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1/*
2 * Symmetric key ciphers.
3 *
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#ifndef _CRYPTO_SKCIPHER_H
14#define _CRYPTO_SKCIPHER_H
15
16#include <linux/crypto.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19
20/**
21 * struct skcipher_givcrypt_request - Crypto request with IV generation
22 * @seq: Sequence number for IV generation
23 * @giv: Space for generated IV
24 * @creq: The crypto request itself
25 */
26struct skcipher_givcrypt_request {
27 u64 seq;
28 u8 *giv;
29
30 struct ablkcipher_request creq;
31};
32
33static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
34 struct skcipher_givcrypt_request *req)
35{
36 return crypto_ablkcipher_reqtfm(&req->creq);
37}
38
39static inline int crypto_skcipher_givencrypt(
40 struct skcipher_givcrypt_request *req)
41{
42 struct ablkcipher_tfm *crt =
43 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
44 return crt->givencrypt(req);
45};
46
47static inline int crypto_skcipher_givdecrypt(
48 struct skcipher_givcrypt_request *req)
49{
50 struct ablkcipher_tfm *crt =
51 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
52 return crt->givdecrypt(req);
53};
54
55static inline void skcipher_givcrypt_set_tfm(
56 struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
57{
58 req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
59}
60
61static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
62 struct crypto_async_request *req)
63{
64 return container_of(ablkcipher_request_cast(req),
65 struct skcipher_givcrypt_request, creq);
66}
67
68static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
69 struct crypto_ablkcipher *tfm, gfp_t gfp)
70{
71 struct skcipher_givcrypt_request *req;
72
73 req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
74 crypto_ablkcipher_reqsize(tfm), gfp);
75
76 if (likely(req))
77 skcipher_givcrypt_set_tfm(req, tfm);
78
79 return req;
80}
81
82static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
83{
84 kfree(req);
85}
86
87static inline void skcipher_givcrypt_set_callback(
88 struct skcipher_givcrypt_request *req, u32 flags,
89 crypto_completion_t complete, void *data)
90{
91 ablkcipher_request_set_callback(&req->creq, flags, complete, data);
92}
93
94static inline void skcipher_givcrypt_set_crypt(
95 struct skcipher_givcrypt_request *req,
96 struct scatterlist *src, struct scatterlist *dst,
97 unsigned int nbytes, void *iv)
98{
99 ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
100}
101
102static inline void skcipher_givcrypt_set_giv(
103 struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
104{
105 req->giv = giv;
106 req->seq = seq;
107}
108
109#endif /* _CRYPTO_SKCIPHER_H */
110
1/*
2 * Symmetric key ciphers.
3 *
4 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#ifndef _CRYPTO_SKCIPHER_H
14#define _CRYPTO_SKCIPHER_H
15
16#include <linux/crypto.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19
20/**
21 * struct skcipher_request - Symmetric key cipher request
22 * @cryptlen: Number of bytes to encrypt or decrypt
23 * @iv: Initialisation Vector
24 * @src: Source SG list
25 * @dst: Destination SG list
26 * @base: Underlying async request request
27 * @__ctx: Start of private context data
28 */
29struct skcipher_request {
30 unsigned int cryptlen;
31
32 u8 *iv;
33
34 struct scatterlist *src;
35 struct scatterlist *dst;
36
37 struct crypto_async_request base;
38
39 void *__ctx[] CRYPTO_MINALIGN_ATTR;
40};
41
42/**
43 * struct skcipher_givcrypt_request - Crypto request with IV generation
44 * @seq: Sequence number for IV generation
45 * @giv: Space for generated IV
46 * @creq: The crypto request itself
47 */
48struct skcipher_givcrypt_request {
49 u64 seq;
50 u8 *giv;
51
52 struct ablkcipher_request creq;
53};
54
55struct crypto_skcipher {
56 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
57 unsigned int keylen);
58 int (*encrypt)(struct skcipher_request *req);
59 int (*decrypt)(struct skcipher_request *req);
60
61 unsigned int ivsize;
62 unsigned int reqsize;
63 unsigned int keysize;
64
65 struct crypto_tfm base;
66};
67
68#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
69 char __##name##_desc[sizeof(struct skcipher_request) + \
70 crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
71 struct skcipher_request *name = (void *)__##name##_desc
72
73static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
74 struct skcipher_givcrypt_request *req)
75{
76 return crypto_ablkcipher_reqtfm(&req->creq);
77}
78
79static inline int crypto_skcipher_givencrypt(
80 struct skcipher_givcrypt_request *req)
81{
82 struct ablkcipher_tfm *crt =
83 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
84 return crt->givencrypt(req);
85};
86
87static inline int crypto_skcipher_givdecrypt(
88 struct skcipher_givcrypt_request *req)
89{
90 struct ablkcipher_tfm *crt =
91 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
92 return crt->givdecrypt(req);
93};
94
95static inline void skcipher_givcrypt_set_tfm(
96 struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
97{
98 req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
99}
100
101static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
102 struct crypto_async_request *req)
103{
104 return container_of(ablkcipher_request_cast(req),
105 struct skcipher_givcrypt_request, creq);
106}
107
108static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
109 struct crypto_ablkcipher *tfm, gfp_t gfp)
110{
111 struct skcipher_givcrypt_request *req;
112
113 req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
114 crypto_ablkcipher_reqsize(tfm), gfp);
115
116 if (likely(req))
117 skcipher_givcrypt_set_tfm(req, tfm);
118
119 return req;
120}
121
122static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
123{
124 kfree(req);
125}
126
127static inline void skcipher_givcrypt_set_callback(
128 struct skcipher_givcrypt_request *req, u32 flags,
129 crypto_completion_t compl, void *data)
130{
131 ablkcipher_request_set_callback(&req->creq, flags, compl, data);
132}
133
134static inline void skcipher_givcrypt_set_crypt(
135 struct skcipher_givcrypt_request *req,
136 struct scatterlist *src, struct scatterlist *dst,
137 unsigned int nbytes, void *iv)
138{
139 ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
140}
141
142static inline void skcipher_givcrypt_set_giv(
143 struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
144{
145 req->giv = giv;
146 req->seq = seq;
147}
148
149/**
150 * DOC: Symmetric Key Cipher API
151 *
152 * Symmetric key cipher API is used with the ciphers of type
153 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
154 *
155 * Asynchronous cipher operations imply that the function invocation for a
156 * cipher request returns immediately before the completion of the operation.
157 * The cipher request is scheduled as a separate kernel thread and therefore
158 * load-balanced on the different CPUs via the process scheduler. To allow
159 * the kernel crypto API to inform the caller about the completion of a cipher
160 * request, the caller must provide a callback function. That function is
161 * invoked with the cipher handle when the request completes.
162 *
163 * To support the asynchronous operation, additional information than just the
164 * cipher handle must be supplied to the kernel crypto API. That additional
165 * information is given by filling in the skcipher_request data structure.
166 *
167 * For the symmetric key cipher API, the state is maintained with the tfm
168 * cipher handle. A single tfm can be used across multiple calls and in
169 * parallel. For asynchronous block cipher calls, context data supplied and
170 * only used by the caller can be referenced the request data structure in
171 * addition to the IV used for the cipher request. The maintenance of such
172 * state information would be important for a crypto driver implementer to
173 * have, because when calling the callback function upon completion of the
174 * cipher operation, that callback function may need some information about
175 * which operation just finished if it invoked multiple in parallel. This
176 * state information is unused by the kernel crypto API.
177 */
178
179static inline struct crypto_skcipher *__crypto_skcipher_cast(
180 struct crypto_tfm *tfm)
181{
182 return container_of(tfm, struct crypto_skcipher, base);
183}
184
185/**
186 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
187 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
188 * skcipher cipher
189 * @type: specifies the type of the cipher
190 * @mask: specifies the mask for the cipher
191 *
192 * Allocate a cipher handle for an skcipher. The returned struct
193 * crypto_skcipher is the cipher handle that is required for any subsequent
194 * API invocation for that skcipher.
195 *
196 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
197 * of an error, PTR_ERR() returns the error code.
198 */
199struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
200 u32 type, u32 mask);
201
202static inline struct crypto_tfm *crypto_skcipher_tfm(
203 struct crypto_skcipher *tfm)
204{
205 return &tfm->base;
206}
207
208/**
209 * crypto_free_skcipher() - zeroize and free cipher handle
210 * @tfm: cipher handle to be freed
211 */
212static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
213{
214 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
215}
216
217/**
218 * crypto_has_skcipher() - Search for the availability of an skcipher.
219 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
220 * skcipher
221 * @type: specifies the type of the cipher
222 * @mask: specifies the mask for the cipher
223 *
224 * Return: true when the skcipher is known to the kernel crypto API; false
225 * otherwise
226 */
227static inline int crypto_has_skcipher(const char *alg_name, u32 type,
228 u32 mask)
229{
230 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
231 crypto_skcipher_mask(mask));
232}
233
234static inline const char *crypto_skcipher_driver_name(
235 struct crypto_skcipher *tfm)
236{
237 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm));
238}
239
240/**
241 * crypto_skcipher_ivsize() - obtain IV size
242 * @tfm: cipher handle
243 *
244 * The size of the IV for the skcipher referenced by the cipher handle is
245 * returned. This IV size may be zero if the cipher does not need an IV.
246 *
247 * Return: IV size in bytes
248 */
249static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
250{
251 return tfm->ivsize;
252}
253
254/**
255 * crypto_skcipher_blocksize() - obtain block size of cipher
256 * @tfm: cipher handle
257 *
258 * The block size for the skcipher referenced with the cipher handle is
259 * returned. The caller may use that information to allocate appropriate
260 * memory for the data returned by the encryption or decryption operation
261 *
262 * Return: block size of cipher
263 */
264static inline unsigned int crypto_skcipher_blocksize(
265 struct crypto_skcipher *tfm)
266{
267 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
268}
269
270static inline unsigned int crypto_skcipher_alignmask(
271 struct crypto_skcipher *tfm)
272{
273 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
274}
275
276static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
277{
278 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
279}
280
281static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
282 u32 flags)
283{
284 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
285}
286
287static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
288 u32 flags)
289{
290 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
291}
292
293/**
294 * crypto_skcipher_setkey() - set key for cipher
295 * @tfm: cipher handle
296 * @key: buffer holding the key
297 * @keylen: length of the key in bytes
298 *
299 * The caller provided key is set for the skcipher referenced by the cipher
300 * handle.
301 *
302 * Note, the key length determines the cipher type. Many block ciphers implement
303 * different cipher modes depending on the key size, such as AES-128 vs AES-192
304 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
305 * is performed.
306 *
307 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
308 */
309static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
310 const u8 *key, unsigned int keylen)
311{
312 return tfm->setkey(tfm, key, keylen);
313}
314
315static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
316{
317 return tfm->keysize;
318}
319
320static inline unsigned int crypto_skcipher_default_keysize(
321 struct crypto_skcipher *tfm)
322{
323 return tfm->keysize;
324}
325
326/**
327 * crypto_skcipher_reqtfm() - obtain cipher handle from request
328 * @req: skcipher_request out of which the cipher handle is to be obtained
329 *
330 * Return the crypto_skcipher handle when furnishing an skcipher_request
331 * data structure.
332 *
333 * Return: crypto_skcipher handle
334 */
335static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
336 struct skcipher_request *req)
337{
338 return __crypto_skcipher_cast(req->base.tfm);
339}
340
341/**
342 * crypto_skcipher_encrypt() - encrypt plaintext
343 * @req: reference to the skcipher_request handle that holds all information
344 * needed to perform the cipher operation
345 *
346 * Encrypt plaintext data using the skcipher_request handle. That data
347 * structure and how it is filled with data is discussed with the
348 * skcipher_request_* functions.
349 *
350 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
351 */
352static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
353{
354 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
355
356 return tfm->encrypt(req);
357}
358
359/**
360 * crypto_skcipher_decrypt() - decrypt ciphertext
361 * @req: reference to the skcipher_request handle that holds all information
362 * needed to perform the cipher operation
363 *
364 * Decrypt ciphertext data using the skcipher_request handle. That data
365 * structure and how it is filled with data is discussed with the
366 * skcipher_request_* functions.
367 *
368 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
369 */
370static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
371{
372 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
373
374 return tfm->decrypt(req);
375}
376
377/**
378 * DOC: Symmetric Key Cipher Request Handle
379 *
380 * The skcipher_request data structure contains all pointers to data
381 * required for the symmetric key cipher operation. This includes the cipher
382 * handle (which can be used by multiple skcipher_request instances), pointer
383 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
384 * as a handle to the skcipher_request_* API calls in a similar way as
385 * skcipher handle to the crypto_skcipher_* API calls.
386 */
387
388/**
389 * crypto_skcipher_reqsize() - obtain size of the request data structure
390 * @tfm: cipher handle
391 *
392 * Return: number of bytes
393 */
394static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
395{
396 return tfm->reqsize;
397}
398
399/**
400 * skcipher_request_set_tfm() - update cipher handle reference in request
401 * @req: request handle to be modified
402 * @tfm: cipher handle that shall be added to the request handle
403 *
404 * Allow the caller to replace the existing skcipher handle in the request
405 * data structure with a different one.
406 */
407static inline void skcipher_request_set_tfm(struct skcipher_request *req,
408 struct crypto_skcipher *tfm)
409{
410 req->base.tfm = crypto_skcipher_tfm(tfm);
411}
412
413static inline struct skcipher_request *skcipher_request_cast(
414 struct crypto_async_request *req)
415{
416 return container_of(req, struct skcipher_request, base);
417}
418
419/**
420 * skcipher_request_alloc() - allocate request data structure
421 * @tfm: cipher handle to be registered with the request
422 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
423 *
424 * Allocate the request data structure that must be used with the skcipher
425 * encrypt and decrypt API calls. During the allocation, the provided skcipher
426 * handle is registered in the request data structure.
427 *
428 * Return: allocated request handle in case of success; IS_ERR() is true in case
429 * of an error, PTR_ERR() returns the error code.
430 */
431static inline struct skcipher_request *skcipher_request_alloc(
432 struct crypto_skcipher *tfm, gfp_t gfp)
433{
434 struct skcipher_request *req;
435
436 req = kmalloc(sizeof(struct skcipher_request) +
437 crypto_skcipher_reqsize(tfm), gfp);
438
439 if (likely(req))
440 skcipher_request_set_tfm(req, tfm);
441
442 return req;
443}
444
445/**
446 * skcipher_request_free() - zeroize and free request data structure
447 * @req: request data structure cipher handle to be freed
448 */
449static inline void skcipher_request_free(struct skcipher_request *req)
450{
451 kzfree(req);
452}
453
454static inline void skcipher_request_zero(struct skcipher_request *req)
455{
456 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
457
458 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm));
459}
460
461/**
462 * skcipher_request_set_callback() - set asynchronous callback function
463 * @req: request handle
464 * @flags: specify zero or an ORing of the flags
465 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
466 * increase the wait queue beyond the initial maximum size;
467 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
468 * @compl: callback function pointer to be registered with the request handle
469 * @data: The data pointer refers to memory that is not used by the kernel
470 * crypto API, but provided to the callback function for it to use. Here,
471 * the caller can provide a reference to memory the callback function can
472 * operate on. As the callback function is invoked asynchronously to the
473 * related functionality, it may need to access data structures of the
474 * related functionality which can be referenced using this pointer. The
475 * callback function can access the memory via the "data" field in the
476 * crypto_async_request data structure provided to the callback function.
477 *
478 * This function allows setting the callback function that is triggered once the
479 * cipher operation completes.
480 *
481 * The callback function is registered with the skcipher_request handle and
482 * must comply with the following template
483 *
484 * void callback_function(struct crypto_async_request *req, int error)
485 */
486static inline void skcipher_request_set_callback(struct skcipher_request *req,
487 u32 flags,
488 crypto_completion_t compl,
489 void *data)
490{
491 req->base.complete = compl;
492 req->base.data = data;
493 req->base.flags = flags;
494}
495
496/**
497 * skcipher_request_set_crypt() - set data buffers
498 * @req: request handle
499 * @src: source scatter / gather list
500 * @dst: destination scatter / gather list
501 * @cryptlen: number of bytes to process from @src
502 * @iv: IV for the cipher operation which must comply with the IV size defined
503 * by crypto_skcipher_ivsize
504 *
505 * This function allows setting of the source data and destination data
506 * scatter / gather lists.
507 *
508 * For encryption, the source is treated as the plaintext and the
509 * destination is the ciphertext. For a decryption operation, the use is
510 * reversed - the source is the ciphertext and the destination is the plaintext.
511 */
512static inline void skcipher_request_set_crypt(
513 struct skcipher_request *req,
514 struct scatterlist *src, struct scatterlist *dst,
515 unsigned int cryptlen, void *iv)
516{
517 req->src = src;
518 req->dst = dst;
519 req->cryptlen = cryptlen;
520 req->iv = iv;
521}
522
523#endif /* _CRYPTO_SKCIPHER_H */
524