[CRYPTO] Add alignmask for low-level cipher implementations
[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  *
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 void *crypto_tfm_ctx(struct crypto_tfm *tfm)
292 {
293         return (void *)&tfm[1];
294 }
295
296 /*
297  * API wrappers.
298  */
299 static inline void crypto_digest_init(struct crypto_tfm *tfm)
300 {
301         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
302         tfm->crt_digest.dit_init(tfm);
303 }
304
305 static inline void crypto_digest_update(struct crypto_tfm *tfm,
306                                         struct scatterlist *sg,
307                                         unsigned int nsg)
308 {
309         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
310         tfm->crt_digest.dit_update(tfm, sg, nsg);
311 }
312
313 static inline void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
314 {
315         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
316         tfm->crt_digest.dit_final(tfm, out);
317 }
318
319 static inline void crypto_digest_digest(struct crypto_tfm *tfm,
320                                         struct scatterlist *sg,
321                                         unsigned int nsg, u8 *out)
322 {
323         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
324         tfm->crt_digest.dit_digest(tfm, sg, nsg, out);
325 }
326
327 static inline int crypto_digest_setkey(struct crypto_tfm *tfm,
328                                        const u8 *key, unsigned int keylen)
329 {
330         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_DIGEST);
331         if (tfm->crt_digest.dit_setkey == NULL)
332                 return -ENOSYS;
333         return tfm->crt_digest.dit_setkey(tfm, key, keylen);
334 }
335
336 static inline int crypto_cipher_setkey(struct crypto_tfm *tfm,
337                                        const u8 *key, unsigned int keylen)
338 {
339         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
340         return tfm->crt_cipher.cit_setkey(tfm, key, keylen);
341 }
342
343 static inline int crypto_cipher_encrypt(struct crypto_tfm *tfm,
344                                         struct scatterlist *dst,
345                                         struct scatterlist *src,
346                                         unsigned int nbytes)
347 {
348         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
349         return tfm->crt_cipher.cit_encrypt(tfm, dst, src, nbytes);
350 }                                        
351
352 static inline int crypto_cipher_encrypt_iv(struct crypto_tfm *tfm,
353                                            struct scatterlist *dst,
354                                            struct scatterlist *src,
355                                            unsigned int nbytes, u8 *iv)
356 {
357         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
358         BUG_ON(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB);
359         return tfm->crt_cipher.cit_encrypt_iv(tfm, dst, src, nbytes, iv);
360 }                                        
361
362 static inline int crypto_cipher_decrypt(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_decrypt(tfm, dst, src, nbytes);
369 }
370
371 static inline int crypto_cipher_decrypt_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_decrypt_iv(tfm, dst, src, nbytes, iv);
379 }
380
381 static inline void crypto_cipher_set_iv(struct crypto_tfm *tfm,
382                                         const u8 *src, unsigned int len)
383 {
384         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
385         memcpy(tfm->crt_cipher.cit_iv, src, len);
386 }
387
388 static inline void crypto_cipher_get_iv(struct crypto_tfm *tfm,
389                                         u8 *dst, unsigned int len)
390 {
391         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER);
392         memcpy(dst, tfm->crt_cipher.cit_iv, len);
393 }
394
395 static inline int crypto_comp_compress(struct crypto_tfm *tfm,
396                                        const u8 *src, unsigned int slen,
397                                        u8 *dst, unsigned int *dlen)
398 {
399         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
400         return tfm->crt_compress.cot_compress(tfm, src, slen, dst, dlen);
401 }
402
403 static inline int crypto_comp_decompress(struct crypto_tfm *tfm,
404                                          const u8 *src, unsigned int slen,
405                                          u8 *dst, unsigned int *dlen)
406 {
407         BUG_ON(crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_COMPRESS);
408         return tfm->crt_compress.cot_decompress(tfm, src, slen, dst, dlen);
409 }
410
411 /*
412  * HMAC support.
413  */
414 #ifdef CONFIG_CRYPTO_HMAC
415 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen);
416 void crypto_hmac_update(struct crypto_tfm *tfm,
417                         struct scatterlist *sg, unsigned int nsg);
418 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
419                        unsigned int *keylen, u8 *out);
420 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
421                  struct scatterlist *sg, unsigned int nsg, u8 *out);
422 #endif  /* CONFIG_CRYPTO_HMAC */
423
424 #endif  /* _LINUX_CRYPTO_H */
425