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
  39 /*
  40  * Transform masks and values (for crt_flags).
  41  */
  42 #define CRYPTO_TFM_MODE_MASK            0x000000ff
  43 #define CRYPTO_TFM_REQ_MASK             0x000fff00
  44 #define CRYPTO_TFM_RES_MASK             0xfff00000
  45
  46 #define CRYPTO_TFM_MODE_ECB             0x00000001
  47 #define CRYPTO_TFM_MODE_CBC             0x00000002
  48 #define CRYPTO_TFM_MODE_CFB             0x00000004
  49 #define CRYPTO_TFM_MODE_CTR             0x00000008
  50
  51 #define CRYPTO_TFM_REQ_WEAK_KEY         0x00000100
  52 #define CRYPTO_TFM_REQ_MAY_SLEEP        0x00000200
  53 #define CRYPTO_TFM_RES_WEAK_KEY         0x00100000
  54 #define CRYPTO_TFM_RES_BAD_KEY_LEN      0x00200000
  55 #define CRYPTO_TFM_RES_BAD_KEY_SCHED    0x00400000
  56 #define CRYPTO_TFM_RES_BAD_BLOCK_LEN    0x00800000
  57 #define CRYPTO_TFM_RES_BAD_FLAGS        0x01000000
  58
  59 /*
  60  * Miscellaneous stuff.
  61  */
  62 #define CRYPTO_UNSPEC                   0
  63 #define CRYPTO_MAX_ALG_NAME             64
  64
  65 #define CRYPTO_DIR_ENCRYPT              1
  66 #define CRYPTO_DIR_DECRYPT              0
  67
  68 /*
  69  * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
  70  * declaration) is used to ensure that the crypto_tfm context structure is
  71  * aligned correctly for the given architecture so that there are no alignment
  72  * faults for C data types.  In particular, this is required on platforms such
  73  * as arm where pointers are 32-bit aligned but there are data types such as
  74  * u64 which require 64-bit alignment.
  75  */
  76 #if defined(ARCH_KMALLOC_MINALIGN)
  77 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
  78 #elif defined(ARCH_SLAB_MINALIGN)
  79 #define CRYPTO_MINALIGN ARCH_SLAB_MINALIGN
  80 #endif
  81
  82 #ifdef CRYPTO_MINALIGN
  83 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
  84 #else
  85 #define CRYPTO_MINALIGN_ATTR
  86 #endif
  87
  88 struct scatterlist;
  89 struct crypto_tfm;
  90
  91 struct cipher_desc {
  92         struct crypto_tfm *tfm;
  93         void (*crfn)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
  94         unsigned int (*prfn)(const struct cipher_desc *desc, u8 *dst,
  95                              const u8 *src, unsigned int nbytes);
  96         void *info;
  97 };
  98
  99 /*
 100  * Algorithms: modular crypto algorithm implementations, managed
 101  * via crypto_register_alg() and crypto_unregister_alg().
 102  */
 103 struct cipher_alg {
 104         unsigned int cia_min_keysize;
 105         unsigned int cia_max_keysize;
 106         int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 107                           unsigned int keylen, u32 *flags);
 108         void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 109         void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
 110
 111         unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,
 112                                         u8 *dst, const u8 *src,
 113                                         unsigned int nbytes);
 114         unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,
 115                                         u8 *dst, const u8 *src,
 116                                         unsigned int nbytes);
 117         unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,
 118                                         u8 *dst, const u8 *src,
 119                                         unsigned int nbytes);
 120         unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,
 121                                         u8 *dst, const u8 *src,
 122                                         unsigned int nbytes);
 123 };
 124
 125 struct digest_alg {
 126         unsigned int dia_digestsize;
 127         void (*dia_init)(struct crypto_tfm *tfm);
 128         void (*dia_update)(struct crypto_tfm *tfm, const u8 *data,
 129                            unsigned int len);
 130         void (*dia_final)(struct crypto_tfm *tfm, u8 *out);
 131         int (*dia_setkey)(struct crypto_tfm *tfm, const u8 *key,
 132                           unsigned int keylen, u32 *flags);
 133 };
 134
 135 struct compress_alg {
 136         int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
 137                             unsigned int slen, u8 *dst, unsigned int *dlen);
 138         int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
 139                               unsigned int slen, u8 *dst, unsigned int *dlen);
 140 };
 141
 142 #define cra_cipher      cra_u.cipher
 143 #define cra_digest      cra_u.digest
 144 #define cra_compress    cra_u.compress
 145
 146 struct crypto_alg {
 147         struct list_head cra_list;
 148         u32 cra_flags;
 149         unsigned int cra_blocksize;
 150         unsigned int cra_ctxsize;
 151         unsigned int cra_alignmask;
 152
 153         int cra_priority;
 154         atomic_t cra_refcnt;
 155
 156         char cra_name[CRYPTO_MAX_ALG_NAME];
 157         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
 158
 159         union {
 160                 struct cipher_alg cipher;
 161                 struct digest_alg digest;
 162                 struct compress_alg compress;
 163         } cra_u;
 164
 165         int (*cra_init)(struct crypto_tfm *tfm);
 166         void (*cra_exit)(struct crypto_tfm *tfm);
 167         void (*cra_destroy)(struct crypto_alg *alg);
 168
 169         struct module *cra_module;
 170 };
 171
 172 /*
 173  * Algorithm registration interface.
 174  */
 175 int crypto_register_alg(struct crypto_alg *alg);
 176 int crypto_unregister_alg(struct crypto_alg *alg);
 177
 178 /*
 179  * Algorithm query interface.
 180  */
 181 #ifdef CONFIG_CRYPTO
 182 int crypto_alg_available(const char *name, u32 flags);
 183 #else
 184 static inline int crypto_alg_available(const char *name, u32 flags)
 185 {
 186         return 0;
 187 }
 188 #endif
 189
 190 /*
 191  * Transforms: user-instantiated objects which encapsulate algorithms
 192  * and core processing logic.  Managed via crypto_alloc_tfm() and
 193  * crypto_free_tfm(), as well as the various helpers below.
 194  */
 195
 196 struct cipher_tfm {
 197         void *cit_iv;
 198         unsigned int cit_ivsize;
 199         u32 cit_mode;
 200         int (*cit_setkey)(struct crypto_tfm *tfm,
 201                           const u8 *key, unsigned int keylen);
 202         int (*cit_encrypt)(struct crypto_tfm *tfm,
 203                            struct scatterlist *dst,
 204                            struct scatterlist *src,
 205                            unsigned int nbytes);
 206         int (*cit_encrypt_iv)(struct crypto_tfm *tfm,
 207                               struct scatterlist *dst,
 208                               struct scatterlist *src,
 209                               unsigned int nbytes, u8 *iv);
 210         int (*cit_decrypt)(struct crypto_tfm *tfm,
 211                            struct scatterlist *dst,
 212                            struct scatterlist *src,
 213                            unsigned int nbytes);
 214         int (*cit_decrypt_iv)(struct crypto_tfm *tfm,
 215                            struct scatterlist *dst,
 216                            struct scatterlist *src,
 217                            unsigned int nbytes, u8 *iv);
 218         void (*cit_xor_block)(u8 *dst, const u8 *src);
 219 };
 220
 221 struct digest_tfm {
 222         void (*dit_init)(struct crypto_tfm *tfm);
 223         void (*dit_update)(struct crypto_tfm *tfm,
 224                            struct scatterlist *sg, unsigned int nsg);
 225         void (*dit_final)(struct crypto_tfm *tfm, u8 *out);
 226         void (*dit_digest)(struct crypto_tfm *tfm, struct scatterlist *sg,
 227                            unsigned int nsg, u8 *out);
 228         int (*dit_setkey)(struct crypto_tfm *tfm,
 229                           const u8 *key, unsigned int keylen);
 230 #ifdef CONFIG_CRYPTO_HMAC
 231         void *dit_hmac_block;
 232 #endif
 233 };
 234
 235 struct compress_tfm {
 236         int (*cot_compress)(struct crypto_tfm *tfm,
 237                             const u8 *src, unsigned int slen,
 238                             u8 *dst, unsigned int *dlen);
 239         int (*cot_decompress)(struct crypto_tfm *tfm,
 240                               const u8 *src, unsigned int slen,
 241                               u8 *dst, unsigned int *dlen);
 242 };
 243
 244 #define crt_cipher      crt_u.cipher
 245 #define crt_digest      crt_u.digest
 246 #define crt_compress    crt_u.compress
 247
 248 struct crypto_tfm {
 249
 250         u32 crt_flags;
 251
 252         union {
 253                 struct cipher_tfm cipher;
 254                 struct digest_tfm digest;
 255                 struct compress_tfm compress;
 256         } crt_u;
 257
 258         struct crypto_alg *__crt_alg;
 259
 260         void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
 261 };
 262
 263 enum {
 264         CRYPTOA_UNSPEC,
 265         CRYPTOA_ALG,
 266 };
 267
 268 struct crypto_attr_alg {
 269         char name[CRYPTO_MAX_ALG_NAME];
 270 };
 271
 272 /*
 273  * Transform user interface.
 274  */
 275
 276 /*
 277  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
 278  * If that fails and the kernel supports dynamically loadable modules, it
 279  * will then attempt to load a module of the same name or alias.  A refcount
 280  * is grabbed on the algorithm which is then associated with the new transform.
 281  *
 282  * crypto_free_tfm() frees up the transform and any associated resources,
 283  * then drops the refcount on the associated algorithm.
 284  */
 285 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
 286 void crypto_free_tfm(struct crypto_tfm *tfm);
 287
 288 /*
 289  * Transform helpers which query the underlying algorithm.
 290  */
 291 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
 292 {
 293         return tfm->__crt_alg->cra_name;
 294 }
 295
 296 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
 297 {
 298         return module_name(tfm->__crt_alg->cra_module);
 299 }
 300
 301 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
 302 {
 303         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
 304 }
 305
 306 static inline unsigned int crypto_tfm_alg_min_keysize(struct crypto_tfm *tfm)
 307 {
 308         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 309         return tfm->__crt_alg->cra_cipher.cia_min_keysize;
 310 }
 311
 312 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
 313 {
 314         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 315         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
 316 }
 317
 318 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
 319 {
 320         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 321         return tfm->crt_cipher.cit_ivsize;
 322 }
 323
 324 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
 325 {
 326         return tfm->__crt_alg->cra_blocksize;
 327 }
 328
 329 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
 330 {
 331         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 332         return tfm->__crt_alg->cra_digest.dia_digestsize;
 333 }
 334
 335 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
 336 {
 337         return tfm->__crt_alg->cra_alignmask;
 338 }
 339
 340 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
 341 {
 342         return tfm->__crt_ctx;
 343 }
 344
 345 static inline unsigned int crypto_tfm_ctx_alignment(void)
 346 {
 347         struct crypto_tfm *tfm;
 348         return __alignof__(tfm->__crt_ctx);
 349 }
 350
 351 /*
 352  * API wrappers.
 353  */
 354 static inline void crypto_digest_init(struct crypto_tfm *tfm)
 355 {
 356         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 357         tfm->crt_digest.dit_init(tfm);
 358 }
 359
 360 static inline void crypto_digest_update(struct crypto_tfm *tfm,
 361                                         struct scatterlist *sg,
 362                                         unsigned int nsg)
 363 {
 364         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 365         tfm->crt_digest.dit_update(tfm, sg, nsg);
 366 }
 367
 368 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
 369 {
 370         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 371         tfm->crt_digest.dit_final(tfm, out);
 372 }
 373
 374 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
 375                                         struct scatterlist *sg,
 376                                         unsigned int nsg, u8 *out)
 377 {
 378         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 379         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
 380 }
 381
 382 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
 383                                        const u8 *key, unsigned int keylen)
 384 {
 385         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
 386         if (tfm->crt_digest.dit_setkey == NULL)
 387                 return -ENOSYS;
 388         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
 389 }
 390
 391 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
 392                                        const u8 *key, unsigned int keylen)
 393 {
 394         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 395         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
 396 }
 397
 398 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
 399                                         struct scatterlist *dst,
 400                                         struct scatterlist *src,
 401                                         unsigned int nbytes)
 402 {
 403         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 404         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
 405 }
 406
 407 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
 408                                            struct scatterlist *dst,
 409                                            struct scatterlist *src,
 410                                            unsigned int nbytes, u8 *iv)
 411 {
 412         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 413         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 414         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
 415 }
 416
 417 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
 418                                         struct scatterlist *dst,
 419                                         struct scatterlist *src,
 420                                         unsigned int nbytes)
 421 {
 422         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 423         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
 424 }
 425
 426 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
 427                                            struct scatterlist *dst,
 428                                            struct scatterlist *src,
 429                                            unsigned int nbytes, u8 *iv)
 430 {
 431         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 432         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
 433         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
 434 }
 435
 436 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
 437                                         const u8 *src, unsigned int len)
 438 {
 439         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 440         memcpy(tfm->crt_cipher.cit_iv, src, len);
 441 }
 442
 443 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
 444                                         u8 *dst, unsigned int len)
 445 {
 446         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
 447         memcpy(dst, tfm->crt_cipher.cit_iv, len);
 448 }
 449
 450 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
 451                                        const u8 *src, unsigned int slen,
 452                                        u8 *dst, unsigned int *dlen)
 453 {
 454         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 455         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
 456 }
 457
 458 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
 459                                          const u8 *src, unsigned int slen,
 460                                          u8 *dst, unsigned int *dlen)
 461 {
 462         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
 463         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
 464 }
 465
 466 /*
 467  * HMAC support.
 468  */
 469 #ifdef CONFIG_CRYPTO_HMAC
 470 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
 471 void crypto_hmac_update(struct crypto_tfm *tfm,
 472                         struct scatterlist *sg, unsigned int nsg);
 473 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
 474                        unsigned int *keylen, u8 *out);
 475 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
 476                  struct scatterlist *sg, unsigned int nsg, u8 *out);
 477 #endif  /* CONFIG_CRYPTO_HMAC */
 478
 479 #endif  /* _LINUX_CRYPTO_H */
 480