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 * @reqsize:	Request context size required by algorithm implementation
 47 * @base:	Common crypto API algorithm data structure
 48 */
 49struct crypto_akcipher {
 50	unsigned int reqsize;
 51
 52	struct crypto_tfm base;
 53};
 54
 55/**
 56 * struct akcipher_alg - generic public key algorithm
 57 *
 58 * @sign:	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 * @verify:	Function performs a complete verify operation as defined by
 63 *		public key algorithm, returning verification status. Requires
 64 *		digest value as input parameter.
 65 * @encrypt:	Function performs an encrypt operation as defined by public key
 66 *		algorithm. In case of error, where the dst_len was insufficient,
 67 *		the req->dst_len will be updated to the size required for the
 68 *		operation
 69 * @decrypt:	Function performs a decrypt operation as defined by public key
 70 *		algorithm. In case of error, where the dst_len was insufficient,
 71 *		the req->dst_len will be updated to the size required for the
 72 *		operation
 73 * @set_pub_key: Function invokes the algorithm specific set public key
 74 *		function, which knows how to decode and interpret
 75 *		the BER encoded public key and parameters
 76 * @set_priv_key: Function invokes the algorithm specific set private key
 77 *		function, which knows how to decode and interpret
 78 *		the BER encoded private key and parameters
 79 * @max_size:	Function returns dest buffer size required for a given key.
 80 * @init:	Initialize the cryptographic transformation object.
 81 *		This function is used to initialize the cryptographic
 82 *		transformation object. This function is called only once at
 83 *		the instantiation time, right after the transformation context
 84 *		was allocated. In case the cryptographic hardware has some
 85 *		special requirements which need to be handled by software, this
 86 *		function shall check for the precise requirement of the
 87 *		transformation and put any software fallbacks in place.
 88 * @exit:	Deinitialize the cryptographic transformation object. This is a
 89 *		counterpart to @init, used to remove various changes set in
 90 *		@init.
 91 *
 92 * @base:	Common crypto API algorithm data structure
 93 */
 94struct akcipher_alg {
 95	int (*sign)(struct akcipher_request *req);
 96	int (*verify)(struct akcipher_request *req);
 97	int (*encrypt)(struct akcipher_request *req);
 98	int (*decrypt)(struct akcipher_request *req);
 99	int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key,
100			   unsigned int keylen);
101	int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key,
102			    unsigned int keylen);
103	unsigned int (*max_size)(struct crypto_akcipher *tfm);
104	int (*init)(struct crypto_akcipher *tfm);
105	void (*exit)(struct crypto_akcipher *tfm);
106
107	struct crypto_alg base;
108};
109
110/**
111 * DOC: Generic Public Key API
112 *
113 * The Public Key API is used with the algorithms of type
114 * CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto)
115 */
116
117/**
118 * crypto_alloc_akcipher() - allocate AKCIPHER tfm handle
119 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
120 *	      public key algorithm e.g. "rsa"
121 * @type: specifies the type of the algorithm
122 * @mask: specifies the mask for the algorithm
123 *
124 * Allocate a handle for public key algorithm. The returned struct
125 * crypto_akcipher is the handle that is required for any subsequent
126 * API invocation for the public key operations.
127 *
128 * Return: allocated handle in case of success; IS_ERR() is true in case
129 *	   of an error, PTR_ERR() returns the error code.
130 */
131struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
132					      u32 mask);
133
134static inline struct crypto_tfm *crypto_akcipher_tfm(
135	struct crypto_akcipher *tfm)
136{
137	return &tfm->base;
138}
139
140static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg)
141{
142	return container_of(alg, struct akcipher_alg, base);
143}
144
145static inline struct crypto_akcipher *__crypto_akcipher_tfm(
146	struct crypto_tfm *tfm)
147{
148	return container_of(tfm, struct crypto_akcipher, base);
149}
150
151static inline struct akcipher_alg *crypto_akcipher_alg(
152	struct crypto_akcipher *tfm)
153{
154	return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg);
155}
156
157static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm)
158{
159	return tfm->reqsize;
160}
161
162static inline void akcipher_request_set_tfm(struct akcipher_request *req,
163					    struct crypto_akcipher *tfm)
164{
165	req->base.tfm = crypto_akcipher_tfm(tfm);
166}
167
168static inline struct crypto_akcipher *crypto_akcipher_reqtfm(
169	struct akcipher_request *req)
170{
171	return __crypto_akcipher_tfm(req->base.tfm);
172}
173
174/**
175 * crypto_free_akcipher() - free AKCIPHER tfm handle
176 *
177 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
178 *
179 * If @tfm is a NULL or error pointer, this function does nothing.
180 */
181static inline void crypto_free_akcipher(struct crypto_akcipher *tfm)
182{
183	crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm));
184}
185
186/**
187 * akcipher_request_alloc() - allocates public key request
188 *
189 * @tfm:	AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
190 * @gfp:	allocation flags
191 *
192 * Return: allocated handle in case of success or NULL in case of an error.
193 */
194static inline struct akcipher_request *akcipher_request_alloc(
195	struct crypto_akcipher *tfm, gfp_t gfp)
196{
197	struct akcipher_request *req;
198
199	req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp);
200	if (likely(req))
201		akcipher_request_set_tfm(req, tfm);
202
203	return req;
204}
205
206/**
207 * akcipher_request_free() - zeroize and free public key request
208 *
209 * @req:	request to free
210 */
211static inline void akcipher_request_free(struct akcipher_request *req)
212{
213	kfree_sensitive(req);
214}
215
216/**
217 * akcipher_request_set_callback() - Sets an asynchronous callback.
218 *
219 * Callback will be called when an asynchronous operation on a given
220 * request is finished.
221 *
222 * @req:	request that the callback will be set for
223 * @flgs:	specify for instance if the operation may backlog
224 * @cmpl:	callback which will be called
225 * @data:	private data used by the caller
226 */
227static inline void akcipher_request_set_callback(struct akcipher_request *req,
228						 u32 flgs,
229						 crypto_completion_t cmpl,
230						 void *data)
231{
232	req->base.complete = cmpl;
233	req->base.data = data;
234	req->base.flags = flgs;
235}
236
237/**
238 * akcipher_request_set_crypt() - Sets request parameters
239 *
240 * Sets parameters required by crypto operation
241 *
242 * @req:	public key request
243 * @src:	ptr to input scatter list
244 * @dst:	ptr to output scatter list or NULL for verify op
245 * @src_len:	size of the src input scatter list to be processed
246 * @dst_len:	size of the dst output scatter list or size of signature
247 *		portion in @src for verify op
248 */
249static inline void akcipher_request_set_crypt(struct akcipher_request *req,
250					      struct scatterlist *src,
251					      struct scatterlist *dst,
252					      unsigned int src_len,
253					      unsigned int dst_len)
254{
255	req->src = src;
256	req->dst = dst;
257	req->src_len = src_len;
258	req->dst_len = dst_len;
259}
260
261/**
262 * crypto_akcipher_maxsize() - Get len for output buffer
263 *
264 * Function returns the dest buffer size required for a given key.
265 * Function assumes that the key is already set in the transformation. If this
266 * function is called without a setkey or with a failed setkey, you will end up
267 * in a NULL dereference.
268 *
269 * @tfm:	AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
270 */
271static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
272{
273	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
274
275	return alg->max_size(tfm);
276}
277
278/**
279 * crypto_akcipher_encrypt() - Invoke public key encrypt operation
280 *
281 * Function invokes the specific public key encrypt operation for a given
282 * public key algorithm
283 *
284 * @req:	asymmetric key request
285 *
286 * Return: zero on success; error code in case of error
287 */
288static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
289{
290	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
291	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
292	struct crypto_alg *calg = tfm->base.__crt_alg;
293	unsigned int src_len = req->src_len;
294	int ret;
295
296	crypto_stats_get(calg);
297	ret = alg->encrypt(req);
298	crypto_stats_akcipher_encrypt(src_len, ret, calg);
299	return ret;
300}
301
302/**
303 * crypto_akcipher_decrypt() - Invoke public key decrypt operation
304 *
305 * Function invokes the specific public key decrypt operation for a given
306 * public key algorithm
307 *
308 * @req:	asymmetric key request
309 *
310 * Return: zero on success; error code in case of error
311 */
312static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
313{
314	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
315	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
316	struct crypto_alg *calg = tfm->base.__crt_alg;
317	unsigned int src_len = req->src_len;
318	int ret;
319
320	crypto_stats_get(calg);
321	ret = alg->decrypt(req);
322	crypto_stats_akcipher_decrypt(src_len, ret, calg);
323	return ret;
324}
325
326/**
327 * crypto_akcipher_sign() - Invoke public key sign operation
328 *
329 * Function invokes the specific public key sign operation for a given
330 * public key algorithm
331 *
332 * @req:	asymmetric key request
333 *
334 * Return: zero on success; error code in case of error
335 */
336static inline int crypto_akcipher_sign(struct akcipher_request *req)
337{
338	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
339	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
340	struct crypto_alg *calg = tfm->base.__crt_alg;
341	int ret;
342
343	crypto_stats_get(calg);
344	ret = alg->sign(req);
345	crypto_stats_akcipher_sign(ret, calg);
346	return ret;
347}
348
349/**
350 * crypto_akcipher_verify() - Invoke public key signature verification
351 *
352 * Function invokes the specific public key signature verification operation
353 * for a given public key algorithm.
354 *
355 * @req:	asymmetric key request
356 *
357 * Note: req->dst should be NULL, req->src should point to SG of size
358 * (req->src_size + req->dst_size), containing signature (of req->src_size
359 * length) with appended digest (of req->dst_size length).
360 *
361 * Return: zero on verification success; error code in case of error.
362 */
363static inline int crypto_akcipher_verify(struct akcipher_request *req)
364{
365	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
366	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
367	struct crypto_alg *calg = tfm->base.__crt_alg;
368	int ret;
369
370	crypto_stats_get(calg);
371	ret = alg->verify(req);
372	crypto_stats_akcipher_verify(ret, calg);
373	return ret;
374}
375
376/**
377 * crypto_akcipher_set_pub_key() - Invoke set public key operation
378 *
379 * Function invokes the algorithm specific set key function, which knows
380 * how to decode and interpret the encoded key and parameters
381 *
382 * @tfm:	tfm handle
383 * @key:	BER encoded public key, algo OID, paramlen, BER encoded
384 *		parameters
385 * @keylen:	length of the key (not including other data)
386 *
387 * Return: zero on success; error code in case of error
388 */
389static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
390					      const void *key,
391					      unsigned int keylen)
392{
393	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
394
395	return alg->set_pub_key(tfm, key, keylen);
396}
397
398/**
399 * crypto_akcipher_set_priv_key() - Invoke set private key operation
400 *
401 * Function invokes the algorithm specific set key function, which knows
402 * how to decode and interpret the encoded key and parameters
403 *
404 * @tfm:	tfm handle
405 * @key:	BER encoded private key, algo OID, paramlen, BER encoded
406 *		parameters
407 * @keylen:	length of the key (not including other data)
408 *
409 * Return: zero on success; error code in case of error
410 */
411static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
412					       const void *key,
413					       unsigned int keylen)
414{
415	struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
416
417	return alg->set_priv_key(tfm, key, keylen);
418}
419#endif