1/*
  2 * Public Key Encryption
  3 *
  4 * Copyright (c) 2015, Intel Corporation
  5 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify it
  8 * under the terms of the GNU General Public License as published by the Free
  9 * Software Foundation; either version 2 of the License, or (at your option)
 10 * any later version.
 11 *
 12 */
 13#ifndef _CRYPTO_AKCIPHER_H
 14#define _CRYPTO_AKCIPHER_H
 15#include <linux/crypto.h>
 16
 17/**
 18 * struct akcipher_request - public key request
 19 *
 20 * @base:	Common attributes for async crypto requests
 21 * @src:	Source data
 22 * @dst:	Destination data
 23 * @src_len:	Size of the input buffer
 24 * @dst_len:	Size of the output buffer. It needs to be at least
 25 *		as big as the expected result depending	on the operation
 26 *		After operation it will be updated with the actual size of the
 27 *		result.
 28 *		In case of error where the dst sgl size was insufficient,
 29 *		it will be updated to the size required for the operation.
 30 * @__ctx:	Start of private context data
 31 */
 32struct akcipher_request {
 33	struct crypto_async_request base;
 34	struct scatterlist *src;
 35	struct scatterlist *dst;
 36	unsigned int src_len;
 37	unsigned int dst_len;
 38	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 39};
 40
 41/**
 42 * struct crypto_akcipher - user-instantiated objects which encapsulate
 43 * algorithms and core processing logic
 44 *
 45 * @base:	Common crypto API algorithm data structure
 46 */
 47struct crypto_akcipher {
 48	struct crypto_tfm base;
 49};
 50
 51/**
 52 * struct akcipher_alg - generic public key algorithm
 53 *
 54 * @sign:	Function performs a sign operation as defined by public key
 55 *		algorithm. In case of error, where the dst_len was insufficient,
 56 *		the req->dst_len will be updated to the size required for the
 57 *		operation
 58 * @verify:	Function performs a sign operation as defined by public key
 59 *		algorithm. In case of error, where the dst_len was insufficient,
 60 *		the req->dst_len will be updated to the size required for the
 61 *		operation
 62 * @encrypt:	Function performs an encrypt operation as defined by public key
 63 *		algorithm. In case of error, where the dst_len was insufficient,
 64 *		the req->dst_len will be updated to the size required for the
 65 *		operation
 66 * @decrypt:	Function performs a decrypt operation as defined by public key
 67 *		algorithm. In case of error, where the dst_len was insufficient,
 68 *		the req->dst_len will be updated to the size required for the
 69 *		operation
 70 * @set_pub_key: Function invokes the algorithm specific set public key
 71 *		function, which knows how to decode and interpret
 72 *		the BER encoded public key
 73 * @set_priv_key: Function invokes the algorithm specific set private key
 74 *		function, which knows how to decode and interpret
 75 *		the BER encoded private key
 76 * @max_size:	Function returns dest buffer size required for a given key.
 77 * @init:	Initialize the cryptographic transformation object.
 78 *		This function is used to initialize the cryptographic
 79 *		transformation object. This function is called only once at
 80 *		the instantiation time, right after the transformation context
 81 *		was allocated. In case the cryptographic hardware has some
 82 *		special requirements which need to be handled by software, this
 83 *		function shall check for the precise requirement of the
 84 *		transformation and put any software fallbacks in place.
 85 * @exit:	Deinitialize the cryptographic transformation object. This is a
 86 *		counterpart to @init, used to remove various changes set in
 87 *		@init.
 88 *
 89 * @reqsize:	Request context size required by algorithm implementation
 90 * @base:	Common crypto API algorithm data structure
 91 */
 92struct akcipher_alg {
 93	int (*sign)(struct akcipher_request *req);
 94	int (*verify)(struct akcipher_request *req);
 95	int (*encrypt)(struct akcipher_request *req);
 96	int (*decrypt)(struct akcipher_request *req);
 97	int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key,
 98			   unsigned int keylen);
 99	int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key,
100			    unsigned int keylen);
101	int (*max_size)(struct crypto_akcipher *tfm);
102	int (*init)(struct crypto_akcipher *tfm);
103	void (*exit)(struct crypto_akcipher *tfm);
104
105	unsigned int reqsize;
106	struct crypto_alg base;
107};
108
109/**
110 * DOC: Generic Public Key API
111 *
112 * The Public Key API is used with the algorithms of type
113 * CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto)
114 */
115
116/**
117 * crypto_alloc_akcipher() - allocate AKCIPHER tfm handle
118 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
119 *	      public key algorithm e.g. "rsa"
120 * @type: specifies the type of the algorithm
121 * @mask: specifies the mask for the algorithm
122 *
123 * Allocate a handle for public key algorithm. The returned struct
124 * crypto_akcipher is the handle that is required for any subsequent
125 * API invocation for the public key operations.
126 *
127 * Return: allocated handle in case of success; IS_ERR() is true in case
128 *	   of an error, PTR_ERR() returns the error code.
129 */
130struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
131					      u32 mask);
132
133static inline struct crypto_tfm *crypto_akcipher_tfm(
134	struct crypto_akcipher *tfm)
135{
136	return &tfm->base;
137}
138
139static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg)
140{
141	return container_of(alg, struct akcipher_alg, base);
142}
143
144static inline struct crypto_akcipher *__crypto_akcipher_tfm(
145	struct crypto_tfm *tfm)
146{
147	return container_of(tfm, struct crypto_akcipher, base);
148}
149
150static inline struct akcipher_alg *crypto_akcipher_alg(
151	struct crypto_akcipher *tfm)
152{
153	return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg);
154}
155
156static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm)
157{
158	return crypto_akcipher_alg(tfm)->reqsize;
159}
160
161static inline void akcipher_request_set_tfm(struct akcipher_request *req,
162					    struct crypto_akcipher *tfm)
163{
164	req->base.tfm = crypto_akcipher_tfm(tfm);
165}
166
167static inline struct crypto_akcipher *crypto_akcipher_reqtfm(
168	struct akcipher_request *req)
169{
170	return __crypto_akcipher_tfm(req->base.tfm);
171}
172
173/**
174 * crypto_free_akcipher() - free AKCIPHER tfm handle
175 *
176 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
177 */
178static inline void crypto_free_akcipher(struct crypto_akcipher *tfm)
179{
180	crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm));
181}
182
183/**
184 * akcipher_request_alloc() - allocates public key request
185 *
186 * @tfm:	AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
187 * @gfp:	allocation flags
188 *
189 * Return: allocated handle in case of success or NULL in case of an error.
190 */
191static inline struct akcipher_request *akcipher_request_alloc(
192	struct crypto_akcipher *tfm, gfp_t gfp)
193{
194	struct akcipher_request *req;
195
196	req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp);
197	if (likely(req))
198		akcipher_request_set_tfm(req, tfm);
199
200	return req;
201}
202
203/**
204 * akcipher_request_free() - zeroize and free public key request
205 *
206 * @req:	request to free
207 */
208static inline void akcipher_request_free(struct akcipher_request *req)
209{
210	kzfree(req);
211}
212
213/**
214 * akcipher_request_set_callback() - Sets an asynchronous callback.
215 *
216 * Callback will be called when an asynchronous operation on a given
217 * request is finished.
218 *
219 * @req:	request that the callback will be set for
220 * @flgs:	specify for instance if the operation may backlog
221 * @cmpl:	callback which will be called
222 * @data:	private data used by the caller
223 */
224static inline void akcipher_request_set_callback(struct akcipher_request *req,
225						 u32 flgs,
226						 crypto_completion_t cmpl,
227						 void *data)
228{
229	req->base.complete = cmpl;
230	req->base.data = data;
231	req->base.flags = flgs;
232}
233
234/**
235 * akcipher_request_set_crypt() - Sets request parameters
236 *
237 * Sets parameters required by crypto operation
238 *
239 * @req:	public key request
240 * @src:	ptr to input scatter list
241 * @dst:	ptr to output scatter list
242 * @src_len:	size of the src input scatter list to be processed
243 * @dst_len:	size of the dst output scatter list
244 */
245static inline void akcipher_request_set_crypt(struct akcipher_request *req,
246					      struct scatterlist *src,
247					      struct scatterlist *dst,
248					      unsigned int src_len,
249					      unsigned int dst_len)
250{
251	req->src = src;
252	req->dst = dst;
253	req->src_len = src_len;
254	req->dst_len = dst_len;
255}
256
257/**
258 * crypto_akcipher_maxsize() - Get len for output buffer
259 *
260 * Function returns the dest buffer size required for a given key
261 *
262 * @tfm:	AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
263 *
264 * Return: minimum len for output buffer or error code in key hasn't been set
265 */
266static inline int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
267{
268	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
269
270	return alg->max_size(tfm);
271}
272
273/**
274 * crypto_akcipher_encrypt() - Invoke public key encrypt operation
275 *
276 * Function invokes the specific public key encrypt operation for a given
277 * public key algorithm
278 *
279 * @req:	asymmetric key request
280 *
281 * Return: zero on success; error code in case of error
282 */
283static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
284{
285	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
286	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
287
288	return alg->encrypt(req);
289}
290
291/**
292 * crypto_akcipher_decrypt() - Invoke public key decrypt operation
293 *
294 * Function invokes the specific public key decrypt operation for a given
295 * public key algorithm
296 *
297 * @req:	asymmetric key request
298 *
299 * Return: zero on success; error code in case of error
300 */
301static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
302{
303	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
304	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
305
306	return alg->decrypt(req);
307}
308
309/**
310 * crypto_akcipher_sign() - Invoke public key sign operation
311 *
312 * Function invokes the specific public key sign operation for a given
313 * public key algorithm
314 *
315 * @req:	asymmetric key request
316 *
317 * Return: zero on success; error code in case of error
318 */
319static inline int crypto_akcipher_sign(struct akcipher_request *req)
320{
321	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
322	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
323
324	return alg->sign(req);
325}
326
327/**
328 * crypto_akcipher_verify() - Invoke public key verify operation
329 *
330 * Function invokes the specific public key verify operation for a given
331 * public key algorithm
332 *
333 * @req:	asymmetric key request
334 *
335 * Return: zero on success; error code in case of error
336 */
337static inline int crypto_akcipher_verify(struct akcipher_request *req)
338{
339	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
340	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
341
342	return alg->verify(req);
343}
344
345/**
346 * crypto_akcipher_set_pub_key() - Invoke set public key operation
347 *
348 * Function invokes the algorithm specific set key function, which knows
349 * how to decode and interpret the encoded key
350 *
351 * @tfm:	tfm handle
352 * @key:	BER encoded public key
353 * @keylen:	length of the key
354 *
355 * Return: zero on success; error code in case of error
356 */
357static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
358					      const void *key,
359					      unsigned int keylen)
360{
361	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
362
363	return alg->set_pub_key(tfm, key, keylen);
364}
365
366/**
367 * crypto_akcipher_set_priv_key() - Invoke set private key operation
368 *
369 * Function invokes the algorithm specific set key function, which knows
370 * how to decode and interpret the encoded key
371 *
372 * @tfm:	tfm handle
373 * @key:	BER encoded private key
374 * @keylen:	length of the key
375 *
376 * Return: zero on success; error code in case of error
377 */
378static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
379					       const void *key,
380					       unsigned int keylen)
381{
382	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
383
384	return alg->set_priv_key(tfm, key, keylen);
385}
386#endif