 | if (!send) { | |
745 | if (l == 0 || l % bs != 0) | |
746 | return 0; | |
747 | } | |
748 | ||
749 | i = EVP_Cipher(ds, rec->data, rec->input, l); | |
750 | if ((EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_CUSTOM_CIPHER) | |
751 | ? (i < 0) | |
752 | : (i == 0)) | |
753 | return -1; /* AEAD can fail to verify MAC */ | |
754 | if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE && !send) { | |
755 | rec->data += EVP_GCM_TLS_EXPLICIT_IV_LEN; | |
756 | rec->input += EVP_GCM_TLS_EXPLICIT_IV_LEN; | |
757 | rec->length -= EVP_GCM_TLS_EXPLICIT_IV_LEN; | |
758 | } | |
02a36fda MC |
759 | |
760 | ret = 1; | |
761 | if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) | |
762 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
763 | if ((bs != 1) && !send) | |
764 | ret = tls1_cbc_remove_padding(s, rec, bs, mac_size); | |
765 | if (pad && !send) | |
766 | rec->length -= pad; | |
767 | } | |
768 | return ret; | |
769 | } | |
770 | ||
771 | int n_ssl3_mac(SSL *ssl, unsigned char *md, int send) | |
772 | { | |
773 | SSL3_RECORD *rec; | |
774 | unsigned char *mac_sec, *seq; | |
775 | EVP_MD_CTX md_ctx; | |
776 | const EVP_MD_CTX *hash; | |
777 | unsigned char *p, rec_char; | |
778 | size_t md_size; | |
779 | int npad; | |
780 | int t; | |
781 | ||
782 | if (send) { | |
783 | rec = RECORD_LAYER_get_wrec(&ssl->rlayer); | |
784 | mac_sec = &(ssl->s3->write_mac_secret[0]); | |
de07f311 | 785 | seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); |
02a36fda MC |
786 | hash = ssl->write_hash; |
787 | } else { | |
788 | rec = RECORD_LAYER_get_rrec(&ssl->rlayer); | |
789 | mac_sec = &(ssl->s3->read_mac_secret[0]); | |
de07f311 | 790 | seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); |
02a36fda MC |
791 | hash = ssl->read_hash; |
792 | } | |
793 | ||
794 | t = EVP_MD_CTX_size(hash); | |
795 | if (t < 0) | |
796 | return -1; | |
797 | md_size = t; | |
798 | npad = (48 / md_size) * md_size; | |
799 | ||
800 | if (!send && | |
801 | EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
802 | ssl3_cbc_record_digest_supported(hash)) { | |
803 | /* | |
804 | * This is a CBC-encrypted record. We must avoid leaking any | |
805 | * timing-side channel information about how many blocks of data we | |
806 | * are hashing because that gives an attacker a timing-oracle. | |
807 | */ | |
808 | ||
809 | /*- | |
810 | * npad is, at most, 48 bytes and that's with MD5: | |
811 | * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75. | |
812 | * | |
813 | * With SHA-1 (the largest hash speced for SSLv3) the hash size | |
814 | * goes up 4, but npad goes down by 8, resulting in a smaller | |
815 | * total size. | |
816 | */ | |
817 | unsigned char header[75]; | |
818 | unsigned j = 0; | |
819 | memcpy(header + j, mac_sec, md_size); | |
820 | j += md_size; | |
821 | memcpy(header + j, ssl3_pad_1, npad); | |
822 | j += npad; | |
823 | memcpy(header + j, seq, 8); | |
824 | j += 8; | |
825 | header[j++] = rec->type; | |
826 | header[j++] = rec->length >> 8; | |
827 | header[j++] = rec->length & 0xff; | |
828 | ||
829 | /* Final param == is SSLv3 */ | |
830 | ssl3_cbc_digest_record(hash, | |
831 | md, &md_size, | |
832 | header, rec->input, | |
833 | rec->length + md_size, rec->orig_len, | |
834 | mac_sec, md_size, 1); | |
835 | } else { | |
836 | unsigned int md_size_u; | |
837 | /* Chop the digest off the end :-) */ | |
838 | EVP_MD_CTX_init(&md_ctx); | |
839 | ||
840 | EVP_MD_CTX_copy_ex(&md_ctx, hash); | |
841 | EVP_DigestUpdate(&md_ctx, mac_sec, md_size); | |
842 | EVP_DigestUpdate(&md_ctx, ssl3_pad_1, npad); | |
843 | EVP_DigestUpdate(&md_ctx, seq, 8); | |
844 | rec_char = rec->type; | |
845 | EVP_DigestUpdate(&md_ctx, &rec_char, 1); | |
846 | p = md; | |
847 | s2n(rec->length, p); | |
848 | EVP_DigestUpdate(&md_ctx, md, 2); | |
849 | EVP_DigestUpdate(&md_ctx, rec->input, rec->length); | |
850 | EVP_DigestFinal_ex(&md_ctx, md, NULL); | |
851 | ||
852 | EVP_MD_CTX_copy_ex(&md_ctx, hash); | |
853 | EVP_DigestUpdate(&md_ctx, mac_sec, md_size); | |
854 | EVP_DigestUpdate(&md_ctx, ssl3_pad_2, npad); | |
855 | EVP_DigestUpdate(&md_ctx, md, md_size); | |
856 | EVP_DigestFinal_ex(&md_ctx, md, &md_size_u); | |
857 | md_size = md_size_u; | |
858 | ||
859 | EVP_MD_CTX_cleanup(&md_ctx); | |
860 | } | |
861 | ||
862 | ssl3_record_sequence_update(seq); | |
863 | return (md_size); | |
864 | } | |
865 | ||
866 | int tls1_mac(SSL *ssl, unsigned char *md, int send) | |
867 | { | |
868 | SSL3_RECORD *rec; | |
869 | unsigned char *seq; | |
870 | EVP_MD_CTX *hash; | |
871 | size_t md_size; | |
872 | int i; | |
873 | EVP_MD_CTX hmac, *mac_ctx; | |
874 | unsigned char header[13]; | |
875 | int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM) | |
876 | : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM)); | |
877 | int t; | |
878 | ||
879 | if (send) { | |
880 | rec = RECORD_LAYER_get_wrec(&ssl->rlayer); | |
de07f311 | 881 | seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); |
02a36fda MC |
882 | hash = ssl->write_hash; |
883 | } else { | |
884 | rec = RECORD_LAYER_get_rrec(&ssl->rlayer); | |
de07f311 | 885 | seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); |
02a36fda MC |
886 | hash = ssl->read_hash; |
887 | } | |
888 | ||
889 | t = EVP_MD_CTX_size(hash); | |
890 | OPENSSL_assert(t >= 0); | |
891 | md_size = t; | |
892 | ||
893 | /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */ | |
894 | if (stream_mac) { | |
895 | mac_ctx = hash; | |
896 | } else { | |
897 | if (!EVP_MD_CTX_copy(&hmac, hash)) | |
898 | return -1; | |
899 | mac_ctx = &hmac; | |
900 | } | |
901 | ||
902 | if (SSL_IS_DTLS(ssl)) { | |
903 | unsigned char dtlsseq[8], *p = dtlsseq; | |
904 | ||
78a39fe7 MC |
905 | s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) : |
906 | DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p); | |
02a36fda MC |
907 | memcpy(p, &seq[2], 6); |
908 | ||
909 | memcpy(header, dtlsseq, 8); | |
910 | } else | |
911 | memcpy(header, seq, 8); | |
912 | ||
913 | header[8] = rec->type; | |
914 | header[9] = (unsigned char)(ssl->version >> 8); | |
915 | header[10] = (unsigned char)(ssl->version); | |
916 | header[11] = (rec->length) >> 8; | |
917 | header[12] = (rec->length) & 0xff; | |
918 | ||
919 | if (!send && !SSL_USE_ETM(ssl) && | |
920 | EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
921 | ssl3_cbc_record_digest_supported(mac_ctx)) { | |
922 | /* | |
923 | * This is a CBC-encrypted record. We must avoid leaking any | |
924 | * timing-side channel information about how many blocks of data we | |
925 | * are hashing because that gives an attacker a timing-oracle. | |
926 | */ | |
927 | /* Final param == not SSLv3 */ | |
928 | ssl3_cbc_digest_record(mac_ctx, | |
929 | md, &md_size, | |
930 | header, rec->input, | |
931 | rec->length + md_size, rec->orig_len, | |
932 | ssl->s3->read_mac_secret, | |
933 | ssl->s3->read_mac_secret_size, 0); | |
934 | } else { | |
935 | EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)); | |
936 | EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length); | |
937 | t = EVP_DigestSignFinal(mac_ctx, md, &md_size); | |
938 | OPENSSL_assert(t > 0); | |
939 | if (!send && !SSL_USE_ETM(ssl) && FIPS_mode()) | |
940 | tls_fips_digest_extra(ssl->enc_read_ctx, | |
941 | mac_ctx, rec->input, | |
942 | rec->length, rec->orig_len); | |
943 | } | |
944 | ||
945 | if (!stream_mac) | |
946 | EVP_MD_CTX_cleanup(&hmac); | |
947 | #ifdef TLS_DEBUG | |
948 | fprintf(stderr, "seq="); | |
949 | { | |
950 | int z; | |
951 | for (z = 0; z < 8; z++) | |
952 | fprintf(stderr, "%02X ", seq[z]); | |
953 | fprintf(stderr, "\n"); | |
954 | } | |
955 | fprintf(stderr, "rec="); | |
956 | { | |
957 | unsigned int z; | |
958 | for (z = 0; z < rec->length; z++) | |
959 | fprintf(stderr, "%02X ", rec->data[z]); | |
960 | fprintf(stderr, "\n"); | |
961 | } | |
962 | #endif | |
963 | ||
964 | if (!SSL_IS_DTLS(ssl)) { | |
965 | for (i = 7; i >= 0; i--) { | |
966 | ++seq[i]; | |
967 | if (seq[i] != 0) | |
968 | break; | |
969 | } | |
970 | } | |
971 | #ifdef TLS_DEBUG | |
972 | { | |
973 | unsigned int z; | |
974 | for (z = 0; z < md_size; z++) | |
975 | fprintf(stderr, "%02X ", md[z]); | |
976 | fprintf(stderr, "\n"); | |
977 | } | |
978 | #endif | |
979 | return (md_size); | |
980 | } | |
981 | ||
982 | /*- | |
983 | * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC | |
984 | * record in |rec| by updating |rec->length| in constant time. | |
985 | * | |
986 | * block_size: the block size of the cipher used to encrypt the record. | |
987 | * returns: | |
988 | * 0: (in non-constant time) if the record is publicly invalid. | |
989 | * 1: if the padding was valid | |
990 | * -1: otherwise. | |
991 | */ | |
992 | int ssl3_cbc_remove_padding(const SSL *s, | |
993 | SSL3_RECORD *rec, | |
994 | unsigned block_size, unsigned mac_size) | |
995 | { | |
996 | unsigned padding_length, good; | |
997 | const unsigned overhead = 1 /* padding length byte */ + mac_size; | |
998 | ||
999 | /* | |
1000 | * These lengths are all public so we can test them in non-constant time. | |
1001 | */ | |
1002 | if (overhead > rec->length) | |
1003 | return 0; | |
1004 | ||
1005 | padding_length = rec->data[rec->length - 1]; | |
1006 | good = constant_time_ge(rec->length, padding_length + overhead); | |
1007 | /* SSLv3 requires that the padding is minimal. */ | |
1008 | good &= constant_time_ge(block_size, padding_length + 1); | |
1009 | rec->length -= good & (padding_length + 1); | |
1010 | return constant_time_select_int(good, 1, -1); | |
1011 | } | |
1012 | ||
1013 | /*- | |
1014 | * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC | |
1015 | * record in |rec| in constant time and returns 1 if the padding is valid and | |
1016 | * -1 otherwise. It also removes any explicit IV from the start of the record | |
1017 | * without leaking any timing about whether there was enough space after the | |
1018 | * padding was removed. | |
1019 | * | |
1020 | * block_size: the block size of the cipher used to encrypt the record. | |
1021 | * returns: | |
1022 | * 0: (in non-constant time) if the record is publicly invalid. | |
1023 | * 1: if the padding was valid | |
1024 | * -1: otherwise. | |
1025 | */ | |
1026 | int tls1_cbc_remove_padding(const SSL *s, | |
1027 | SSL3_RECORD *rec, | |
1028 | unsigned block_size, unsigned mac_size) | |
1029 | { | |
1030 | unsigned padding_length, good, to_check, i; | |
1031 | const unsigned overhead = 1 /* padding length byte */ + mac_size; | |
1032 | /* Check if version requires explicit IV */ | |
1033 | if (SSL_USE_EXPLICIT_IV(s)) { | |
1034 | /* | |
1035 | * These lengths are all public so we can test them in non-constant | |
1036 | * time. | |
1037 | */ | |
1038 | if (overhead + block_size > rec->length) | |
1039 | return 0; | |
1040 | /* We can now safely skip explicit IV */ | |
1041 | rec->data += block_size; | |
1042 | rec->input += block_size; | |
1043 | rec->length -= block_size; | |
1044 | rec->orig_len -= block_size; | |
1045 | } else if (overhead > rec->length) | |
1046 | return 0; | |
1047 | ||
1048 | padding_length = rec->data[rec->length - 1]; | |
1049 | ||
1050 | /* | |
1051 | * NB: if compression is in operation the first packet may not be of even | |
1052 | * length so the padding bug check cannot be performed. This bug | |
1053 | * workaround has been around since SSLeay so hopefully it is either | |
1054 | * fixed now or no buggy implementation supports compression [steve] | |
1055 | */ | |
1056 | if ((s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) && !s->expand) { | |
1057 | /* First packet is even in size, so check */ | |
de07f311 MC |
1058 | if ((memcmp(RECORD_LAYER_get_read_sequence(&s->rlayer), |
1059 | "\0\0\0\0\0\0\0\0", 8) == 0) && | |
02a36fda MC |
1060 | !(padding_length & 1)) { |
1061 | s->s3->flags |= TLS1_FLAGS_TLS_PADDING_BUG; | |
1062 | } | |
1063 | if ((s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) && padding_length > 0) { | |
1064 | padding_length--; | |
1065 | } | |
1066 | } | |
1067 | ||
1068 | if (EVP_CIPHER_flags(s->enc_read_ctx->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) { | |
1069 | /* padding is already verified */ | |
1070 | rec->length -= padding_length + 1; | |
1071 | return 1; | |
1072 | } | |
1073 | ||
1074 | good = constant_time_ge(rec->length, overhead + padding_length); | |
1075 | /* | |
1076 | * The padding consists of a length byte at the end of the record and | |
1077 | * then that many bytes of padding, all with the same value as the length | |
1078 | * byte. Thus, with the length byte included, there are i+1 bytes of | |
1079 | * padding. We can't check just |padding_length+1| bytes because that | |
1080 | * leaks decrypted information. Therefore we always have to check the | |
1081 | * maximum amount of padding possible. (Again, the length of the record | |
1082 | * is public information so we can use it.) | |
1083 | */ | |
1084 | to_check = 255; /* maximum amount of padding. */ | |
1085 | if (to_check > rec->length - 1) | |
1086 | to_check = rec->length - 1; | |
1087 | ||
1088 | for (i = 0; i < to_check; i++) { | |
1089 | unsigned char mask = constant_time_ge_8(padding_length, i); | |
1090 | unsigned char b = rec->data[rec->length - 1 - i]; | |
1091 | /* | |
1092 | * The final |padding_length+1| bytes should all have the value | |
1093 | * |padding_length|. Therefore the XOR should be zero. | |
1094 | */ | |
1095 | good &= ~(mask & (padding_length ^ b)); | |
1096 | } | |
1097 | ||
1098 | /* | |
1099 | * If any of the final |padding_length+1| bytes had the wrong value, one | |
1100 | * or more of the lower eight bits of |good| will be cleared. | |
1101 | */ | |
1102 | good = constant_time_eq(0xff, good & 0xff); | |
1103 | rec->length -= good & (padding_length + 1); | |
1104 | ||
1105 | return constant_time_select_int(good, 1, -1); | |
1106 | } | |
1107 | ||
1108 | /*- | |
1109 | * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in | |
1110 | * constant time (independent of the concrete value of rec->length, which may | |
1111 | * vary within a 256-byte window). | |
1112 | * | |
1113 | * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to | |
1114 | * this function. | |
1115 | * | |
1116 | * On entry: | |
1117 | * rec->orig_len >= md_size | |
1118 | * md_size <= EVP_MAX_MD_SIZE | |
1119 | * | |
1120 | * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with | |
1121 | * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into | |
1122 | * a single or pair of cache-lines, then the variable memory accesses don't | |
1123 | * actually affect the timing. CPUs with smaller cache-lines [if any] are | |
1124 | * not multi-core and are not considered vulnerable to cache-timing attacks. | |
1125 | */ | |
1126 | #define CBC_MAC_ROTATE_IN_PLACE | |
1127 | ||
1128 | void ssl3_cbc_copy_mac(unsigned char *out, | |
1129 | const SSL3_RECORD *rec, unsigned md_size) | |
1130 | { | |
1131 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1132 | unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE]; | |
1133 | unsigned char *rotated_mac; | |
1134 | #else | |
1135 | unsigned char rotated_mac[EVP_MAX_MD_SIZE]; | |
1136 | #endif | |
1137 | ||
1138 | /* | |
1139 | * mac_end is the index of |rec->data| just after the end of the MAC. | |
1140 | */ | |
1141 | unsigned mac_end = rec->length; | |
1142 | unsigned mac_start = mac_end - md_size; | |
1143 | /* | |
1144 | * scan_start contains the number of bytes that we can ignore because the | |
1145 | * MAC's position can only vary by 255 bytes. | |
1146 | */ | |
1147 | unsigned scan_start = 0; | |
1148 | unsigned i, j; | |
1149 | unsigned div_spoiler; | |
1150 | unsigned rotate_offset; | |
1151 | ||
1152 | OPENSSL_assert(rec->orig_len >= md_size); | |
1153 | OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE); | |
1154 | ||
1155 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1156 | rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63); | |
1157 | #endif | |
1158 | ||
1159 | /* This information is public so it's safe to branch based on it. */ | |
1160 | if (rec->orig_len > md_size + 255 + 1) | |
1161 | scan_start = rec->orig_len - (md_size + 255 + 1); | |
1162 | /* | |
1163 | * div_spoiler contains a multiple of md_size that is used to cause the | |
1164 | * modulo operation to be constant time. Without this, the time varies | |
1165 | * based on the amount of padding when running on Intel chips at least. | |
1166 | * The aim of right-shifting md_size is so that the compiler doesn't | |
1167 | * figure out that it can remove div_spoiler as that would require it to | |
1168 | * prove that md_size is always even, which I hope is beyond it. | |
1169 | */ | |
1170 | div_spoiler = md_size >> 1; | |
1171 | div_spoiler <<= (sizeof(div_spoiler) - 1) * 8; | |
1172 | rotate_offset = (div_spoiler + mac_start - scan_start) % md_size; | |
1173 | ||
1174 | memset(rotated_mac, 0, md_size); | |
1175 | for (i = scan_start, j = 0; i < rec->orig_len; i++) { | |
1176 | unsigned char mac_started = constant_time_ge_8(i, mac_start); | |
1177 | unsigned char mac_ended = constant_time_ge_8(i, mac_end); | |
1178 | unsigned char b = rec->data[i]; | |
1179 | rotated_mac[j++] |= b & mac_started & ~mac_ended; | |
1180 | j &= constant_time_lt(j, md_size); | |
1181 | } | |
1182 | ||
1183 | /* Now rotate the MAC */ | |
1184 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1185 | j = 0; | |
1186 | for (i = 0; i < md_size; i++) { | |
1187 | /* in case cache-line is 32 bytes, touch second line */ | |
1188 | ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32]; | |
1189 | out[j++] = rotated_mac[rotate_offset++]; | |
1190 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1191 | } | |
1192 | #else | |
1193 | memset(out, 0, md_size); | |
1194 | rotate_offset = md_size - rotate_offset; | |
1195 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1196 | for (i = 0; i < md_size; i++) { | |
1197 | for (j = 0; j < md_size; j++) | |
1198 | out[j] |= rotated_mac[i] & constant_time_eq_8(j, rotate_offset); | |
1199 | rotate_offset++; | |
1200 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1201 | } | |
1202 | #endif | |
1203 | } | |
1204 | ||
fe589e61 MC |
1205 | int dtls1_process_record(SSL *s) |
1206 | { | |
1207 | int i, al; | |
1208 | int enc_err; | |
1209 | SSL_SESSION *sess; | |
1210 | SSL3_RECORD *rr; | |
1211 | unsigned int mac_size; | |
1212 | unsigned char md[EVP_MAX_MD_SIZE]; | |
1213 | ||
1214 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
1215 | sess = s->session; | |
1216 | ||
1217 | /* | |
1218 | * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, | |
1219 | * and we have that many bytes in s->packet | |
1220 | */ | |
7a7048af | 1221 | rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]); |
fe589e61 MC |
1222 | |
1223 | /* | |
1224 | * ok, we can now read from 's->packet' data into 'rr' rr->input points | |
1225 | * at rr->length bytes, which need to be copied into rr->data by either | |
1226 | * the decryption or by the decompression When the data is 'copied' into | |
1227 | * the rr->data buffer, rr->input will be pointed at the new buffer | |
1228 | */ | |
1229 | ||
1230 | /* | |
1231 | * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length | |
1232 | * bytes of encrypted compressed stuff. | |
1233 | */ | |
1234 | ||
1235 | /* check is not needed I believe */ | |
1236 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { | |
1237 | al = SSL_AD_RECORD_OVERFLOW; | |
1238 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); | |
1239 | goto f_err; | |
1240 | } | |
1241 | ||
1242 | /* decrypt in place in 'rr->input' */ | |
1243 | rr->data = rr->input; | |
1244 | rr->orig_len = rr->length; | |
1245 | ||
1246 | enc_err = s->method->ssl3_enc->enc(s, 0); | |
1247 | /*- | |
1248 | * enc_err is: | |
1249 | * 0: (in non-constant time) if the record is publically invalid. | |
1250 | * 1: if the padding is valid | |
1251 | * -1: if the padding is invalid | |
1252 | */ | |
1253 | if (enc_err == 0) { | |
1254 | /* For DTLS we simply ignore bad packets. */ | |
1255 | rr->length = 0; | |
7a7048af | 1256 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1257 | goto err; |
1258 | } | |
1259 | #ifdef TLS_DEBUG | |
1260 | printf("dec %d\n", rr->length); | |
1261 | { | |
1262 | unsigned int z; | |
1263 | for (z = 0; z < rr->length; z++) | |
1264 | printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); | |
1265 | } | |
1266 | printf("\n"); | |
1267 | #endif | |
1268 | ||
1269 | /* r->length is now the compressed data plus mac */ | |
1270 | if ((sess != NULL) && | |
1271 | (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { | |
1272 | /* s->read_hash != NULL => mac_size != -1 */ | |
1273 | unsigned char *mac = NULL; | |
1274 | unsigned char mac_tmp[EVP_MAX_MD_SIZE]; | |
1275 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
1276 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
1277 | ||
1278 | /* | |
1279 | * orig_len is the length of the record before any padding was | |
1280 | * removed. This is public information, as is the MAC in use, | |
1281 | * therefore we can safely process the record in a different amount | |
1282 | * of time if it's too short to possibly contain a MAC. | |
1283 | */ | |
1284 | if (rr->orig_len < mac_size || | |
1285 | /* CBC records must have a padding length byte too. */ | |
1286 | (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
1287 | rr->orig_len < mac_size + 1)) { | |
1288 | al = SSL_AD_DECODE_ERROR; | |
1289 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
1290 | goto f_err; | |
1291 | } | |
1292 | ||
1293 | if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { | |
1294 | /* | |
1295 | * We update the length so that the TLS header bytes can be | |
1296 | * constructed correctly but we need to extract the MAC in | |
1297 | * constant time from within the record, without leaking the | |
1298 | * contents of the padding bytes. | |
1299 | */ | |
1300 | mac = mac_tmp; | |
1301 | ssl3_cbc_copy_mac(mac_tmp, rr, mac_size); | |
1302 | rr->length -= mac_size; | |
1303 | } else { | |
1304 | /* | |
1305 | * In this case there's no padding, so |rec->orig_len| equals | |
1306 | * |rec->length| and we checked that there's enough bytes for | |
1307 | * |mac_size| above. | |
1308 | */ | |
1309 | rr->length -= mac_size; | |
1310 | mac = &rr->data[rr->length]; | |
1311 | } | |
1312 | ||
1313 | i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); | |
1314 | if (i < 0 || mac == NULL | |
1315 | || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) | |
1316 | enc_err = -1; | |
1317 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) | |
1318 | enc_err = -1; | |
1319 | } | |
1320 | ||
1321 | if (enc_err < 0) { | |
1322 | /* decryption failed, silently discard message */ | |
1323 | rr->length = 0; | |
7a7048af | 1324 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1325 | goto err; |
1326 | } | |
1327 | ||
1328 | /* r->length is now just compressed */ | |
1329 | if (s->expand != NULL) { | |
1330 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { | |
1331 | al = SSL_AD_RECORD_OVERFLOW; | |
1332 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, | |
1333 | SSL_R_COMPRESSED_LENGTH_TOO_LONG); | |
1334 | goto f_err; | |
1335 | } | |
1336 | if (!ssl3_do_uncompress(s)) { | |
1337 | al = SSL_AD_DECOMPRESSION_FAILURE; | |
1338 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION); | |
1339 | goto f_err; | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { | |
1344 | al = SSL_AD_RECORD_OVERFLOW; | |
1345 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); | |
1346 | goto f_err; | |
1347 | } | |
1348 | ||
1349 | rr->off = 0; | |
1350 | /*- | |
1351 | * So at this point the following is true | |
1352 | * ssl->s3->rrec.type is the type of record | |
1353 | * ssl->s3->rrec.length == number of bytes in record | |
1354 | * ssl->s3->rrec.off == offset to first valid byte | |
1355 | * ssl->s3->rrec.data == where to take bytes from, increment | |
1356 | * after use :-). | |
1357 | */ | |
1358 | ||
1359 | /* we have pulled in a full packet so zero things */ | |
7a7048af | 1360 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1361 | return (1); |
1362 | ||
1363 | f_err: | |
1364 | ssl3_send_alert(s, SSL3_AL_FATAL, al); | |
1365 | err: | |
1366 | return (0); | |
1367 | } | |
1368 | ||
1369 | ||
1370 | /* | |
1371 | * retrieve a buffered record that belongs to the current epoch, ie, | |
1372 | * processed | |
1373 | */ | |
1374 | #define dtls1_get_processed_record(s) \ | |
1375 | dtls1_retrieve_buffered_record((s), \ | |
cb2ce7ab | 1376 | &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer))) |
fe589e61 MC |
1377 | |
1378 | /*- | |
1379 | * Call this to get a new input record. | |
1380 | * It will return <= 0 if more data is needed, normally due to an error | |
1381 | * or non-blocking IO. | |
1382 | * When it finishes, one packet has been decoded and can be found in | |
1383 | * ssl->s3->rrec.type - is the type of record | |
1384 | * ssl->s3->rrec.data, - data | |
1385 | * ssl->s3->rrec.length, - number of bytes | |
1386 | */ | |
1387 | /* used only by dtls1_read_bytes */ | |
1388 | int dtls1_get_record(SSL *s) | |
1389 | { | |
1390 | int ssl_major, ssl_minor; | |
1391 | int i, n; | |
1392 | SSL3_RECORD *rr; | |
1393 | unsigned char *p = NULL; | |
1394 | unsigned short version; | |
1395 | DTLS1_BITMAP *bitmap; | |
1396 | unsigned int is_next_epoch; | |
1397 | ||
1398 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
1399 | ||
1400 | /* | |
1401 | * The epoch may have changed. If so, process all the pending records. | |
1402 | * This is a non-blocking operation. | |
1403 | */ | |
1404 | if (dtls1_process_buffered_records(s) < 0) | |
1405 | return -1; | |
1406 | ||
1407 | /* if we're renegotiating, then there may be buffered records */ | |
1408 | if (dtls1_get_processed_record(s)) | |
1409 | return 1; | |
1410 | ||
1411 | /* get something from the wire */ | |
1412 | again: | |
1413 | /* check if we have the header */ | |
295c3f41 | 1414 | if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || |
7a7048af | 1415 | (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) { |
fe589e61 | 1416 | n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, |
88c23039 | 1417 | SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0); |
fe589e61 MC |
1418 | /* read timeout is handled by dtls1_read_bytes */ |
1419 | if (n <= 0) | |
1420 | return (n); /* error or non-blocking */ | |
1421 | ||
1422 | /* this packet contained a partial record, dump it */ | |
7a7048af MC |
1423 | if (RECORD_LAYER_get_packet_length(&s->rlayer) != DTLS1_RT_HEADER_LENGTH) { |
1424 | RECORD_LAYER_reset_packet_length(&s->rlayer); | |
fe589e61 MC |
1425 | goto again; |
1426 | } | |
1427 | ||
295c3f41 | 1428 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); |
fe589e61 | 1429 | |
7a7048af | 1430 | p = RECORD_LAYER_get_packet(&s->rlayer); |
fe589e61 MC |
1431 | |
1432 | if (s->msg_callback) | |
1433 | s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, | |
1434 | s, s->msg_callback_arg); | |
1435 | ||
1436 | /* Pull apart the header into the DTLS1_RECORD */ | |
1437 | rr->type = *(p++); | |
1438 | ssl_major = *(p++); | |
1439 | ssl_minor = *(p++); | |
1440 | version = (ssl_major << 8) | ssl_minor; | |
1441 | ||
1442 | /* sequence number is 64 bits, with top 2 bytes = epoch */ | |
1443 | n2s(p, rr->epoch); | |
1444 | ||
de07f311 | 1445 | memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6); |
fe589e61 MC |
1446 | p += 6; |
1447 | ||
1448 | n2s(p, rr->length); | |
1449 | ||
1450 | /* Lets check version */ | |
1451 | if (!s->first_packet) { | |
1452 | if (version != s->version) { | |
1453 | /* unexpected version, silently discard */ | |
1454 | rr->length = 0; | |
7a7048af | 1455 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1456 | goto again; |
1457 | } | |
1458 | } | |
1459 | ||
1460 | if ((version & 0xff00) != (s->version & 0xff00)) { | |
1461 | /* wrong version, silently discard record */ | |
1462 | rr->length = 0; | |
7a7048af | 1463 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1464 | goto again; |
1465 | } | |
1466 | ||
1467 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { | |
1468 | /* record too long, silently discard it */ | |
1469 | rr->length = 0; | |
7a7048af | 1470 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1471 | goto again; |
1472 | } | |
1473 | ||
295c3f41 | 1474 | /* now s->rlayer.rstate == SSL_ST_READ_BODY */ |
fe589e61 MC |
1475 | } |
1476 | ||
295c3f41 | 1477 | /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */ |
fe589e61 | 1478 | |
7a7048af MC |
1479 | if (rr->length > |
1480 | RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) { | |
fe589e61 MC |
1481 | /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ |
1482 | i = rr->length; | |
1483 | n = ssl3_read_n(s, i, i, 1); | |
1484 | /* this packet contained a partial record, dump it */ | |
1485 | if (n != i) { | |
1486 | rr->length = 0; | |
7a7048af | 1487 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1488 | goto again; |
1489 | } | |
1490 | ||
1491 | /* | |
1492 | * now n == rr->length, and s->packet_length == | |
1493 | * DTLS1_RT_HEADER_LENGTH + rr->length | |
1494 | */ | |
1495 | } | |
295c3f41 MC |
1496 | /* set state for later operations */ |
1497 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); | |
fe589e61 MC |
1498 | |
1499 | /* match epochs. NULL means the packet is dropped on the floor */ | |
1500 | bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); | |
1501 | if (bitmap == NULL) { | |
1502 | rr->length = 0; | |
7a7048af | 1503 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1504 | goto again; /* get another record */ |
1505 | } | |
1506 | #ifndef OPENSSL_NO_SCTP | |
1507 | /* Only do replay check if no SCTP bio */ | |
1508 | if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { | |
1509 | #endif | |
1510 | /* | |
1511 | * Check whether this is a repeat, or aged record. Don't check if | |
1512 | * we're listening and this message is a ClientHello. They can look | |
1513 | * as if they're replayed, since they arrive from different | |
1514 | * connections and would be dropped unnecessarily. | |
1515 | */ | |
1516 | if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE && | |
7a7048af MC |
1517 | RECORD_LAYER_get_packet_length(&s->rlayer) |
1518 | > DTLS1_RT_HEADER_LENGTH && | |
1519 | RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH] | |
1520 | == SSL3_MT_CLIENT_HELLO) && | |
fe589e61 MC |
1521 | !dtls1_record_replay_check(s, bitmap)) { |
1522 | rr->length = 0; | |
7a7048af | 1523 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1524 | goto again; /* get another record */ |
1525 | } | |
1526 | #ifndef OPENSSL_NO_SCTP | |
1527 | } | |
1528 | #endif | |
1529 | ||
1530 | /* just read a 0 length packet */ | |
1531 | if (rr->length == 0) | |
1532 | goto again; | |
1533 | ||
1534 | /* | |
1535 | * If this record is from the next epoch (either HM or ALERT), and a | |
1536 | * handshake is currently in progress, buffer it since it cannot be | |
1537 | * processed at this time. However, do not buffer anything while | |
1538 | * listening. | |
1539 | */ | |
1540 | if (is_next_epoch) { | |
1541 | if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) { | |
1542 | if (dtls1_buffer_record | |
cb2ce7ab MC |
1543 | (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)), |
1544 | rr->seq_num) < 0) | |
fe589e61 MC |
1545 | return -1; |
1546 | /* Mark receipt of record. */ | |
1547 | dtls1_record_bitmap_update(s, bitmap); | |
1548 | } | |
1549 | rr->length = 0; | |
7a7048af | 1550 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1551 | goto again; |
1552 | } | |
1553 | ||
1554 | if (!dtls1_process_record(s)) { | |
1555 | rr->length = 0; | |
7a7048af | 1556 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1557 | goto again; /* get another record */ |
1558 | } | |
1559 | dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */ | |
1560 | ||
1561 | return (1); | |
1562 | ||
1563 | } | |
1564 |