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  *
   7  * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
   8  * and Nettle, by Niels Möller.
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 2 of the License, or (at your option)
  13  * any later version.
  14  *
  15  */
  16 #ifndef _LINUX_CRYPTO_H
  17 #define _LINUX_CRYPTO_H
  18
  19 #include <linux/config.h>
  20 #include <linux/module.h>
  21 #include <linux/kernel.h>
  22 #include <linux/types.h>
  23 #include <linux/list.h>
  24 #include <linux/string.h>
  25 #include <asm/page.h>
  26
  27 /*
  28  * Algorithm masks and types.
  29  */
  30 #define CRYPTO_ALG_TYPE_MASK            0x000000ff
  31 #define CRYPTO_ALG_TYPE_CIPHER          0x00000001
  32 #define CRYPTO_ALG_TYPE_DIGEST          0x00000002
  33 #define CRYPTO_ALG_TYPE_COMPRESS        0x00000004
  34
  35 /*
  36  * Transform masks and values (for crt_flags).
  37  */
  38 #define CRYPTO_TFM_MODE_MASK            0x000000ff
  39 #define CRYPTO_TFM_REQ_MASK             0x000fff00
  40 #define CRYPTO_TFM_RES_MASK             0xfff00000
  41
  42 #define CRYPTO_TFM_MODE_ECB             0x00000001
  43 #define CRYPTO_TFM_MODE_CBC             0x00000002
  44 #define CRYPTO_TFM_MODE_CFB             0x00000004
  45 #define CRYPTO_TFM_MODE_CTR             0x00000008
  46
  47 #define CRYPTO_TFM_REQ_WEAK_KEY         0x00000100
  48 #define CRYPTO_TFM_RES_WEAK_KEY         0x00100000
  49 #define CRYPTO_TFM_RES_BAD_KEY_LEN      0x00200000
  50 #define CRYPTO_TFM_RES_BAD_KEY_SCHED    0x00400000
  51 #define CRYPTO_TFM_RES_BAD_BLOCK_LEN    0x00800000
  52 #define CRYPTO_TFM_RES_BAD_FLAGS        0x01000000
  53
  54 /*
  55  * Miscellaneous stuff.
  56  */
  57 #define CRYPTO_UNSPEC                   0
  58 #define CRYPTO_MAX_ALG_NAME             64
  59
  60 #define CRYPTO_DIR_ENCRYPT              1
  61 #define CRYPTO_DIR_DECRYPT              0
  62
  63 struct scatterlist;
  64 struct crypto_tfm;
  65
  66 struct cipher_desc {
  67         struct crypto_tfm *tfm;
  68         void (*crfn)(void *ctx, u8 *dst, const u8 *src);
  69         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  70                              const u8 *src, unsigned int nbytes);
  71         void *info;
  72 };
  73
  74 /*
  75  * Algorithms: modular crypto algorithm implementations, managed
  76  * via crypto_register_alg() and crypto_unregister_alg().
  77  */
  78 struct cipher_alg {
  79         unsigned int cia_min_keysize;
  80         unsigned int cia_max_keysize;
  81         int (*cia_setkey)(void *ctx, const u8 *key,
  82                           unsigned int keylen, u32 *flags);
  83         void (*cia_encrypt)(void *ctx, u8 *dst, const u8 *src);
  84         void (*cia_decrypt)(void *ctx, u8 *dst, const u8 *src);
  85
  86         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
  87                                         u8 *dst, const u8 *src,
  88                                         unsigned int nbytes);
  89         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
  90                                         u8 *dst, const u8 *src,
  91                                         unsigned int nbytes);
  92         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
  93                                         u8 *dst, const u8 *src,
  94                                         unsigned int nbytes);
  95         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
  96                                         u8 *dst, const u8 *src,
  97                                         unsigned int nbytes);
  98 };
  99
 100 struct digest_alg {
 101         unsigned int dia_digestsize;
 102         void (*dia_init)(void *ctx);
 103         void (*dia_update)(void *ctx, const u8 *data, unsigned int len);
 104         void (*dia_final)(void *ctx, u8 *out);
 105         int (*dia_setkey)(void *ctx, const u8 *key,
 106                           unsigned int keylen, u32 *flags);
 107 };
 108
 109 struct compress_alg {
 110         int (*coa_init)(void *ctx);
 111         void (*coa_exit)(void *ctx);
 112         int (*coa_compress)(void *ctx, const u8 *src, unsigned int slen,
 113                             u8 *dst, unsigned int *dlen);
 114         int (*coa_decompress)(void *ctx, const u8 *src, unsigned int slen,
 115                               u8 *dst, unsigned int *dlen);
 116 };
 117
 118 #define cra_cipher      cra_u.cipher
 119 #define cra_digest      cra_u.digest
 120 #define cra_compress    cra_u.compress
 121
 122 struct crypto_alg {
 123         struct list_head cra_list;
 124         u32 cra_flags;
 125         unsigned int cra_blocksize;
 126         unsigned int cra_ctxsize;
 127         unsigned int cra_alignmask;
 128         const char cra_name[CRYPTO_MAX_ALG_NAME];
 129
 130         union {
 131                 struct cipher_alg cipher;
 132                 struct digest_alg digest;
 133                 struct compress_alg compress;
 134         } cra_u;
 135
 136         struct module *cra_module;
 137 };
 138
 139 /*
 140  * Algorithm registration interface.
 141  */
 142 int crypto_register_alg(struct crypto_alg *alg);
 143 int crypto_unregister_alg(struct crypto_alg *alg);
 144
 145 /*
 146  * Algorithm query interface.
 147  */
 148 #ifdef CONFIG_CRYPTO
 149 int crypto_alg_available(const char *name, u32 flags);
 150 #else
 151 static inline int crypto_alg_available(const char *name, u32 flags)
 152 {
 153         return 0;
 154 }
 155 #endif
 156
 157 /*
 158  * Transforms: user-instantiated objects which encapsulate algorithms
 159  * and core processing logic.  Managed via crypto_alloc_tfm() and
 160  * crypto_free_tfm(), as well as the various helpers below.
 161  */
 162
 163 struct cipher_tfm {
 164         void *cit_iv;
 165         unsigned int cit_ivsize;
 166         u32 cit_mode;
 167         int (*cit_setkey)(struct crypto_tfm *tfm,
 168                           const u8 *key, unsigned int keylen);
 169         int (*cit_encrypt)(struct crypto_tfm *tfm,
 170                            struct scatterlist *dst,
 171                            struct scatterlist *src,
 172                            unsigned int nbytes);
 173         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 174                               struct scatterlist *dst,
 175                               struct scatterlist *src,
 176                               unsigned int nbytes, u8 *iv);
 177         int (*cit_decrypt)(struct crypto_tfm *tfm,
 178                            struct scatterlist *dst,
 179                            struct scatterlist *src,
 180                            unsigned int nbytes);
 181         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 182                            struct scatterlist *dst,
 183                            struct scatterlist *src,
 184                            unsigned int nbytes, u8 *iv);
 185         void (*cit_xor_block)(u8 *dst, const u8 *src);
 186 };
 187
 188 struct digest_tfm {
 189         void (*dit_init)(struct crypto_tfm *tfm);
 190         void (*dit_update)(struct crypto_tfm *tfm,
 191                            struct scatterlist *sg, unsigned int nsg);
 192         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 193         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 194                            unsigned int nsg, u8 *out);
 195         int (*dit_setkey)(struct crypto_tfm *tfm,
 196                           const u8 *key, unsigned int keylen);
 197 #ifdef CONFIG_CRYPTO_HMAC
 198         void *dit_hmac_block;
 199 #endif
 200 };
 201
 202 struct compress_tfm {
 203         int (*cot_compress)(struct crypto_tfm *tfm,
 204                             const u8 *src, unsigned int slen,
 205                             u8 *dst, unsigned int *dlen);
 206         int (*cot_decompress)(struct crypto_tfm *tfm,
 207                               const u8 *src, unsigned int slen,
 208                               u8 *dst, unsigned int *dlen);
 209 };
 210
 211 #define crt_cipher      crt_u.cipher
 212 #define crt_digest      crt_u.digest
 213 #define crt_compress    crt_u.compress
 214
 215 struct crypto_tfm {
 216
 217         u32 crt_flags;
 218
 219         union {
 220                 struct cipher_tfm cipher;
 221                 struct digest_tfm digest;
 222                 struct compress_tfm compress;
 223         } crt_u;
 224
 225         struct crypto_alg *__crt_alg;
 226 };
 227
 228 /*
 229  * Transform user interface.
 230  */
 231
 232 /*
 233  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
 234  * If that fails and the kernel supports dynamically loadable modules, it
 235  * will then attempt to load a module of the same name or alias.  A refcount
 236  * is grabbed on the algorithm which is then associated with the new transform.
 237  *
 238  * crypto_free_tfm() frees up the transform and any associated resources,
 239  * then drops the refcount on the associated algorithm.
 240  */
 241 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 242 void crypto_free_tfm(struct crypto_tfm *tfm);
 243
 244 /*
 245  * Transform helpers which query the underlying algorithm.
 246  */
 247 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 248 {
 249         return tfm->__crt_alg->cra_name;
 250 }
 251
 252 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 253 {
 254         return module_name(tfm->__crt_alg->cra_module);
 255 }
 256
 257 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 258 {
 259         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 260 }
 261
 262 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 263 {
 264         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 265         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 266 }
 267
 268 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 269 {
 270         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 271         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 272 }
 273
 274 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 275 {
 276         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 277         return tfm->crt_cipher.cit_ivsize;
 278 }
 279
 280 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 281 {
 282         return tfm->__crt_alg->cra_blocksize;
 283 }
 284
 285 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 286 {
 287         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 288         return tfm->__crt_alg->cra_digest.dia_digestsize;
 289 }
 290
 291 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 292 {
 293         return tfm->__crt_alg->cra_alignmask;
 294 }
 295
 296 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 297 {
 298         return (void *)&tfm[1];
 299 }
 300
 301 /*
 302  * API wrappers.
 303  */
 304 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 305 {
 306         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 307         tfm->crt_digest.dit_init(tfm);
 308 }
 309
 310 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 311                                         struct scatterlist *sg,
 312                                         unsigned int nsg)
 313 {
 314         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 315         tfm->crt_digest.dit_update(tfm, sg, nsg);
 316 }
 317
 318 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 319 {
 320         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 321         tfm->crt_digest.dit_final(tfm, out);
 322 }
 323
 324 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 325                                         struct scatterlist *sg,
 326                                         unsigned int nsg, u8 *out)
 327 {
 328         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 329         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 330 }
 331
 332 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 333                                        const u8 *key, unsigned int keylen)
 334 {
 335         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 336         if (tfm->crt_digest.dit_setkey == NULL)
 337                 return -ENOSYS;
 338         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 339 }
 340
 341 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 342                                        const u8 *key, unsigned int keylen)
 343 {
 344         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 345         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 346 }
 347
 348 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 349                                         struct scatterlist *dst,
 350                                         struct scatterlist *src,
 351                                         unsigned int nbytes)
 352 {
 353         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 354         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 355 }
 356
 357 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 358                                            struct scatterlist *dst,
 359                                            struct scatterlist *src,
 360                                            unsigned int nbytes, u8 *iv)
 361 {
 362         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 363         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 364         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 365 }
 366
 367 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 368                                         struct scatterlist *dst,
 369                                         struct scatterlist *src,
 370                                         unsigned int nbytes)
 371 {
 372         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 373         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 374 }
 375
 376 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 377                                            struct scatterlist *dst,
 378                                            struct scatterlist *src,
 379                                            unsigned int nbytes, u8 *iv)
 380 {
 381         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 382         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 383         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 384 }
 385
 386 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 387                                         const u8 *src, unsigned int len)
 388 {
 389         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 390         memcpy(tfm->crt_cipher.cit_iv, src, len);
 391 }
 392
 393 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 394                                         u8 *dst, unsigned int len)
 395 {
 396         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 397         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 398 }
 399
 400 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 401                                        const u8 *src, unsigned int slen,
 402                                        u8 *dst, unsigned int *dlen)
 403 {
 404         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 405         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 406 }
 407
 408 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 409                                          const u8 *src, unsigned int slen,
 410                                          u8 *dst, unsigned int *dlen)
 411 {
 412         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 413         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 414 }
 415
 416 /*
 417  * HMAC support.
 418  */
 419 #ifdef CONFIG_CRYPTO_HMAC
 420 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 421 void crypto_hmac_update(struct crypto_tfm *tfm,
 422                         struct scatterlist *sg, unsigned int nsg);
 423 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 424                        unsigned int *keylen, u8 *out);
 425 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 426                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 427 #endif  /* CONFIG_CRYPTO_HMAC */
 428
 429 #endif  /* _LINUX_CRYPTO_H */
 430