include/linux/crypto.h

   1 /*
   2  * Scatterlist Cryptographic API.
   3  *
   4  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
   5  * Copyright (c) 2002 David S. Miller (davem@redhat.com)
   6  * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
   7  *
   8  * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
   9  * and Nettle, by Niels Möller.
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 2 of the License, or (at your option)
  14  * any later version.
  15  *
  16  */
  17 #ifndef _LINUX_CRYPTO_H
  18 #define _LINUX_CRYPTO_H
  19
  20 #include <asm/atomic.h>
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/types.h>
  24 #include <linux/list.h>
  25 #include <linux/slab.h>
  26 #include <linux/string.h>
  27 #include <linux/uaccess.h>
  28
  29 /*
  30  * Algorithm masks and types.
  31  */
  32 #define CRYPTO_ALG_TYPE_MASK            0x0000000f
  33 #define CRYPTO_ALG_TYPE_CIPHER          0x00000001
  34 #define CRYPTO_ALG_TYPE_DIGEST          0x00000002
  35 #define CRYPTO_ALG_TYPE_COMPRESS        0x00000004
  36
  37 #define CRYPTO_ALG_LARVAL               0x00000010
  38 #define CRYPTO_ALG_DEAD                 0x00000020
  39 #define CRYPTO_ALG_DYING                0x00000040
  40 #define CRYPTO_ALG_ASYNC                0x00000080
  41
  42 /*
  43  * Transform masks and values (for crt_flags).
  44  */
  45 #define CRYPTO_TFM_MODE_MASK            0x000000ff
  46 #define CRYPTO_TFM_REQ_MASK             0x000fff00
  47 #define CRYPTO_TFM_RES_MASK             0xfff00000
  48
  49 #define CRYPTO_TFM_MODE_ECB             0x00000001
  50 #define CRYPTO_TFM_MODE_CBC             0x00000002
  51 #define CRYPTO_TFM_MODE_CFB             0x00000004
  52 #define CRYPTO_TFM_MODE_CTR             0x00000008
  53
  54 #define CRYPTO_TFM_REQ_WEAK_KEY         0x00000100
  55 #define CRYPTO_TFM_REQ_MAY_SLEEP        0x00000200
  56 #define CRYPTO_TFM_RES_WEAK_KEY         0x00100000
  57 #define CRYPTO_TFM_RES_BAD_KEY_LEN      0x00200000
  58 #define CRYPTO_TFM_RES_BAD_KEY_SCHED    0x00400000
  59 #define CRYPTO_TFM_RES_BAD_BLOCK_LEN    0x00800000
  60 #define CRYPTO_TFM_RES_BAD_FLAGS        0x01000000
  61
  62 /*
  63  * Miscellaneous stuff.
  64  */
  65 #define CRYPTO_UNSPEC                   0
  66 #define CRYPTO_MAX_ALG_NAME             64
  67
  68 #define CRYPTO_DIR_ENCRYPT              1
  69 #define CRYPTO_DIR_DECRYPT              0
  70
  71 /*
  72  * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
  73  * declaration) is used to ensure that the crypto_tfm context structure is
  74  * aligned correctly for the given architecture so that there are no alignment
  75  * faults for C data types.  In particular, this is required on platforms such
  76  * as arm where pointers are 32-bit aligned but there are data types such as
  77  * u64 which require 64-bit alignment.
  78  */
  79 #if defined(ARCH_KMALLOC_MINALIGN)
  80 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
  81 #elif defined(ARCH_SLAB_MINALIGN)
  82 #define CRYPTO_MINALIGN ARCH_SLAB_MINALIGN
  83 #endif
  84
  85 #ifdef CRYPTO_MINALIGN
  86 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
  87 #else
  88 #define CRYPTO_MINALIGN_ATTR
  89 #endif
  90
  91 struct scatterlist;
  92 struct crypto_tfm;
  93 struct crypto_type;
  94
  95 struct cipher_desc {
  96         struct crypto_tfm *tfm;
  97         void (*crfn)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
  98         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  99                              const u8 *src, unsigned int nbytes);
 100         void *info;
 101 };
 102
 103 /*
 104  * Algorithms: modular crypto algorithm implementations, managed
 105  * via crypto_register_alg() and crypto_unregister_alg().
 106  */
 107 struct cipher_alg {
 108         unsigned int cia_min_keysize;
 109         unsigned int cia_max_keysize;
 110         int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 111                           unsigned int keylen);
 112         void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 113         void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 114
 115         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
 116                                         u8 *dst, const u8 *src,
 117                                         unsigned int nbytes);
 118         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
 119                                         u8 *dst, const u8 *src,
 120                                         unsigned int nbytes);
 121         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
 122                                         u8 *dst, const u8 *src,
 123                                         unsigned int nbytes);
 124         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
 125                                         u8 *dst, const u8 *src,
 126                                         unsigned int nbytes);
 127 };
 128
 129 struct digest_alg {
 130         unsigned int dia_digestsize;
 131         void (*dia_init)(struct crypto_tfm *tfm);
 132         void (*dia_update)(struct crypto_tfm *tfm, const u8 *data,
 133                            unsigned int len);
 134         void (*dia_final)(struct crypto_tfm *tfm, u8 *out);
 135         int (*dia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 136                           unsigned int keylen);
 137 };
 138
 139 struct compress_alg {
 140         int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
 141                             unsigned int slen, u8 *dst, unsigned int *dlen);
 142         int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
 143                               unsigned int slen, u8 *dst, unsigned int *dlen);
 144 };
 145
 146 #define cra_cipher      cra_u.cipher
 147 #define cra_digest      cra_u.digest
 148 #define cra_compress    cra_u.compress
 149
 150 struct crypto_alg {
 151         struct list_head cra_list;
 152         struct list_head cra_users;
 153
 154         u32 cra_flags;
 155         unsigned int cra_blocksize;
 156         unsigned int cra_ctxsize;
 157         unsigned int cra_alignmask;
 158
 159         int cra_priority;
 160         atomic_t cra_refcnt;
 161
 162         char cra_name[CRYPTO_MAX_ALG_NAME];
 163         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
 164
 165         const struct crypto_type *cra_type;
 166
 167         union {
 168                 struct cipher_alg cipher;
 169                 struct digest_alg digest;
 170                 struct compress_alg compress;
 171         } cra_u;
 172
 173         int (*cra_init)(struct crypto_tfm *tfm);
 174         void (*cra_exit)(struct crypto_tfm *tfm);
 175         void (*cra_destroy)(struct crypto_alg *alg);
 176
 177         struct module *cra_module;
 178 };
 179
 180 /*
 181  * Algorithm registration interface.
 182  */
 183 int crypto_register_alg(struct crypto_alg *alg);
 184 int crypto_unregister_alg(struct crypto_alg *alg);
 185
 186 /*
 187  * Algorithm query interface.
 188  */
 189 #ifdef CONFIG_CRYPTO
 190 int crypto_alg_available(const char *name, u32 flags);
 191 #else
 192 static inline int crypto_alg_available(const char *name, u32 flags)
 193 {
 194         return 0;
 195 }
 196 #endif
 197
 198 /*
 199  * Transforms: user-instantiated objects which encapsulate algorithms
 200  * and core processing logic.  Managed via crypto_alloc_*() and
 201  * crypto_free_*(), as well as the various helpers below.
 202  */
 203
 204 struct cipher_tfm {
 205         void *cit_iv;
 206         unsigned int cit_ivsize;
 207         u32 cit_mode;
 208         int (*cit_setkey)(struct crypto_tfm *tfm,
 209                           const u8 *key, unsigned int keylen);
 210         int (*cit_encrypt)(struct crypto_tfm *tfm,
 211                            struct scatterlist *dst,
 212                            struct scatterlist *src,
 213                            unsigned int nbytes);
 214         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 215                               struct scatterlist *dst,
 216                               struct scatterlist *src,
 217                               unsigned int nbytes, u8 *iv);
 218         int (*cit_decrypt)(struct crypto_tfm *tfm,
 219                            struct scatterlist *dst,
 220                            struct scatterlist *src,
 221                            unsigned int nbytes);
 222         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 223                            struct scatterlist *dst,
 224                            struct scatterlist *src,
 225                            unsigned int nbytes, u8 *iv);
 226         void (*cit_xor_block)(u8 *dst, const u8 *src);
 227         void (*cit_encrypt_one)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 228         void (*cit_decrypt_one)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 229 };
 230
 231 struct digest_tfm {
 232         void (*dit_init)(struct crypto_tfm *tfm);
 233         void (*dit_update)(struct crypto_tfm *tfm,
 234                            struct scatterlist *sg, unsigned int nsg);
 235         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 236         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 237                            unsigned int nsg, u8 *out);
 238         int (*dit_setkey)(struct crypto_tfm *tfm,
 239                           const u8 *key, unsigned int keylen);
 240 #ifdef CONFIG_CRYPTO_HMAC
 241         void *dit_hmac_block;
 242 #endif
 243 };
 244
 245 struct compress_tfm {
 246         int (*cot_compress)(struct crypto_tfm *tfm,
 247                             const u8 *src, unsigned int slen,
 248                             u8 *dst, unsigned int *dlen);
 249         int (*cot_decompress)(struct crypto_tfm *tfm,
 250                               const u8 *src, unsigned int slen,
 251                               u8 *dst, unsigned int *dlen);
 252 };
 253
 254 #define crt_cipher      crt_u.cipher
 255 #define crt_digest      crt_u.digest
 256 #define crt_compress    crt_u.compress
 257
 258 struct crypto_tfm {
 259
 260         u32 crt_flags;
 261
 262         union {
 263                 struct cipher_tfm cipher;
 264                 struct digest_tfm digest;
 265                 struct compress_tfm compress;
 266         } crt_u;
 267
 268         struct crypto_alg *__crt_alg;
 269
 270         void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 271 };
 272
 273 #define crypto_cipher crypto_tfm
 274
 275 enum {
 276         CRYPTOA_UNSPEC,
 277         CRYPTOA_ALG,
 278 };
 279
 280 struct crypto_attr_alg {
 281         char name[CRYPTO_MAX_ALG_NAME];
 282 };
 283
 284 /*
 285  * Transform user interface.
 286  */
 287
 288 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 289 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask);
 290 void crypto_free_tfm(struct crypto_tfm *tfm);
 291
 292 /*
 293  * Transform helpers which query the underlying algorithm.
 294  */
 295 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 296 {
 297         return tfm->__crt_alg->cra_name;
 298 }
 299
 300 static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm)
 301 {
 302         return tfm->__crt_alg->cra_driver_name;
 303 }
 304
 305 static inline int crypto_tfm_alg_priority(struct crypto_tfm *tfm)
 306 {
 307         return tfm->__crt_alg->cra_priority;
 308 }
 309
 310 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 311 {
 312         return module_name(tfm->__crt_alg->cra_module);
 313 }
 314
 315 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 316 {
 317         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 318 }
 319
 320 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 321 {
 322         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 323         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 324 }
 325
 326 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 327 {
 328         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 329         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 330 }
 331
 332 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 333 {
 334         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 335         return tfm->crt_cipher.cit_ivsize;
 336 }
 337
 338 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 339 {
 340         return tfm->__crt_alg->cra_blocksize;
 341 }
 342
 343 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 344 {
 345         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 346         return tfm->__crt_alg->cra_digest.dia_digestsize;
 347 }
 348
 349 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 350 {
 351         return tfm->__crt_alg->cra_alignmask;
 352 }
 353
 354 static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm)
 355 {
 356         return tfm->crt_flags;
 357 }
 358
 359 static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags)
 360 {
 361         tfm->crt_flags |= flags;
 362 }
 363
 364 static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags)
 365 {
 366         tfm->crt_flags &= ~flags;
 367 }
 368
 369 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 370 {
 371         return tfm->__crt_ctx;
 372 }
 373
 374 static inline unsigned int crypto_tfm_ctx_alignment(void)
 375 {
 376         struct crypto_tfm *tfm;
 377         return __alignof__(tfm->__crt_ctx);
 378 }
 379
 380 /*
 381  * API wrappers.
 382  */
 383 static inline struct crypto_cipher *__crypto_cipher_cast(struct crypto_tfm *tfm)
 384 {
 385         return (struct crypto_cipher *)tfm;
 386 }
 387
 388 static inline struct crypto_cipher *crypto_cipher_cast(struct crypto_tfm *tfm)
 389 {
 390         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 391         return __crypto_cipher_cast(tfm);
 392 }
 393
 394 static inline struct crypto_cipher *crypto_alloc_cipher(const char *alg_name,
 395                                                         u32 type, u32 mask)
 396 {
 397         type &= ~CRYPTO_ALG_TYPE_MASK;
 398         type |= CRYPTO_ALG_TYPE_CIPHER;
 399         mask |= CRYPTO_ALG_TYPE_MASK;
 400
 401         return __crypto_cipher_cast(crypto_alloc_base(alg_name, type, mask));
 402 }
 403
 404 static inline struct crypto_tfm *crypto_cipher_tfm(struct crypto_cipher *tfm)
 405 {
 406         return tfm;
 407 }
 408
 409 static inline void crypto_free_cipher(struct crypto_cipher *tfm)
 410 {
 411         crypto_free_tfm(crypto_cipher_tfm(tfm));
 412 }
 413
 414 static inline struct cipher_tfm *crypto_cipher_crt(struct crypto_cipher *tfm)
 415 {
 416         return &crypto_cipher_tfm(tfm)->crt_cipher;
 417 }
 418
 419 static inline unsigned int crypto_cipher_blocksize(struct crypto_cipher *tfm)
 420 {
 421         return crypto_tfm_alg_blocksize(crypto_cipher_tfm(tfm));
 422 }
 423
 424 static inline unsigned int crypto_cipher_alignmask(struct crypto_cipher *tfm)
 425 {
 426         return crypto_tfm_alg_alignmask(crypto_cipher_tfm(tfm));
 427 }
 428
 429 static inline u32 crypto_cipher_get_flags(struct crypto_cipher *tfm)
 430 {
 431         return crypto_tfm_get_flags(crypto_cipher_tfm(tfm));
 432 }
 433
 434 static inline void crypto_cipher_set_flags(struct crypto_cipher *tfm,
 435                                            u32 flags)
 436 {
 437         crypto_tfm_set_flags(crypto_cipher_tfm(tfm), flags);
 438 }
 439
 440 static inline void crypto_cipher_clear_flags(struct crypto_cipher *tfm,
 441                                              u32 flags)
 442 {
 443         crypto_tfm_clear_flags(crypto_cipher_tfm(tfm), flags);
 444 }
 445
 446 static inline void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
 447                                              u8 *dst, const u8 *src)
 448 {
 449         crypto_cipher_crt(tfm)->cit_encrypt_one(crypto_cipher_tfm(tfm),
 450                                                 dst, src);
 451 }
 452
 453 static inline void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
 454                                              u8 *dst, const u8 *src)
 455 {
 456         crypto_cipher_crt(tfm)->cit_decrypt_one(crypto_cipher_tfm(tfm),
 457                                                 dst, src);
 458 }
 459
 460 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 461 {
 462         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 463         tfm->crt_digest.dit_init(tfm);
 464 }
 465
 466 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 467                                         struct scatterlist *sg,
 468                                         unsigned int nsg)
 469 {
 470         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 471         tfm->crt_digest.dit_update(tfm, sg, nsg);
 472 }
 473
 474 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 475 {
 476         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 477         tfm->crt_digest.dit_final(tfm, out);
 478 }
 479
 480 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 481                                         struct scatterlist *sg,
 482                                         unsigned int nsg, u8 *out)
 483 {
 484         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 485         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 486 }
 487
 488 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 489                                        const u8 *key, unsigned int keylen)
 490 {
 491         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 492         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 493 }
 494
 495 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 496                                        const u8 *key, unsigned int keylen)
 497 {
 498         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 499         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 500 }
 501
 502 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 503                                         struct scatterlist *dst,
 504                                         struct scatterlist *src,
 505                                         unsigned int nbytes)
 506 {
 507         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 508         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 509 }
 510
 511 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 512                                            struct scatterlist *dst,
 513                                            struct scatterlist *src,
 514                                            unsigned int nbytes, u8 *iv)
 515 {
 516         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 517         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 518 }
 519
 520 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 521                                         struct scatterlist *dst,
 522                                         struct scatterlist *src,
 523                                         unsigned int nbytes)
 524 {
 525         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 526         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 527 }
 528
 529 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 530                                            struct scatterlist *dst,
 531                                            struct scatterlist *src,
 532                                            unsigned int nbytes, u8 *iv)
 533 {
 534         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 535         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 536 }
 537
 538 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 539                                         const u8 *src, unsigned int len)
 540 {
 541         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 542         memcpy(tfm->crt_cipher.cit_iv, src, len);
 543 }
 544
 545 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 546                                         u8 *dst, unsigned int len)
 547 {
 548         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 549         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 550 }
 551
 552 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 553                                        const u8 *src, unsigned int slen,
 554                                        u8 *dst, unsigned int *dlen)
 555 {
 556         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 557         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 558 }
 559
 560 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 561                                          const u8 *src, unsigned int slen,
 562                                          u8 *dst, unsigned int *dlen)
 563 {
 564         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 565         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 566 }
 567
 568 /*
 569  * HMAC support.
 570  */
 571 #ifdef CONFIG_CRYPTO_HMAC
 572 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 573 void crypto_hmac_update(struct crypto_tfm *tfm,
 574                         struct scatterlist *sg, unsigned int nsg);
 575 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 576                        unsigned int *keylen, u8 *out);
 577 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 578                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 579 #endif  /* CONFIG_CRYPTO_HMAC */
 580
 581 #endif  /* _LINUX_CRYPTO_H */
 582