src/libpolarssl/cipher.h

   1 /**
   2  * \file cipher.h
   3  *
   4  * \brief Generic cipher wrapper.
   5  *
   6  * \author Adriaan de Jong <dejong@fox-it.com>
   7  *
   8  *  Copyright (C) 2006-2012, Brainspark B.V.
   9  *
  10  *  This file is part of PolarSSL (http://www.polarssl.org)
  11  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
  12  *
  13  *  All rights reserved.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License as published by
  17  *  the Free Software Foundation; either version 2 of the License, or
  18  *  (at your option) any later version.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License along
  26  *  with this program; if not, write to the Free Software Foundation, Inc.,
  27  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  28  */
  29
  30 #ifndef POLARSSL_CIPHER_H
  31 #define POLARSSL_CIPHER_H
  32
  33 #include <string.h>
  34
  35 #if defined(_MSC_VER) && !defined(inline)
  36 #define inline _inline
  37 #else
  38 #if defined(__ARMCC_VERSION) && !defined(inline)
  39 #define inline __inline
  40 #endif /* __ARMCC_VERSION */
  41 #endif /*_MSC_VER */
  42
  43 #define POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE            -0x6080  /**< The selected feature is not available. */
  44 #define POLARSSL_ERR_CIPHER_BAD_INPUT_DATA                 -0x6100  /**< Bad input parameters to function. */
  45 #define POLARSSL_ERR_CIPHER_ALLOC_FAILED                   -0x6180  /**< Failed to allocate memory. */
  46 #define POLARSSL_ERR_CIPHER_INVALID_PADDING                -0x6200  /**< Input data contains invalid padding and is rejected. */
  47 #define POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED            -0x6280  /**< Decryption of block requires a full block. */
  48
  49 typedef enum {
  50     POLARSSL_CIPHER_ID_NONE = 0,
  51     POLARSSL_CIPHER_ID_NULL,
  52     POLARSSL_CIPHER_ID_AES,
  53     POLARSSL_CIPHER_ID_DES,
  54     POLARSSL_CIPHER_ID_3DES,
  55     POLARSSL_CIPHER_ID_CAMELLIA,
  56     POLARSSL_CIPHER_ID_BLOWFISH,
  57 } cipher_id_t;
  58
  59 typedef enum {
  60     POLARSSL_CIPHER_NONE = 0,
  61     POLARSSL_CIPHER_NULL,
  62     POLARSSL_CIPHER_AES_128_CBC,
  63     POLARSSL_CIPHER_AES_192_CBC,
  64     POLARSSL_CIPHER_AES_256_CBC,
  65     POLARSSL_CIPHER_AES_128_CFB128,
  66     POLARSSL_CIPHER_AES_192_CFB128,
  67     POLARSSL_CIPHER_AES_256_CFB128,
  68     POLARSSL_CIPHER_AES_128_CTR,
  69     POLARSSL_CIPHER_AES_192_CTR,
  70     POLARSSL_CIPHER_AES_256_CTR,
  71     POLARSSL_CIPHER_CAMELLIA_128_CBC,
  72     POLARSSL_CIPHER_CAMELLIA_192_CBC,
  73     POLARSSL_CIPHER_CAMELLIA_256_CBC,
  74     POLARSSL_CIPHER_CAMELLIA_128_CFB128,
  75     POLARSSL_CIPHER_CAMELLIA_192_CFB128,
  76     POLARSSL_CIPHER_CAMELLIA_256_CFB128,
  77     POLARSSL_CIPHER_CAMELLIA_128_CTR,
  78     POLARSSL_CIPHER_CAMELLIA_192_CTR,
  79     POLARSSL_CIPHER_CAMELLIA_256_CTR,
  80     POLARSSL_CIPHER_DES_CBC,
  81     POLARSSL_CIPHER_DES_EDE_CBC,
  82     POLARSSL_CIPHER_DES_EDE3_CBC,
  83     POLARSSL_CIPHER_BLOWFISH_CBC,
  84     POLARSSL_CIPHER_BLOWFISH_CFB64,
  85     POLARSSL_CIPHER_BLOWFISH_CTR,
  86 } cipher_type_t;
  87
  88 typedef enum {
  89     POLARSSL_MODE_NONE = 0,
  90     POLARSSL_MODE_NULL,
  91     POLARSSL_MODE_CBC,
  92     POLARSSL_MODE_CFB,
  93     POLARSSL_MODE_OFB,
  94     POLARSSL_MODE_CTR,
  95 } cipher_mode_t;
  96
  97 typedef enum {
  98     POLARSSL_OPERATION_NONE = -1,
  99     POLARSSL_DECRYPT = 0,
 100     POLARSSL_ENCRYPT,
 101 } operation_t;
 102
 103 enum {
 104     /** Undefined key length */
 105     POLARSSL_KEY_LENGTH_NONE = 0,
 106     /** Key length, in bits (including parity), for DES keys */
 107     POLARSSL_KEY_LENGTH_DES  = 64,
 108     /** Key length, in bits (including parity), for DES in two key EDE */
 109     POLARSSL_KEY_LENGTH_DES_EDE = 128,
 110     /** Key length, in bits (including parity), for DES in three-key EDE */
 111     POLARSSL_KEY_LENGTH_DES_EDE3 = 192,
 112     /** Maximum length of any IV, in bytes */
 113     POLARSSL_MAX_IV_LENGTH = 16,
 114 };
 115
 116 /**
 117  * Base cipher information. The non-mode specific functions and values.
 118  */
 119 typedef struct {
 120
 121     /** Base Cipher type (e.g. POLARSSL_CIPHER_ID_AES) */
 122     cipher_id_t cipher;
 123
 124     /** Encrypt using CBC */
 125     int (*cbc_func)( void *ctx, operation_t mode, size_t length, unsigned char *iv,
 126             const unsigned char *input, unsigned char *output );
 127
 128     /** Encrypt using CFB (Full length) */
 129     int (*cfb_func)( void *ctx, operation_t mode, size_t length, size_t *iv_off,
 130             unsigned char *iv, const unsigned char *input, unsigned char *output );
 131
 132     /** Encrypt using CTR */
 133     int (*ctr_func)( void *ctx, size_t length, size_t *nc_off, unsigned char *nonce_counter,
 134             unsigned char *stream_block, const unsigned char *input, unsigned char *output );
 135
 136     /** Set key for encryption purposes */
 137     int (*setkey_enc_func)( void *ctx, const unsigned char *key, unsigned int key_length);
 138
 139     /** Set key for decryption purposes */
 140     int (*setkey_dec_func)( void *ctx, const unsigned char *key, unsigned int key_length);
 141
 142     /** Allocate a new context */
 143     void * (*ctx_alloc_func)( void );
 144
 145     /** Free the given context */
 146     void (*ctx_free_func)( void *ctx );
 147
 148 } cipher_base_t;
 149
 150 /**
 151  * Cipher information. Allows cipher functions to be called in a generic way.
 152  */
 153 typedef struct {
 154     /** Full cipher identifier (e.g. POLARSSL_CIPHER_AES_256_CBC) */
 155     cipher_type_t type;
 156
 157     /** Cipher mode (e.g. POLARSSL_MODE_CBC) */
 158     cipher_mode_t mode;
 159
 160     /** Cipher key length, in bits (default length for variable sized ciphers)
 161      *  (Includes parity bits for ciphers like DES) */
 162     unsigned int key_length;
 163
 164     /** Name of the cipher */
 165     const char * name;
 166
 167     /** IV size, in bytes */
 168     unsigned int iv_size;
 169
 170     /** block size, in bytes */
 171     unsigned int block_size;
 172
 173     /** Base cipher information and functions */
 174     const cipher_base_t *base;
 175
 176 } cipher_info_t;
 177
 178 /**
 179  * Generic cipher context.
 180  */
 181 typedef struct {
 182     /** Information about the associated cipher */
 183     const cipher_info_t *cipher_info;
 184
 185     /** Key length to use */
 186     int key_length;
 187
 188     /** Operation that the context's key has been initialised for */
 189     operation_t operation;
 190
 191     /** Buffer for data that hasn't been encrypted yet */
 192     unsigned char unprocessed_data[POLARSSL_MAX_IV_LENGTH];
 193
 194     /** Number of bytes that still need processing */
 195     size_t unprocessed_len;
 196
 197     /** Current IV or NONCE_COUNTER for CTR-mode */
 198     unsigned char iv[POLARSSL_MAX_IV_LENGTH];
 199
 200     /** Cipher-specific context */
 201     void *cipher_ctx;
 202 } cipher_context_t;
 203
 204 #ifdef __cplusplus
 205 extern "C" {
 206 #endif
 207
 208 /**
 209  * \brief Returns the list of ciphers supported by the generic cipher module.
 210  *
 211  * \return              a statically allocated array of ciphers, the last entry
 212  *                      is 0.
 213  */
 214 const int *cipher_list( void );
 215
 216 /**
 217  * \brief               Returns the cipher information structure associated
 218  *                      with the given cipher name.
 219  *
 220  * \param cipher_name   Name of the cipher to search for.
 221  *
 222  * \return              the cipher information structure associated with the
 223  *                      given cipher_name, or NULL if not found.
 224  */
 225 const cipher_info_t *cipher_info_from_string( const char *cipher_name );
 226
 227 /**
 228  * \brief               Returns the cipher information structure associated
 229  *                      with the given cipher type.
 230  *
 231  * \param cipher_type   Type of the cipher to search for.
 232  *
 233  * \return              the cipher information structure associated with the
 234  *                      given cipher_type, or NULL if not found.
 235  */
 236 const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type );
 237
 238 /**
 239  * \brief               Initialises and fills the cipher context structure with
 240  *                      the appropriate values.
 241  *
 242  * \param ctx           context to initialise. May not be NULL.
 243  * \param cipher_info   cipher to use.
 244  *
 245  * \return              \c 0 on success,
 246  *                      \c POLARSSL_ERR_CIPHER_BAD_INPUT_DATA on parameter failure,
 247  *                      \c POLARSSL_ERR_CIPHER_ALLOC_FAILED if allocation of the
 248  *                      cipher-specific context failed.
 249  */
 250 int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info );
 251
 252 /**
 253  * \brief               Free the cipher-specific context of ctx. Freeing ctx
 254  *                      itself remains the responsibility of the caller.
 255  *
 256  * \param ctx           Free the cipher-specific context
 257  *
 258  * \returns             0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
 259  *                      parameter verification fails.
 260  */
 261 int cipher_free_ctx( cipher_context_t *ctx );
 262
 263 /**
 264  * \brief               Returns the block size of the given cipher.
 265  *
 266  * \param ctx           cipher's context. Must have been initialised.
 267  *
 268  * \return              size of the cipher's blocks, or 0 if ctx has not been
 269  *                      initialised.
 270  */
 271 static inline unsigned int cipher_get_block_size( const cipher_context_t *ctx )
 272 {
 273     if( NULL == ctx || NULL == ctx->cipher_info )
 274         return 0;
 275
 276     return ctx->cipher_info->block_size;
 277 }
 278
 279 /**
 280  * \brief               Returns the mode of operation for the cipher.
 281  *                      (e.g. POLARSSL_MODE_CBC)
 282  *
 283  * \param ctx           cipher's context. Must have been initialised.
 284  *
 285  * \return              mode of operation, or POLARSSL_MODE_NONE if ctx
 286  *                      has not been initialised.
 287  */
 288 static inline cipher_mode_t cipher_get_cipher_mode( const cipher_context_t *ctx )
 289 {
 290     if( NULL == ctx || NULL == ctx->cipher_info )
 291         return POLARSSL_MODE_NONE;
 292
 293     return ctx->cipher_info->mode;
 294 }
 295
 296 /**
 297  * \brief               Returns the size of the cipher's IV.
 298  *
 299  * \param ctx           cipher's context. Must have been initialised.
 300  *
 301  * \return              size of the cipher's IV, or 0 if ctx has not been
 302  *                      initialised.
 303  */
 304 static inline int cipher_get_iv_size( const cipher_context_t *ctx )
 305 {
 306     if( NULL == ctx || NULL == ctx->cipher_info )
 307         return 0;
 308
 309     return ctx->cipher_info->iv_size;
 310 }
 311
 312 /**
 313  * \brief               Returns the type of the given cipher.
 314  *
 315  * \param ctx           cipher's context. Must have been initialised.
 316  *
 317  * \return              type of the cipher, or POLARSSL_CIPHER_NONE if ctx has
 318  *                      not been initialised.
 319  */
 320 static inline cipher_type_t cipher_get_type( const cipher_context_t *ctx )
 321 {
 322     if( NULL == ctx || NULL == ctx->cipher_info )
 323         return POLARSSL_CIPHER_NONE;
 324
 325     return ctx->cipher_info->type;
 326 }
 327
 328 /**
 329  * \brief               Returns the name of the given cipher, as a string.
 330  *
 331  * \param ctx           cipher's context. Must have been initialised.
 332  *
 333  * \return              name of the cipher, or NULL if ctx was not initialised.
 334  */
 335 static inline const char *cipher_get_name( const cipher_context_t *ctx )
 336 {
 337     if( NULL == ctx || NULL == ctx->cipher_info )
 338         return 0;
 339
 340     return ctx->cipher_info->name;
 341 }
 342
 343 /**
 344  * \brief               Returns the key length of the cipher.
 345  *
 346  * \param ctx           cipher's context. Must have been initialised.
 347  *
 348  * \return              cipher's key length, in bits, or
 349  *                      POLARSSL_KEY_LENGTH_NONE if ctx has not been
 350  *                      initialised.
 351  */
 352 static inline int cipher_get_key_size ( const cipher_context_t *ctx )
 353 {
 354     if( NULL == ctx )
 355         return POLARSSL_KEY_LENGTH_NONE;
 356
 357     return ctx->key_length;
 358 }
 359
 360 /**
 361  * \brief               Returns the operation of the given cipher.
 362  *
 363  * \param ctx           cipher's context. Must have been initialised.
 364  *
 365  * \return              operation (POLARSSL_ENCRYPT or POLARSSL_DECRYPT),
 366  *                      or POLARSSL_OPERATION_NONE if ctx has not been
 367  *                      initialised.
 368  */
 369 static inline operation_t cipher_get_operation( const cipher_context_t *ctx )
 370 {
 371     if( NULL == ctx || NULL == ctx->cipher_info )
 372         return POLARSSL_OPERATION_NONE;
 373
 374     return ctx->operation;
 375 }
 376
 377 /**
 378  * \brief               Set the key to use with the given context.
 379  *
 380  * \param ctx           generic cipher context. May not be NULL. Must have been
 381  *                      initialised using cipher_context_from_type or
 382  *                      cipher_context_from_string.
 383  * \param key           The key to use.
 384  * \param key_length    key length to use, in bits.
 385  * \param operation     Operation that the key will be used for, either
 386  *                      POLARSSL_ENCRYPT or POLARSSL_DECRYPT.
 387  *
 388  * \returns             0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
 389  *                      parameter verification fails or a cipher specific
 390  *                      error code.
 391  */
 392 int cipher_setkey( cipher_context_t *ctx, const unsigned char *key, int key_length,
 393         const operation_t operation );
 394
 395 /**
 396  * \brief               Reset the given context, setting the IV to iv
 397  *
 398  * \param ctx           generic cipher context
 399  * \param iv            IV to use or NONCE_COUNTER in the case of a CTR-mode cipher
 400  *
 401  * \returns             0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
 402  *                      if parameter verification fails.
 403  */
 404 int cipher_reset( cipher_context_t *ctx, const unsigned char *iv );
 405
 406 /**
 407  * \brief               Generic cipher update function. Encrypts/decrypts
 408  *                      using the given cipher context. Writes as many block
 409  *                      size'd blocks of data as possible to output. Any data
 410  *                      that cannot be written immediately will either be added
 411  *                      to the next block, or flushed when cipher_final is
 412  *                      called.
 413  *
 414  * \param ctx           generic cipher context
 415  * \param input         buffer holding the input data
 416  * \param ilen          length of the input data
 417  * \param output        buffer for the output data. Should be able to hold at
 418  *                      least ilen + block_size. Cannot be the same buffer as
 419  *                      input!
 420  * \param olen          length of the output data, will be filled with the
 421  *                      actual number of bytes written.
 422  *
 423  * \returns             0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
 424  *                      parameter verification fails,
 425  *                      POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE on an
 426  *                      unsupported mode for a cipher or a cipher specific
 427  *                      error code.
 428  */
 429 int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ilen,
 430         unsigned char *output, size_t *olen );
 431
 432 /**
 433  * \brief               Generic cipher finalisation function. If data still
 434  *                      needs to be flushed from an incomplete block, data
 435  *                      contained within it will be padded with the size of
 436  *                      the last block, and written to the output buffer.
 437  *
 438  * \param ctx           Generic cipher context
 439  * \param output        buffer to write data to. Needs block_size data available.
 440  * \param olen          length of the data written to the output buffer.
 441  *
 442  * \returns             0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
 443  *                      parameter verification fails,
 444  *                      POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
 445  *                      expected a full block but was not provided one,
 446  *                      POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding
 447  *                      while decrypting or a cipher specific error code.
 448  */
 449 int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen);
 450
 451
 452 /**
 453  * \brief          Checkup routine
 454  *
 455  * \return         0 if successful, or 1 if the test failed
 456  */
 457 int cipher_self_test( int verbose );
 458
 459 #ifdef __cplusplus
 460 }
 461 #endif
 462
 463 #endif /* POLARSSL_MD_H */