[CRYPTO] Allow multiple implementations of the same algorithm
[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 <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
234 /* 
235  * Transform user interface.
236  */
237  
238 /*
239  * crypto_alloc_tfm() will first attempt to locate an already loaded algorithm.
240  * If that fails and the kernel supports dynamically loadable modules, it
241  * will then attempt to load a module of the same name or alias.  A refcount
242  * is grabbed on the algorithm which is then associated with the new transform.
243  *
244  * crypto_free_tfm() frees up the transform and any associated resources,
245  * then drops the refcount on the associated algorithm.
246  */
247 struct crypto_tfm *crypto_alloc_tfm(const char *alg_name, u32 tfm_flags);
248 void crypto_free_tfm(struct crypto_tfm *tfm);
249
250 /*
251  * Transform helpers which query the underlying algorithm.
252  */
253 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
254 {
255         return tfm->__crt_alg->cra_name;
256 }
257
258 static inline const char *crypto_tfm_alg_modname(struct crypto_tfm *tfm)
259 {
260         return module_name(tfm->__crt_alg->cra_module);
261 }
262
263 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm)
264 {
265         return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
266 }
267
268 static inline unsigned int crypto_tfm_alg_min_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_min_keysize;
272 }
273
274 static inline unsigned int crypto_tfm_alg_max_keysize(struct crypto_tfm *tfm)
275 {
276         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
277         return tfm->__crt_alg->cra_cipher.cia_max_keysize;
278 }
279
280 static inline unsigned int crypto_tfm_alg_ivsize(struct crypto_tfm *tfm)
281 {
282         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
283         return tfm->crt_cipher.cit_ivsize;
284 }
285
286 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
287 {
288         return tfm->__crt_alg->cra_blocksize;
289 }
290
291 static inline unsigned int crypto_tfm_alg_digestsize(struct crypto_tfm *tfm)
292 {
293         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
294         return tfm->__crt_alg->cra_digest.dia_digestsize;
295 }
296
297 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
298 {
299         return tfm->__crt_alg->cra_alignmask;
300 }
301
302 static inline void *crypto_tfm_ctx(struct crypto_tfm *tfm)
303 {
304         return (void *)&tfm[1];
305 }
306
307 /*
308  * API wrappers.
309  */
310 static inline void crypto_digest_init(struct crypto_tfm *tfm)
311 {
312         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
313         tfm->crt_digest.dit_init(tfm);
314 }
315
316 static inline void crypto_digest_update(struct crypto_tfm *tfm,
317                                         struct scatterlist *sg,
318                                         unsigned int nsg)
319 {
320         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
321         tfm->crt_digest.dit_update(tfm, sg, nsg);
322 }
323
324 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
325 {
326         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
327         tfm->crt_digest.dit_final(tfm, out);
328 }
329
330 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
331                                         struct scatterlist *sg,
332                                         unsigned int nsg, u8 *out)
333 {
334         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
335         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
336 }
337
338 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
339                                        const u8 *key, unsigned int keylen)
340 {
341         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
342         if (tfm->crt_digest.dit_setkey == NULL)
343                 return -ENOSYS;
344         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
345 }
346
347 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
348                                        const u8 *key, unsigned int keylen)
349 {
350         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
351         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
352 }
353
354 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
355                                         struct scatterlist *dst,
356                                         struct scatterlist *src,
357                                         unsigned int nbytes)
358 {
359         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
360         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
361 }                                        
362
363 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
364                                            struct scatterlist *dst,
365                                            struct scatterlist *src,
366                                            unsigned int nbytes, u8 *iv)
367 {
368         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
369         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
370         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
371 }                                        
372
373 static inline int crypto_cipher_decrypt(struct crypto_tfm *tfm,
374                                         struct scatterlist *dst,
375                                         struct scatterlist *src,
376                                         unsigned int nbytes)
377 {
378         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
379         return tfm->crt_cipher.cit_decrypt(tfm, dst, src, nbytes);
380 }
381
382 static inline int crypto_cipher_decrypt_iv(struct crypto_tfm *tfm,
383                                            struct scatterlist *dst,
384                                            struct scatterlist *src,
385                                            unsigned int nbytes, u8 *iv)
386 {
387         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
388         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
389         return tfm->crt_cipher.cit_decrypt_iv(tfm, dst, src, nbytes, iv);
390 }
391
392 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
393                                         const u8 *src, unsigned int len)
394 {
395         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
396         memcpy(tfm->crt_cipher.cit_iv, src, len);
397 }
398
399 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
400                                         u8 *dst, unsigned int len)
401 {
402         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
403         memcpy(dst, tfm->crt_cipher.cit_iv, len);
404 }
405
406 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
407                                        const u8 *src, unsigned int slen,
408                                        u8 *dst, unsigned int *dlen)
409 {
410         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
411         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
412 }
413
414 static inline int crypto_comp_decompress(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_decompress(tfm, src, slen, dst, dlen);
420 }
421
422 /*
423  * HMAC support.
424  */
425 #ifdef CONFIG_CRYPTO_HMAC
426 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
427 void crypto_hmac_update(struct crypto_tfm *tfm,
428                         struct scatterlist *sg, unsigned int nsg);
429 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
430                        unsigned int *keylen, u8 *out);
431 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
432                  struct scatterlist *sg, unsigned int nsg, u8 *out);
433 #endif  /* CONFIG_CRYPTO_HMAC */
434
435 #endif  /* _LINUX_CRYPTO_H */
436