2 * Symmetric key ciphers.
4 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
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)
13 #ifndef _CRYPTO_SKCIPHER_H
14 #define _CRYPTO_SKCIPHER_H
16 #include <linux/crypto.h>
17 #include <linux/kernel.h>
18 #include <linux/slab.h>
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
29 struct skcipher_request {
30 unsigned int cryptlen;
34 struct scatterlist *src;
35 struct scatterlist *dst;
37 struct crypto_async_request base;
39 void *__ctx[] CRYPTO_MINALIGN_ATTR;
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
48 struct skcipher_givcrypt_request {
52 struct ablkcipher_request creq;
55 struct crypto_skcipher {
56 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key,
58 int (*encrypt)(struct skcipher_request *req);
59 int (*decrypt)(struct skcipher_request *req);
64 struct crypto_tfm base;
67 #define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
68 char __##name##_desc[sizeof(struct skcipher_request) + \
69 crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
70 struct skcipher_request *name = (void *)__##name##_desc
72 static inline struct crypto_ablkcipher *skcipher_givcrypt_reqtfm(
73 struct skcipher_givcrypt_request *req)
75 return crypto_ablkcipher_reqtfm(&req->creq);
78 static inline int crypto_skcipher_givencrypt(
79 struct skcipher_givcrypt_request *req)
81 struct ablkcipher_tfm *crt =
82 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
83 return crt->givencrypt(req);
86 static inline int crypto_skcipher_givdecrypt(
87 struct skcipher_givcrypt_request *req)
89 struct ablkcipher_tfm *crt =
90 crypto_ablkcipher_crt(skcipher_givcrypt_reqtfm(req));
91 return crt->givdecrypt(req);
94 static inline void skcipher_givcrypt_set_tfm(
95 struct skcipher_givcrypt_request *req, struct crypto_ablkcipher *tfm)
97 req->creq.base.tfm = crypto_ablkcipher_tfm(tfm);
100 static inline struct skcipher_givcrypt_request *skcipher_givcrypt_cast(
101 struct crypto_async_request *req)
103 return container_of(ablkcipher_request_cast(req),
104 struct skcipher_givcrypt_request, creq);
107 static inline struct skcipher_givcrypt_request *skcipher_givcrypt_alloc(
108 struct crypto_ablkcipher *tfm, gfp_t gfp)
110 struct skcipher_givcrypt_request *req;
112 req = kmalloc(sizeof(struct skcipher_givcrypt_request) +
113 crypto_ablkcipher_reqsize(tfm), gfp);
116 skcipher_givcrypt_set_tfm(req, tfm);
121 static inline void skcipher_givcrypt_free(struct skcipher_givcrypt_request *req)
126 static inline void skcipher_givcrypt_set_callback(
127 struct skcipher_givcrypt_request *req, u32 flags,
128 crypto_completion_t compl, void *data)
130 ablkcipher_request_set_callback(&req->creq, flags, compl, data);
133 static inline void skcipher_givcrypt_set_crypt(
134 struct skcipher_givcrypt_request *req,
135 struct scatterlist *src, struct scatterlist *dst,
136 unsigned int nbytes, void *iv)
138 ablkcipher_request_set_crypt(&req->creq, src, dst, nbytes, iv);
141 static inline void skcipher_givcrypt_set_giv(
142 struct skcipher_givcrypt_request *req, u8 *giv, u64 seq)
149 * DOC: Symmetric Key Cipher API
151 * Symmetric key cipher API is used with the ciphers of type
152 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto).
154 * Asynchronous cipher operations imply that the function invocation for a
155 * cipher request returns immediately before the completion of the operation.
156 * The cipher request is scheduled as a separate kernel thread and therefore
157 * load-balanced on the different CPUs via the process scheduler. To allow
158 * the kernel crypto API to inform the caller about the completion of a cipher
159 * request, the caller must provide a callback function. That function is
160 * invoked with the cipher handle when the request completes.
162 * To support the asynchronous operation, additional information than just the
163 * cipher handle must be supplied to the kernel crypto API. That additional
164 * information is given by filling in the skcipher_request data structure.
166 * For the symmetric key cipher API, the state is maintained with the tfm
167 * cipher handle. A single tfm can be used across multiple calls and in
168 * parallel. For asynchronous block cipher calls, context data supplied and
169 * only used by the caller can be referenced the request data structure in
170 * addition to the IV used for the cipher request. The maintenance of such
171 * state information would be important for a crypto driver implementer to
172 * have, because when calling the callback function upon completion of the
173 * cipher operation, that callback function may need some information about
174 * which operation just finished if it invoked multiple in parallel. This
175 * state information is unused by the kernel crypto API.
178 static inline struct crypto_skcipher *__crypto_skcipher_cast(
179 struct crypto_tfm *tfm)
181 return container_of(tfm, struct crypto_skcipher, base);
185 * crypto_alloc_skcipher() - allocate symmetric key cipher handle
186 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
188 * @type: specifies the type of the cipher
189 * @mask: specifies the mask for the cipher
191 * Allocate a cipher handle for an skcipher. The returned struct
192 * crypto_skcipher is the cipher handle that is required for any subsequent
193 * API invocation for that skcipher.
195 * Return: allocated cipher handle in case of success; IS_ERR() is true in case
196 * of an error, PTR_ERR() returns the error code.
198 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
201 static inline struct crypto_tfm *crypto_skcipher_tfm(
202 struct crypto_skcipher *tfm)
208 * crypto_free_skcipher() - zeroize and free cipher handle
209 * @tfm: cipher handle to be freed
211 static inline void crypto_free_skcipher(struct crypto_skcipher *tfm)
213 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm));
217 * crypto_has_skcipher() - Search for the availability of an skcipher.
218 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
220 * @type: specifies the type of the cipher
221 * @mask: specifies the mask for the cipher
223 * Return: true when the skcipher is known to the kernel crypto API; false
226 static inline int crypto_has_skcipher(const char *alg_name, u32 type,
229 return crypto_has_alg(alg_name, crypto_skcipher_type(type),
230 crypto_skcipher_mask(mask));
234 * crypto_skcipher_ivsize() - obtain IV size
235 * @tfm: cipher handle
237 * The size of the IV for the skcipher referenced by the cipher handle is
238 * returned. This IV size may be zero if the cipher does not need an IV.
240 * Return: IV size in bytes
242 static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm)
248 * crypto_skcipher_blocksize() - obtain block size of cipher
249 * @tfm: cipher handle
251 * The block size for the skcipher referenced with the cipher handle is
252 * returned. The caller may use that information to allocate appropriate
253 * memory for the data returned by the encryption or decryption operation
255 * Return: block size of cipher
257 static inline unsigned int crypto_skcipher_blocksize(
258 struct crypto_skcipher *tfm)
260 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm));
263 static inline unsigned int crypto_skcipher_alignmask(
264 struct crypto_skcipher *tfm)
266 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm));
269 static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm)
271 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm));
274 static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm,
277 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags);
280 static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm,
283 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags);
287 * crypto_skcipher_setkey() - set key for cipher
288 * @tfm: cipher handle
289 * @key: buffer holding the key
290 * @keylen: length of the key in bytes
292 * The caller provided key is set for the skcipher referenced by the cipher
295 * Note, the key length determines the cipher type. Many block ciphers implement
296 * different cipher modes depending on the key size, such as AES-128 vs AES-192
297 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128
300 * Return: 0 if the setting of the key was successful; < 0 if an error occurred
302 static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm,
303 const u8 *key, unsigned int keylen)
305 return tfm->setkey(tfm, key, keylen);
309 * crypto_skcipher_reqtfm() - obtain cipher handle from request
310 * @req: skcipher_request out of which the cipher handle is to be obtained
312 * Return the crypto_skcipher handle when furnishing an skcipher_request
315 * Return: crypto_skcipher handle
317 static inline struct crypto_skcipher *crypto_skcipher_reqtfm(
318 struct skcipher_request *req)
320 return __crypto_skcipher_cast(req->base.tfm);
324 * crypto_skcipher_encrypt() - encrypt plaintext
325 * @req: reference to the skcipher_request handle that holds all information
326 * needed to perform the cipher operation
328 * Encrypt plaintext data using the skcipher_request handle. That data
329 * structure and how it is filled with data is discussed with the
330 * skcipher_request_* functions.
332 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
334 static inline int crypto_skcipher_encrypt(struct skcipher_request *req)
336 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
338 return tfm->encrypt(req);
342 * crypto_skcipher_decrypt() - decrypt ciphertext
343 * @req: reference to the skcipher_request handle that holds all information
344 * needed to perform the cipher operation
346 * Decrypt ciphertext 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.
350 * Return: 0 if the cipher operation was successful; < 0 if an error occurred
352 static inline int crypto_skcipher_decrypt(struct skcipher_request *req)
354 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
356 return tfm->decrypt(req);
360 * DOC: Symmetric Key Cipher Request Handle
362 * The skcipher_request data structure contains all pointers to data
363 * required for the symmetric key cipher operation. This includes the cipher
364 * handle (which can be used by multiple skcipher_request instances), pointer
365 * to plaintext and ciphertext, asynchronous callback function, etc. It acts
366 * as a handle to the skcipher_request_* API calls in a similar way as
367 * skcipher handle to the crypto_skcipher_* API calls.
371 * crypto_skcipher_reqsize() - obtain size of the request data structure
372 * @tfm: cipher handle
374 * Return: number of bytes
376 static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm)
382 * skcipher_request_set_tfm() - update cipher handle reference in request
383 * @req: request handle to be modified
384 * @tfm: cipher handle that shall be added to the request handle
386 * Allow the caller to replace the existing skcipher handle in the request
387 * data structure with a different one.
389 static inline void skcipher_request_set_tfm(struct skcipher_request *req,
390 struct crypto_skcipher *tfm)
392 req->base.tfm = crypto_skcipher_tfm(tfm);
395 static inline struct skcipher_request *skcipher_request_cast(
396 struct crypto_async_request *req)
398 return container_of(req, struct skcipher_request, base);
402 * skcipher_request_alloc() - allocate request data structure
403 * @tfm: cipher handle to be registered with the request
404 * @gfp: memory allocation flag that is handed to kmalloc by the API call.
406 * Allocate the request data structure that must be used with the skcipher
407 * encrypt and decrypt API calls. During the allocation, the provided skcipher
408 * handle is registered in the request data structure.
410 * Return: allocated request handle in case of success; IS_ERR() is true in case
411 * of an error, PTR_ERR() returns the error code.
413 static inline struct skcipher_request *skcipher_request_alloc(
414 struct crypto_skcipher *tfm, gfp_t gfp)
416 struct skcipher_request *req;
418 req = kmalloc(sizeof(struct skcipher_request) +
419 crypto_skcipher_reqsize(tfm), gfp);
422 skcipher_request_set_tfm(req, tfm);
428 * skcipher_request_free() - zeroize and free request data structure
429 * @req: request data structure cipher handle to be freed
431 static inline void skcipher_request_free(struct skcipher_request *req)
437 * skcipher_request_set_callback() - set asynchronous callback function
438 * @req: request handle
439 * @flags: specify zero or an ORing of the flags
440 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and
441 * increase the wait queue beyond the initial maximum size;
442 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep
443 * @compl: callback function pointer to be registered with the request handle
444 * @data: The data pointer refers to memory that is not used by the kernel
445 * crypto API, but provided to the callback function for it to use. Here,
446 * the caller can provide a reference to memory the callback function can
447 * operate on. As the callback function is invoked asynchronously to the
448 * related functionality, it may need to access data structures of the
449 * related functionality which can be referenced using this pointer. The
450 * callback function can access the memory via the "data" field in the
451 * crypto_async_request data structure provided to the callback function.
453 * This function allows setting the callback function that is triggered once the
454 * cipher operation completes.
456 * The callback function is registered with the skcipher_request handle and
457 * must comply with the following template
459 * void callback_function(struct crypto_async_request *req, int error)
461 static inline void skcipher_request_set_callback(struct skcipher_request *req,
463 crypto_completion_t compl,
466 req->base.complete = compl;
467 req->base.data = data;
468 req->base.flags = flags;
472 * skcipher_request_set_crypt() - set data buffers
473 * @req: request handle
474 * @src: source scatter / gather list
475 * @dst: destination scatter / gather list
476 * @cryptlen: number of bytes to process from @src
477 * @iv: IV for the cipher operation which must comply with the IV size defined
478 * by crypto_skcipher_ivsize
480 * This function allows setting of the source data and destination data
481 * scatter / gather lists.
483 * For encryption, the source is treated as the plaintext and the
484 * destination is the ciphertext. For a decryption operation, the use is
485 * reversed - the source is the ciphertext and the destination is the plaintext.
487 static inline void skcipher_request_set_crypt(
488 struct skcipher_request *req,
489 struct scatterlist *src, struct scatterlist *dst,
490 unsigned int cryptlen, void *iv)
494 req->cryptlen = cryptlen;
498 #endif /* _CRYPTO_SKCIPHER_H */