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