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            0x000000ff
  33 #define CRYPTO_ALG_TYPE_CIPHER          0x00000001
  34 #define CRYPTO_ALG_TYPE_DIGEST          0x00000002
  35 #define CRYPTO_ALG_TYPE_COMPRESS        0x00000004
  36
  37 /*
  38  * Transform masks and values (for crt_flags).
  39  */
  40 #define CRYPTO_TFM_MODE_MASK            0x000000ff
  41 #define CRYPTO_TFM_REQ_MASK             0x000fff00
  42 #define CRYPTO_TFM_RES_MASK             0xfff00000
  43
  44 #define CRYPTO_TFM_MODE_ECB             0x00000001
  45 #define CRYPTO_TFM_MODE_CBC             0x00000002
  46 #define CRYPTO_TFM_MODE_CFB             0x00000004
  47 #define CRYPTO_TFM_MODE_CTR             0x00000008
  48
  49 #define CRYPTO_TFM_REQ_WEAK_KEY         0x00000100
  50 #define CRYPTO_TFM_REQ_MAY_SLEEP        0x00000200
  51 #define CRYPTO_TFM_RES_WEAK_KEY         0x00100000
  52 #define CRYPTO_TFM_RES_BAD_KEY_LEN      0x00200000
  53 #define CRYPTO_TFM_RES_BAD_KEY_SCHED    0x00400000
  54 #define CRYPTO_TFM_RES_BAD_BLOCK_LEN    0x00800000
  55 #define CRYPTO_TFM_RES_BAD_FLAGS        0x01000000
  56
  57 /*
  58  * Miscellaneous stuff.
  59  */
  60 #define CRYPTO_UNSPEC                   0
  61 #define CRYPTO_MAX_ALG_NAME             64
  62
  63 #define CRYPTO_DIR_ENCRYPT              1
  64 #define CRYPTO_DIR_DECRYPT              0
  65
  66 /*
  67  * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
  68  * declaration) is used to ensure that the crypto_tfm context structure is
  69  * aligned correctly for the given architecture so that there are no alignment
  70  * faults for C data types.  In particular, this is required on platforms such
  71  * as arm where pointers are 32-bit aligned but there are data types such as
  72  * u64 which require 64-bit alignment.
  73  */
  74 #if defined(ARCH_KMALLOC_MINALIGN)
  75 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
  76 #elif defined(ARCH_SLAB_MINALIGN)
  77 #define CRYPTO_MINALIGN ARCH_SLAB_MINALIGN
  78 #endif
  79
  80 #ifdef CRYPTO_MINALIGN
  81 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
  82 #else
  83 #define CRYPTO_MINALIGN_ATTR
  84 #endif
  85
  86 struct scatterlist;
  87 struct crypto_tfm;
  88
  89 struct cipher_desc {
  90         struct crypto_tfm *tfm;
  91         void (*crfn)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
  92         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  93                              const u8 *src, unsigned int nbytes);
  94         void *info;
  95 };
  96
  97 /*
  98  * Algorithms: modular crypto algorithm implementations, managed
  99  * via crypto_register_alg() and crypto_unregister_alg().
 100  */
 101 struct cipher_alg {
 102         unsigned int cia_min_keysize;
 103         unsigned int cia_max_keysize;
 104         int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 105                           unsigned int keylen, u32 *flags);
 106         void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 107         void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 108
 109         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
 110                                         u8 *dst, const u8 *src,
 111                                         unsigned int nbytes);
 112         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
 113                                         u8 *dst, const u8 *src,
 114                                         unsigned int nbytes);
 115         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
 116                                         u8 *dst, const u8 *src,
 117                                         unsigned int nbytes);
 118         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
 119                                         u8 *dst, const u8 *src,
 120                                         unsigned int nbytes);
 121 };
 122
 123 struct digest_alg {
 124         unsigned int dia_digestsize;
 125         void (*dia_init)(struct crypto_tfm *tfm);
 126         void (*dia_update)(struct crypto_tfm *tfm, const u8 *data,
 127                            unsigned int len);
 128         void (*dia_final)(struct crypto_tfm *tfm, u8 *out);
 129         int (*dia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 130                           unsigned int keylen, u32 *flags);
 131 };
 132
 133 struct compress_alg {
 134         int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
 135                             unsigned int slen, u8 *dst, unsigned int *dlen);
 136         int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
 137                               unsigned int slen, u8 *dst, unsigned int *dlen);
 138 };
 139
 140 #define cra_cipher      cra_u.cipher
 141 #define cra_digest      cra_u.digest
 142 #define cra_compress    cra_u.compress
 143
 144 struct crypto_alg {
 145         struct list_head cra_list;
 146         u32 cra_flags;
 147         unsigned int cra_blocksize;
 148         unsigned int cra_ctxsize;
 149         unsigned int cra_alignmask;
 150
 151         int cra_priority;
 152         atomic_t cra_refcnt;
 153
 154         char cra_name[CRYPTO_MAX_ALG_NAME];
 155         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
 156
 157         union {
 158                 struct cipher_alg cipher;
 159                 struct digest_alg digest;
 160                 struct compress_alg compress;
 161         } cra_u;
 162
 163         int (*cra_init)(struct crypto_tfm *tfm);
 164         void (*cra_exit)(struct crypto_tfm *tfm);
 165         void (*cra_destroy)(struct crypto_alg *alg);
 166
 167         struct module *cra_module;
 168 };
 169
 170 /*
 171  * Algorithm registration interface.
 172  */
 173 int crypto_register_alg(struct crypto_alg *alg);
 174 int crypto_unregister_alg(struct crypto_alg *alg);
 175
 176 /*
 177  * Algorithm query interface.
 178  */
 179 #ifdef CONFIG_CRYPTO
 180 int crypto_alg_available(const char *name, u32 flags);
 181 #else
 182 static inline int crypto_alg_available(const char *name, u32 flags)
 183 {
 184         return 0;
 185 }
 186 #endif
 187
 188 /*
 189  * Transforms: user-instantiated objects which encapsulate algorithms
 190  * and core processing logic.  Managed via crypto_alloc_tfm() and
 191  * crypto_free_tfm(), as well as the various helpers below.
 192  */
 193
 194 struct cipher_tfm {
 195         void *cit_iv;
 196         unsigned int cit_ivsize;
 197         u32 cit_mode;
 198         int (*cit_setkey)(struct crypto_tfm *tfm,
 199                           const u8 *key, unsigned int keylen);
 200         int (*cit_encrypt)(struct crypto_tfm *tfm,
 201                            struct scatterlist *dst,
 202                            struct scatterlist *src,
 203                            unsigned int nbytes);
 204         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 205                               struct scatterlist *dst,
 206                               struct scatterlist *src,
 207                               unsigned int nbytes, u8 *iv);
 208         int (*cit_decrypt)(struct crypto_tfm *tfm,
 209                            struct scatterlist *dst,
 210                            struct scatterlist *src,
 211                            unsigned int nbytes);
 212         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 213                            struct scatterlist *dst,
 214                            struct scatterlist *src,
 215                            unsigned int nbytes, u8 *iv);
 216         void (*cit_xor_block)(u8 *dst, const u8 *src);
 217 };
 218
 219 struct digest_tfm {
 220         void (*dit_init)(struct crypto_tfm *tfm);
 221         void (*dit_update)(struct crypto_tfm *tfm,
 222                            struct scatterlist *sg, unsigned int nsg);
 223         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 224         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 225                            unsigned int nsg, u8 *out);
 226         int (*dit_setkey)(struct crypto_tfm *tfm,
 227                           const u8 *key, unsigned int keylen);
 228 #ifdef CONFIG_CRYPTO_HMAC
 229         void *dit_hmac_block;
 230 #endif
 231 };
 232
 233 struct compress_tfm {
 234         int (*cot_compress)(struct crypto_tfm *tfm,
 235                             const u8 *src, unsigned int slen,
 236                             u8 *dst, unsigned int *dlen);
 237         int (*cot_decompress)(struct crypto_tfm *tfm,
 238                               const u8 *src, unsigned int slen,
 239                               u8 *dst, unsigned int *dlen);
 240 };
 241
 242 #define crt_cipher      crt_u.cipher
 243 #define crt_digest      crt_u.digest
 244 #define crt_compress    crt_u.compress
 245
 246 struct crypto_tfm {
 247
 248         u32 crt_flags;
 249
 250         union {
 251                 struct cipher_tfm cipher;
 252                 struct digest_tfm digest;
 253                 struct compress_tfm compress;
 254         } crt_u;
 255
 256         struct crypto_alg *__crt_alg;
 257
 258         void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 259 };
 260
 261 /*
 262  * Transform user interface.
 263  */
 264
 265 /*
 266  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
 267  * If that fails and the kernel supports dynamically loadable modules, it
 268  * will then attempt to load a module of the same name or alias.  A refcount
 269  * is grabbed on the algorithm which is then associated with the new transform.
 270  *
 271  * crypto_free_tfm() frees up the transform and any associated resources,
 272  * then drops the refcount on the associated algorithm.
 273  */
 274 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 275 void crypto_free_tfm(struct crypto_tfm *tfm);
 276
 277 /*
 278  * Transform helpers which query the underlying algorithm.
 279  */
 280 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 281 {
 282         return tfm->__crt_alg->cra_name;
 283 }
 284
 285 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 286 {
 287         return module_name(tfm->__crt_alg->cra_module);
 288 }
 289
 290 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 291 {
 292         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 293 }
 294
 295 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 296 {
 297         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 298         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 299 }
 300
 301 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 302 {
 303         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 304         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 305 }
 306
 307 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 308 {
 309         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 310         return tfm->crt_cipher.cit_ivsize;
 311 }
 312
 313 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 314 {
 315         return tfm->__crt_alg->cra_blocksize;
 316 }
 317
 318 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 319 {
 320         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 321         return tfm->__crt_alg->cra_digest.dia_digestsize;
 322 }
 323
 324 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 325 {
 326         return tfm->__crt_alg->cra_alignmask;
 327 }
 328
 329 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 330 {
 331         return tfm->__crt_ctx;
 332 }
 333
 334 static inline unsigned int crypto_tfm_ctx_alignment(void)
 335 {
 336         struct crypto_tfm *tfm;
 337         return __alignof__(tfm->__crt_ctx);
 338 }
 339
 340 /*
 341  * API wrappers.
 342  */
 343 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 344 {
 345         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 346         tfm->crt_digest.dit_init(tfm);
 347 }
 348
 349 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 350                                         struct scatterlist *sg,
 351                                         unsigned int nsg)
 352 {
 353         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 354         tfm->crt_digest.dit_update(tfm, sg, nsg);
 355 }
 356
 357 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 358 {
 359         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 360         tfm->crt_digest.dit_final(tfm, out);
 361 }
 362
 363 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 364                                         struct scatterlist *sg,
 365                                         unsigned int nsg, u8 *out)
 366 {
 367         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 368         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 369 }
 370
 371 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 372                                        const u8 *key, unsigned int keylen)
 373 {
 374         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 375         if (tfm->crt_digest.dit_setkey == NULL)
 376                 return -ENOSYS;
 377         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 378 }
 379
 380 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 381                                        const u8 *key, unsigned int keylen)
 382 {
 383         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 384         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 385 }
 386
 387 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 388                                         struct scatterlist *dst,
 389                                         struct scatterlist *src,
 390                                         unsigned int nbytes)
 391 {
 392         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 393         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 394 }
 395
 396 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 397                                            struct scatterlist *dst,
 398                                            struct scatterlist *src,
 399                                            unsigned int nbytes, u8 *iv)
 400 {
 401         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 402         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 403         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 404 }
 405
 406 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 407                                         struct scatterlist *dst,
 408                                         struct scatterlist *src,
 409                                         unsigned int nbytes)
 410 {
 411         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 412         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 413 }
 414
 415 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 416                                            struct scatterlist *dst,
 417                                            struct scatterlist *src,
 418                                            unsigned int nbytes, u8 *iv)
 419 {
 420         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 421         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 422         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 423 }
 424
 425 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 426                                         const u8 *src, unsigned int len)
 427 {
 428         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 429         memcpy(tfm->crt_cipher.cit_iv, src, len);
 430 }
 431
 432 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 433                                         u8 *dst, unsigned int len)
 434 {
 435         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 436         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 437 }
 438
 439 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 440                                        const u8 *src, unsigned int slen,
 441                                        u8 *dst, unsigned int *dlen)
 442 {
 443         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 444         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 445 }
 446
 447 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 448                                          const u8 *src, unsigned int slen,
 449                                          u8 *dst, unsigned int *dlen)
 450 {
 451         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 452         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 453 }
 454
 455 /*
 456  * HMAC support.
 457  */
 458 #ifdef CONFIG_CRYPTO_HMAC
 459 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 460 void crypto_hmac_update(struct crypto_tfm *tfm,
 461                         struct scatterlist *sg, unsigned int nsg);
 462 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 463                        unsigned int *keylen, u8 *out);
 464 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 465                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 466 #endif  /* CONFIG_CRYPTO_HMAC */
 467
 468 #endif  /* _LINUX_CRYPTO_H */
 469