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 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
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 * Function assumes that the key is already set in the transformation. If this
262 * function is called without a setkey or with a failed setkey, you will end up
263 * in a NULL dereference.
264 *
265 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
266 */
267static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
268{
269 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
270
271 return alg->max_size(tfm);
272}
273
274/**
275 * crypto_akcipher_encrypt() - Invoke public key encrypt operation
276 *
277 * Function invokes the specific public key encrypt operation for a given
278 * public key algorithm
279 *
280 * @req: asymmetric key request
281 *
282 * Return: zero on success; error code in case of error
283 */
284static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
285{
286 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
287 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
288 struct crypto_alg *calg = tfm->base.__crt_alg;
289 unsigned int src_len = req->src_len;
290 int ret;
291
292 crypto_stats_get(calg);
293 ret = alg->encrypt(req);
294 crypto_stats_akcipher_encrypt(src_len, ret, calg);
295 return ret;
296}
297
298/**
299 * crypto_akcipher_decrypt() - Invoke public key decrypt operation
300 *
301 * Function invokes the specific public key decrypt operation for a given
302 * public key algorithm
303 *
304 * @req: asymmetric key request
305 *
306 * Return: zero on success; error code in case of error
307 */
308static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
309{
310 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
311 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
312 struct crypto_alg *calg = tfm->base.__crt_alg;
313 unsigned int src_len = req->src_len;
314 int ret;
315
316 crypto_stats_get(calg);
317 ret = alg->decrypt(req);
318 crypto_stats_akcipher_decrypt(src_len, ret, calg);
319 return ret;
320}
321
322/**
323 * crypto_akcipher_sign() - Invoke public key sign operation
324 *
325 * Function invokes the specific public key sign operation for a given
326 * public key algorithm
327 *
328 * @req: asymmetric key request
329 *
330 * Return: zero on success; error code in case of error
331 */
332static inline int crypto_akcipher_sign(struct akcipher_request *req)
333{
334 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
335 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
336 struct crypto_alg *calg = tfm->base.__crt_alg;
337 int ret;
338
339 crypto_stats_get(calg);
340 ret = alg->sign(req);
341 crypto_stats_akcipher_sign(ret, calg);
342 return ret;
343}
344
345/**
346 * crypto_akcipher_verify() - Invoke public key verify operation
347 *
348 * Function invokes the specific public key verify operation for a given
349 * public key algorithm
350 *
351 * @req: asymmetric key request
352 *
353 * Return: zero on success; error code in case of error
354 */
355static inline int crypto_akcipher_verify(struct akcipher_request *req)
356{
357 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
358 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
359 struct crypto_alg *calg = tfm->base.__crt_alg;
360 int ret;
361
362 crypto_stats_get(calg);
363 ret = alg->verify(req);
364 crypto_stats_akcipher_verify(ret, calg);
365 return ret;
366}
367
368/**
369 * crypto_akcipher_set_pub_key() - Invoke set public key operation
370 *
371 * Function invokes the algorithm specific set key function, which knows
372 * how to decode and interpret the encoded key
373 *
374 * @tfm: tfm handle
375 * @key: BER encoded public key
376 * @keylen: length of the key
377 *
378 * Return: zero on success; error code in case of error
379 */
380static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
381 const void *key,
382 unsigned int keylen)
383{
384 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
385
386 return alg->set_pub_key(tfm, key, keylen);
387}
388
389/**
390 * crypto_akcipher_set_priv_key() - Invoke set private key operation
391 *
392 * Function invokes the algorithm specific set key function, which knows
393 * how to decode and interpret the encoded key
394 *
395 * @tfm: tfm handle
396 * @key: BER encoded private key
397 * @keylen: length of the key
398 *
399 * Return: zero on success; error code in case of error
400 */
401static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
402 const void *key,
403 unsigned int keylen)
404{
405 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
406
407 return alg->set_priv_key(tfm, key, keylen);
408}
409#endif
410