ssl/packet_locl.h

   1 /*
   2  * Written by Matt Caswell for the OpenSSL project.
   3  */
   4 /* ====================================================================
   5  * Copyright (c) 2015 The OpenSSL Project.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  *
  19  * 3. All advertising materials mentioning features or use of this
  20  *    software must display the following acknowledgment:
  21  *    "This product includes software developed by the OpenSSL Project
  22  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  23  *
  24  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  25  *    endorse or promote products derived from this software without
  26  *    prior written permission. For written permission, please contact
  27  *    openssl-core@openssl.org.
  28  *
  29  * 5. Products derived from this software may not be called "OpenSSL"
  30  *    nor may "OpenSSL" appear in their names without prior written
  31  *    permission of the OpenSSL Project.
  32  *
  33  * 6. Redistributions of any form whatsoever must retain the following
  34  *    acknowledgment:
  35  *    "This product includes software developed by the OpenSSL Project
  36  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  39  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  40  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  41  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  42  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  43  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  44  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  45  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  47  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  48  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  49  * OF THE POSSIBILITY OF SUCH DAMAGE.
  50  * ====================================================================
  51  *
  52  * This product includes cryptographic software written by Eric Young
  53  * (eay@cryptsoft.com).  This product includes software written by Tim
  54  * Hudson (tjh@cryptsoft.com).
  55  *
  56  */
  57
  58 #ifndef HEADER_PACKET_LOCL_H
  59 # define HEADER_PACKET_LOCL_H
  60
  61 # include <string.h>
  62 # include <openssl/bn.h>
  63 # include <openssl/buffer.h>
  64 # include <openssl/crypto.h>
  65 # include <openssl/e_os2.h>
  66
  67 # include "internal/numbers.h"
  68
  69 # ifdef __cplusplus
  70 extern "C" {
  71 # endif
  72
  73 typedef struct {
  74     /* Pointer to where we are currently reading from */
  75     unsigned char *curr;
  76     /* Number of bytes remaining */
  77     size_t remaining;
  78 } PACKET;
  79
  80 /* Internal unchecked shorthand; don't use outside this file. */
  81 static ossl_inline void packet_forward(PACKET *pkt, size_t len)
  82 {
  83     pkt->curr += len;
  84     pkt->remaining -= len;
  85 }
  86
  87 /*
  88  * Returns the number of bytes remaining to be read in the PACKET
  89  */
  90 static ossl_inline size_t PACKET_remaining(const PACKET *pkt)
  91 {
  92     return pkt->remaining;
  93 }
  94
  95 /*
  96  * Returns a pointer to the PACKET's current position.
  97  * For use in non-PACKETized APIs.
  98  * TODO(openssl-team): this should return 'const unsigned char*' but can't
  99  * currently because legacy code passes 'unsigned char*'s around.
 100  */
 101 static ossl_inline unsigned char *PACKET_data(const PACKET *pkt)
 102 {
 103     return pkt->curr;
 104 }
 105
 106 /*
 107  * Initialise a PACKET with |len| bytes held in |buf|. This does not make a
 108  * copy of the data so |buf| must be present for the whole time that the PACKET
 109  * is being used.
 110  */
 111 __owur static ossl_inline int PACKET_buf_init(PACKET *pkt, unsigned char *buf,
 112                                               size_t len)
 113 {
 114     /* Sanity check for negative values. */
 115     if (len > (size_t)(SIZE_MAX / 2))
 116         return 0;
 117
 118     pkt->curr = buf;
 119     pkt->remaining = len;
 120     return 1;
 121 }
 122
 123 /* Initialize a PACKET to hold zero bytes. */
 124 static ossl_inline void PACKET_null_init(PACKET *pkt)
 125 {
 126     pkt->curr = NULL;
 127     pkt->remaining = 0;
 128 }
 129
 130 /*
 131  * Returns 1 if the packet has length |num| and its contents equal the |num|
 132  * bytes read from |ptr|. Returns 0 otherwise (lengths or contents not equal).
 133  * If lengths are equal, performs the comparison in constant time.
 134  */
 135 __owur static ossl_inline int PACKET_equal(const PACKET *pkt, const void *ptr,
 136                                            size_t num)
 137 {
 138     if (PACKET_remaining(pkt) != num)
 139         return 0;
 140     return CRYPTO_memcmp(pkt->curr, ptr, num) == 0;
 141 }
 142
 143 /*
 144  * Peek ahead and initialize |subpkt| with the next |len| bytes read from |pkt|.
 145  * Data is not copied: the |subpkt| packet will share its underlying buffer with
 146  * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
 147  */
 148 __owur static ossl_inline int PACKET_peek_sub_packet(const PACKET *pkt,
 149                                                      PACKET *subpkt,
 150                                                      size_t len)
 151 {
 152     if (PACKET_remaining(pkt) < len)
 153         return 0;
 154
 155     return PACKET_buf_init(subpkt, pkt->curr, len);
 156 }
 157
 158 /*
 159  * Initialize |subpkt| with the next |len| bytes read from |pkt|. Data is not
 160  * copied: the |subpkt| packet will share its underlying buffer with the
 161  * original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
 162  */
 163 __owur static ossl_inline int PACKET_get_sub_packet(PACKET *pkt,
 164                                                     PACKET *subpkt,
 165                                                     size_t len)
 166 {
 167     if (!PACKET_peek_sub_packet(pkt, subpkt, len))
 168         return 0;
 169
 170     packet_forward(pkt, len);
 171
 172     return 1;
 173 }
 174
 175 /*
 176  * Peek ahead at 2 bytes in network order from |pkt| and store the value in
 177  * |*data|
 178  */
 179 __owur static ossl_inline int PACKET_peek_net_2(const PACKET *pkt,
 180                                                 unsigned int *data)
 181 {
 182     if (PACKET_remaining(pkt) < 2)
 183         return 0;
 184
 185     *data = ((unsigned int)(*pkt->curr)) << 8;
 186     *data |= *(pkt->curr + 1);
 187
 188     return 1;
 189 }
 190
 191 /* Equivalent of n2s */
 192 /* Get 2 bytes in network order from |pkt| and store the value in |*data| */
 193 __owur static ossl_inline int PACKET_get_net_2(PACKET *pkt,
 194                                                unsigned int *data)
 195 {
 196     if (!PACKET_peek_net_2(pkt, data))
 197         return 0;
 198
 199     packet_forward(pkt, 2);
 200
 201     return 1;
 202 }
 203
 204 /*
 205  * Peek ahead at 3 bytes in network order from |pkt| and store the value in
 206  * |*data|
 207  */
 208 __owur static ossl_inline int PACKET_peek_net_3(const PACKET *pkt,
 209                                                 unsigned long *data)
 210 {
 211     if (PACKET_remaining(pkt) < 3)
 212         return 0;
 213
 214     *data = ((unsigned long)(*pkt->curr)) << 16;
 215     *data |= ((unsigned long)(*(pkt->curr + 1))) << 8;
 216     *data |= *(pkt->curr + 2);
 217
 218     return 1;
 219 }
 220
 221 /* Equivalent of n2l3 */
 222 /* Get 3 bytes in network order from |pkt| and store the value in |*data| */
 223 __owur static ossl_inline int PACKET_get_net_3(PACKET *pkt,
 224                                                unsigned long *data)
 225 {
 226     if (!PACKET_peek_net_3(pkt, data))
 227         return 0;
 228
 229     packet_forward(pkt, 3);
 230
 231     return 1;
 232 }
 233
 234 /*
 235  * Peek ahead at 4 bytes in network order from |pkt| and store the value in
 236  * |*data|
 237  */
 238 __owur static ossl_inline int PACKET_peek_net_4(const PACKET *pkt,
 239                                                 unsigned long *data)
 240 {
 241     if (PACKET_remaining(pkt) < 4)
 242         return 0;
 243
 244     *data = ((unsigned long)(*pkt->curr)) << 24;
 245     *data |= ((unsigned long)(*(pkt->curr + 1))) << 16;
 246     *data |= ((unsigned long)(*(pkt->curr + 2))) << 8;
 247     *data |= *(pkt->curr + 3);
 248
 249     return 1;
 250 }
 251
 252 /* Equivalent of n2l */
 253 /* Get 4 bytes in network order from |pkt| and store the value in |*data| */
 254 __owur static ossl_inline int PACKET_get_net_4(PACKET *pkt,
 255                                                unsigned long *data)
 256 {
 257     if (!PACKET_peek_net_4(pkt, data))
 258         return 0;
 259
 260     packet_forward(pkt, 4);
 261
 262     return 1;
 263 }
 264
 265 /* Peek ahead at 1 byte from |pkt| and store the value in |*data| */
 266 __owur static ossl_inline int PACKET_peek_1(const PACKET *pkt,
 267                                             unsigned int *data)
 268 {
 269     if (!PACKET_remaining(pkt))
 270         return 0;
 271
 272     *data = *pkt->curr;
 273
 274     return 1;
 275 }
 276
 277 /* Get 1 byte from |pkt| and store the value in |*data| */
 278 __owur static ossl_inline int PACKET_get_1(PACKET *pkt, unsigned int *data)
 279 {
 280     if (!PACKET_peek_1(pkt, data))
 281         return 0;
 282
 283     packet_forward(pkt, 1);
 284
 285     return 1;
 286 }
 287
 288 /*
 289  * Peek ahead at 4 bytes in reverse network order from |pkt| and store the value
 290  * in |*data|
 291  */
 292 __owur static ossl_inline int PACKET_peek_4(const PACKET *pkt,
 293                                             unsigned long *data)
 294 {
 295     if (PACKET_remaining(pkt) < 4)
 296         return 0;
 297
 298     *data = *pkt->curr;
 299     *data |= ((unsigned long)(*(pkt->curr + 1))) << 8;
 300     *data |= ((unsigned long)(*(pkt->curr + 2))) << 16;
 301     *data |= ((unsigned long)(*(pkt->curr + 3))) << 24;
 302
 303     return 1;
 304 }
 305
 306 /* Equivalent of c2l */
 307 /*
 308  * Get 4 bytes in reverse network order from |pkt| and store the value in
 309  * |*data|
 310  */
 311 __owur static ossl_inline int PACKET_get_4(PACKET *pkt, unsigned long *data)
 312 {
 313     if (!PACKET_peek_4(pkt, data))
 314         return 0;
 315
 316     packet_forward(pkt, 4);
 317
 318     return 1;
 319 }
 320
 321 /*
 322  * Peek ahead at |len| bytes from the |pkt| and store a pointer to them in
 323  * |*data|. This just points at the underlying buffer that |pkt| is using. The
 324  * caller should not free this data directly (it will be freed when the
 325  * underlying buffer gets freed
 326  */
 327 __owur static ossl_inline int PACKET_peek_bytes(const PACKET *pkt,
 328                                                 unsigned char **data,
 329                                                 size_t len)
 330 {
 331     if (PACKET_remaining(pkt) < len)
 332         return 0;
 333
 334     *data = pkt->curr;
 335
 336     return 1;
 337 }
 338
 339 /*
 340  * Read |len| bytes from the |pkt| and store a pointer to them in |*data|. This
 341  * just points at the underlying buffer that |pkt| is using. The caller should
 342  * not free this data directly (it will be freed when the underlying buffer gets
 343  * freed
 344  */
 345 __owur static ossl_inline int PACKET_get_bytes(PACKET *pkt,
 346                                                unsigned char **data,
 347                                                size_t len)
 348 {
 349     if (!PACKET_peek_bytes(pkt, data, len))
 350         return 0;
 351
 352     packet_forward(pkt, len);
 353
 354     return 1;
 355 }
 356
 357 /* Peek ahead at |len| bytes from |pkt| and copy them to |data| */
 358 __owur static ossl_inline int PACKET_peek_copy_bytes(const PACKET *pkt,
 359                                                      unsigned char *data,
 360                                                      size_t len)
 361 {
 362     if (PACKET_remaining(pkt) < len)
 363         return 0;
 364
 365     memcpy(data, pkt->curr, len);
 366
 367     return 1;
 368 }
 369
 370 /*
 371  * Read |len| bytes from |pkt| and copy them to |data|.
 372  * The caller is responsible for ensuring that |data| can hold |len| bytes.
 373  */
 374 __owur static ossl_inline int PACKET_copy_bytes(PACKET *pkt,
 375                                                 unsigned char *data,
 376                                                 size_t len)
 377 {
 378     if (!PACKET_peek_copy_bytes(pkt, data, len))
 379         return 0;
 380
 381     packet_forward(pkt, len);
 382
 383     return 1;
 384 }
 385
 386 /*
 387  * Copy packet data to |dest|, and set |len| to the number of copied bytes.
 388  * If the packet has more than |dest_len| bytes, nothing is copied.
 389  * Returns 1 if the packet data fits in |dest_len| bytes, 0 otherwise.
 390  * Does not forward PACKET position (because it is typically the last thing
 391  * done with a given PACKET).
 392  */
 393 __owur static ossl_inline int PACKET_copy_all(const PACKET *pkt,
 394                                               unsigned char *dest,
 395                                               size_t dest_len, size_t *len)
 396 {
 397     if (PACKET_remaining(pkt) > dest_len) {
 398         *len = 0;
 399         return 0;
 400     }
 401     *len = pkt->remaining;
 402     memcpy(dest, pkt->curr, pkt->remaining);
 403     return 1;
 404 }
 405
 406 /*
 407  * Copy |pkt| bytes to a newly allocated buffer and store a pointer to the
 408  * result in |*data|, and the length in |len|.
 409  * If |*data| is not NULL, the old data is OPENSSL_free'd.
 410  * If the packet is empty, or malloc fails, |*data| will be set to NULL.
 411  * Returns 1 if the malloc succeeds and 0 otherwise.
 412  * Does not forward PACKET position (because it is typically the last thing
 413  * done with a given PACKET).
 414  */
 415 __owur static ossl_inline int PACKET_memdup(const PACKET *pkt,
 416                                             unsigned char **data, size_t *len)
 417 {
 418     size_t length;
 419
 420     OPENSSL_free(*data);
 421     *data = NULL;
 422     *len = 0;
 423
 424     length = PACKET_remaining(pkt);
 425
 426     if (length == 0)
 427         return 1;
 428
 429     *data = OPENSSL_memdup(pkt->curr, length);
 430     if (*data == NULL)
 431         return 0;
 432
 433     *len = length;
 434     return 1;
 435 }
 436
 437 /*
 438  * Read a C string from |pkt| and copy to a newly allocated, NUL-terminated
 439  * buffer. Store a pointer to the result in |*data|.
 440  * If |*data| is not NULL, the old data is OPENSSL_free'd.
 441  * If the data in |pkt| does not contain a NUL-byte, the entire data is
 442  * copied and NUL-terminated.
 443  * Returns 1 if the malloc succeeds and 0 otherwise.
 444  * Does not forward PACKET position (because it is typically the last thing done
 445  * with a given PACKET).
 446  */
 447 __owur static ossl_inline int PACKET_strndup(const PACKET *pkt, char **data)
 448 {
 449     OPENSSL_free(*data);
 450
 451     /* This will succeed on an empty packet, unless pkt->curr == NULL. */
 452     *data = OPENSSL_strndup((const char *)pkt->curr, PACKET_remaining(pkt));
 453     return (*data != NULL);
 454 }
 455
 456 /* Move the current reading position forward |len| bytes */
 457 __owur static ossl_inline int PACKET_forward(PACKET *pkt, size_t len)
 458 {
 459     if (PACKET_remaining(pkt) < len)
 460         return 0;
 461
 462     packet_forward(pkt, len);
 463
 464     return 1;
 465 }
 466
 467 /*
 468  * Reads a variable-length vector prefixed with a one-byte length, and stores
 469  * the contents in |subpkt|. |pkt| can equal |subpkt|.
 470  * Data is not copied: the |subpkt| packet will share its underlying buffer with
 471  * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
 472  * Upon failure, the original |pkt| and |subpkt| are not modified.
 473  */
 474 __owur static ossl_inline int PACKET_get_length_prefixed_1(PACKET *pkt,
 475                                                            PACKET *subpkt)
 476 {
 477     unsigned int length;
 478     unsigned char *data;
 479     PACKET tmp = *pkt;
 480     if (!PACKET_get_1(&tmp, &length) ||
 481         !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
 482         return 0;
 483     }
 484
 485     *pkt = tmp;
 486     subpkt->curr = data;
 487     subpkt->remaining = length;
 488
 489     return 1;
 490 }
 491
 492 /*
 493  * Reads a variable-length vector prefixed with a two-byte length, and stores
 494  * the contents in |subpkt|. |pkt| can equal |subpkt|.
 495  * Data is not copied: the |subpkt| packet will share its underlying buffer with
 496  * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
 497  * Upon failure, the original |pkt| and |subpkt| are not modified.
 498  */
 499 __owur static ossl_inline int PACKET_get_length_prefixed_2(PACKET *pkt,
 500                                                            PACKET *subpkt)
 501 {
 502     unsigned int length;
 503     unsigned char *data;
 504     PACKET tmp = *pkt;
 505     if (!PACKET_get_net_2(&tmp, &length) ||
 506         !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
 507         return 0;
 508     }
 509
 510     *pkt = tmp;
 511     subpkt->curr = data;
 512     subpkt->remaining = length;
 513
 514     return 1;
 515 }
 516
 517 /*
 518  * Reads a variable-length vector prefixed with a three-byte length, and stores
 519  * the contents in |subpkt|. |pkt| can equal |subpkt|.
 520  * Data is not copied: the |subpkt| packet will share its underlying buffer with
 521  * the original |pkt|, so data wrapped by |pkt| must outlive the |subpkt|.
 522  * Upon failure, the original |pkt| and |subpkt| are not modified.
 523  */
 524 __owur static ossl_inline int PACKET_get_length_prefixed_3(PACKET *pkt,
 525                                                            PACKET *subpkt)
 526 {
 527     unsigned long length;
 528     unsigned char *data;
 529     PACKET tmp = *pkt;
 530     if (!PACKET_get_net_3(&tmp, &length) ||
 531         !PACKET_get_bytes(&tmp, &data, (size_t)length)) {
 532         return 0;
 533     }
 534
 535     *pkt = tmp;
 536     subpkt->curr = data;
 537     subpkt->remaining = length;
 538
 539     return 1;
 540 }
 541 # ifdef __cplusplus
 542 }
 543 # endif
 544
 545 #endif                          /* HEADER_PACKET_LOCL_H */