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 <linux/module.h>
  21 #include <linux/kernel.h>
  22 #include <linux/types.h>
  23 #include <linux/list.h>
  24 #include <linux/slab.h>
  25 #include <linux/string.h>
  26 #include <linux/uaccess.h>
  27
  28 /*
  29  * Algorithm masks and types.
  30  */
  31 #define CRYPTO_ALG_TYPE_MASK            0x000000ff
  32 #define CRYPTO_ALG_TYPE_CIPHER          0x00000001
  33 #define CRYPTO_ALG_TYPE_DIGEST          0x00000002
  34 #define CRYPTO_ALG_TYPE_COMPRESS        0x00000004
  35
  36 /*
  37  * Transform masks and values (for crt_flags).
  38  */
  39 #define CRYPTO_TFM_MODE_MASK            0x000000ff
  40 #define CRYPTO_TFM_REQ_MASK             0x000fff00
  41 #define CRYPTO_TFM_RES_MASK             0xfff00000
  42
  43 #define CRYPTO_TFM_MODE_ECB             0x00000001
  44 #define CRYPTO_TFM_MODE_CBC             0x00000002
  45 #define CRYPTO_TFM_MODE_CFB             0x00000004
  46 #define CRYPTO_TFM_MODE_CTR             0x00000008
  47
  48 #define CRYPTO_TFM_REQ_WEAK_KEY         0x00000100
  49 #define CRYPTO_TFM_REQ_MAY_SLEEP        0x00000200
  50 #define CRYPTO_TFM_RES_WEAK_KEY         0x00100000
  51 #define CRYPTO_TFM_RES_BAD_KEY_LEN      0x00200000
  52 #define CRYPTO_TFM_RES_BAD_KEY_SCHED    0x00400000
  53 #define CRYPTO_TFM_RES_BAD_BLOCK_LEN    0x00800000
  54 #define CRYPTO_TFM_RES_BAD_FLAGS        0x01000000
  55
  56 /*
  57  * Miscellaneous stuff.
  58  */
  59 #define CRYPTO_UNSPEC                   0
  60 #define CRYPTO_MAX_ALG_NAME             64
  61
  62 #define CRYPTO_DIR_ENCRYPT              1
  63 #define CRYPTO_DIR_DECRYPT              0
  64
  65 /*
  66  * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
  67  * declaration) is used to ensure that the crypto_tfm context structure is
  68  * aligned correctly for the given architecture so that there are no alignment
  69  * faults for C data types.  In particular, this is required on platforms such
  70  * as arm where pointers are 32-bit aligned but there are data types such as
  71  * u64 which require 64-bit alignment.
  72  */
  73 #if defined(ARCH_KMALLOC_MINALIGN)
  74 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
  75 #elif defined(ARCH_SLAB_MINALIGN)
  76 #define CRYPTO_MINALIGN ARCH_SLAB_MINALIGN
  77 #endif
  78
  79 #ifdef CRYPTO_MINALIGN
  80 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
  81 #else
  82 #define CRYPTO_MINALIGN_ATTR
  83 #endif
  84
  85 struct scatterlist;
  86 struct crypto_tfm;
  87
  88 struct cipher_desc {
  89         struct crypto_tfm *tfm;
  90         void (*crfn)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
  91         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  92                              const u8 *src, unsigned int nbytes);
  93         void *info;
  94 };
  95
  96 /*
  97  * Algorithms: modular crypto algorithm implementations, managed
  98  * via crypto_register_alg() and crypto_unregister_alg().
  99  */
 100 struct cipher_alg {
 101         unsigned int cia_min_keysize;
 102         unsigned int cia_max_keysize;
 103         int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 104                           unsigned int keylen, u32 *flags);
 105         void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 106         void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 107
 108         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
 109                                         u8 *dst, const u8 *src,
 110                                         unsigned int nbytes);
 111         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
 112                                         u8 *dst, const u8 *src,
 113                                         unsigned int nbytes);
 114         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
 115                                         u8 *dst, const u8 *src,
 116                                         unsigned int nbytes);
 117         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
 118                                         u8 *dst, const u8 *src,
 119                                         unsigned int nbytes);
 120 };
 121
 122 struct digest_alg {
 123         unsigned int dia_digestsize;
 124         void (*dia_init)(struct crypto_tfm *tfm);
 125         void (*dia_update)(struct crypto_tfm *tfm, const u8 *data,
 126                            unsigned int len);
 127         void (*dia_final)(struct crypto_tfm *tfm, u8 *out);
 128         int (*dia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 129                           unsigned int keylen, u32 *flags);
 130 };
 131
 132 struct compress_alg {
 133         int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
 134                             unsigned int slen, u8 *dst, unsigned int *dlen);
 135         int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
 136                               unsigned int slen, u8 *dst, unsigned int *dlen);
 137 };
 138
 139 #define cra_cipher      cra_u.cipher
 140 #define cra_digest      cra_u.digest
 141 #define cra_compress    cra_u.compress
 142
 143 struct crypto_alg {
 144         struct list_head cra_list;
 145         u32 cra_flags;
 146         unsigned int cra_blocksize;
 147         unsigned int cra_ctxsize;
 148         unsigned int cra_alignmask;
 149
 150         int cra_priority;
 151
 152         char cra_name[CRYPTO_MAX_ALG_NAME];
 153         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
 154
 155         union {
 156                 struct cipher_alg cipher;
 157                 struct digest_alg digest;
 158                 struct compress_alg compress;
 159         } cra_u;
 160
 161         int (*cra_init)(struct crypto_tfm *tfm);
 162         void (*cra_exit)(struct crypto_tfm *tfm);
 163
 164         struct module *cra_module;
 165 };
 166
 167 /*
 168  * Algorithm registration interface.
 169  */
 170 int crypto_register_alg(struct crypto_alg *alg);
 171 int crypto_unregister_alg(struct crypto_alg *alg);
 172
 173 /*
 174  * Algorithm query interface.
 175  */
 176 #ifdef CONFIG_CRYPTO
 177 int crypto_alg_available(const char *name, u32 flags);
 178 #else
 179 static inline int crypto_alg_available(const char *name, u32 flags)
 180 {
 181         return 0;
 182 }
 183 #endif
 184
 185 /*
 186  * Transforms: user-instantiated objects which encapsulate algorithms
 187  * and core processing logic.  Managed via crypto_alloc_tfm() and
 188  * crypto_free_tfm(), as well as the various helpers below.
 189  */
 190
 191 struct cipher_tfm {
 192         void *cit_iv;
 193         unsigned int cit_ivsize;
 194         u32 cit_mode;
 195         int (*cit_setkey)(struct crypto_tfm *tfm,
 196                           const u8 *key, unsigned int keylen);
 197         int (*cit_encrypt)(struct crypto_tfm *tfm,
 198                            struct scatterlist *dst,
 199                            struct scatterlist *src,
 200                            unsigned int nbytes);
 201         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 202                               struct scatterlist *dst,
 203                               struct scatterlist *src,
 204                               unsigned int nbytes, u8 *iv);
 205         int (*cit_decrypt)(struct crypto_tfm *tfm,
 206                            struct scatterlist *dst,
 207                            struct scatterlist *src,
 208                            unsigned int nbytes);
 209         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 210                            struct scatterlist *dst,
 211                            struct scatterlist *src,
 212                            unsigned int nbytes, u8 *iv);
 213         void (*cit_xor_block)(u8 *dst, const u8 *src);
 214 };
 215
 216 struct digest_tfm {
 217         void (*dit_init)(struct crypto_tfm *tfm);
 218         void (*dit_update)(struct crypto_tfm *tfm,
 219                            struct scatterlist *sg, unsigned int nsg);
 220         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 221         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 222                            unsigned int nsg, u8 *out);
 223         int (*dit_setkey)(struct crypto_tfm *tfm,
 224                           const u8 *key, unsigned int keylen);
 225 #ifdef CONFIG_CRYPTO_HMAC
 226         void *dit_hmac_block;
 227 #endif
 228 };
 229
 230 struct compress_tfm {
 231         int (*cot_compress)(struct crypto_tfm *tfm,
 232                             const u8 *src, unsigned int slen,
 233                             u8 *dst, unsigned int *dlen);
 234         int (*cot_decompress)(struct crypto_tfm *tfm,
 235                               const u8 *src, unsigned int slen,
 236                               u8 *dst, unsigned int *dlen);
 237 };
 238
 239 #define crt_cipher      crt_u.cipher
 240 #define crt_digest      crt_u.digest
 241 #define crt_compress    crt_u.compress
 242
 243 struct crypto_tfm {
 244
 245         u32 crt_flags;
 246
 247         union {
 248                 struct cipher_tfm cipher;
 249                 struct digest_tfm digest;
 250                 struct compress_tfm compress;
 251         } crt_u;
 252
 253         struct crypto_alg *__crt_alg;
 254
 255         void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 256 };
 257
 258 /*
 259  * Transform user interface.
 260  */
 261
 262 /*
 263  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
 264  * If that fails and the kernel supports dynamically loadable modules, it
 265  * will then attempt to load a module of the same name or alias.  A refcount
 266  * is grabbed on the algorithm which is then associated with the new transform.
 267  *
 268  * crypto_free_tfm() frees up the transform and any associated resources,
 269  * then drops the refcount on the associated algorithm.
 270  */
 271 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 272 void crypto_free_tfm(struct crypto_tfm *tfm);
 273
 274 /*
 275  * Transform helpers which query the underlying algorithm.
 276  */
 277 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 278 {
 279         return tfm->__crt_alg->cra_name;
 280 }
 281
 282 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 283 {
 284         return module_name(tfm->__crt_alg->cra_module);
 285 }
 286
 287 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 288 {
 289         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 290 }
 291
 292 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 293 {
 294         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 295         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 296 }
 297
 298 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 299 {
 300         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 301         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 302 }
 303
 304 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 305 {
 306         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 307         return tfm->crt_cipher.cit_ivsize;
 308 }
 309
 310 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 311 {
 312         return tfm->__crt_alg->cra_blocksize;
 313 }
 314
 315 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 316 {
 317         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 318         return tfm->__crt_alg->cra_digest.dia_digestsize;
 319 }
 320
 321 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 322 {
 323         return tfm->__crt_alg->cra_alignmask;
 324 }
 325
 326 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 327 {
 328         return tfm->__crt_ctx;
 329 }
 330
 331 static inline unsigned int crypto_tfm_ctx_alignment(void)
 332 {
 333         struct crypto_tfm *tfm;
 334         return __alignof__(tfm->__crt_ctx);
 335 }
 336
 337 /*
 338  * API wrappers.
 339  */
 340 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 341 {
 342         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 343         tfm->crt_digest.dit_init(tfm);
 344 }
 345
 346 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 347                                         struct scatterlist *sg,
 348                                         unsigned int nsg)
 349 {
 350         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 351         tfm->crt_digest.dit_update(tfm, sg, nsg);
 352 }
 353
 354 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 355 {
 356         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 357         tfm->crt_digest.dit_final(tfm, out);
 358 }
 359
 360 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 361                                         struct scatterlist *sg,
 362                                         unsigned int nsg, u8 *out)
 363 {
 364         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 365         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 366 }
 367
 368 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 369                                        const u8 *key, unsigned int keylen)
 370 {
 371         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 372         if (tfm->crt_digest.dit_setkey == NULL)
 373                 return -ENOSYS;
 374         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 375 }
 376
 377 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 378                                        const u8 *key, unsigned int keylen)
 379 {
 380         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 381         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 382 }
 383
 384 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 385                                         struct scatterlist *dst,
 386                                         struct scatterlist *src,
 387                                         unsigned int nbytes)
 388 {
 389         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 390         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 391 }
 392
 393 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 394                                            struct scatterlist *dst,
 395                                            struct scatterlist *src,
 396                                            unsigned int nbytes, u8 *iv)
 397 {
 398         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 399         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 400         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 401 }
 402
 403 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 404                                         struct scatterlist *dst,
 405                                         struct scatterlist *src,
 406                                         unsigned int nbytes)
 407 {
 408         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 409         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 410 }
 411
 412 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 413                                            struct scatterlist *dst,
 414                                            struct scatterlist *src,
 415                                            unsigned int nbytes, u8 *iv)
 416 {
 417         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 418         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 419         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 420 }
 421
 422 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 423                                         const u8 *src, unsigned int len)
 424 {
 425         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 426         memcpy(tfm->crt_cipher.cit_iv, src, len);
 427 }
 428
 429 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 430                                         u8 *dst, unsigned int len)
 431 {
 432         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 433         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 434 }
 435
 436 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 437                                        const u8 *src, unsigned int slen,
 438                                        u8 *dst, unsigned int *dlen)
 439 {
 440         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 441         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 442 }
 443
 444 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 445                                          const u8 *src, unsigned int slen,
 446                                          u8 *dst, unsigned int *dlen)
 447 {
 448         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 449         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 450 }
 451
 452 /*
 453  * HMAC support.
 454  */
 455 #ifdef CONFIG_CRYPTO_HMAC
 456 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 457 void crypto_hmac_update(struct crypto_tfm *tfm,
 458                         struct scatterlist *sg, unsigned int nsg);
 459 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 460                        unsigned int *keylen, u8 *out);
 461 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 462                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 463 #endif  /* CONFIG_CRYPTO_HMAC */
 464
 465 #endif  /* _LINUX_CRYPTO_H */
 466