/usr/include/polarssl/cipher.h is in libpolarssl-dev 1.3.9-2.1+deb8u3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 | /**
* \file cipher.h
*
* \brief Generic cipher wrapper.
*
* \author Adriaan de Jong <dejong@fox-it.com>
*
* Copyright (C) 2006-2014, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_CIPHER_H
#define POLARSSL_CIPHER_H
#if !defined(POLARSSL_CONFIG_FILE)
#include "config.h"
#else
#include POLARSSL_CONFIG_FILE
#endif
#if defined(POLARSSL_GCM_C) || defined(POLARSSL_CCM_C)
#define POLARSSL_CIPHER_MODE_AEAD
#endif
#if defined(POLARSSL_CIPHER_MODE_CBC)
#define POLARSSL_CIPHER_MODE_WITH_PADDING
#endif
#include <string.h>
#if defined(_MSC_VER) && !defined(inline)
#define inline _inline
#else
#if defined(__ARMCC_VERSION) && !defined(inline)
#define inline __inline
#endif /* __ARMCC_VERSION */
#endif /*_MSC_VER */
#define POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
#define POLARSSL_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters to function. */
#define POLARSSL_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
#define POLARSSL_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
#define POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
#define POLARSSL_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
#define POLARSSL_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length */
#define POLARSSL_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length */
#ifdef __cplusplus
extern "C" {
#endif
typedef enum {
POLARSSL_CIPHER_ID_NONE = 0,
POLARSSL_CIPHER_ID_NULL,
POLARSSL_CIPHER_ID_AES,
POLARSSL_CIPHER_ID_DES,
POLARSSL_CIPHER_ID_3DES,
POLARSSL_CIPHER_ID_CAMELLIA,
POLARSSL_CIPHER_ID_BLOWFISH,
POLARSSL_CIPHER_ID_ARC4,
} cipher_id_t;
typedef enum {
POLARSSL_CIPHER_NONE = 0,
POLARSSL_CIPHER_NULL,
POLARSSL_CIPHER_AES_128_ECB,
POLARSSL_CIPHER_AES_192_ECB,
POLARSSL_CIPHER_AES_256_ECB,
POLARSSL_CIPHER_AES_128_CBC,
POLARSSL_CIPHER_AES_192_CBC,
POLARSSL_CIPHER_AES_256_CBC,
POLARSSL_CIPHER_AES_128_CFB128,
POLARSSL_CIPHER_AES_192_CFB128,
POLARSSL_CIPHER_AES_256_CFB128,
POLARSSL_CIPHER_AES_128_CTR,
POLARSSL_CIPHER_AES_192_CTR,
POLARSSL_CIPHER_AES_256_CTR,
POLARSSL_CIPHER_AES_128_GCM,
POLARSSL_CIPHER_AES_192_GCM,
POLARSSL_CIPHER_AES_256_GCM,
POLARSSL_CIPHER_CAMELLIA_128_ECB,
POLARSSL_CIPHER_CAMELLIA_192_ECB,
POLARSSL_CIPHER_CAMELLIA_256_ECB,
POLARSSL_CIPHER_CAMELLIA_128_CBC,
POLARSSL_CIPHER_CAMELLIA_192_CBC,
POLARSSL_CIPHER_CAMELLIA_256_CBC,
POLARSSL_CIPHER_CAMELLIA_128_CFB128,
POLARSSL_CIPHER_CAMELLIA_192_CFB128,
POLARSSL_CIPHER_CAMELLIA_256_CFB128,
POLARSSL_CIPHER_CAMELLIA_128_CTR,
POLARSSL_CIPHER_CAMELLIA_192_CTR,
POLARSSL_CIPHER_CAMELLIA_256_CTR,
POLARSSL_CIPHER_CAMELLIA_128_GCM,
POLARSSL_CIPHER_CAMELLIA_192_GCM,
POLARSSL_CIPHER_CAMELLIA_256_GCM,
POLARSSL_CIPHER_DES_ECB,
POLARSSL_CIPHER_DES_CBC,
POLARSSL_CIPHER_DES_EDE_ECB,
POLARSSL_CIPHER_DES_EDE_CBC,
POLARSSL_CIPHER_DES_EDE3_ECB,
POLARSSL_CIPHER_DES_EDE3_CBC,
POLARSSL_CIPHER_BLOWFISH_ECB,
POLARSSL_CIPHER_BLOWFISH_CBC,
POLARSSL_CIPHER_BLOWFISH_CFB64,
POLARSSL_CIPHER_BLOWFISH_CTR,
POLARSSL_CIPHER_ARC4_128,
POLARSSL_CIPHER_AES_128_CCM,
POLARSSL_CIPHER_AES_192_CCM,
POLARSSL_CIPHER_AES_256_CCM,
POLARSSL_CIPHER_CAMELLIA_128_CCM,
POLARSSL_CIPHER_CAMELLIA_192_CCM,
POLARSSL_CIPHER_CAMELLIA_256_CCM,
} cipher_type_t;
typedef enum {
POLARSSL_MODE_NONE = 0,
POLARSSL_MODE_ECB,
POLARSSL_MODE_CBC,
POLARSSL_MODE_CFB,
POLARSSL_MODE_OFB, /* Unused! */
POLARSSL_MODE_CTR,
POLARSSL_MODE_GCM,
POLARSSL_MODE_STREAM,
POLARSSL_MODE_CCM,
} cipher_mode_t;
typedef enum {
POLARSSL_PADDING_PKCS7 = 0, /**< PKCS7 padding (default) */
POLARSSL_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding */
POLARSSL_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding */
POLARSSL_PADDING_ZEROS, /**< zero padding (not reversible!) */
POLARSSL_PADDING_NONE, /**< never pad (full blocks only) */
} cipher_padding_t;
typedef enum {
POLARSSL_OPERATION_NONE = -1,
POLARSSL_DECRYPT = 0,
POLARSSL_ENCRYPT,
} operation_t;
enum {
/** Undefined key length */
POLARSSL_KEY_LENGTH_NONE = 0,
/** Key length, in bits (including parity), for DES keys */
POLARSSL_KEY_LENGTH_DES = 64,
/** Key length, in bits (including parity), for DES in two key EDE */
POLARSSL_KEY_LENGTH_DES_EDE = 128,
/** Key length, in bits (including parity), for DES in three-key EDE */
POLARSSL_KEY_LENGTH_DES_EDE3 = 192,
};
/** Maximum length of any IV, in bytes */
#define POLARSSL_MAX_IV_LENGTH 16
/** Maximum block size of any cipher, in bytes */
#define POLARSSL_MAX_BLOCK_LENGTH 16
/**
* Base cipher information. The non-mode specific functions and values.
*/
typedef struct {
/** Base Cipher type (e.g. POLARSSL_CIPHER_ID_AES) */
cipher_id_t cipher;
/** Encrypt using ECB */
int (*ecb_func)( void *ctx, operation_t mode,
const unsigned char *input, unsigned char *output );
/** Encrypt using CBC */
int (*cbc_func)( void *ctx, operation_t mode, size_t length,
unsigned char *iv, const unsigned char *input,
unsigned char *output );
/** Encrypt using CFB (Full length) */
int (*cfb_func)( void *ctx, operation_t mode, size_t length, size_t *iv_off,
unsigned char *iv, const unsigned char *input,
unsigned char *output );
/** Encrypt using CTR */
int (*ctr_func)( void *ctx, size_t length, size_t *nc_off,
unsigned char *nonce_counter, unsigned char *stream_block,
const unsigned char *input, unsigned char *output );
/** Encrypt using STREAM */
int (*stream_func)( void *ctx, size_t length,
const unsigned char *input, unsigned char *output );
/** Set key for encryption purposes */
int (*setkey_enc_func)( void *ctx, const unsigned char *key,
unsigned int key_length );
/** Set key for decryption purposes */
int (*setkey_dec_func)( void *ctx, const unsigned char *key,
unsigned int key_length);
/** Allocate a new context */
void * (*ctx_alloc_func)( void );
/** Free the given context */
void (*ctx_free_func)( void *ctx );
} cipher_base_t;
/**
* Cipher information. Allows cipher functions to be called in a generic way.
*/
typedef struct {
/** Full cipher identifier (e.g. POLARSSL_CIPHER_AES_256_CBC) */
cipher_type_t type;
/** Cipher mode (e.g. POLARSSL_MODE_CBC) */
cipher_mode_t mode;
/** Cipher key length, in bits (default length for variable sized ciphers)
* (Includes parity bits for ciphers like DES) */
unsigned int key_length;
/** Name of the cipher */
const char * name;
/** IV/NONCE size, in bytes.
* For cipher that accept many sizes: recommended size */
unsigned int iv_size;
/** Flags for variable IV size, variable key size, etc. */
int flags;
/** block size, in bytes */
unsigned int block_size;
/** Base cipher information and functions */
const cipher_base_t *base;
} cipher_info_t;
/**
* Generic cipher context.
*/
typedef struct {
/** Information about the associated cipher */
const cipher_info_t *cipher_info;
/** Key length to use */
int key_length;
/** Operation that the context's key has been initialised for */
operation_t operation;
/** Padding functions to use, if relevant for cipher mode */
void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
/** Buffer for data that hasn't been encrypted yet */
unsigned char unprocessed_data[POLARSSL_MAX_BLOCK_LENGTH];
/** Number of bytes that still need processing */
size_t unprocessed_len;
/** Current IV or NONCE_COUNTER for CTR-mode */
unsigned char iv[POLARSSL_MAX_IV_LENGTH];
/** IV size in bytes (for ciphers with variable-length IVs) */
size_t iv_size;
/** Cipher-specific context */
void *cipher_ctx;
} cipher_context_t;
/**
* \brief Returns the list of ciphers supported by the generic cipher module.
*
* \return a statically allocated array of ciphers, the last entry
* is 0.
*/
const int *cipher_list( void );
/**
* \brief Returns the cipher information structure associated
* with the given cipher name.
*
* \param cipher_name Name of the cipher to search for.
*
* \return the cipher information structure associated with the
* given cipher_name, or NULL if not found.
*/
const cipher_info_t *cipher_info_from_string( const char *cipher_name );
/**
* \brief Returns the cipher information structure associated
* with the given cipher type.
*
* \param cipher_type Type of the cipher to search for.
*
* \return the cipher information structure associated with the
* given cipher_type, or NULL if not found.
*/
const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type );
/**
* \brief Returns the cipher information structure associated
* with the given cipher id, key size and mode.
*
* \param cipher_id Id of the cipher to search for
* (e.g. POLARSSL_CIPHER_ID_AES)
* \param key_length Length of the key in bits
* \param mode Cipher mode (e.g. POLARSSL_MODE_CBC)
*
* \return the cipher information structure associated with the
* given cipher_type, or NULL if not found.
*/
const cipher_info_t *cipher_info_from_values( const cipher_id_t cipher_id,
int key_length,
const cipher_mode_t mode );
/**
* \brief Initialize a cipher_context (as NONE)
*/
void cipher_init( cipher_context_t *ctx );
/**
* \brief Free and clear the cipher-specific context of ctx.
* Freeing ctx itself remains the responsibility of the
* caller.
*/
void cipher_free( cipher_context_t *ctx );
/**
* \brief Initialises and fills the cipher context structure with
* the appropriate values.
*
* \note Currently also clears structure. In future versions you
* will be required to call cipher_init() on the structure
* first.
*
* \param ctx context to initialise. May not be NULL.
* \param cipher_info cipher to use.
*
* \return 0 on success,
* POLARSSL_ERR_CIPHER_BAD_INPUT_DATA on parameter failure,
* POLARSSL_ERR_CIPHER_ALLOC_FAILED if allocation of the
* cipher-specific context failed.
*/
int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info );
/**
* \brief Free the cipher-specific context of ctx. Freeing ctx
* itself remains the responsibility of the caller.
*
* \note Deprecated: Redirects to cipher_free()
*
* \param ctx Free the cipher-specific context
*
* \returns 0
*/
int cipher_free_ctx( cipher_context_t *ctx );
/**
* \brief Returns the block size of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return size of the cipher's blocks, or 0 if ctx has not been
* initialised.
*/
static inline unsigned int cipher_get_block_size( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->block_size;
}
/**
* \brief Returns the mode of operation for the cipher.
* (e.g. POLARSSL_MODE_CBC)
*
* \param ctx cipher's context. Must have been initialised.
*
* \return mode of operation, or POLARSSL_MODE_NONE if ctx
* has not been initialised.
*/
static inline cipher_mode_t cipher_get_cipher_mode( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_MODE_NONE;
return ctx->cipher_info->mode;
}
/**
* \brief Returns the size of the cipher's IV/NONCE in bytes.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return If IV has not been set yet: (recommended) IV size
* (0 for ciphers not using IV/NONCE).
* If IV has already been set: actual size.
*/
static inline int cipher_get_iv_size( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
if( ctx->iv_size != 0 )
return (int) ctx->iv_size;
return ctx->cipher_info->iv_size;
}
/**
* \brief Returns the type of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return type of the cipher, or POLARSSL_CIPHER_NONE if ctx has
* not been initialised.
*/
static inline cipher_type_t cipher_get_type( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_CIPHER_NONE;
return ctx->cipher_info->type;
}
/**
* \brief Returns the name of the given cipher, as a string.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return name of the cipher, or NULL if ctx was not initialised.
*/
static inline const char *cipher_get_name( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->name;
}
/**
* \brief Returns the key length of the cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return cipher's key length, in bits, or
* POLARSSL_KEY_LENGTH_NONE if ctx has not been
* initialised.
*/
static inline int cipher_get_key_size ( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_KEY_LENGTH_NONE;
return ctx->cipher_info->key_length;
}
/**
* \brief Returns the operation of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return operation (POLARSSL_ENCRYPT or POLARSSL_DECRYPT),
* or POLARSSL_OPERATION_NONE if ctx has not been
* initialised.
*/
static inline operation_t cipher_get_operation( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_OPERATION_NONE;
return ctx->operation;
}
/**
* \brief Set the key to use with the given context.
*
* \param ctx generic cipher context. May not be NULL. Must have been
* initialised using cipher_context_from_type or
* cipher_context_from_string.
* \param key The key to use.
* \param key_length key length to use, in bits.
* \param operation Operation that the key will be used for, either
* POLARSSL_ENCRYPT or POLARSSL_DECRYPT.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails or a cipher specific
* error code.
*/
int cipher_setkey( cipher_context_t *ctx, const unsigned char *key,
int key_length, const operation_t operation );
#if defined(POLARSSL_CIPHER_MODE_WITH_PADDING)
/**
* \brief Set padding mode, for cipher modes that use padding.
* (Default: PKCS7 padding.)
*
* \param ctx generic cipher context
* \param mode padding mode
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE
* if selected padding mode is not supported, or
* POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
* does not support padding.
*/
int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode );
#endif /* POLARSSL_CIPHER_MODE_WITH_PADDING */
/**
* \brief Set the initialization vector (IV) or nonce
*
* \param ctx generic cipher context
* \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
* \param iv_len IV length for ciphers with variable-size IV;
* discarded by ciphers with fixed-size IV.
*
* \returns 0 on success, or POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
*
* \note Some ciphers don't use IVs nor NONCE. For these
* ciphers, this function has no effect.
*/
int cipher_set_iv( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len );
/**
* \brief Finish preparation of the given context
*
* \param ctx generic cipher context
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
* if parameter verification fails.
*/
int cipher_reset( cipher_context_t *ctx );
#if defined(POLARSSL_GCM_C)
/**
* \brief Add additional data (for AEAD ciphers).
* Currently only supported with GCM.
* Must be called exactly once, after cipher_reset().
*
* \param ctx generic cipher context
* \param ad Additional data to use.
* \param ad_len Length of ad.
*
* \return 0 on success, or a specific error code.
*/
int cipher_update_ad( cipher_context_t *ctx,
const unsigned char *ad, size_t ad_len );
#endif /* POLARSSL_GCM_C */
/**
* \brief Generic cipher update function. Encrypts/decrypts
* using the given cipher context. Writes as many block
* size'd blocks of data as possible to output. Any data
* that cannot be written immediately will either be added
* to the next block, or flushed when cipher_final is
* called.
* Exception: for POLARSSL_MODE_ECB, expects single block
* in size (e.g. 16 bytes for AES)
*
* \param ctx generic cipher context
* \param input buffer holding the input data
* \param ilen length of the input data
* \param output buffer for the output data. Should be able to hold at
* least ilen + block_size. Cannot be the same buffer as
* input!
* \param olen length of the output data, will be filled with the
* actual number of bytes written.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails,
* POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE on an
* unsupported mode for a cipher or a cipher specific
* error code.
*
* \note If the underlying cipher is GCM, all calls to this
* function, except the last one before cipher_finish(),
* must have ilen a multiple of the block size.
*/
int cipher_update( cipher_context_t *ctx, const unsigned char *input,
size_t ilen, unsigned char *output, size_t *olen );
/**
* \brief Generic cipher finalisation function. If data still
* needs to be flushed from an incomplete block, data
* contained within it will be padded with the size of
* the last block, and written to the output buffer.
*
* \param ctx Generic cipher context
* \param output buffer to write data to. Needs block_size available.
* \param olen length of the data written to the output buffer.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails,
* POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
* expected a full block but was not provided one,
* POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting or a cipher specific error code.
*/
int cipher_finish( cipher_context_t *ctx,
unsigned char *output, size_t *olen );
#if defined(POLARSSL_GCM_C)
/**
* \brief Write tag for AEAD ciphers.
* Currently only supported with GCM.
* Must be called after cipher_finish().
*
* \param ctx Generic cipher context
* \param tag buffer to write the tag
* \param tag_len Length of the tag to write
*
* \return 0 on success, or a specific error code.
*/
int cipher_write_tag( cipher_context_t *ctx,
unsigned char *tag, size_t tag_len );
/**
* \brief Check tag for AEAD ciphers.
* Currently only supported with GCM.
* Must be called after cipher_finish().
*
* \param ctx Generic cipher context
* \param tag Buffer holding the tag
* \param tag_len Length of the tag to check
*
* \return 0 on success, or a specific error code.
*/
int cipher_check_tag( cipher_context_t *ctx,
const unsigned char *tag, size_t tag_len );
#endif /* POLARSSL_GCM_C */
/**
* \brief Generic all-in-one encryption/decryption
* (for all ciphers except AEAD constructs).
*
* \param ctx generic cipher context
* \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
* \param iv_len IV length for ciphers with variable-size IV;
* discarded by ciphers with fixed-size IV.
* \param input buffer holding the input data
* \param ilen length of the input data
* \param output buffer for the output data. Should be able to hold at
* least ilen + block_size. Cannot be the same buffer as
* input!
* \param olen length of the output data, will be filled with the
* actual number of bytes written.
*
* \note Some ciphers don't use IVs nor NONCE. For these
* ciphers, use iv = NULL and iv_len = 0.
*
* \returns 0 on success, or
* POLARSSL_ERR_CIPHER_BAD_INPUT_DATA, or
* POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
* expected a full block but was not provided one, or
* POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting, or
* a cipher specific error code.
*/
int cipher_crypt( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen );
#if defined(POLARSSL_CIPHER_MODE_AEAD)
/**
* \brief Generic autenticated encryption (AEAD ciphers).
*
* \param ctx generic cipher context
* \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
* \param iv_len IV length for ciphers with variable-size IV;
* discarded by ciphers with fixed-size IV.
* \param ad Additional data to authenticate.
* \param ad_len Length of ad.
* \param input buffer holding the input data
* \param ilen length of the input data
* \param output buffer for the output data.
* Should be able to hold at least ilen.
* \param olen length of the output data, will be filled with the
* actual number of bytes written.
* \param tag buffer for the authentication tag
* \param tag_len desired tag length
*
* \returns 0 on success, or
* POLARSSL_ERR_CIPHER_BAD_INPUT_DATA, or
* a cipher specific error code.
*/
int cipher_auth_encrypt( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len );
/**
* \brief Generic autenticated decryption (AEAD ciphers).
*
* \param ctx generic cipher context
* \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
* \param iv_len IV length for ciphers with variable-size IV;
* discarded by ciphers with fixed-size IV.
* \param ad Additional data to be authenticated.
* \param ad_len Length of ad.
* \param input buffer holding the input data
* \param ilen length of the input data
* \param output buffer for the output data.
* Should be able to hold at least ilen.
* \param olen length of the output data, will be filled with the
* actual number of bytes written.
* \param tag buffer holding the authentication tag
* \param tag_len length of the authentication tag
*
* \returns 0 on success, or
* POLARSSL_ERR_CIPHER_BAD_INPUT_DATA, or
* POLARSSL_ERR_CIPHER_AUTH_FAILED if data isn't authentic,
* or a cipher specific error code.
*
* \note If the data is not authentic, then the output buffer
* is zeroed out to prevent the unauthentic plaintext to
* be used by mistake, making this interface safer.
*/
int cipher_auth_decrypt( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len,
const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen,
const unsigned char *tag, size_t tag_len );
#endif /* POLARSSL_CIPHER_MODE_AEAD */
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int cipher_self_test( int verbose );
#ifdef __cplusplus
}
#endif
#endif /* POLARSSL_CIPHER_H */
|