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