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
  94 struct cipher_desc {
  95         struct crypto_tfm *tfm;
  96         void (*crfn)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
  97         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  98                              const u8 *src, unsigned int nbytes);
  99         void *info;
 100 };
 101
 102 /*
 103  * Algorithms: modular crypto algorithm implementations, managed
 104  * via crypto_register_alg() and crypto_unregister_alg().
 105  */
 106 struct cipher_alg {
 107         unsigned int cia_min_keysize;
 108         unsigned int cia_max_keysize;
 109         int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 110                           unsigned int keylen);
 111         void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 112         void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 113
 114         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
 115                                         u8 *dst, const u8 *src,
 116                                         unsigned int nbytes);
 117         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
 118                                         u8 *dst, const u8 *src,
 119                                         unsigned int nbytes);
 120         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
 121                                         u8 *dst, const u8 *src,
 122                                         unsigned int nbytes);
 123         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
 124                                         u8 *dst, const u8 *src,
 125                                         unsigned int nbytes);
 126 };
 127
 128 struct digest_alg {
 129         unsigned int dia_digestsize;
 130         void (*dia_init)(struct crypto_tfm *tfm);
 131         void (*dia_update)(struct crypto_tfm *tfm, const u8 *data,
 132                            unsigned int len);
 133         void (*dia_final)(struct crypto_tfm *tfm, u8 *out);
 134         int (*dia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 135                           unsigned int keylen);
 136 };
 137
 138 struct compress_alg {
 139         int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
 140                             unsigned int slen, u8 *dst, unsigned int *dlen);
 141         int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
 142                               unsigned int slen, u8 *dst, unsigned int *dlen);
 143 };
 144
 145 #define cra_cipher      cra_u.cipher
 146 #define cra_digest      cra_u.digest
 147 #define cra_compress    cra_u.compress
 148
 149 struct crypto_alg {
 150         struct list_head cra_list;
 151         struct list_head cra_users;
 152
 153         u32 cra_flags;
 154         unsigned int cra_blocksize;
 155         unsigned int cra_ctxsize;
 156         unsigned int cra_alignmask;
 157
 158         int cra_priority;
 159         atomic_t cra_refcnt;
 160
 161         char cra_name[CRYPTO_MAX_ALG_NAME];
 162         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
 163
 164         union {
 165                 struct cipher_alg cipher;
 166                 struct digest_alg digest;
 167                 struct compress_alg compress;
 168         } cra_u;
 169
 170         int (*cra_init)(struct crypto_tfm *tfm);
 171         void (*cra_exit)(struct crypto_tfm *tfm);
 172         void (*cra_destroy)(struct crypto_alg *alg);
 173
 174         struct module *cra_module;
 175 };
 176
 177 /*
 178  * Algorithm registration interface.
 179  */
 180 int crypto_register_alg(struct crypto_alg *alg);
 181 int crypto_unregister_alg(struct crypto_alg *alg);
 182
 183 /*
 184  * Algorithm query interface.
 185  */
 186 #ifdef CONFIG_CRYPTO
 187 int crypto_alg_available(const char *name, u32 flags);
 188 #else
 189 static inline int crypto_alg_available(const char *name, u32 flags)
 190 {
 191         return 0;
 192 }
 193 #endif
 194
 195 /*
 196  * Transforms: user-instantiated objects which encapsulate algorithms
 197  * and core processing logic.  Managed via crypto_alloc_tfm() and
 198  * crypto_free_tfm(), as well as the various helpers below.
 199  */
 200
 201 struct cipher_tfm {
 202         void *cit_iv;
 203         unsigned int cit_ivsize;
 204         u32 cit_mode;
 205         int (*cit_setkey)(struct crypto_tfm *tfm,
 206                           const u8 *key, unsigned int keylen);
 207         int (*cit_encrypt)(struct crypto_tfm *tfm,
 208                            struct scatterlist *dst,
 209                            struct scatterlist *src,
 210                            unsigned int nbytes);
 211         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 212                               struct scatterlist *dst,
 213                               struct scatterlist *src,
 214                               unsigned int nbytes, u8 *iv);
 215         int (*cit_decrypt)(struct crypto_tfm *tfm,
 216                            struct scatterlist *dst,
 217                            struct scatterlist *src,
 218                            unsigned int nbytes);
 219         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 220                            struct scatterlist *dst,
 221                            struct scatterlist *src,
 222                            unsigned int nbytes, u8 *iv);
 223         void (*cit_xor_block)(u8 *dst, const u8 *src);
 224 };
 225
 226 struct digest_tfm {
 227         void (*dit_init)(struct crypto_tfm *tfm);
 228         void (*dit_update)(struct crypto_tfm *tfm,
 229                            struct scatterlist *sg, unsigned int nsg);
 230         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 231         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 232                            unsigned int nsg, u8 *out);
 233         int (*dit_setkey)(struct crypto_tfm *tfm,
 234                           const u8 *key, unsigned int keylen);
 235 #ifdef CONFIG_CRYPTO_HMAC
 236         void *dit_hmac_block;
 237 #endif
 238 };
 239
 240 struct compress_tfm {
 241         int (*cot_compress)(struct crypto_tfm *tfm,
 242                             const u8 *src, unsigned int slen,
 243                             u8 *dst, unsigned int *dlen);
 244         int (*cot_decompress)(struct crypto_tfm *tfm,
 245                               const u8 *src, unsigned int slen,
 246                               u8 *dst, unsigned int *dlen);
 247 };
 248
 249 #define crt_cipher      crt_u.cipher
 250 #define crt_digest      crt_u.digest
 251 #define crt_compress    crt_u.compress
 252
 253 struct crypto_tfm {
 254
 255         u32 crt_flags;
 256
 257         union {
 258                 struct cipher_tfm cipher;
 259                 struct digest_tfm digest;
 260                 struct compress_tfm compress;
 261         } crt_u;
 262
 263         struct crypto_alg *__crt_alg;
 264
 265         void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 266 };
 267
 268 enum {
 269         CRYPTOA_UNSPEC,
 270         CRYPTOA_ALG,
 271 };
 272
 273 struct crypto_attr_alg {
 274         char name[CRYPTO_MAX_ALG_NAME];
 275 };
 276
 277 /*
 278  * Transform user interface.
 279  */
 280
 281 /*
 282  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
 283  * If that fails and the kernel supports dynamically loadable modules, it
 284  * will then attempt to load a module of the same name or alias.  A refcount
 285  * is grabbed on the algorithm which is then associated with the new transform.
 286  *
 287  * crypto_free_tfm() frees up the transform and any associated resources,
 288  * then drops the refcount on the associated algorithm.
 289  */
 290 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 291 void crypto_free_tfm(struct crypto_tfm *tfm);
 292
 293 /*
 294  * Transform helpers which query the underlying algorithm.
 295  */
 296 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 297 {
 298         return tfm->__crt_alg->cra_name;
 299 }
 300
 301 static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm)
 302 {
 303         return tfm->__crt_alg->cra_driver_name;
 304 }
 305
 306 static inline int crypto_tfm_alg_priority(struct crypto_tfm *tfm)
 307 {
 308         return tfm->__crt_alg->cra_priority;
 309 }
 310
 311 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 312 {
 313         return module_name(tfm->__crt_alg->cra_module);
 314 }
 315
 316 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 317 {
 318         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 319 }
 320
 321 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 322 {
 323         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 324         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 325 }
 326
 327 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 328 {
 329         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 330         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 331 }
 332
 333 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 334 {
 335         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 336         return tfm->crt_cipher.cit_ivsize;
 337 }
 338
 339 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 340 {
 341         return tfm->__crt_alg->cra_blocksize;
 342 }
 343
 344 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 345 {
 346         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 347         return tfm->__crt_alg->cra_digest.dia_digestsize;
 348 }
 349
 350 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 351 {
 352         return tfm->__crt_alg->cra_alignmask;
 353 }
 354
 355 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 356 {
 357         return tfm->__crt_ctx;
 358 }
 359
 360 static inline unsigned int crypto_tfm_ctx_alignment(void)
 361 {
 362         struct crypto_tfm *tfm;
 363         return __alignof__(tfm->__crt_ctx);
 364 }
 365
 366 /*
 367  * API wrappers.
 368  */
 369 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 370 {
 371         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 372         tfm->crt_digest.dit_init(tfm);
 373 }
 374
 375 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 376                                         struct scatterlist *sg,
 377                                         unsigned int nsg)
 378 {
 379         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 380         tfm->crt_digest.dit_update(tfm, sg, nsg);
 381 }
 382
 383 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 384 {
 385         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 386         tfm->crt_digest.dit_final(tfm, out);
 387 }
 388
 389 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 390                                         struct scatterlist *sg,
 391                                         unsigned int nsg, u8 *out)
 392 {
 393         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 394         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 395 }
 396
 397 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 398                                        const u8 *key, unsigned int keylen)
 399 {
 400         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 401         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 402 }
 403
 404 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 405                                        const u8 *key, unsigned int keylen)
 406 {
 407         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 408         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 409 }
 410
 411 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 412                                         struct scatterlist *dst,
 413                                         struct scatterlist *src,
 414                                         unsigned int nbytes)
 415 {
 416         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 417         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 418 }
 419
 420 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 421                                            struct scatterlist *dst,
 422                                            struct scatterlist *src,
 423                                            unsigned int nbytes, u8 *iv)
 424 {
 425         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 426         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 427 }
 428
 429 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 430                                         struct scatterlist *dst,
 431                                         struct scatterlist *src,
 432                                         unsigned int nbytes)
 433 {
 434         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 435         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 436 }
 437
 438 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 439                                            struct scatterlist *dst,
 440                                            struct scatterlist *src,
 441                                            unsigned int nbytes, u8 *iv)
 442 {
 443         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 444         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 445 }
 446
 447 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 448                                         const u8 *src, unsigned int len)
 449 {
 450         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 451         memcpy(tfm->crt_cipher.cit_iv, src, len);
 452 }
 453
 454 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 455                                         u8 *dst, unsigned int len)
 456 {
 457         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 458         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 459 }
 460
 461 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 462                                        const u8 *src, unsigned int slen,
 463                                        u8 *dst, unsigned int *dlen)
 464 {
 465         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 466         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 467 }
 468
 469 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 470                                          const u8 *src, unsigned int slen,
 471                                          u8 *dst, unsigned int *dlen)
 472 {
 473         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 474         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 475 }
 476
 477 /*
 478  * HMAC support.
 479  */
 480 #ifdef CONFIG_CRYPTO_HMAC
 481 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 482 void crypto_hmac_update(struct crypto_tfm *tfm,
 483                         struct scatterlist *sg, unsigned int nsg);
 484 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 485                        unsigned int *keylen, u8 *out);
 486 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 487                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 488 #endif  /* CONFIG_CRYPTO_HMAC */
 489
 490 #endif  /* _LINUX_CRYPTO_H */
 491