1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * Public Key Encryption
  4 *
  5 * Copyright (c) 2015, Intel Corporation
  6 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
  7 */
  8#ifndef _CRYPTO_AKCIPHER_H
  9#define _CRYPTO_AKCIPHER_H
 10#include <linux/crypto.h>
 11
 12/**
 13 * struct akcipher_request - public key request
 14 *
 15 * @base:	Common attributes for async crypto requests
 16 * @src:	Source data
 17 *		For verify op this is signature + digest, in that case
 18 *		total size of @src is @src_len + @dst_len.
 19 * @dst:	Destination data (Should be NULL for verify op)
 20 * @src_len:	Size of the input buffer
 21 *		For verify op it's size of signature part of @src, this part
 22 *		is supposed to be operated by cipher.
 23 * @dst_len:	Size of @dst buffer (for all ops except verify).
 24 *		It needs to be at least	as big as the expected result
 25 *		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 *		For verify op this is size of digest part in @src.
 31 * @__ctx:	Start of private context data
 32 */
 33struct akcipher_request {
 34	struct crypto_async_request base;
 35	struct scatterlist *src;
 36	struct scatterlist *dst;
 37	unsigned int src_len;
 38	unsigned int dst_len;
 39	void *__ctx[] CRYPTO_MINALIGN_ATTR;
 40};
 41
 42/**
 43 * struct crypto_akcipher - user-instantiated objects which encapsulate
 44 * algorithms and core processing logic
 45 *
 46 * @base:	Common crypto API algorithm data structure
 47 */
 48struct crypto_akcipher {
 49	struct crypto_tfm base;
 50};
 51
 52/**
 53 * struct akcipher_alg - generic public key algorithm
 54 *
 55 * @sign:	Function performs a sign operation as defined by public key
 56 *		algorithm. In case of error, where the dst_len was insufficient,
 57 *		the req->dst_len will be updated to the size required for the
 58 *		operation
 59 * @verify:	Function performs a complete verify operation as defined by
 60 *		public key algorithm, returning verification status. Requires
 61 *		digest value as input parameter.
 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 and parameters
 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 and parameters
 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	unsigned 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 or NULL for verify op
242 * @src_len:	size of the src input scatter list to be processed
243 * @dst_len:	size of the dst output scatter list or size of signature
244 *		portion in @src for verify op
245 */
246static inline void akcipher_request_set_crypt(struct akcipher_request *req,
247					      struct scatterlist *src,
248					      struct scatterlist *dst,
249					      unsigned int src_len,
250					      unsigned int dst_len)
251{
252	req->src = src;
253	req->dst = dst;
254	req->src_len = src_len;
255	req->dst_len = dst_len;
256}
257
258/**
259 * crypto_akcipher_maxsize() - Get len for output buffer
260 *
261 * Function returns the dest buffer size required for a given key.
262 * Function assumes that the key is already set in the transformation. If this
263 * function is called without a setkey or with a failed setkey, you will end up
264 * in a NULL dereference.
265 *
266 * @tfm:	AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
267 */
268static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
269{
270	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
271
272	return alg->max_size(tfm);
273}
274
275/**
276 * crypto_akcipher_encrypt() - Invoke public key encrypt operation
277 *
278 * Function invokes the specific public key encrypt operation for a given
279 * public key algorithm
280 *
281 * @req:	asymmetric key request
282 *
283 * Return: zero on success; error code in case of error
284 */
285static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
286{
287	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
288	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
289	struct crypto_alg *calg = tfm->base.__crt_alg;
290	unsigned int src_len = req->src_len;
291	int ret;
292
293	crypto_stats_get(calg);
294	ret = alg->encrypt(req);
295	crypto_stats_akcipher_encrypt(src_len, ret, calg);
296	return ret;
297}
298
299/**
300 * crypto_akcipher_decrypt() - Invoke public key decrypt operation
301 *
302 * Function invokes the specific public key decrypt operation for a given
303 * public key algorithm
304 *
305 * @req:	asymmetric key request
306 *
307 * Return: zero on success; error code in case of error
308 */
309static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
310{
311	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
312	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
313	struct crypto_alg *calg = tfm->base.__crt_alg;
314	unsigned int src_len = req->src_len;
315	int ret;
316
317	crypto_stats_get(calg);
318	ret = alg->decrypt(req);
319	crypto_stats_akcipher_decrypt(src_len, ret, calg);
320	return ret;
321}
322
323/**
324 * crypto_akcipher_sign() - Invoke public key sign operation
325 *
326 * Function invokes the specific public key sign operation for a given
327 * public key algorithm
328 *
329 * @req:	asymmetric key request
330 *
331 * Return: zero on success; error code in case of error
332 */
333static inline int crypto_akcipher_sign(struct akcipher_request *req)
334{
335	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
336	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
337	struct crypto_alg *calg = tfm->base.__crt_alg;
338	int ret;
339
340	crypto_stats_get(calg);
341	ret = alg->sign(req);
342	crypto_stats_akcipher_sign(ret, calg);
343	return ret;
344}
345
346/**
347 * crypto_akcipher_verify() - Invoke public key signature verification
348 *
349 * Function invokes the specific public key signature verification operation
350 * for a given public key algorithm.
351 *
352 * @req:	asymmetric key request
353 *
354 * Note: req->dst should be NULL, req->src should point to SG of size
355 * (req->src_size + req->dst_size), containing signature (of req->src_size
356 * length) with appended digest (of req->dst_size length).
357 *
358 * Return: zero on verification success; error code in case of error.
359 */
360static inline int crypto_akcipher_verify(struct akcipher_request *req)
361{
362	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
363	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
364	struct crypto_alg *calg = tfm->base.__crt_alg;
365	int ret;
366
367	crypto_stats_get(calg);
368	ret = alg->verify(req);
369	crypto_stats_akcipher_verify(ret, calg);
370	return ret;
371}
372
373/**
374 * crypto_akcipher_set_pub_key() - Invoke set public key operation
375 *
376 * Function invokes the algorithm specific set key function, which knows
377 * how to decode and interpret the encoded key and parameters
378 *
379 * @tfm:	tfm handle
380 * @key:	BER encoded public key, algo OID, paramlen, BER encoded
381 *		parameters
382 * @keylen:	length of the key (not including other data)
383 *
384 * Return: zero on success; error code in case of error
385 */
386static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
387					      const void *key,
388					      unsigned int keylen)
389{
390	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
391
392	return alg->set_pub_key(tfm, key, keylen);
393}
394
395/**
396 * crypto_akcipher_set_priv_key() - Invoke set private key operation
397 *
398 * Function invokes the algorithm specific set key function, which knows
399 * how to decode and interpret the encoded key and parameters
400 *
401 * @tfm:	tfm handle
402 * @key:	BER encoded private key, algo OID, paramlen, BER encoded
403 *		parameters
404 * @keylen:	length of the key (not including other data)
405 *
406 * Return: zero on success; error code in case of error
407 */
408static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
409					       const void *key,
410					       unsigned int keylen)
411{
412	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
413
414	return alg->set_priv_key(tfm, key, keylen);
415}
416#endif