Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 1 | /* DTLS implementation written by Nagendra Modadugu |
| 2 | * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */ |
| 3 | /* ==================================================================== |
| 4 | * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * |
| 18 | * 3. All advertising materials mentioning features or use of this |
| 19 | * software must display the following acknowledgment: |
| 20 | * "This product includes software developed by the OpenSSL Project |
| 21 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| 22 | * |
| 23 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| 24 | * endorse or promote products derived from this software without |
| 25 | * prior written permission. For written permission, please contact |
| 26 | * openssl-core@openssl.org. |
| 27 | * |
| 28 | * 5. Products derived from this software may not be called "OpenSSL" |
| 29 | * nor may "OpenSSL" appear in their names without prior written |
| 30 | * permission of the OpenSSL Project. |
| 31 | * |
| 32 | * 6. Redistributions of any form whatsoever must retain the following |
| 33 | * acknowledgment: |
| 34 | * "This product includes software developed by the OpenSSL Project |
| 35 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| 36 | * |
| 37 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| 38 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 39 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 40 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| 41 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 42 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 43 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 44 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 45 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 46 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 47 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 48 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 49 | * ==================================================================== |
| 50 | * |
| 51 | * This product includes cryptographic software written by Eric Young |
| 52 | * (eay@cryptsoft.com). This product includes software written by Tim |
| 53 | * Hudson (tjh@cryptsoft.com). |
| 54 | * |
| 55 | */ |
| 56 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 57 | * All rights reserved. |
| 58 | * |
| 59 | * This package is an SSL implementation written |
| 60 | * by Eric Young (eay@cryptsoft.com). |
| 61 | * The implementation was written so as to conform with Netscapes SSL. |
| 62 | * |
| 63 | * This library is free for commercial and non-commercial use as long as |
| 64 | * the following conditions are aheared to. The following conditions |
| 65 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 66 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 67 | * included with this distribution is covered by the same copyright terms |
| 68 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 69 | * |
| 70 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 71 | * the code are not to be removed. |
| 72 | * If this package is used in a product, Eric Young should be given attribution |
| 73 | * as the author of the parts of the library used. |
| 74 | * This can be in the form of a textual message at program startup or |
| 75 | * in documentation (online or textual) provided with the package. |
| 76 | * |
| 77 | * Redistribution and use in source and binary forms, with or without |
| 78 | * modification, are permitted provided that the following conditions |
| 79 | * are met: |
| 80 | * 1. Redistributions of source code must retain the copyright |
| 81 | * notice, this list of conditions and the following disclaimer. |
| 82 | * 2. Redistributions in binary form must reproduce the above copyright |
| 83 | * notice, this list of conditions and the following disclaimer in the |
| 84 | * documentation and/or other materials provided with the distribution. |
| 85 | * 3. All advertising materials mentioning features or use of this software |
| 86 | * must display the following acknowledgement: |
| 87 | * "This product includes cryptographic software written by |
| 88 | * Eric Young (eay@cryptsoft.com)" |
| 89 | * The word 'cryptographic' can be left out if the rouines from the library |
| 90 | * being used are not cryptographic related :-). |
| 91 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 92 | * the apps directory (application code) you must include an acknowledgement: |
| 93 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 94 | * |
| 95 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 96 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 97 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 98 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 99 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 100 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 101 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 102 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 103 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 104 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 105 | * SUCH DAMAGE. |
| 106 | * |
| 107 | * The licence and distribution terms for any publically available version or |
| 108 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 109 | * copied and put under another distribution licence |
| 110 | * [including the GNU Public Licence.] */ |
| 111 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 112 | #include <assert.h> |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 113 | #include <stdio.h> |
| 114 | #include <string.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 115 | |
| 116 | #include <openssl/buf.h> |
| 117 | #include <openssl/mem.h> |
| 118 | #include <openssl/evp.h> |
| 119 | #include <openssl/err.h> |
| 120 | #include <openssl/rand.h> |
| 121 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 122 | #include "internal.h" |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 123 | |
| 124 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 125 | /* mod 128 saturating subtract of two 64-bit values in big-endian order */ |
| 126 | static int satsub64be(const uint8_t *v1, const uint8_t *v2) { |
| 127 | int ret, sat, brw, i; |
| 128 | |
| 129 | if (sizeof(long) == 8) { |
| 130 | do { |
| 131 | const union { |
| 132 | long one; |
| 133 | char little; |
| 134 | } is_endian = {1}; |
| 135 | long l; |
| 136 | |
| 137 | if (is_endian.little) { |
| 138 | break; |
| 139 | } |
| 140 | /* not reached on little-endians */ |
| 141 | /* following test is redundant, because input is |
| 142 | * always aligned, but I take no chances... */ |
| 143 | if (((size_t)v1 | (size_t)v2) & 0x7) { |
| 144 | break; |
| 145 | } |
| 146 | |
| 147 | l = *((long *)v1); |
| 148 | l -= *((long *)v2); |
| 149 | if (l > 128) { |
| 150 | return 128; |
| 151 | } else if (l < -128) { |
| 152 | return -128; |
| 153 | } else { |
| 154 | return (int)l; |
| 155 | } |
| 156 | } while (0); |
| 157 | } |
| 158 | |
| 159 | ret = (int)v1[7] - (int)v2[7]; |
| 160 | sat = 0; |
| 161 | brw = ret >> 8; /* brw is either 0 or -1 */ |
| 162 | if (ret & 0x80) { |
| 163 | for (i = 6; i >= 0; i--) { |
| 164 | brw += (int)v1[i] - (int)v2[i]; |
| 165 | sat |= ~brw; |
| 166 | brw >>= 8; |
| 167 | } |
| 168 | } else { |
| 169 | for (i = 6; i >= 0; i--) { |
| 170 | brw += (int)v1[i] - (int)v2[i]; |
| 171 | sat |= brw; |
| 172 | brw >>= 8; |
| 173 | } |
| 174 | } |
| 175 | brw <<= 8; /* brw is either 0 or -256 */ |
| 176 | |
| 177 | if (sat & 0xff) { |
| 178 | return brw | 0x80; |
| 179 | } else { |
| 180 | return brw + (ret & 0xFF); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap); |
| 185 | static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap); |
| 186 | static int dtls1_process_record(SSL *s); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 187 | static int do_dtls1_write(SSL *s, int type, const uint8_t *buf, |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 188 | unsigned int len, enum dtls1_use_epoch_t use_epoch); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 189 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 190 | static int dtls1_process_record(SSL *s) { |
| 191 | int al; |
| 192 | SSL3_RECORD *rr = &s->s3->rrec; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 193 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 194 | /* check is not needed I believe */ |
| 195 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { |
| 196 | al = SSL_AD_RECORD_OVERFLOW; |
| 197 | OPENSSL_PUT_ERROR(SSL, dtls1_process_record, |
| 198 | SSL_R_ENCRYPTED_LENGTH_TOO_LONG); |
| 199 | goto f_err; |
| 200 | } |
| 201 | |
| 202 | /* |rr->data| points to |rr->length| bytes of ciphertext in |s->packet|. */ |
| 203 | rr->data = &s->packet[DTLS1_RT_HEADER_LENGTH]; |
| 204 | |
| 205 | uint8_t seq[8]; |
| 206 | seq[0] = rr->epoch >> 8; |
| 207 | seq[1] = rr->epoch & 0xff; |
| 208 | memcpy(&seq[2], &rr->seq_num[2], 6); |
| 209 | |
| 210 | /* Decrypt the packet in-place. Note it is important that |SSL_AEAD_CTX_open| |
| 211 | * not write beyond |rr->length|. There may be another record in the packet. |
| 212 | * |
| 213 | * TODO(davidben): This assumes |s->version| is the same as the record-layer |
| 214 | * version which isn't always true, but it only differs with the NULL cipher |
| 215 | * which ignores the parameter. */ |
| 216 | size_t plaintext_len; |
| 217 | if (!SSL_AEAD_CTX_open(s->aead_read_ctx, rr->data, &plaintext_len, rr->length, |
| 218 | rr->type, s->version, seq, rr->data, rr->length)) { |
| 219 | /* Bad packets are silently dropped in DTLS. Clear the error queue of any |
| 220 | * errors decryption may have added. */ |
| 221 | ERR_clear_error(); |
| 222 | rr->length = 0; |
| 223 | s->packet_length = 0; |
| 224 | goto err; |
| 225 | } |
| 226 | |
| 227 | if (plaintext_len > SSL3_RT_MAX_PLAIN_LENGTH) { |
| 228 | al = SSL_AD_RECORD_OVERFLOW; |
| 229 | OPENSSL_PUT_ERROR(SSL, dtls1_process_record, SSL_R_DATA_LENGTH_TOO_LONG); |
| 230 | goto f_err; |
| 231 | } |
| 232 | assert(plaintext_len < (1u << 16)); |
| 233 | rr->length = plaintext_len; |
| 234 | |
| 235 | rr->off = 0; |
| 236 | /* So at this point the following is true |
| 237 | * ssl->s3->rrec.type is the type of record |
| 238 | * ssl->s3->rrec.length == number of bytes in record |
| 239 | * ssl->s3->rrec.off == offset to first valid byte |
| 240 | * ssl->s3->rrec.data == the first byte of the record body. */ |
| 241 | |
| 242 | /* we have pulled in a full packet so zero things */ |
| 243 | s->packet_length = 0; |
| 244 | return 1; |
| 245 | |
| 246 | f_err: |
| 247 | ssl3_send_alert(s, SSL3_AL_FATAL, al); |
| 248 | |
| 249 | err: |
| 250 | return 0; |
| 251 | } |
| 252 | |
| 253 | /* Call this to get a new input record. |
| 254 | * It will return <= 0 if more data is needed, normally due to an error |
| 255 | * or non-blocking IO. |
| 256 | * When it finishes, one packet has been decoded and can be found in |
| 257 | * ssl->s3->rrec.type - is the type of record |
| 258 | * ssl->s3->rrec.data, - data |
| 259 | * ssl->s3->rrec.length, - number of bytes |
| 260 | * |
| 261 | * used only by dtls1_read_bytes */ |
| 262 | int dtls1_get_record(SSL *s) { |
| 263 | uint8_t ssl_major, ssl_minor; |
| 264 | int n; |
| 265 | SSL3_RECORD *rr; |
| 266 | uint8_t *p = NULL; |
| 267 | uint16_t version; |
| 268 | |
| 269 | rr = &(s->s3->rrec); |
| 270 | |
| 271 | /* get something from the wire */ |
| 272 | again: |
| 273 | /* check if we have the header */ |
| 274 | if ((s->rstate != SSL_ST_READ_BODY) || |
| 275 | (s->packet_length < DTLS1_RT_HEADER_LENGTH)) { |
| 276 | n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, 0); |
| 277 | /* read timeout is handled by dtls1_read_bytes */ |
| 278 | if (n <= 0) { |
| 279 | return n; /* error or non-blocking */ |
| 280 | } |
| 281 | |
| 282 | /* this packet contained a partial record, dump it */ |
| 283 | if (s->packet_length != DTLS1_RT_HEADER_LENGTH) { |
| 284 | s->packet_length = 0; |
| 285 | goto again; |
| 286 | } |
| 287 | |
| 288 | s->rstate = SSL_ST_READ_BODY; |
| 289 | |
| 290 | p = s->packet; |
| 291 | |
| 292 | if (s->msg_callback) { |
| 293 | s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, |
| 294 | s->msg_callback_arg); |
| 295 | } |
| 296 | |
| 297 | /* Pull apart the header into the DTLS1_RECORD */ |
| 298 | rr->type = *(p++); |
| 299 | ssl_major = *(p++); |
| 300 | ssl_minor = *(p++); |
| 301 | version = (((uint16_t)ssl_major) << 8) | ssl_minor; |
| 302 | |
| 303 | /* sequence number is 64 bits, with top 2 bytes = epoch */ |
| 304 | n2s(p, rr->epoch); |
| 305 | |
| 306 | memcpy(&(s->s3->read_sequence[2]), p, 6); |
| 307 | p += 6; |
| 308 | |
| 309 | n2s(p, rr->length); |
| 310 | |
| 311 | /* Lets check version */ |
| 312 | if (s->s3->have_version) { |
| 313 | if (version != s->version) { |
| 314 | /* The record's version doesn't match, so silently drop it. |
| 315 | * |
| 316 | * TODO(davidben): This doesn't work. The DTLS record layer is not |
| 317 | * packet-based, so the remainder of the packet isn't dropped and we |
| 318 | * get a framing error. It's also unclear what it means to silently |
| 319 | * drop a record in a packet containing two records. */ |
| 320 | rr->length = 0; |
| 321 | s->packet_length = 0; |
| 322 | goto again; |
| 323 | } |
| 324 | } |
| 325 | |
| 326 | if ((version & 0xff00) != (s->version & 0xff00)) { |
| 327 | /* wrong version, silently discard record */ |
| 328 | rr->length = 0; |
| 329 | s->packet_length = 0; |
| 330 | goto again; |
| 331 | } |
| 332 | |
| 333 | if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { |
| 334 | /* record too long, silently discard it */ |
| 335 | rr->length = 0; |
| 336 | s->packet_length = 0; |
| 337 | goto again; |
| 338 | } |
| 339 | |
| 340 | /* now s->rstate == SSL_ST_READ_BODY */ |
| 341 | } |
| 342 | |
| 343 | /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ |
| 344 | |
| 345 | if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) { |
| 346 | /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */ |
| 347 | n = ssl3_read_n(s, rr->length, 1); |
| 348 | /* This packet contained a partial record, dump it. */ |
| 349 | if (n != rr->length) { |
| 350 | rr->length = 0; |
| 351 | s->packet_length = 0; |
| 352 | goto again; |
| 353 | } |
| 354 | |
| 355 | /* now n == rr->length, |
| 356 | * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */ |
| 357 | } |
| 358 | s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ |
| 359 | |
| 360 | if (rr->epoch != s->d1->r_epoch) { |
| 361 | /* This record is from the wrong epoch. If it is the next epoch, it could be |
| 362 | * buffered. For simplicity, drop it and expect retransmit to handle it |
| 363 | * later; DTLS is supposed to handle packet loss. */ |
| 364 | rr->length = 0; |
| 365 | s->packet_length = 0; |
Adam Langley | 1e4884f | 2015-09-24 10:57:52 -0700 | [diff] [blame] | 366 | goto again; |
| 367 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 368 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 369 | /* Check whether this is a repeat, or aged record. */ |
| 370 | if (!dtls1_record_replay_check(s, &s->d1->bitmap)) { |
| 371 | rr->length = 0; |
| 372 | s->packet_length = 0; /* dump this record */ |
| 373 | goto again; /* get another record */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 374 | } |
| 375 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 376 | /* just read a 0 length packet */ |
| 377 | if (rr->length == 0) { |
| 378 | goto again; |
| 379 | } |
| 380 | |
| 381 | if (!dtls1_process_record(s)) { |
| 382 | rr->length = 0; |
| 383 | s->packet_length = 0; /* dump this record */ |
| 384 | goto again; /* get another record */ |
| 385 | } |
| 386 | dtls1_record_bitmap_update(s, &s->d1->bitmap); /* Mark receipt of record. */ |
| 387 | |
| 388 | return 1; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 389 | } |
| 390 | |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 391 | int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) { |
| 392 | return dtls1_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek); |
| 393 | } |
| 394 | |
| 395 | void dtls1_read_close_notify(SSL *ssl) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 396 | dtls1_read_bytes(ssl, 0, NULL, 0, 0); |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 397 | } |
| 398 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 399 | /* Return up to 'len' payload bytes received in 'type' records. |
| 400 | * 'type' is one of the following: |
| 401 | * |
| 402 | * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) |
| 403 | * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 404 | * - 0 (during a shutdown, no data has to be returned) |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 405 | * |
| 406 | * If we don't have stored data to work from, read a SSL/TLS record first |
| 407 | * (possibly multiple records if we still don't have anything to return). |
| 408 | * |
| 409 | * This function must handle any surprises the peer may have for us, such as |
| 410 | * Alert records (e.g. close_notify), ChangeCipherSpec records (not really |
| 411 | * a surprise, but handled as if it were), or renegotiation requests. |
| 412 | * Also if record payloads contain fragments too small to process, we store |
| 413 | * them until there is enough for the respective protocol (the record protocol |
| 414 | * may use arbitrary fragmentation and even interleaving): |
| 415 | * Change cipher spec protocol |
| 416 | * just 1 byte needed, no need for keeping anything stored |
| 417 | * Alert protocol |
| 418 | * 2 bytes needed (AlertLevel, AlertDescription) |
| 419 | * Handshake protocol |
| 420 | * 4 bytes needed (HandshakeType, uint24 length) -- we just have |
| 421 | * to detect unexpected Client Hello and Hello Request messages |
| 422 | * here, anything else is handled by higher layers |
| 423 | * Application data protocol |
| 424 | * none of our business |
| 425 | */ |
| 426 | int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 427 | int al, i, ret; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 428 | unsigned int n; |
| 429 | SSL3_RECORD *rr; |
| 430 | void (*cb)(const SSL *ssl, int type2, int val) = NULL; |
| 431 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 432 | /* XXX: check what the second '&& type' is about */ |
| 433 | if ((type && (type != SSL3_RT_APPLICATION_DATA) && |
| 434 | (type != SSL3_RT_HANDSHAKE) && type) || |
| 435 | (peek && (type != SSL3_RT_APPLICATION_DATA))) { |
| 436 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, ERR_R_INTERNAL_ERROR); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 437 | return -1; |
| 438 | } |
| 439 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 440 | if (!s->in_handshake && SSL_in_init(s)) { |
| 441 | /* type == SSL3_RT_APPLICATION_DATA */ |
| 442 | i = s->handshake_func(s); |
| 443 | if (i < 0) { |
| 444 | return i; |
| 445 | } |
| 446 | if (i == 0) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 447 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_SSL_HANDSHAKE_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 448 | return -1; |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | start: |
| 453 | s->rwstate = SSL_NOTHING; |
| 454 | |
| 455 | /* s->s3->rrec.type - is the type of record |
| 456 | * s->s3->rrec.data - data |
| 457 | * s->s3->rrec.off - offset into 'data' for next read |
| 458 | * s->s3->rrec.length - number of bytes. */ |
| 459 | rr = &s->s3->rrec; |
| 460 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 461 | /* Check for timeout */ |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 462 | if (DTLSv1_handle_timeout(s) > 0) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 463 | goto start; |
| 464 | } |
| 465 | |
| 466 | /* get new packet if necessary */ |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 467 | if (rr->length == 0 || s->rstate == SSL_ST_READ_BODY) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 468 | ret = dtls1_get_record(s); |
| 469 | if (ret <= 0) { |
| 470 | ret = dtls1_read_failed(s, ret); |
| 471 | /* anything other than a timeout is an error */ |
| 472 | if (ret <= 0) { |
| 473 | return ret; |
| 474 | } else { |
| 475 | goto start; |
| 476 | } |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | /* we now have a packet which can be read and processed */ |
| 481 | |
| 482 | /* |change_cipher_spec is set when we receive a ChangeCipherSpec and reset by |
| 483 | * ssl3_get_finished. */ |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 484 | if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE && |
| 485 | rr->type != SSL3_RT_ALERT) { |
| 486 | /* We now have an unexpected record between CCS and Finished. Most likely |
| 487 | * the packets were reordered on their way. DTLS is unreliable, so drop the |
| 488 | * packet and expect the peer to retransmit. */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 489 | rr->length = 0; |
| 490 | goto start; |
| 491 | } |
| 492 | |
| 493 | /* If the other end has shut down, throw anything we read away (even in |
| 494 | * 'peek' mode) */ |
| 495 | if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { |
| 496 | rr->length = 0; |
| 497 | s->rwstate = SSL_NOTHING; |
| 498 | return 0; |
| 499 | } |
| 500 | |
| 501 | |
| 502 | if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ |
| 503 | /* make sure that we are not getting application data when we |
| 504 | * are doing a handshake for the first time */ |
| 505 | if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && |
| 506 | (s->aead_read_ctx == NULL)) { |
| 507 | /* TODO(davidben): Is this check redundant with the handshake_func |
| 508 | * check? */ |
| 509 | al = SSL_AD_UNEXPECTED_MESSAGE; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 510 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_APP_DATA_IN_HANDSHAKE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 511 | goto f_err; |
| 512 | } |
| 513 | |
| 514 | if (len <= 0) { |
| 515 | return len; |
| 516 | } |
| 517 | |
| 518 | if ((unsigned int)len > rr->length) { |
| 519 | n = rr->length; |
| 520 | } else { |
| 521 | n = (unsigned int)len; |
| 522 | } |
| 523 | |
| 524 | memcpy(buf, &(rr->data[rr->off]), n); |
| 525 | if (!peek) { |
| 526 | rr->length -= n; |
| 527 | rr->off += n; |
| 528 | if (rr->length == 0) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 529 | s->rstate = SSL_ST_READ_HEADER; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 530 | rr->off = 0; |
| 531 | } |
| 532 | } |
| 533 | |
| 534 | return n; |
| 535 | } |
| 536 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 537 | /* If we get here, then type != rr->type. */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 538 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 539 | /* If an alert record, process one alert out of the record. Note that we allow |
| 540 | * a single record to contain multiple alerts. */ |
| 541 | if (rr->type == SSL3_RT_ALERT) { |
| 542 | /* Alerts may not be fragmented. */ |
| 543 | if (rr->length < 2) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 544 | al = SSL_AD_DECODE_ERROR; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 545 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_ALERT); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 546 | goto f_err; |
| 547 | } |
| 548 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 549 | if (s->msg_callback) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 550 | s->msg_callback(0, s->version, SSL3_RT_ALERT, &rr->data[rr->off], 2, s, |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 551 | s->msg_callback_arg); |
| 552 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 553 | const uint8_t alert_level = rr->data[rr->off++]; |
| 554 | const uint8_t alert_descr = rr->data[rr->off++]; |
| 555 | rr->length -= 2; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 556 | |
| 557 | if (s->info_callback != NULL) { |
| 558 | cb = s->info_callback; |
| 559 | } else if (s->ctx->info_callback != NULL) { |
| 560 | cb = s->ctx->info_callback; |
| 561 | } |
| 562 | |
| 563 | if (cb != NULL) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 564 | uint16_t alert = (alert_level << 8) | alert_descr; |
| 565 | cb(s, SSL_CB_READ_ALERT, alert); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 566 | } |
| 567 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 568 | if (alert_level == SSL3_AL_WARNING) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 569 | s->s3->warn_alert = alert_descr; |
| 570 | if (alert_descr == SSL_AD_CLOSE_NOTIFY) { |
| 571 | s->shutdown |= SSL_RECEIVED_SHUTDOWN; |
| 572 | return 0; |
| 573 | } |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 574 | } else if (alert_level == SSL3_AL_FATAL) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 575 | char tmp[16]; |
| 576 | |
| 577 | s->rwstate = SSL_NOTHING; |
| 578 | s->s3->fatal_alert = alert_descr; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 579 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, |
| 580 | SSL_AD_REASON_OFFSET + alert_descr); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 581 | BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); |
| 582 | ERR_add_error_data(2, "SSL alert number ", tmp); |
| 583 | s->shutdown |= SSL_RECEIVED_SHUTDOWN; |
| 584 | SSL_CTX_remove_session(s->ctx, s->session); |
| 585 | return 0; |
| 586 | } else { |
| 587 | al = SSL_AD_ILLEGAL_PARAMETER; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 588 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNKNOWN_ALERT_TYPE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 589 | goto f_err; |
| 590 | } |
| 591 | |
| 592 | goto start; |
| 593 | } |
| 594 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 595 | if (s->shutdown & SSL_SENT_SHUTDOWN) { |
| 596 | /* but we have not received a shutdown */ |
| 597 | s->rwstate = SSL_NOTHING; |
| 598 | rr->length = 0; |
| 599 | return 0; |
| 600 | } |
| 601 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 602 | if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 603 | /* 'Change Cipher Spec' is just a single byte, so we know exactly what the |
| 604 | * record payload has to look like */ |
| 605 | if (rr->length != 1 || rr->off != 0 || rr->data[0] != SSL3_MT_CCS) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 606 | al = SSL_AD_ILLEGAL_PARAMETER; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 607 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_CHANGE_CIPHER_SPEC); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 608 | goto f_err; |
| 609 | } |
| 610 | |
| 611 | rr->length = 0; |
| 612 | |
| 613 | if (s->msg_callback) { |
| 614 | s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, |
| 615 | s->msg_callback_arg); |
| 616 | } |
| 617 | |
| 618 | /* We can't process a CCS now, because previous handshake |
| 619 | * messages are still missing, so just drop it. |
| 620 | */ |
| 621 | if (!s->d1->change_cipher_spec_ok) { |
| 622 | goto start; |
| 623 | } |
| 624 | |
| 625 | s->d1->change_cipher_spec_ok = 0; |
| 626 | |
| 627 | s->s3->change_cipher_spec = 1; |
| 628 | if (!ssl3_do_change_cipher_spec(s)) { |
| 629 | goto err; |
| 630 | } |
| 631 | |
| 632 | /* do this whenever CCS is processed */ |
| 633 | dtls1_reset_seq_numbers(s, SSL3_CC_READ); |
| 634 | |
| 635 | goto start; |
| 636 | } |
| 637 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 638 | /* Unexpected handshake message. It may be a retransmitted Finished (the only |
| 639 | * post-CCS message). Otherwise, it's a pre-CCS handshake message from an |
| 640 | * unsupported renegotiation attempt. */ |
| 641 | if (rr->type == SSL3_RT_HANDSHAKE && !s->in_handshake) { |
| 642 | if (rr->length < DTLS1_HM_HEADER_LENGTH) { |
| 643 | al = SSL_AD_DECODE_ERROR; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 644 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_BAD_HANDSHAKE_RECORD); |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 645 | goto f_err; |
| 646 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 647 | struct hm_header_st msg_hdr; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 648 | dtls1_get_message_header(&rr->data[rr->off], &msg_hdr); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 649 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 650 | /* Ignore a stray Finished from the previous handshake. */ |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 651 | if (msg_hdr.type == SSL3_MT_FINISHED) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 652 | if (msg_hdr.frag_off == 0) { |
| 653 | /* Retransmit our last flight of messages. If the peer sends the second |
| 654 | * Finished, they may not have received ours. Only do this for the |
| 655 | * first fragment, in case the Finished was fragmented. */ |
| 656 | if (dtls1_check_timeout_num(s) < 0) { |
| 657 | return -1; |
| 658 | } |
| 659 | |
| 660 | dtls1_retransmit_buffered_messages(s); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 661 | } |
| 662 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 663 | rr->length = 0; |
| 664 | goto start; |
| 665 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 666 | } |
| 667 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 668 | /* We already handled these. */ |
| 669 | assert(rr->type != SSL3_RT_CHANGE_CIPHER_SPEC && rr->type != SSL3_RT_ALERT); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 670 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 671 | al = SSL_AD_UNEXPECTED_MESSAGE; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 672 | OPENSSL_PUT_ERROR(SSL, dtls1_read_bytes, SSL_R_UNEXPECTED_RECORD); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 673 | |
| 674 | f_err: |
| 675 | ssl3_send_alert(s, SSL3_AL_FATAL, al); |
| 676 | err: |
| 677 | return -1; |
| 678 | } |
| 679 | |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 680 | int dtls1_write_app_data(SSL *s, const void *buf_, int len) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 681 | int i; |
| 682 | |
| 683 | if (SSL_in_init(s) && !s->in_handshake) { |
| 684 | i = s->handshake_func(s); |
| 685 | if (i < 0) { |
| 686 | return i; |
| 687 | } |
| 688 | if (i == 0) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 689 | OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data, SSL_R_SSL_HANDSHAKE_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 690 | return -1; |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | if (len > SSL3_RT_MAX_PLAIN_LENGTH) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 695 | OPENSSL_PUT_ERROR(SSL, dtls1_write_app_data, SSL_R_DTLS_MESSAGE_TOO_BIG); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 696 | return -1; |
| 697 | } |
| 698 | |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 699 | i = dtls1_write_bytes(s, SSL3_RT_APPLICATION_DATA, buf_, len, |
| 700 | dtls1_use_current_epoch); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 701 | return i; |
| 702 | } |
| 703 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 704 | /* Call this to write data in records of type 'type' It will return <= 0 if not |
| 705 | * all data has been sent or non-blocking IO. */ |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 706 | int dtls1_write_bytes(SSL *s, int type, const void *buf, int len, |
| 707 | enum dtls1_use_epoch_t use_epoch) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 708 | int i; |
| 709 | |
| 710 | assert(len <= SSL3_RT_MAX_PLAIN_LENGTH); |
| 711 | s->rwstate = SSL_NOTHING; |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 712 | i = do_dtls1_write(s, type, buf, len, use_epoch); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 713 | return i; |
| 714 | } |
| 715 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 716 | /* dtls1_seal_record seals a new record of type |type| and plaintext |in| and |
| 717 | * writes it to |out|. At most |max_out| bytes will be written. It returns one |
| 718 | * on success and zero on error. On success, it updates the write sequence |
| 719 | * number. */ |
| 720 | static int dtls1_seal_record(SSL *s, uint8_t *out, size_t *out_len, |
| 721 | size_t max_out, uint8_t type, const uint8_t *in, |
| 722 | size_t in_len, enum dtls1_use_epoch_t use_epoch) { |
| 723 | if (max_out < DTLS1_RT_HEADER_LENGTH) { |
| 724 | OPENSSL_PUT_ERROR(SSL, dtls1_seal_record, SSL_R_BUFFER_TOO_SMALL); |
| 725 | return 0; |
| 726 | } |
| 727 | |
| 728 | /* Determine the parameters for the current epoch. */ |
| 729 | uint16_t epoch = s->d1->w_epoch; |
| 730 | SSL_AEAD_CTX *aead = s->aead_write_ctx; |
| 731 | uint8_t *seq = s->s3->write_sequence; |
| 732 | if (use_epoch == dtls1_use_previous_epoch) { |
| 733 | /* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1 |
| 734 | * (negotiated cipher) exist. */ |
| 735 | assert(s->d1->w_epoch == 1); |
| 736 | epoch = s->d1->w_epoch - 1; |
| 737 | aead = NULL; |
| 738 | seq = s->d1->last_write_sequence; |
| 739 | } |
| 740 | |
| 741 | out[0] = type; |
| 742 | |
| 743 | uint16_t wire_version = s->s3->have_version ? s->version : DTLS1_VERSION; |
| 744 | out[1] = wire_version >> 8; |
| 745 | out[2] = wire_version & 0xff; |
| 746 | |
| 747 | out[3] = epoch >> 8; |
| 748 | out[4] = epoch & 0xff; |
| 749 | memcpy(&out[5], &seq[2], 6); |
| 750 | |
| 751 | size_t ciphertext_len; |
| 752 | if (!SSL_AEAD_CTX_seal(aead, out + DTLS1_RT_HEADER_LENGTH, &ciphertext_len, |
| 753 | max_out - DTLS1_RT_HEADER_LENGTH, type, wire_version, |
| 754 | &out[3] /* seq */, in, in_len) || |
| 755 | !ssl3_record_sequence_update(&seq[2], 6)) { |
| 756 | return 0; |
| 757 | } |
| 758 | |
| 759 | if (ciphertext_len >= 1 << 16) { |
| 760 | OPENSSL_PUT_ERROR(SSL, dtls1_seal_record, ERR_R_OVERFLOW); |
| 761 | return 0; |
| 762 | } |
| 763 | out[11] = ciphertext_len >> 8; |
| 764 | out[12] = ciphertext_len & 0xff; |
| 765 | |
| 766 | *out_len = DTLS1_RT_HEADER_LENGTH + ciphertext_len; |
| 767 | |
| 768 | if (s->msg_callback) { |
| 769 | s->msg_callback(1 /* write */, 0, SSL3_RT_HEADER, out, |
| 770 | DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); |
| 771 | } |
| 772 | |
| 773 | return 1; |
| 774 | } |
| 775 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 776 | static int do_dtls1_write(SSL *s, int type, const uint8_t *buf, |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 777 | unsigned int len, enum dtls1_use_epoch_t use_epoch) { |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 778 | SSL3_BUFFER *wb = &s->s3->wbuf; |
| 779 | |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 780 | /* ssl3_write_pending drops the write if |BIO_write| fails in DTLS, so there |
| 781 | * is never pending data. */ |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 782 | assert(s->s3->wbuf.left == 0); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 783 | |
| 784 | /* If we have an alert to send, lets send it */ |
| 785 | if (s->s3->alert_dispatch) { |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 786 | int ret = s->method->ssl_dispatch_alert(s); |
| 787 | if (ret <= 0) { |
| 788 | return ret; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 789 | } |
| 790 | /* if it went, fall through and send more stuff */ |
| 791 | } |
| 792 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 793 | if (wb->buf == NULL && !ssl3_setup_write_buffer(s)) { |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 794 | return -1; |
| 795 | } |
| 796 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 797 | if (len == 0) { |
| 798 | return 0; |
| 799 | } |
| 800 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 801 | /* Align the output so the ciphertext is aligned to |SSL3_ALIGN_PAYLOAD|. */ |
| 802 | uintptr_t align = (uintptr_t)wb->buf + DTLS1_RT_HEADER_LENGTH; |
| 803 | align = (0 - align) & (SSL3_ALIGN_PAYLOAD - 1); |
| 804 | uint8_t *out = wb->buf + align; |
| 805 | wb->offset = align; |
| 806 | size_t max_out = wb->len - wb->offset; |
| 807 | |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 808 | size_t ciphertext_len; |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 809 | if (!dtls1_seal_record(s, out, &ciphertext_len, max_out, type, buf, len, |
| 810 | use_epoch)) { |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 811 | return -1; |
| 812 | } |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 813 | |
| 814 | /* now let's set up wb */ |
| 815 | wb->left = ciphertext_len; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 816 | |
| 817 | /* memorize arguments so that ssl3_write_pending can detect bad write retries |
| 818 | * later */ |
| 819 | s->s3->wpend_tot = len; |
| 820 | s->s3->wpend_buf = buf; |
| 821 | s->s3->wpend_type = type; |
| 822 | s->s3->wpend_ret = len; |
| 823 | |
| 824 | /* we now just need to write the buffer */ |
| 825 | return ssl3_write_pending(s, type, buf, len); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 826 | } |
| 827 | |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame^] | 828 | static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap) { |
| 829 | int cmp; |
| 830 | unsigned int shift; |
| 831 | const uint8_t *seq = s->s3->read_sequence; |
| 832 | |
| 833 | cmp = satsub64be(seq, bitmap->max_seq_num); |
| 834 | if (cmp > 0) { |
| 835 | memcpy(s->s3->rrec.seq_num, seq, 8); |
| 836 | return 1; /* this record in new */ |
| 837 | } |
| 838 | shift = -cmp; |
| 839 | if (shift >= sizeof(bitmap->map) * 8) { |
| 840 | return 0; /* stale, outside the window */ |
| 841 | } else if (bitmap->map & (((uint64_t)1) << shift)) { |
| 842 | return 0; /* record previously received */ |
| 843 | } |
| 844 | |
| 845 | memcpy(s->s3->rrec.seq_num, seq, 8); |
| 846 | return 1; |
| 847 | } |
| 848 | |
| 849 | static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap) { |
| 850 | int cmp; |
| 851 | unsigned int shift; |
| 852 | const uint8_t *seq = s->s3->read_sequence; |
| 853 | |
| 854 | cmp = satsub64be(seq, bitmap->max_seq_num); |
| 855 | if (cmp > 0) { |
| 856 | shift = cmp; |
| 857 | if (shift < sizeof(bitmap->map) * 8) { |
| 858 | bitmap->map <<= shift, bitmap->map |= 1UL; |
| 859 | } else { |
| 860 | bitmap->map = 1UL; |
| 861 | } |
| 862 | memcpy(bitmap->max_seq_num, seq, 8); |
| 863 | } else { |
| 864 | shift = -cmp; |
| 865 | if (shift < sizeof(bitmap->map) * 8) { |
| 866 | bitmap->map |= ((uint64_t)1) << shift; |
| 867 | } |
| 868 | } |
| 869 | } |
| 870 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 871 | int dtls1_dispatch_alert(SSL *s) { |
| 872 | int i, j; |
| 873 | void (*cb)(const SSL *ssl, int type, int val) = NULL; |
| 874 | uint8_t buf[DTLS1_AL_HEADER_LENGTH]; |
| 875 | uint8_t *ptr = &buf[0]; |
| 876 | |
| 877 | s->s3->alert_dispatch = 0; |
| 878 | |
| 879 | memset(buf, 0x00, sizeof(buf)); |
| 880 | *ptr++ = s->s3->send_alert[0]; |
| 881 | *ptr++ = s->s3->send_alert[1]; |
| 882 | |
Adam Langley | f4e4272 | 2015-06-04 17:45:09 -0700 | [diff] [blame] | 883 | i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), |
| 884 | dtls1_use_current_epoch); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 885 | if (i <= 0) { |
| 886 | s->s3->alert_dispatch = 1; |
| 887 | } else { |
| 888 | if (s->s3->send_alert[0] == SSL3_AL_FATAL) { |
| 889 | (void)BIO_flush(s->wbio); |
| 890 | } |
| 891 | |
| 892 | if (s->msg_callback) { |
| 893 | s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, |
| 894 | s->msg_callback_arg); |
| 895 | } |
| 896 | |
| 897 | if (s->info_callback != NULL) { |
| 898 | cb = s->info_callback; |
| 899 | } else if (s->ctx->info_callback != NULL) { |
| 900 | cb = s->ctx->info_callback; |
| 901 | } |
| 902 | |
| 903 | if (cb != NULL) { |
| 904 | j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; |
| 905 | cb(s, SSL_CB_WRITE_ALERT, j); |
| 906 | } |
| 907 | } |
| 908 | |
| 909 | return i; |
| 910 | } |
| 911 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 912 | void dtls1_reset_seq_numbers(SSL *s, int rw) { |
| 913 | uint8_t *seq; |
| 914 | unsigned int seq_bytes = sizeof(s->s3->read_sequence); |
| 915 | |
| 916 | if (rw & SSL3_CC_READ) { |
| 917 | seq = s->s3->read_sequence; |
| 918 | s->d1->r_epoch++; |
Adam Langley | e9ada86 | 2015-05-11 17:20:37 -0700 | [diff] [blame] | 919 | memset(&s->d1->bitmap, 0, sizeof(DTLS1_BITMAP)); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 920 | } else { |
| 921 | seq = s->s3->write_sequence; |
| 922 | memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence)); |
| 923 | s->d1->w_epoch++; |
| 924 | } |
| 925 | |
| 926 | memset(seq, 0x00, seq_bytes); |
| 927 | } |