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Commit | Line | Data |
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846e33c7 RS |
1 | /* |
2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. | |
258f8721 | 3 | * |
846e33c7 RS |
4 | * Licensed under the OpenSSL license (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy | |
6 | * in the file LICENSE in the source distribution or at | |
7 | * https://www.openssl.org/source/license.html | |
258f8721 MC |
8 | */ |
9 | ||
10 | #include "../ssl_locl.h" | |
68570797 | 11 | #include "internal/constant_time_locl.h" |
02a36fda | 12 | #include <openssl/rand.h> |
c99c4c11 | 13 | #include "record_locl.h" |
02a36fda MC |
14 | |
15 | static const unsigned char ssl3_pad_1[48] = { | |
16 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
17 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
18 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
19 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
20 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, | |
21 | 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36 | |
22 | }; | |
23 | ||
24 | static const unsigned char ssl3_pad_2[48] = { | |
25 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
26 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
27 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
28 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
29 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, | |
30 | 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c | |
31 | }; | |
258f8721 | 32 | |
6b41b3f5 MC |
33 | /* |
34 | * Clear the contents of an SSL3_RECORD but retain any memory allocated | |
35 | */ | |
94777c9c | 36 | void SSL3_RECORD_clear(SSL3_RECORD *r, unsigned int num_recs) |
258f8721 | 37 | { |
94777c9c MC |
38 | unsigned char *comp; |
39 | unsigned int i; | |
6b41b3f5 | 40 | |
94777c9c MC |
41 | for (i = 0; i < num_recs; i++) { |
42 | comp = r[i].comp; | |
43 | ||
44 | memset(&r[i], 0, sizeof(*r)); | |
45 | r[i].comp = comp; | |
46 | } | |
258f8721 MC |
47 | } |
48 | ||
94777c9c | 49 | void SSL3_RECORD_release(SSL3_RECORD *r, unsigned int num_recs) |
258f8721 | 50 | { |
94777c9c MC |
51 | unsigned int i; |
52 | ||
53 | for (i = 0; i < num_recs; i++) { | |
54 | OPENSSL_free(r[i].comp); | |
55 | r[i].comp = NULL; | |
56 | } | |
258f8721 MC |
57 | } |
58 | ||
258f8721 MC |
59 | void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num) |
60 | { | |
e5bf62f7 | 61 | memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE); |
258f8721 | 62 | } |
fe589e61 | 63 | |
94777c9c MC |
64 | /* |
65 | * Peeks ahead into "read_ahead" data to see if we have a whole record waiting | |
66 | * for us in the buffer. | |
67 | */ | |
ea71906e | 68 | static int ssl3_record_app_data_waiting(SSL *s) |
94777c9c MC |
69 | { |
70 | SSL3_BUFFER *rbuf; | |
71 | int left, len; | |
72 | unsigned char *p; | |
73 | ||
74 | rbuf = RECORD_LAYER_get_rbuf(&s->rlayer); | |
75 | ||
76 | p = SSL3_BUFFER_get_buf(rbuf); | |
77 | if (p == NULL) | |
78 | return 0; | |
79 | ||
80 | left = SSL3_BUFFER_get_left(rbuf); | |
81 | ||
82 | if (left < SSL3_RT_HEADER_LENGTH) | |
83 | return 0; | |
84 | ||
85 | p += SSL3_BUFFER_get_offset(rbuf); | |
86 | ||
87 | /* | |
88 | * We only check the type and record length, we will sanity check version | |
89 | * etc later | |
90 | */ | |
91 | if (*p != SSL3_RT_APPLICATION_DATA) | |
92 | return 0; | |
93 | ||
94 | p += 3; | |
95 | n2s(p, len); | |
96 | ||
97 | if (left < SSL3_RT_HEADER_LENGTH + len) | |
98 | return 0; | |
99 | ||
100 | return 1; | |
101 | } | |
102 | ||
fe589e61 MC |
103 | /* |
104 | * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that | |
105 | * will be processed per call to ssl3_get_record. Without this limit an | |
106 | * attacker could send empty records at a faster rate than we can process and | |
107 | * cause ssl3_get_record to loop forever. | |
108 | */ | |
109 | #define MAX_EMPTY_RECORDS 32 | |
110 | ||
32ec4153 | 111 | #define SSL2_RT_HEADER_LENGTH 2 |
fe589e61 | 112 | /*- |
94777c9c | 113 | * Call this to get new input records. |
fe589e61 MC |
114 | * It will return <= 0 if more data is needed, normally due to an error |
115 | * or non-blocking IO. | |
94777c9c MC |
116 | * When it finishes, |numrpipes| records have been decoded. For each record 'i': |
117 | * rr[i].type - is the type of record | |
118 | * rr[i].data, - data | |
119 | * rr[i].length, - number of bytes | |
120 | * Multiple records will only be returned if the record types are all | |
121 | * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <= | |
122 | * |max_pipelines| | |
fe589e61 MC |
123 | */ |
124 | /* used only by ssl3_read_bytes */ | |
125 | int ssl3_get_record(SSL *s) | |
126 | { | |
127 | int ssl_major, ssl_minor, al; | |
128 | int enc_err, n, i, ret = -1; | |
129 | SSL3_RECORD *rr; | |
94777c9c | 130 | SSL3_BUFFER *rbuf; |
fe589e61 MC |
131 | SSL_SESSION *sess; |
132 | unsigned char *p; | |
133 | unsigned char md[EVP_MAX_MD_SIZE]; | |
134 | short version; | |
135 | unsigned mac_size; | |
94777c9c MC |
136 | unsigned int num_recs = 0; |
137 | unsigned int max_recs; | |
138 | unsigned int j; | |
fe589e61 MC |
139 | |
140 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
94777c9c MC |
141 | rbuf = RECORD_LAYER_get_rbuf(&s->rlayer); |
142 | max_recs = s->max_pipelines; | |
143 | if (max_recs == 0) | |
144 | max_recs = 1; | |
fe589e61 MC |
145 | sess = s->session; |
146 | ||
94777c9c MC |
147 | do { |
148 | /* check if we have the header */ | |
149 | if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || | |
150 | (RECORD_LAYER_get_packet_length(&s->rlayer) | |
151 | < SSL3_RT_HEADER_LENGTH)) { | |
152 | n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, | |
a230b26e EK |
153 | SSL3_BUFFER_get_len(rbuf), 0, |
154 | num_recs == 0 ? 1 : 0); | |
94777c9c | 155 | if (n <= 0) |
a230b26e | 156 | return (n); /* error or non-blocking */ |
94777c9c MC |
157 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); |
158 | ||
159 | p = RECORD_LAYER_get_packet(&s->rlayer); | |
fe589e61 | 160 | |
94777c9c | 161 | /* |
78fcddbb | 162 | * The first record received by the server may be a V2ClientHello. |
94777c9c | 163 | */ |
78fcddbb | 164 | if (s->server && RECORD_LAYER_is_first_record(&s->rlayer) |
a230b26e | 165 | && (p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) { |
be9c8deb MC |
166 | /* |
167 | * SSLv2 style record | |
168 | * | |
169 | * |num_recs| here will actually always be 0 because | |
170 | * |num_recs > 0| only ever occurs when we are processing | |
171 | * multiple app data records - which we know isn't the case here | |
172 | * because it is an SSLv2ClientHello. We keep it using | |
173 | * |num_recs| for the sake of consistency | |
174 | */ | |
94777c9c MC |
175 | rr[num_recs].type = SSL3_RT_HANDSHAKE; |
176 | rr[num_recs].rec_version = SSL2_VERSION; | |
177 | ||
178 | rr[num_recs].length = ((p[0] & 0x7f) << 8) | p[1]; | |
179 | ||
6da57392 | 180 | if (rr[num_recs].length > SSL3_BUFFER_get_len(rbuf) |
a230b26e | 181 | - SSL2_RT_HEADER_LENGTH) { |
94777c9c MC |
182 | al = SSL_AD_RECORD_OVERFLOW; |
183 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG); | |
184 | goto f_err; | |
185 | } | |
fe589e61 | 186 | |
94777c9c MC |
187 | if (rr[num_recs].length < MIN_SSL2_RECORD_LEN) { |
188 | al = SSL_AD_HANDSHAKE_FAILURE; | |
189 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
190 | goto f_err; | |
191 | } | |
192 | } else { | |
193 | /* SSLv3+ style record */ | |
194 | if (s->msg_callback) | |
195 | s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, | |
196 | s->msg_callback_arg); | |
197 | ||
198 | /* Pull apart the header into the SSL3_RECORD */ | |
199 | rr[num_recs].type = *(p++); | |
200 | ssl_major = *(p++); | |
201 | ssl_minor = *(p++); | |
202 | version = (ssl_major << 8) | ssl_minor; | |
203 | rr[num_recs].rec_version = version; | |
204 | n2s(p, rr[num_recs].length); | |
205 | ||
206 | /* Lets check version */ | |
207 | if (!s->first_packet && version != s->version) { | |
208 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER); | |
209 | if ((s->version & 0xFF00) == (version & 0xFF00) | |
210 | && !s->enc_write_ctx && !s->write_hash) { | |
211 | if (rr->type == SSL3_RT_ALERT) { | |
212 | /* | |
213 | * The record is using an incorrect version number, | |
214 | * but what we've got appears to be an alert. We | |
215 | * haven't read the body yet to check whether its a | |
216 | * fatal or not - but chances are it is. We probably | |
217 | * shouldn't send a fatal alert back. We'll just | |
218 | * end. | |
219 | */ | |
a230b26e | 220 | goto err; |
94777c9c | 221 | } |
02db21df | 222 | /* |
94777c9c | 223 | * Send back error using their minor version number :-) |
02db21df | 224 | */ |
94777c9c | 225 | s->version = (unsigned short)version; |
02db21df | 226 | } |
94777c9c MC |
227 | al = SSL_AD_PROTOCOL_VERSION; |
228 | goto f_err; | |
02db21df | 229 | } |
32ec4153 | 230 | |
94777c9c | 231 | if ((version >> 8) != SSL3_VERSION_MAJOR) { |
a01c86a2 | 232 | if (RECORD_LAYER_is_first_record(&s->rlayer)) { |
94777c9c MC |
233 | /* Go back to start of packet, look at the five bytes |
234 | * that we have. */ | |
235 | p = RECORD_LAYER_get_packet(&s->rlayer); | |
236 | if (strncmp((char *)p, "GET ", 4) == 0 || | |
237 | strncmp((char *)p, "POST ", 5) == 0 || | |
238 | strncmp((char *)p, "HEAD ", 5) == 0 || | |
239 | strncmp((char *)p, "PUT ", 4) == 0) { | |
240 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST); | |
241 | goto err; | |
242 | } else if (strncmp((char *)p, "CONNE", 5) == 0) { | |
243 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
244 | SSL_R_HTTPS_PROXY_REQUEST); | |
245 | goto err; | |
246 | } | |
a01c86a2 MC |
247 | |
248 | /* Doesn't look like TLS - don't send an alert */ | |
249 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
250 | SSL_R_WRONG_VERSION_NUMBER); | |
251 | goto err; | |
252 | } else { | |
253 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
254 | SSL_R_WRONG_VERSION_NUMBER); | |
255 | al = SSL_AD_PROTOCOL_VERSION; | |
256 | goto f_err; | |
124f6ff4 RJ |
257 | } |
258 | } | |
32ec4153 | 259 | |
94777c9c | 260 | if (rr[num_recs].length > |
a230b26e | 261 | SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) { |
94777c9c MC |
262 | al = SSL_AD_RECORD_OVERFLOW; |
263 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG); | |
264 | goto f_err; | |
265 | } | |
32ec4153 | 266 | } |
94777c9c MC |
267 | |
268 | /* now s->rlayer.rstate == SSL_ST_READ_BODY */ | |
fe589e61 MC |
269 | } |
270 | ||
94777c9c MC |
271 | /* |
272 | * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data. | |
273 | * Calculate how much more data we need to read for the rest of the | |
274 | * record | |
275 | */ | |
276 | if (rr[num_recs].rec_version == SSL2_VERSION) { | |
277 | i = rr[num_recs].length + SSL2_RT_HEADER_LENGTH | |
278 | - SSL3_RT_HEADER_LENGTH; | |
279 | } else { | |
280 | i = rr[num_recs].length; | |
281 | } | |
282 | if (i > 0) { | |
283 | /* now s->packet_length == SSL3_RT_HEADER_LENGTH */ | |
fe589e61 | 284 | |
94777c9c MC |
285 | n = ssl3_read_n(s, i, i, 1, 0); |
286 | if (n <= 0) | |
a230b26e | 287 | return (n); /* error or non-blocking io */ |
94777c9c | 288 | } |
32ec4153 | 289 | |
94777c9c MC |
290 | /* set state for later operations */ |
291 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); | |
fe589e61 | 292 | |
94777c9c MC |
293 | /* |
294 | * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length, | |
295 | * or s->packet_length == SSL2_RT_HEADER_LENGTH + rr->length | |
296 | * and we have that many bytes in s->packet | |
297 | */ | |
e8aa8b6c | 298 | if (rr[num_recs].rec_version == SSL2_VERSION) { |
94777c9c MC |
299 | rr[num_recs].input = |
300 | &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]); | |
301 | } else { | |
302 | rr[num_recs].input = | |
303 | &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]); | |
304 | } | |
fe589e61 | 305 | |
94777c9c MC |
306 | /* |
307 | * ok, we can now read from 's->packet' data into 'rr' rr->input points | |
308 | * at rr->length bytes, which need to be copied into rr->data by either | |
309 | * the decryption or by the decompression When the data is 'copied' into | |
310 | * the rr->data buffer, rr->input will be pointed at the new buffer | |
311 | */ | |
fe589e61 | 312 | |
94777c9c MC |
313 | /* |
314 | * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length | |
315 | * bytes of encrypted compressed stuff. | |
316 | */ | |
fe589e61 | 317 | |
94777c9c MC |
318 | /* check is not needed I believe */ |
319 | if (rr[num_recs].length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { | |
320 | al = SSL_AD_RECORD_OVERFLOW; | |
321 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); | |
322 | goto f_err; | |
323 | } | |
324 | ||
325 | /* decrypt in place in 'rr->input' */ | |
326 | rr[num_recs].data = rr[num_recs].input; | |
327 | rr[num_recs].orig_len = rr[num_recs].length; | |
255cfeac MC |
328 | |
329 | /* Mark this record as not read by upper layers yet */ | |
330 | rr[num_recs].read = 0; | |
331 | ||
94777c9c MC |
332 | num_recs++; |
333 | ||
334 | /* we have pulled in a full packet so zero things */ | |
335 | RECORD_LAYER_reset_packet_length(&s->rlayer); | |
78fcddbb | 336 | RECORD_LAYER_clear_first_record(&s->rlayer); |
de0717eb | 337 | } while (num_recs < max_recs |
a230b26e | 338 | && rr[num_recs - 1].type == SSL3_RT_APPLICATION_DATA |
94777c9c MC |
339 | && SSL_USE_EXPLICIT_IV(s) |
340 | && s->enc_read_ctx != NULL | |
341 | && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) | |
a230b26e | 342 | & EVP_CIPH_FLAG_PIPELINE) |
ea71906e | 343 | && ssl3_record_app_data_waiting(s)); |
fe589e61 | 344 | |
fe589e61 MC |
345 | /* |
346 | * If in encrypt-then-mac mode calculate mac from encrypted record. All | |
347 | * the details below are public so no timing details can leak. | |
348 | */ | |
349 | if (SSL_USE_ETM(s) && s->read_hash) { | |
350 | unsigned char *mac; | |
351 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
352 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
94777c9c MC |
353 | for (j = 0; j < num_recs; j++) { |
354 | if (rr[j].length < mac_size) { | |
355 | al = SSL_AD_DECODE_ERROR; | |
356 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
357 | goto f_err; | |
358 | } | |
359 | rr[j].length -= mac_size; | |
360 | mac = rr[j].data + rr[j].length; | |
361 | i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ ); | |
362 | if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) { | |
363 | al = SSL_AD_BAD_RECORD_MAC; | |
364 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
365 | SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); | |
366 | goto f_err; | |
367 | } | |
fe589e61 MC |
368 | } |
369 | } | |
370 | ||
94777c9c | 371 | enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0); |
fe589e61 MC |
372 | /*- |
373 | * enc_err is: | |
374 | * 0: (in non-constant time) if the record is publically invalid. | |
375 | * 1: if the padding is valid | |
376 | * -1: if the padding is invalid | |
377 | */ | |
378 | if (enc_err == 0) { | |
379 | al = SSL_AD_DECRYPTION_FAILED; | |
380 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); | |
381 | goto f_err; | |
382 | } | |
d63a5e5e | 383 | #ifdef SSL_DEBUG |
fe589e61 MC |
384 | printf("dec %d\n", rr->length); |
385 | { | |
386 | unsigned int z; | |
387 | for (z = 0; z < rr->length; z++) | |
388 | printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); | |
389 | } | |
390 | printf("\n"); | |
391 | #endif | |
392 | ||
393 | /* r->length is now the compressed data plus mac */ | |
394 | if ((sess != NULL) && | |
395 | (s->enc_read_ctx != NULL) && | |
396 | (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) { | |
397 | /* s->read_hash != NULL => mac_size != -1 */ | |
398 | unsigned char *mac = NULL; | |
399 | unsigned char mac_tmp[EVP_MAX_MD_SIZE]; | |
94777c9c | 400 | |
fe589e61 MC |
401 | mac_size = EVP_MD_CTX_size(s->read_hash); |
402 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
403 | ||
a230b26e | 404 | for (j = 0; j < num_recs; j++) { |
fe589e61 | 405 | /* |
94777c9c MC |
406 | * orig_len is the length of the record before any padding was |
407 | * removed. This is public information, as is the MAC in use, | |
408 | * therefore we can safely process the record in a different amount | |
409 | * of time if it's too short to possibly contain a MAC. | |
fe589e61 | 410 | */ |
94777c9c MC |
411 | if (rr[j].orig_len < mac_size || |
412 | /* CBC records must have a padding length byte too. */ | |
413 | (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
414 | rr[j].orig_len < mac_size + 1)) { | |
415 | al = SSL_AD_DECODE_ERROR; | |
416 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
417 | goto f_err; | |
418 | } | |
fe589e61 | 419 | |
94777c9c MC |
420 | if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { |
421 | /* | |
422 | * We update the length so that the TLS header bytes can be | |
423 | * constructed correctly but we need to extract the MAC in | |
424 | * constant time from within the record, without leaking the | |
425 | * contents of the padding bytes. | |
426 | */ | |
427 | mac = mac_tmp; | |
428 | ssl3_cbc_copy_mac(mac_tmp, &rr[j], mac_size); | |
429 | rr[j].length -= mac_size; | |
430 | } else { | |
431 | /* | |
432 | * In this case there's no padding, so |rec->orig_len| equals | |
433 | * |rec->length| and we checked that there's enough bytes for | |
434 | * |mac_size| above. | |
435 | */ | |
436 | rr[j].length -= mac_size; | |
437 | mac = &rr[j].data[rr[j].length]; | |
438 | } | |
439 | ||
440 | i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ ); | |
441 | if (i < 0 || mac == NULL | |
442 | || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) | |
443 | enc_err = -1; | |
444 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) | |
445 | enc_err = -1; | |
446 | } | |
fe589e61 MC |
447 | } |
448 | ||
449 | if (enc_err < 0) { | |
450 | /* | |
451 | * A separate 'decryption_failed' alert was introduced with TLS 1.0, | |
452 | * SSL 3.0 only has 'bad_record_mac'. But unless a decryption | |
453 | * failure is directly visible from the ciphertext anyway, we should | |
454 | * not reveal which kind of error occurred -- this might become | |
455 | * visible to an attacker (e.g. via a logfile) | |
456 | */ | |
457 | al = SSL_AD_BAD_RECORD_MAC; | |
458 | SSLerr(SSL_F_SSL3_GET_RECORD, | |
459 | SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); | |
460 | goto f_err; | |
461 | } | |
462 | ||
94777c9c MC |
463 | for (j = 0; j < num_recs; j++) { |
464 | /* rr[j].length is now just compressed */ | |
465 | if (s->expand != NULL) { | |
466 | if (rr[j].length > SSL3_RT_MAX_COMPRESSED_LENGTH) { | |
467 | al = SSL_AD_RECORD_OVERFLOW; | |
468 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG); | |
469 | goto f_err; | |
470 | } | |
471 | if (!ssl3_do_uncompress(s, &rr[j])) { | |
472 | al = SSL_AD_DECOMPRESSION_FAILURE; | |
473 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION); | |
474 | goto f_err; | |
475 | } | |
fe589e61 | 476 | } |
94777c9c MC |
477 | |
478 | if (rr[j].length > SSL3_RT_MAX_PLAIN_LENGTH) { | |
479 | al = SSL_AD_RECORD_OVERFLOW; | |
480 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); | |
fe589e61 MC |
481 | goto f_err; |
482 | } | |
fe589e61 | 483 | |
94777c9c MC |
484 | rr[j].off = 0; |
485 | /*- | |
486 | * So at this point the following is true | |
487 | * rr[j].type is the type of record | |
488 | * rr[j].length == number of bytes in record | |
489 | * rr[j].off == offset to first valid byte | |
490 | * rr[j].data == where to take bytes from, increment after use :-). | |
491 | */ | |
fe589e61 | 492 | |
94777c9c MC |
493 | /* just read a 0 length packet */ |
494 | if (rr[j].length == 0) { | |
255cfeac MC |
495 | RECORD_LAYER_inc_empty_record_count(&s->rlayer); |
496 | if (RECORD_LAYER_get_empty_record_count(&s->rlayer) | |
a230b26e | 497 | > MAX_EMPTY_RECORDS) { |
94777c9c MC |
498 | al = SSL_AD_UNEXPECTED_MESSAGE; |
499 | SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL); | |
500 | goto f_err; | |
501 | } | |
255cfeac MC |
502 | } else { |
503 | RECORD_LAYER_reset_empty_record_count(&s->rlayer); | |
fe589e61 | 504 | } |
94777c9c | 505 | } |
fe589e61 | 506 | |
94777c9c MC |
507 | RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs); |
508 | return 1; | |
fe589e61 MC |
509 | |
510 | f_err: | |
511 | ssl3_send_alert(s, SSL3_AL_FATAL, al); | |
512 | err: | |
94777c9c | 513 | return ret; |
fe589e61 MC |
514 | } |
515 | ||
94777c9c | 516 | int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr) |
fe589e61 MC |
517 | { |
518 | #ifndef OPENSSL_NO_COMP | |
519 | int i; | |
fe589e61 | 520 | |
0220fee4 MC |
521 | if (rr->comp == NULL) { |
522 | rr->comp = (unsigned char *) | |
523 | OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH); | |
524 | } | |
525 | if (rr->comp == NULL) | |
526 | return 0; | |
527 | ||
fe589e61 | 528 | i = COMP_expand_block(ssl->expand, rr->comp, |
a230b26e | 529 | SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length); |
fe589e61 | 530 | if (i < 0) |
0220fee4 | 531 | return 0; |
fe589e61 MC |
532 | else |
533 | rr->length = i; | |
534 | rr->data = rr->comp; | |
535 | #endif | |
0220fee4 | 536 | return 1; |
fe589e61 MC |
537 | } |
538 | ||
d102d9df | 539 | int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr) |
fe589e61 MC |
540 | { |
541 | #ifndef OPENSSL_NO_COMP | |
542 | int i; | |
fe589e61 | 543 | |
fe589e61 MC |
544 | i = COMP_compress_block(ssl->compress, wr->data, |
545 | SSL3_RT_MAX_COMPRESSED_LENGTH, | |
546 | wr->input, (int)wr->length); | |
547 | if (i < 0) | |
548 | return (0); | |
549 | else | |
550 | wr->length = i; | |
551 | ||
552 | wr->input = wr->data; | |
553 | #endif | |
554 | return (1); | |
555 | } | |
556 | ||
02a36fda | 557 | /*- |
37205971 | 558 | * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs| |
02a36fda MC |
559 | * |
560 | * Returns: | |
561 | * 0: (in non-constant time) if the record is publically invalid (i.e. too | |
562 | * short etc). | |
563 | * 1: if the record's padding is valid / the encryption was successful. | |
564 | * -1: if the record's padding is invalid or, if sending, an internal error | |
565 | * occurred. | |
566 | */ | |
37205971 | 567 | int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, unsigned int n_recs, int send) |
02a36fda MC |
568 | { |
569 | SSL3_RECORD *rec; | |
570 | EVP_CIPHER_CTX *ds; | |
571 | unsigned long l; | |
572 | int bs, i, mac_size = 0; | |
573 | const EVP_CIPHER *enc; | |
574 | ||
d102d9df | 575 | rec = inrecs; |
37205971 MC |
576 | /* |
577 | * We shouldn't ever be called with more than one record in the SSLv3 case | |
578 | */ | |
579 | if (n_recs != 1) | |
580 | return 0; | |
02a36fda MC |
581 | if (send) { |
582 | ds = s->enc_write_ctx; | |
02a36fda MC |
583 | if (s->enc_write_ctx == NULL) |
584 | enc = NULL; | |
585 | else | |
586 | enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx); | |
587 | } else { | |
588 | ds = s->enc_read_ctx; | |
02a36fda MC |
589 | if (s->enc_read_ctx == NULL) |
590 | enc = NULL; | |
591 | else | |
592 | enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx); | |
593 | } | |
594 | ||
595 | if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { | |
596 | memmove(rec->data, rec->input, rec->length); | |
597 | rec->input = rec->data; | |
598 | } else { | |
599 | l = rec->length; | |
846ec07d | 600 | bs = EVP_CIPHER_CTX_block_size(ds); |
02a36fda MC |
601 | |
602 | /* COMPRESS */ | |
603 | ||
604 | if ((bs != 1) && send) { | |
605 | i = bs - ((int)l % bs); | |
606 | ||
607 | /* we need to add 'i-1' padding bytes */ | |
608 | l += i; | |
609 | /* | |
610 | * the last of these zero bytes will be overwritten with the | |
611 | * padding length. | |
612 | */ | |
613 | memset(&rec->input[rec->length], 0, i); | |
614 | rec->length += i; | |
615 | rec->input[l - 1] = (i - 1); | |
616 | } | |
617 | ||
618 | if (!send) { | |
619 | if (l == 0 || l % bs != 0) | |
620 | return 0; | |
621 | /* otherwise, rec->length >= bs */ | |
622 | } | |
623 | ||
624 | if (EVP_Cipher(ds, rec->data, rec->input, l) < 1) | |
625 | return -1; | |
626 | ||
627 | if (EVP_MD_CTX_md(s->read_hash) != NULL) | |
628 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
629 | if ((bs != 1) && !send) | |
a773b52a | 630 | return ssl3_cbc_remove_padding(rec, bs, mac_size); |
02a36fda MC |
631 | } |
632 | return (1); | |
633 | } | |
634 | ||
635 | /*- | |
37205971 | 636 | * tls1_enc encrypts/decrypts |n_recs| in |recs|. |
02a36fda MC |
637 | * |
638 | * Returns: | |
639 | * 0: (in non-constant time) if the record is publically invalid (i.e. too | |
640 | * short etc). | |
641 | * 1: if the record's padding is valid / the encryption was successful. | |
642 | * -1: if the record's padding/AEAD-authenticator is invalid or, if sending, | |
643 | * an internal error occurred. | |
644 | */ | |
37205971 | 645 | int tls1_enc(SSL *s, SSL3_RECORD *recs, unsigned int n_recs, int send) |
02a36fda | 646 | { |
02a36fda | 647 | EVP_CIPHER_CTX *ds; |
d102d9df MC |
648 | size_t reclen[SSL_MAX_PIPELINES]; |
649 | unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN]; | |
02a36fda MC |
650 | int bs, i, j, k, pad = 0, ret, mac_size = 0; |
651 | const EVP_CIPHER *enc; | |
d102d9df | 652 | unsigned int ctr; |
02a36fda MC |
653 | |
654 | if (send) { | |
655 | if (EVP_MD_CTX_md(s->write_hash)) { | |
656 | int n = EVP_MD_CTX_size(s->write_hash); | |
657 | OPENSSL_assert(n >= 0); | |
658 | } | |
659 | ds = s->enc_write_ctx; | |
02a36fda MC |
660 | if (s->enc_write_ctx == NULL) |
661 | enc = NULL; | |
662 | else { | |
663 | int ivlen; | |
664 | enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx); | |
665 | /* For TLSv1.1 and later explicit IV */ | |
666 | if (SSL_USE_EXPLICIT_IV(s) | |
667 | && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE) | |
668 | ivlen = EVP_CIPHER_iv_length(enc); | |
669 | else | |
670 | ivlen = 0; | |
671 | if (ivlen > 1) { | |
37205971 | 672 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
673 | if (recs[ctr].data != recs[ctr].input) { |
674 | /* | |
675 | * we can't write into the input stream: Can this ever | |
676 | * happen?? (steve) | |
677 | */ | |
678 | SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR); | |
679 | return -1; | |
680 | } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) { | |
681 | SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR); | |
682 | return -1; | |
683 | } | |
684 | } | |
02a36fda MC |
685 | } |
686 | } | |
687 | } else { | |
688 | if (EVP_MD_CTX_md(s->read_hash)) { | |
689 | int n = EVP_MD_CTX_size(s->read_hash); | |
690 | OPENSSL_assert(n >= 0); | |
691 | } | |
692 | ds = s->enc_read_ctx; | |
02a36fda MC |
693 | if (s->enc_read_ctx == NULL) |
694 | enc = NULL; | |
695 | else | |
696 | enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx); | |
697 | } | |
698 | ||
02a36fda | 699 | if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { |
37205971 | 700 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
701 | memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length); |
702 | recs[ctr].input = recs[ctr].data; | |
703 | } | |
02a36fda MC |
704 | ret = 1; |
705 | } else { | |
d102d9df MC |
706 | bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds)); |
707 | ||
37205971 | 708 | if (n_recs > 1) { |
e8aa8b6c | 709 | if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds)) |
a230b26e | 710 | & EVP_CIPH_FLAG_PIPELINE)) { |
d102d9df MC |
711 | /* |
712 | * We shouldn't have been called with pipeline data if the | |
713 | * cipher doesn't support pipelining | |
714 | */ | |
715 | SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE); | |
716 | return -1; | |
717 | } | |
718 | } | |
37205971 | 719 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
720 | reclen[ctr] = recs[ctr].length; |
721 | ||
722 | if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds)) | |
a230b26e | 723 | & EVP_CIPH_FLAG_AEAD_CIPHER) { |
d102d9df MC |
724 | unsigned char *seq; |
725 | ||
726 | seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer) | |
727 | : RECORD_LAYER_get_read_sequence(&s->rlayer); | |
728 | ||
729 | if (SSL_IS_DTLS(s)) { | |
730 | /* DTLS does not support pipelining */ | |
731 | unsigned char dtlsseq[9], *p = dtlsseq; | |
732 | ||
733 | s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) : | |
734 | DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p); | |
735 | memcpy(p, &seq[2], 6); | |
736 | memcpy(buf[ctr], dtlsseq, 8); | |
737 | } else { | |
738 | memcpy(buf[ctr], seq, 8); | |
739 | for (i = 7; i >= 0; i--) { /* increment */ | |
740 | ++seq[i]; | |
741 | if (seq[i] != 0) | |
742 | break; | |
743 | } | |
744 | } | |
02a36fda | 745 | |
d102d9df MC |
746 | buf[ctr][8] = recs[ctr].type; |
747 | buf[ctr][9] = (unsigned char)(s->version >> 8); | |
748 | buf[ctr][10] = (unsigned char)(s->version); | |
749 | buf[ctr][11] = recs[ctr].length >> 8; | |
750 | buf[ctr][12] = recs[ctr].length & 0xff; | |
751 | pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD, | |
752 | EVP_AEAD_TLS1_AAD_LEN, buf[ctr]); | |
753 | if (pad <= 0) | |
754 | return -1; | |
755 | ||
756 | if (send) { | |
757 | reclen[ctr] += pad; | |
758 | recs[ctr].length += pad; | |
02a36fda | 759 | } |
02a36fda | 760 | |
d102d9df MC |
761 | } else if ((bs != 1) && send) { |
762 | i = bs - ((int)reclen[ctr] % bs); | |
02a36fda | 763 | |
d102d9df | 764 | /* Add weird padding of upto 256 bytes */ |
02a36fda | 765 | |
d102d9df MC |
766 | /* we need to add 'i' padding bytes of value j */ |
767 | j = i - 1; | |
768 | for (k = (int)reclen[ctr]; k < (int)(reclen[ctr] + i); k++) | |
769 | recs[ctr].input[k] = j; | |
770 | reclen[ctr] += i; | |
771 | recs[ctr].length += i; | |
772 | } | |
773 | ||
774 | if (!send) { | |
775 | if (reclen[ctr] == 0 || reclen[ctr] % bs != 0) | |
776 | return 0; | |
777 | } | |
02a36fda | 778 | } |
37205971 | 779 | if (n_recs > 1) { |
d102d9df | 780 | unsigned char *data[SSL_MAX_PIPELINES]; |
02a36fda | 781 | |
d102d9df | 782 | /* Set the output buffers */ |
e8aa8b6c | 783 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
784 | data[ctr] = recs[ctr].data; |
785 | } | |
786 | if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS, | |
a230b26e | 787 | n_recs, data) <= 0) { |
d102d9df MC |
788 | SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE); |
789 | } | |
790 | /* Set the input buffers */ | |
e8aa8b6c | 791 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
792 | data[ctr] = recs[ctr].input; |
793 | } | |
794 | if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS, | |
a230b26e | 795 | n_recs, data) <= 0 |
d102d9df | 796 | || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS, |
a230b26e | 797 | n_recs, reclen) <= 0) { |
d102d9df MC |
798 | SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE); |
799 | return -1; | |
800 | } | |
02a36fda MC |
801 | } |
802 | ||
d102d9df MC |
803 | i = EVP_Cipher(ds, recs[0].data, recs[0].input, reclen[0]); |
804 | if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds)) | |
a230b26e | 805 | & EVP_CIPH_FLAG_CUSTOM_CIPHER) |
02a36fda MC |
806 | ? (i < 0) |
807 | : (i == 0)) | |
808 | return -1; /* AEAD can fail to verify MAC */ | |
e75c5a79 DSH |
809 | if (send == 0) { |
810 | if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) { | |
37205971 | 811 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
812 | recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN; |
813 | recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN; | |
814 | recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN; | |
815 | } | |
e75c5a79 | 816 | } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) { |
37205971 | 817 | for (ctr = 0; ctr < n_recs; ctr++) { |
d102d9df MC |
818 | recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN; |
819 | recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN; | |
820 | recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN; | |
821 | } | |
e75c5a79 | 822 | } |
02a36fda | 823 | } |
02a36fda MC |
824 | |
825 | ret = 1; | |
826 | if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) | |
827 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
d102d9df | 828 | if ((bs != 1) && !send) { |
94777c9c | 829 | int tmpret; |
37205971 | 830 | for (ctr = 0; ctr < n_recs; ctr++) { |
94777c9c | 831 | tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size); |
f9cf774c MC |
832 | /* |
833 | * If tmpret == 0 then this means publicly invalid so we can | |
834 | * short circuit things here. Otherwise we must respect constant | |
835 | * time behaviour. | |
836 | */ | |
837 | if (tmpret == 0) | |
838 | return 0; | |
839 | ret = constant_time_select_int(constant_time_eq_int(tmpret, 1), | |
840 | ret, -1); | |
94777c9c MC |
841 | } |
842 | } | |
843 | if (pad && !send) { | |
37205971 | 844 | for (ctr = 0; ctr < n_recs; ctr++) { |
94777c9c MC |
845 | recs[ctr].length -= pad; |
846 | } | |
d102d9df | 847 | } |
02a36fda MC |
848 | } |
849 | return ret; | |
850 | } | |
851 | ||
d102d9df | 852 | int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send) |
02a36fda | 853 | { |
02a36fda | 854 | unsigned char *mac_sec, *seq; |
02a36fda MC |
855 | const EVP_MD_CTX *hash; |
856 | unsigned char *p, rec_char; | |
857 | size_t md_size; | |
858 | int npad; | |
859 | int t; | |
860 | ||
861 | if (send) { | |
02a36fda | 862 | mac_sec = &(ssl->s3->write_mac_secret[0]); |
de07f311 | 863 | seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); |
02a36fda MC |
864 | hash = ssl->write_hash; |
865 | } else { | |
02a36fda | 866 | mac_sec = &(ssl->s3->read_mac_secret[0]); |
de07f311 | 867 | seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); |
02a36fda MC |
868 | hash = ssl->read_hash; |
869 | } | |
870 | ||
871 | t = EVP_MD_CTX_size(hash); | |
872 | if (t < 0) | |
873 | return -1; | |
874 | md_size = t; | |
875 | npad = (48 / md_size) * md_size; | |
876 | ||
877 | if (!send && | |
878 | EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
879 | ssl3_cbc_record_digest_supported(hash)) { | |
880 | /* | |
881 | * This is a CBC-encrypted record. We must avoid leaking any | |
882 | * timing-side channel information about how many blocks of data we | |
883 | * are hashing because that gives an attacker a timing-oracle. | |
884 | */ | |
885 | ||
886 | /*- | |
887 | * npad is, at most, 48 bytes and that's with MD5: | |
888 | * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75. | |
889 | * | |
890 | * With SHA-1 (the largest hash speced for SSLv3) the hash size | |
891 | * goes up 4, but npad goes down by 8, resulting in a smaller | |
892 | * total size. | |
893 | */ | |
894 | unsigned char header[75]; | |
895 | unsigned j = 0; | |
896 | memcpy(header + j, mac_sec, md_size); | |
897 | j += md_size; | |
898 | memcpy(header + j, ssl3_pad_1, npad); | |
899 | j += npad; | |
900 | memcpy(header + j, seq, 8); | |
901 | j += 8; | |
902 | header[j++] = rec->type; | |
903 | header[j++] = rec->length >> 8; | |
904 | header[j++] = rec->length & 0xff; | |
905 | ||
906 | /* Final param == is SSLv3 */ | |
5f3d93e4 MC |
907 | if (ssl3_cbc_digest_record(hash, |
908 | md, &md_size, | |
909 | header, rec->input, | |
910 | rec->length + md_size, rec->orig_len, | |
911 | mac_sec, md_size, 1) <= 0) | |
912 | return -1; | |
02a36fda MC |
913 | } else { |
914 | unsigned int md_size_u; | |
915 | /* Chop the digest off the end :-) */ | |
bfb0641f | 916 | EVP_MD_CTX *md_ctx = EVP_MD_CTX_new(); |
6e59a892 RL |
917 | |
918 | if (md_ctx == NULL) | |
919 | return -1; | |
02a36fda | 920 | |
02a36fda | 921 | rec_char = rec->type; |
02a36fda MC |
922 | p = md; |
923 | s2n(rec->length, p); | |
6e59a892 | 924 | if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0 |
a230b26e EK |
925 | || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0 |
926 | || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0 | |
927 | || EVP_DigestUpdate(md_ctx, seq, 8) <= 0 | |
928 | || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0 | |
929 | || EVP_DigestUpdate(md_ctx, md, 2) <= 0 | |
930 | || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0 | |
931 | || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0 | |
932 | || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0 | |
933 | || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0 | |
934 | || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0 | |
935 | || EVP_DigestUpdate(md_ctx, md, md_size) <= 0 | |
936 | || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) { | |
bfb0641f | 937 | EVP_MD_CTX_reset(md_ctx); |
5f3d93e4 MC |
938 | return -1; |
939 | } | |
02a36fda MC |
940 | md_size = md_size_u; |
941 | ||
bfb0641f | 942 | EVP_MD_CTX_free(md_ctx); |
02a36fda MC |
943 | } |
944 | ||
945 | ssl3_record_sequence_update(seq); | |
946 | return (md_size); | |
947 | } | |
948 | ||
d102d9df | 949 | int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send) |
02a36fda | 950 | { |
02a36fda MC |
951 | unsigned char *seq; |
952 | EVP_MD_CTX *hash; | |
953 | size_t md_size; | |
954 | int i; | |
6e59a892 | 955 | EVP_MD_CTX *hmac = NULL, *mac_ctx; |
02a36fda MC |
956 | unsigned char header[13]; |
957 | int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM) | |
958 | : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM)); | |
959 | int t; | |
960 | ||
961 | if (send) { | |
de07f311 | 962 | seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); |
02a36fda MC |
963 | hash = ssl->write_hash; |
964 | } else { | |
de07f311 | 965 | seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); |
02a36fda MC |
966 | hash = ssl->read_hash; |
967 | } | |
968 | ||
969 | t = EVP_MD_CTX_size(hash); | |
970 | OPENSSL_assert(t >= 0); | |
971 | md_size = t; | |
972 | ||
973 | /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */ | |
974 | if (stream_mac) { | |
975 | mac_ctx = hash; | |
976 | } else { | |
bfb0641f | 977 | hmac = EVP_MD_CTX_new(); |
a230b26e | 978 | if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash)) |
02a36fda | 979 | return -1; |
6e59a892 | 980 | mac_ctx = hmac; |
02a36fda MC |
981 | } |
982 | ||
983 | if (SSL_IS_DTLS(ssl)) { | |
984 | unsigned char dtlsseq[8], *p = dtlsseq; | |
985 | ||
78a39fe7 MC |
986 | s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) : |
987 | DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p); | |
02a36fda MC |
988 | memcpy(p, &seq[2], 6); |
989 | ||
990 | memcpy(header, dtlsseq, 8); | |
991 | } else | |
992 | memcpy(header, seq, 8); | |
993 | ||
994 | header[8] = rec->type; | |
995 | header[9] = (unsigned char)(ssl->version >> 8); | |
996 | header[10] = (unsigned char)(ssl->version); | |
997 | header[11] = (rec->length) >> 8; | |
998 | header[12] = (rec->length) & 0xff; | |
999 | ||
1000 | if (!send && !SSL_USE_ETM(ssl) && | |
1001 | EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
1002 | ssl3_cbc_record_digest_supported(mac_ctx)) { | |
1003 | /* | |
1004 | * This is a CBC-encrypted record. We must avoid leaking any | |
1005 | * timing-side channel information about how many blocks of data we | |
1006 | * are hashing because that gives an attacker a timing-oracle. | |
1007 | */ | |
1008 | /* Final param == not SSLv3 */ | |
5f3d93e4 MC |
1009 | if (ssl3_cbc_digest_record(mac_ctx, |
1010 | md, &md_size, | |
1011 | header, rec->input, | |
1012 | rec->length + md_size, rec->orig_len, | |
1013 | ssl->s3->read_mac_secret, | |
1014 | ssl->s3->read_mac_secret_size, 0) <= 0) { | |
bfb0641f | 1015 | EVP_MD_CTX_free(hmac); |
5f3d93e4 MC |
1016 | return -1; |
1017 | } | |
02a36fda | 1018 | } else { |
5f3d93e4 | 1019 | if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0 |
a230b26e EK |
1020 | || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0 |
1021 | || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) { | |
bfb0641f | 1022 | EVP_MD_CTX_free(hmac); |
6929b447 | 1023 | return -1; |
5f3d93e4 | 1024 | } |
02a36fda | 1025 | if (!send && !SSL_USE_ETM(ssl) && FIPS_mode()) |
d166ed8c DSH |
1026 | if (!tls_fips_digest_extra(ssl->enc_read_ctx, |
1027 | mac_ctx, rec->input, | |
1028 | rec->length, rec->orig_len)) { | |
1029 | EVP_MD_CTX_free(hmac); | |
1030 | return -1; | |
a230b26e | 1031 | } |
02a36fda MC |
1032 | } |
1033 | ||
bfb0641f | 1034 | EVP_MD_CTX_free(hmac); |
5f3d93e4 | 1035 | |
d63a5e5e | 1036 | #ifdef SSL_DEBUG |
02a36fda MC |
1037 | fprintf(stderr, "seq="); |
1038 | { | |
1039 | int z; | |
1040 | for (z = 0; z < 8; z++) | |
1041 | fprintf(stderr, "%02X ", seq[z]); | |
1042 | fprintf(stderr, "\n"); | |
1043 | } | |
1044 | fprintf(stderr, "rec="); | |
1045 | { | |
1046 | unsigned int z; | |
1047 | for (z = 0; z < rec->length; z++) | |
1048 | fprintf(stderr, "%02X ", rec->data[z]); | |
1049 | fprintf(stderr, "\n"); | |
1050 | } | |
1051 | #endif | |
1052 | ||
1053 | if (!SSL_IS_DTLS(ssl)) { | |
1054 | for (i = 7; i >= 0; i--) { | |
1055 | ++seq[i]; | |
1056 | if (seq[i] != 0) | |
1057 | break; | |
1058 | } | |
1059 | } | |
d63a5e5e | 1060 | #ifdef SSL_DEBUG |
02a36fda MC |
1061 | { |
1062 | unsigned int z; | |
1063 | for (z = 0; z < md_size; z++) | |
1064 | fprintf(stderr, "%02X ", md[z]); | |
1065 | fprintf(stderr, "\n"); | |
1066 | } | |
1067 | #endif | |
1068 | return (md_size); | |
1069 | } | |
1070 | ||
1071 | /*- | |
1072 | * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC | |
1073 | * record in |rec| by updating |rec->length| in constant time. | |
1074 | * | |
1075 | * block_size: the block size of the cipher used to encrypt the record. | |
1076 | * returns: | |
1077 | * 0: (in non-constant time) if the record is publicly invalid. | |
1078 | * 1: if the padding was valid | |
1079 | * -1: otherwise. | |
1080 | */ | |
a773b52a | 1081 | int ssl3_cbc_remove_padding(SSL3_RECORD *rec, |
02a36fda MC |
1082 | unsigned block_size, unsigned mac_size) |
1083 | { | |
1084 | unsigned padding_length, good; | |
1085 | const unsigned overhead = 1 /* padding length byte */ + mac_size; | |
1086 | ||
1087 | /* | |
1088 | * These lengths are all public so we can test them in non-constant time. | |
1089 | */ | |
1090 | if (overhead > rec->length) | |
1091 | return 0; | |
1092 | ||
1093 | padding_length = rec->data[rec->length - 1]; | |
1094 | good = constant_time_ge(rec->length, padding_length + overhead); | |
1095 | /* SSLv3 requires that the padding is minimal. */ | |
1096 | good &= constant_time_ge(block_size, padding_length + 1); | |
1097 | rec->length -= good & (padding_length + 1); | |
1098 | return constant_time_select_int(good, 1, -1); | |
1099 | } | |
1100 | ||
1101 | /*- | |
1102 | * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC | |
1103 | * record in |rec| in constant time and returns 1 if the padding is valid and | |
1104 | * -1 otherwise. It also removes any explicit IV from the start of the record | |
1105 | * without leaking any timing about whether there was enough space after the | |
1106 | * padding was removed. | |
1107 | * | |
1108 | * block_size: the block size of the cipher used to encrypt the record. | |
1109 | * returns: | |
1110 | * 0: (in non-constant time) if the record is publicly invalid. | |
1111 | * 1: if the padding was valid | |
1112 | * -1: otherwise. | |
1113 | */ | |
1114 | int tls1_cbc_remove_padding(const SSL *s, | |
1115 | SSL3_RECORD *rec, | |
1116 | unsigned block_size, unsigned mac_size) | |
1117 | { | |
1118 | unsigned padding_length, good, to_check, i; | |
1119 | const unsigned overhead = 1 /* padding length byte */ + mac_size; | |
1120 | /* Check if version requires explicit IV */ | |
1121 | if (SSL_USE_EXPLICIT_IV(s)) { | |
1122 | /* | |
1123 | * These lengths are all public so we can test them in non-constant | |
1124 | * time. | |
1125 | */ | |
1126 | if (overhead + block_size > rec->length) | |
1127 | return 0; | |
1128 | /* We can now safely skip explicit IV */ | |
1129 | rec->data += block_size; | |
1130 | rec->input += block_size; | |
1131 | rec->length -= block_size; | |
1132 | rec->orig_len -= block_size; | |
1133 | } else if (overhead > rec->length) | |
1134 | return 0; | |
1135 | ||
1136 | padding_length = rec->data[rec->length - 1]; | |
1137 | ||
a230b26e EK |
1138 | if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) & |
1139 | EVP_CIPH_FLAG_AEAD_CIPHER) { | |
02a36fda MC |
1140 | /* padding is already verified */ |
1141 | rec->length -= padding_length + 1; | |
1142 | return 1; | |
1143 | } | |
1144 | ||
1145 | good = constant_time_ge(rec->length, overhead + padding_length); | |
1146 | /* | |
1147 | * The padding consists of a length byte at the end of the record and | |
1148 | * then that many bytes of padding, all with the same value as the length | |
1149 | * byte. Thus, with the length byte included, there are i+1 bytes of | |
1150 | * padding. We can't check just |padding_length+1| bytes because that | |
1151 | * leaks decrypted information. Therefore we always have to check the | |
1152 | * maximum amount of padding possible. (Again, the length of the record | |
1153 | * is public information so we can use it.) | |
1154 | */ | |
eea8723c AL |
1155 | to_check = 256; /* maximum amount of padding, inc length byte. */ |
1156 | if (to_check > rec->length) | |
1157 | to_check = rec->length; | |
02a36fda MC |
1158 | |
1159 | for (i = 0; i < to_check; i++) { | |
1160 | unsigned char mask = constant_time_ge_8(padding_length, i); | |
1161 | unsigned char b = rec->data[rec->length - 1 - i]; | |
1162 | /* | |
1163 | * The final |padding_length+1| bytes should all have the value | |
1164 | * |padding_length|. Therefore the XOR should be zero. | |
1165 | */ | |
1166 | good &= ~(mask & (padding_length ^ b)); | |
1167 | } | |
1168 | ||
1169 | /* | |
1170 | * If any of the final |padding_length+1| bytes had the wrong value, one | |
1171 | * or more of the lower eight bits of |good| will be cleared. | |
1172 | */ | |
1173 | good = constant_time_eq(0xff, good & 0xff); | |
1174 | rec->length -= good & (padding_length + 1); | |
1175 | ||
1176 | return constant_time_select_int(good, 1, -1); | |
1177 | } | |
1178 | ||
1179 | /*- | |
1180 | * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in | |
1181 | * constant time (independent of the concrete value of rec->length, which may | |
1182 | * vary within a 256-byte window). | |
1183 | * | |
1184 | * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to | |
1185 | * this function. | |
1186 | * | |
1187 | * On entry: | |
1188 | * rec->orig_len >= md_size | |
1189 | * md_size <= EVP_MAX_MD_SIZE | |
1190 | * | |
1191 | * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with | |
1192 | * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into | |
1193 | * a single or pair of cache-lines, then the variable memory accesses don't | |
1194 | * actually affect the timing. CPUs with smaller cache-lines [if any] are | |
1195 | * not multi-core and are not considered vulnerable to cache-timing attacks. | |
1196 | */ | |
1197 | #define CBC_MAC_ROTATE_IN_PLACE | |
1198 | ||
1199 | void ssl3_cbc_copy_mac(unsigned char *out, | |
1200 | const SSL3_RECORD *rec, unsigned md_size) | |
1201 | { | |
1202 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1203 | unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE]; | |
1204 | unsigned char *rotated_mac; | |
1205 | #else | |
1206 | unsigned char rotated_mac[EVP_MAX_MD_SIZE]; | |
1207 | #endif | |
1208 | ||
1209 | /* | |
1210 | * mac_end is the index of |rec->data| just after the end of the MAC. | |
1211 | */ | |
1212 | unsigned mac_end = rec->length; | |
1213 | unsigned mac_start = mac_end - md_size; | |
1214 | /* | |
1215 | * scan_start contains the number of bytes that we can ignore because the | |
1216 | * MAC's position can only vary by 255 bytes. | |
1217 | */ | |
1218 | unsigned scan_start = 0; | |
1219 | unsigned i, j; | |
1220 | unsigned div_spoiler; | |
1221 | unsigned rotate_offset; | |
1222 | ||
1223 | OPENSSL_assert(rec->orig_len >= md_size); | |
1224 | OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE); | |
1225 | ||
1226 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1227 | rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63); | |
1228 | #endif | |
1229 | ||
1230 | /* This information is public so it's safe to branch based on it. */ | |
1231 | if (rec->orig_len > md_size + 255 + 1) | |
1232 | scan_start = rec->orig_len - (md_size + 255 + 1); | |
1233 | /* | |
1234 | * div_spoiler contains a multiple of md_size that is used to cause the | |
1235 | * modulo operation to be constant time. Without this, the time varies | |
1236 | * based on the amount of padding when running on Intel chips at least. | |
1237 | * The aim of right-shifting md_size is so that the compiler doesn't | |
1238 | * figure out that it can remove div_spoiler as that would require it to | |
1239 | * prove that md_size is always even, which I hope is beyond it. | |
1240 | */ | |
1241 | div_spoiler = md_size >> 1; | |
1242 | div_spoiler <<= (sizeof(div_spoiler) - 1) * 8; | |
1243 | rotate_offset = (div_spoiler + mac_start - scan_start) % md_size; | |
1244 | ||
1245 | memset(rotated_mac, 0, md_size); | |
1246 | for (i = scan_start, j = 0; i < rec->orig_len; i++) { | |
1247 | unsigned char mac_started = constant_time_ge_8(i, mac_start); | |
1248 | unsigned char mac_ended = constant_time_ge_8(i, mac_end); | |
1249 | unsigned char b = rec->data[i]; | |
1250 | rotated_mac[j++] |= b & mac_started & ~mac_ended; | |
1251 | j &= constant_time_lt(j, md_size); | |
1252 | } | |
1253 | ||
1254 | /* Now rotate the MAC */ | |
1255 | #if defined(CBC_MAC_ROTATE_IN_PLACE) | |
1256 | j = 0; | |
1257 | for (i = 0; i < md_size; i++) { | |
1258 | /* in case cache-line is 32 bytes, touch second line */ | |
1259 | ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32]; | |
1260 | out[j++] = rotated_mac[rotate_offset++]; | |
1261 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1262 | } | |
1263 | #else | |
1264 | memset(out, 0, md_size); | |
1265 | rotate_offset = md_size - rotate_offset; | |
1266 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1267 | for (i = 0; i < md_size; i++) { | |
1268 | for (j = 0; j < md_size; j++) | |
1269 | out[j] |= rotated_mac[i] & constant_time_eq_8(j, rotate_offset); | |
1270 | rotate_offset++; | |
1271 | rotate_offset &= constant_time_lt(rotate_offset, md_size); | |
1272 | } | |
1273 | #endif | |
1274 | } | |
1275 | ||
1fb9fdc3 | 1276 | int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap) |
fe589e61 MC |
1277 | { |
1278 | int i, al; | |
1279 | int enc_err; | |
1280 | SSL_SESSION *sess; | |
1281 | SSL3_RECORD *rr; | |
1282 | unsigned int mac_size; | |
1283 | unsigned char md[EVP_MAX_MD_SIZE]; | |
1284 | ||
1285 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
1286 | sess = s->session; | |
1287 | ||
1288 | /* | |
1289 | * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, | |
1290 | * and we have that many bytes in s->packet | |
1291 | */ | |
7a7048af | 1292 | rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]); |
fe589e61 MC |
1293 | |
1294 | /* | |
1295 | * ok, we can now read from 's->packet' data into 'rr' rr->input points | |
1296 | * at rr->length bytes, which need to be copied into rr->data by either | |
1297 | * the decryption or by the decompression When the data is 'copied' into | |
1298 | * the rr->data buffer, rr->input will be pointed at the new buffer | |
1299 | */ | |
1300 | ||
1301 | /* | |
1302 | * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length | |
1303 | * bytes of encrypted compressed stuff. | |
1304 | */ | |
1305 | ||
1306 | /* check is not needed I believe */ | |
1307 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { | |
1308 | al = SSL_AD_RECORD_OVERFLOW; | |
1309 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); | |
1310 | goto f_err; | |
1311 | } | |
1312 | ||
1313 | /* decrypt in place in 'rr->input' */ | |
1314 | rr->data = rr->input; | |
1315 | rr->orig_len = rr->length; | |
1316 | ||
d102d9df | 1317 | enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0); |
fe589e61 MC |
1318 | /*- |
1319 | * enc_err is: | |
1320 | * 0: (in non-constant time) if the record is publically invalid. | |
1321 | * 1: if the padding is valid | |
1322 | * -1: if the padding is invalid | |
1323 | */ | |
1324 | if (enc_err == 0) { | |
1325 | /* For DTLS we simply ignore bad packets. */ | |
1326 | rr->length = 0; | |
7a7048af | 1327 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1328 | goto err; |
1329 | } | |
d63a5e5e | 1330 | #ifdef SSL_DEBUG |
fe589e61 MC |
1331 | printf("dec %d\n", rr->length); |
1332 | { | |
1333 | unsigned int z; | |
1334 | for (z = 0; z < rr->length; z++) | |
1335 | printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); | |
1336 | } | |
1337 | printf("\n"); | |
1338 | #endif | |
1339 | ||
1340 | /* r->length is now the compressed data plus mac */ | |
1341 | if ((sess != NULL) && | |
1342 | (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { | |
1343 | /* s->read_hash != NULL => mac_size != -1 */ | |
1344 | unsigned char *mac = NULL; | |
1345 | unsigned char mac_tmp[EVP_MAX_MD_SIZE]; | |
1346 | mac_size = EVP_MD_CTX_size(s->read_hash); | |
1347 | OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); | |
1348 | ||
1349 | /* | |
1350 | * orig_len is the length of the record before any padding was | |
1351 | * removed. This is public information, as is the MAC in use, | |
1352 | * therefore we can safely process the record in a different amount | |
1353 | * of time if it's too short to possibly contain a MAC. | |
1354 | */ | |
1355 | if (rr->orig_len < mac_size || | |
1356 | /* CBC records must have a padding length byte too. */ | |
1357 | (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && | |
1358 | rr->orig_len < mac_size + 1)) { | |
1359 | al = SSL_AD_DECODE_ERROR; | |
1360 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT); | |
1361 | goto f_err; | |
1362 | } | |
1363 | ||
1364 | if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { | |
1365 | /* | |
1366 | * We update the length so that the TLS header bytes can be | |
1367 | * constructed correctly but we need to extract the MAC in | |
1368 | * constant time from within the record, without leaking the | |
1369 | * contents of the padding bytes. | |
1370 | */ | |
1371 | mac = mac_tmp; | |
1372 | ssl3_cbc_copy_mac(mac_tmp, rr, mac_size); | |
1373 | rr->length -= mac_size; | |
1374 | } else { | |
1375 | /* | |
1376 | * In this case there's no padding, so |rec->orig_len| equals | |
1377 | * |rec->length| and we checked that there's enough bytes for | |
1378 | * |mac_size| above. | |
1379 | */ | |
1380 | rr->length -= mac_size; | |
1381 | mac = &rr->data[rr->length]; | |
1382 | } | |
1383 | ||
d102d9df | 1384 | i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ ); |
fe589e61 MC |
1385 | if (i < 0 || mac == NULL |
1386 | || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) | |
1387 | enc_err = -1; | |
1388 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) | |
1389 | enc_err = -1; | |
1390 | } | |
1391 | ||
1392 | if (enc_err < 0) { | |
1393 | /* decryption failed, silently discard message */ | |
1394 | rr->length = 0; | |
7a7048af | 1395 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1396 | goto err; |
1397 | } | |
1398 | ||
1399 | /* r->length is now just compressed */ | |
1400 | if (s->expand != NULL) { | |
1401 | if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { | |
1402 | al = SSL_AD_RECORD_OVERFLOW; | |
1403 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, | |
1404 | SSL_R_COMPRESSED_LENGTH_TOO_LONG); | |
1405 | goto f_err; | |
1406 | } | |
94777c9c | 1407 | if (!ssl3_do_uncompress(s, rr)) { |
fe589e61 MC |
1408 | al = SSL_AD_DECOMPRESSION_FAILURE; |
1409 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION); | |
1410 | goto f_err; | |
1411 | } | |
1412 | } | |
1413 | ||
1414 | if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { | |
1415 | al = SSL_AD_RECORD_OVERFLOW; | |
1416 | SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); | |
1417 | goto f_err; | |
1418 | } | |
1419 | ||
1420 | rr->off = 0; | |
1421 | /*- | |
1422 | * So at this point the following is true | |
1423 | * ssl->s3->rrec.type is the type of record | |
1424 | * ssl->s3->rrec.length == number of bytes in record | |
1425 | * ssl->s3->rrec.off == offset to first valid byte | |
1426 | * ssl->s3->rrec.data == where to take bytes from, increment | |
1427 | * after use :-). | |
1428 | */ | |
1429 | ||
1430 | /* we have pulled in a full packet so zero things */ | |
7a7048af | 1431 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
1fb9fdc3 MC |
1432 | |
1433 | /* Mark receipt of record. */ | |
1434 | dtls1_record_bitmap_update(s, bitmap); | |
1435 | ||
fe589e61 MC |
1436 | return (1); |
1437 | ||
1438 | f_err: | |
1439 | ssl3_send_alert(s, SSL3_AL_FATAL, al); | |
1440 | err: | |
1441 | return (0); | |
1442 | } | |
1443 | ||
fe589e61 MC |
1444 | /* |
1445 | * retrieve a buffered record that belongs to the current epoch, ie, | |
1446 | * processed | |
1447 | */ | |
1448 | #define dtls1_get_processed_record(s) \ | |
1449 | dtls1_retrieve_buffered_record((s), \ | |
cb2ce7ab | 1450 | &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer))) |
fe589e61 MC |
1451 | |
1452 | /*- | |
1453 | * Call this to get a new input record. | |
1454 | * It will return <= 0 if more data is needed, normally due to an error | |
1455 | * or non-blocking IO. | |
1456 | * When it finishes, one packet has been decoded and can be found in | |
1457 | * ssl->s3->rrec.type - is the type of record | |
1458 | * ssl->s3->rrec.data, - data | |
1459 | * ssl->s3->rrec.length, - number of bytes | |
1460 | */ | |
1461 | /* used only by dtls1_read_bytes */ | |
1462 | int dtls1_get_record(SSL *s) | |
1463 | { | |
1464 | int ssl_major, ssl_minor; | |
1465 | int i, n; | |
1466 | SSL3_RECORD *rr; | |
1467 | unsigned char *p = NULL; | |
1468 | unsigned short version; | |
1469 | DTLS1_BITMAP *bitmap; | |
1470 | unsigned int is_next_epoch; | |
1471 | ||
1472 | rr = RECORD_LAYER_get_rrec(&s->rlayer); | |
1473 | ||
738ad946 | 1474 | again: |
fe589e61 MC |
1475 | /* |
1476 | * The epoch may have changed. If so, process all the pending records. | |
1477 | * This is a non-blocking operation. | |
1478 | */ | |
1fb9fdc3 | 1479 | if (!dtls1_process_buffered_records(s)) |
fe589e61 MC |
1480 | return -1; |
1481 | ||
1482 | /* if we're renegotiating, then there may be buffered records */ | |
1483 | if (dtls1_get_processed_record(s)) | |
1484 | return 1; | |
1485 | ||
1486 | /* get something from the wire */ | |
738ad946 | 1487 | |
fe589e61 | 1488 | /* check if we have the header */ |
295c3f41 | 1489 | if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || |
7a7048af | 1490 | (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) { |
fe589e61 | 1491 | n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, |
a230b26e | 1492 | SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1); |
fe589e61 MC |
1493 | /* read timeout is handled by dtls1_read_bytes */ |
1494 | if (n <= 0) | |
1495 | return (n); /* error or non-blocking */ | |
1496 | ||
1497 | /* this packet contained a partial record, dump it */ | |
a230b26e EK |
1498 | if (RECORD_LAYER_get_packet_length(&s->rlayer) != |
1499 | DTLS1_RT_HEADER_LENGTH) { | |
7a7048af | 1500 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1501 | goto again; |
1502 | } | |
1503 | ||
295c3f41 | 1504 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); |
fe589e61 | 1505 | |
7a7048af | 1506 | p = RECORD_LAYER_get_packet(&s->rlayer); |
fe589e61 MC |
1507 | |
1508 | if (s->msg_callback) | |
1509 | s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, | |
1510 | s, s->msg_callback_arg); | |
1511 | ||
1512 | /* Pull apart the header into the DTLS1_RECORD */ | |
1513 | rr->type = *(p++); | |
1514 | ssl_major = *(p++); | |
1515 | ssl_minor = *(p++); | |
1516 | version = (ssl_major << 8) | ssl_minor; | |
1517 | ||
1518 | /* sequence number is 64 bits, with top 2 bytes = epoch */ | |
1519 | n2s(p, rr->epoch); | |
1520 | ||
de07f311 | 1521 | memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6); |
fe589e61 MC |
1522 | p += 6; |
1523 | ||
1524 | n2s(p, rr->length); | |
1525 | ||
1526 | /* Lets check version */ | |
1527 | if (!s->first_packet) { | |
1528 | if (version != s->version) { | |
1529 | /* unexpected version, silently discard */ | |
1530 | rr->length = 0; | |
7a7048af | 1531 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1532 | goto again; |
1533 | } | |
1534 | } | |
1535 | ||
1536 | if ((version & 0xff00) != (s->version & 0xff00)) { | |
1537 | /* wrong version, silently discard record */ | |
1538 | rr->length = 0; | |
7a7048af | 1539 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1540 | goto again; |
1541 | } | |
1542 | ||
1543 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { | |
1544 | /* record too long, silently discard it */ | |
1545 | rr->length = 0; | |
7a7048af | 1546 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1547 | goto again; |
1548 | } | |
1549 | ||
295c3f41 | 1550 | /* now s->rlayer.rstate == SSL_ST_READ_BODY */ |
fe589e61 MC |
1551 | } |
1552 | ||
295c3f41 | 1553 | /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */ |
fe589e61 | 1554 | |
7a7048af MC |
1555 | if (rr->length > |
1556 | RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) { | |
fe589e61 MC |
1557 | /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ |
1558 | i = rr->length; | |
94777c9c | 1559 | n = ssl3_read_n(s, i, i, 1, 1); |
fe589e61 MC |
1560 | /* this packet contained a partial record, dump it */ |
1561 | if (n != i) { | |
1562 | rr->length = 0; | |
7a7048af | 1563 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1564 | goto again; |
1565 | } | |
1566 | ||
1567 | /* | |
1568 | * now n == rr->length, and s->packet_length == | |
1569 | * DTLS1_RT_HEADER_LENGTH + rr->length | |
1570 | */ | |
1571 | } | |
295c3f41 MC |
1572 | /* set state for later operations */ |
1573 | RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); | |
fe589e61 MC |
1574 | |
1575 | /* match epochs. NULL means the packet is dropped on the floor */ | |
1576 | bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); | |
1577 | if (bitmap == NULL) { | |
1578 | rr->length = 0; | |
a230b26e | 1579 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1580 | goto again; /* get another record */ |
1581 | } | |
1582 | #ifndef OPENSSL_NO_SCTP | |
1583 | /* Only do replay check if no SCTP bio */ | |
1584 | if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { | |
1585 | #endif | |
912c89c5 | 1586 | /* Check whether this is a repeat, or aged record. */ |
1fb9fdc3 MC |
1587 | /* |
1588 | * TODO: Does it make sense to have replay protection in epoch 0 where | |
1589 | * we have no integrity negotiated yet? | |
1590 | */ | |
912c89c5 | 1591 | if (!dtls1_record_replay_check(s, bitmap)) { |
fe589e61 | 1592 | rr->length = 0; |
7a7048af | 1593 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1594 | goto again; /* get another record */ |
1595 | } | |
1596 | #ifndef OPENSSL_NO_SCTP | |
1597 | } | |
1598 | #endif | |
1599 | ||
1600 | /* just read a 0 length packet */ | |
1601 | if (rr->length == 0) | |
1602 | goto again; | |
1603 | ||
1604 | /* | |
1605 | * If this record is from the next epoch (either HM or ALERT), and a | |
1606 | * handshake is currently in progress, buffer it since it cannot be | |
912c89c5 | 1607 | * processed at this time. |
fe589e61 MC |
1608 | */ |
1609 | if (is_next_epoch) { | |
024f543c | 1610 | if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) { |
fe589e61 | 1611 | if (dtls1_buffer_record |
cb2ce7ab | 1612 | (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)), |
a230b26e | 1613 | rr->seq_num) < 0) |
fe589e61 | 1614 | return -1; |
fe589e61 MC |
1615 | } |
1616 | rr->length = 0; | |
7a7048af | 1617 | RECORD_LAYER_reset_packet_length(&s->rlayer); |
fe589e61 MC |
1618 | goto again; |
1619 | } | |
1620 | ||
1fb9fdc3 | 1621 | if (!dtls1_process_record(s, bitmap)) { |
fe589e61 | 1622 | rr->length = 0; |
a230b26e | 1623 | RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ |
fe589e61 MC |
1624 | goto again; /* get another record */ |
1625 | } | |
fe589e61 MC |
1626 | |
1627 | return (1); | |
1628 | ||
1629 | } |