[CRYPTO] api: Allow algorithm lookup by type
[linux-2.6.git] / 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