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 request
16 *
17 * @base: Common attributes for async crypto requests
18 * @src: Source data
19 * For verify op this is signature + digest, in that case
20 * total size of @src is @src_len + @dst_len.
21 * @dst: Destination data (Should be NULL for verify op)
22 * @src_len: Size of the input buffer
23 * For verify op it's size of signature part of @src, this part
24 * is supposed to be operated by cipher.
25 * @dst_len: Size of @dst buffer (for all ops except verify).
26 * It needs to be at least as big as the expected result
27 * depending on the operation.
28 * After operation it will be updated with the actual size of the
29 * result.
30 * In case of error where the dst sgl size was insufficient,
31 * it will be updated to the size required for the operation.
32 * For verify op this is size of digest part in @src.
33 * @__ctx: Start of private context data
34 */
35 struct akcipher_request {
36 struct crypto_async_request base;
37 struct scatterlist *src;
38 struct scatterlist *dst;
39 unsigned int src_len;
40 unsigned int dst_len;
41 void *__ctx[] CRYPTO_MINALIGN_ATTR;
42 };
43
44 /**
45 * struct crypto_akcipher - user-instantiated objects which encapsulate
46 * algorithms and core processing logic
47 *
48 * @reqsize: Request context size required by algorithm implementation
49 * @base: Common crypto API algorithm data structure
50 */
51 struct crypto_akcipher {
52 unsigned int reqsize;
53
54 struct crypto_tfm base;
55 };
56
57 /**
58 * struct akcipher_alg - generic public key algorithm
59 *
60 * @sign: Function performs a sign operation as defined by public key
61 * algorithm. In case of error, where the dst_len was insufficient,
62 * the req->dst_len will be updated to the size required for the
63 * operation
64 * @verify: Function performs a complete verify operation as defined by
65 * public key algorithm, returning verification status. Requires
66 * digest value as input parameter.
67 * @encrypt: Function performs an encrypt operation as defined by public key
68 * algorithm. In case of error, where the dst_len was insufficient,
69 * the req->dst_len will be updated to the size required for the
70 * operation
71 * @decrypt: Function performs a decrypt operation as defined by public key
72 * algorithm. In case of error, where the dst_len was insufficient,
73 * the req->dst_len will be updated to the size required for the
74 * operation
75 * @set_pub_key: Function invokes the algorithm specific set public key
76 * function, which knows how to decode and interpret
77 * the BER encoded public key and parameters
78 * @set_priv_key: Function invokes the algorithm specific set private key
79 * function, which knows how to decode and interpret
80 * the BER encoded private key and parameters
81 * @max_size: Function returns dest buffer size required for a given key.
82 * @init: Initialize the cryptographic transformation object.
83 * This function is used to initialize the cryptographic
84 * transformation object. This function is called only once at
85 * the instantiation time, right after the transformation context
86 * was allocated. In case the cryptographic hardware has some
87 * special requirements which need to be handled by software, this
88 * function shall check for the precise requirement of the
89 * transformation and put any software fallbacks in place.
90 * @exit: Deinitialize the cryptographic transformation object. This is a
91 * counterpart to @init, used to remove various changes set in
92 * @init.
93 *
94 * @base: Common crypto API algorithm data structure
95 */
96 struct akcipher_alg {
97 int (*sign)(struct akcipher_request *req);
98 int (*verify)(struct akcipher_request *req);
99 int (*encrypt)(struct akcipher_request *req);
100 int (*decrypt)(struct akcipher_request *req);
101 int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key,
102 unsigned int keylen);
103 int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key,
104 unsigned int keylen);
105 unsigned int (*max_size)(struct crypto_akcipher *tfm);
106 int (*init)(struct crypto_akcipher *tfm);
107 void (*exit)(struct crypto_akcipher *tfm);
108
109 struct crypto_alg base;
110 };
111
112 /**
113 * DOC: Generic Public Key API
114 *
115 * The Public Key API is used with the algorithms of type
116 * CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto)
117 */
118
119 /**
120 * crypto_alloc_akcipher() - allocate AKCIPHER tfm handle
121 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
122 * public key algorithm e.g. "rsa"
123 * @type: specifies the type of the algorithm
124 * @mask: specifies the mask for the algorithm
125 *
126 * Allocate a handle for public key algorithm. The returned struct
127 * crypto_akcipher is the handle that is required for any subsequent
128 * API invocation for the public key operations.
129 *
130 * Return: allocated handle in case of success; IS_ERR() is true in case
131 * of an error, PTR_ERR() returns the error code.
132 */
133 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
134 u32 mask);
135
136 static inline struct crypto_tfm *crypto_akcipher_tfm(
137 struct crypto_akcipher *tfm)
138 {
139 return &tfm->base;
140 }
141
142 static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg)
143 {
144 return container_of(alg, struct akcipher_alg, base);
145 }
146
147 static inline struct crypto_akcipher *__crypto_akcipher_tfm(
148 struct crypto_tfm *tfm)
149 {
150 return container_of(tfm, struct crypto_akcipher, base);
151 }
152
153 static inline struct akcipher_alg *crypto_akcipher_alg(
154 struct crypto_akcipher *tfm)
155 {
156 return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg);
157 }
158
159 static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm)
160 {
161 return tfm->reqsize;
162 }
163
164 static inline void akcipher_request_set_tfm(struct akcipher_request *req,
165 struct crypto_akcipher *tfm)
166 {
167 req->base.tfm = crypto_akcipher_tfm(tfm);
168 }
169
170 static inline struct crypto_akcipher *crypto_akcipher_reqtfm(
171 struct akcipher_request *req)
172 {
173 return __crypto_akcipher_tfm(req->base.tfm);
174 }
175
176 /**
177 * crypto_free_akcipher() - free AKCIPHER tfm handle
178 *
179 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
180 *
181 * If @tfm is a NULL or error pointer, this function does nothing.
182 */
183 static inline void crypto_free_akcipher(struct crypto_akcipher *tfm)
184 {
185 crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm));
186 }
187
188 /**
189 * akcipher_request_alloc() - allocates public key request
190 *
191 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
192 * @gfp: allocation flags
193 *
194 * Return: allocated handle in case of success or NULL in case of an error.
195 */
196 static inline struct akcipher_request *akcipher_request_alloc(
197 struct crypto_akcipher *tfm, gfp_t gfp)
198 {
199 struct akcipher_request *req;
200
201 req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp);
202 if (likely(req))
203 akcipher_request_set_tfm(req, tfm);
204
205 return req;
206 }
207
208 /**
209 * akcipher_request_free() - zeroize and free public key request
210 *
211 * @req: request to free
212 */
213 static inline void akcipher_request_free(struct akcipher_request *req)
214 {
215 kfree_sensitive(req);
216 }
217
218 /**
219 * akcipher_request_set_callback() - Sets an asynchronous callback.
220 *
221 * Callback will be called when an asynchronous operation on a given
222 * request is finished.
223 *
224 * @req: request that the callback will be set for
225 * @flgs: specify for instance if the operation may backlog
226 * @cmpl: callback which will be called
227 * @data: private data used by the caller
228 */
229 static inline void akcipher_request_set_callback(struct akcipher_request *req,
230 u32 flgs,
231 crypto_completion_t cmpl,
232 void *data)
233 {
234 req->base.complete = cmpl;
235 req->base.data = data;
236 req->base.flags = flgs;
237 }
238
239 /**
240 * akcipher_request_set_crypt() - Sets request parameters
241 *
242 * Sets parameters required by crypto operation
243 *
244 * @req: public key request
245 * @src: ptr to input scatter list
246 * @dst: ptr to output scatter list or NULL for verify op
247 * @src_len: size of the src input scatter list to be processed
248 * @dst_len: size of the dst output scatter list or size of signature
249 * portion in @src for verify op
250 */
251 static inline void akcipher_request_set_crypt(struct akcipher_request *req,
252 struct scatterlist *src,
253 struct scatterlist *dst,
254 unsigned int src_len,
255 unsigned int dst_len)
256 {
257 req->src = src;
258 req->dst = dst;
259 req->src_len = src_len;
260 req->dst_len = dst_len;
261 }
262
263 /**
264 * crypto_akcipher_maxsize() - Get len for output buffer
265 *
266 * Function returns the dest buffer size required for a given key.
267 * Function assumes that the key is already set in the transformation. If this
268 * function is called without a setkey or with a failed setkey, you will end up
269 * in a NULL dereference.
270 *
271 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
272 */
273 static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
274 {
275 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
276
277 return alg->max_size(tfm);
278 }
279
280 /**
281 * crypto_akcipher_encrypt() - Invoke public key encrypt operation
282 *
283 * Function invokes the specific public key encrypt operation for a given
284 * public key algorithm
285 *
286 * @req: asymmetric key request
287 *
288 * Return: zero on success; error code in case of error
289 */
290 static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
291 {
292 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
293
294 return crypto_akcipher_alg(tfm)->encrypt(req);
295 }
296
297 /**
298 * crypto_akcipher_decrypt() - Invoke public key decrypt operation
299 *
300 * Function invokes the specific public key decrypt operation for a given
301 * public key algorithm
302 *
303 * @req: asymmetric key request
304 *
305 * Return: zero on success; error code in case of error
306 */
307 static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
308 {
309 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
310
311 return crypto_akcipher_alg(tfm)->decrypt(req);
312 }
313
314 /**
315 * crypto_akcipher_sync_encrypt() - Invoke public key encrypt operation
316 *
317 * Function invokes the specific public key encrypt operation for a given
318 * public key algorithm
319 *
320 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
321 * @src: source buffer
322 * @slen: source length
323 * @dst: destination obuffer
324 * @dlen: destination length
325 *
326 * Return: zero on success; error code in case of error
327 */
328 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm,
329 const void *src, unsigned int slen,
330 void *dst, unsigned int dlen);
331
332 /**
333 * crypto_akcipher_sync_decrypt() - Invoke public key decrypt operation
334 *
335 * Function invokes the specific public key decrypt operation for a given
336 * public key algorithm
337 *
338 * @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
339 * @src: source buffer
340 * @slen: source length
341 * @dst: destination obuffer
342 * @dlen: destination length
343 *
344 * Return: Output length on success; error code in case of error
345 */
346 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm,
347 const void *src, unsigned int slen,
348 void *dst, unsigned int dlen);
349
350 /**
351 * crypto_akcipher_sign() - Invoke public key sign operation
352 *
353 * Function invokes the specific public key sign operation for a given
354 * public key algorithm
355 *
356 * @req: asymmetric key request
357 *
358 * Return: zero on success; error code in case of error
359 */
360 static inline int crypto_akcipher_sign(struct akcipher_request *req)
361 {
362 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
363
364 return crypto_akcipher_alg(tfm)->sign(req);
365 }
366
367 /**
368 * crypto_akcipher_verify() - Invoke public key signature verification
369 *
370 * Function invokes the specific public key signature verification operation
371 * for a given public key algorithm.
372 *
373 * @req: asymmetric key request
374 *
375 * Note: req->dst should be NULL, req->src should point to SG of size
376 * (req->src_size + req->dst_size), containing signature (of req->src_size
377 * length) with appended digest (of req->dst_size length).
378 *
379 * Return: zero on verification success; error code in case of error.
380 */
381 static inline int crypto_akcipher_verify(struct akcipher_request *req)
382 {
383 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
384
385 return crypto_akcipher_alg(tfm)->verify(req);
386 }
387
388 /**
389 * crypto_akcipher_set_pub_key() - Invoke set public key operation
390 *
391 * Function invokes the algorithm specific set key function, which knows
392 * how to decode and interpret the encoded key and parameters
393 *
394 * @tfm: tfm handle
395 * @key: BER encoded public key, algo OID, paramlen, BER encoded
396 * parameters
397 * @keylen: length of the key (not including other data)
398 *
399 * Return: zero on success; error code in case of error
400 */
401 static inline int crypto_akcipher_set_pub_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_pub_key(tfm, key, keylen);
408 }
409
410 /**
411 * crypto_akcipher_set_priv_key() - Invoke set private key operation
412 *
413 * Function invokes the algorithm specific set key function, which knows
414 * how to decode and interpret the encoded key and parameters
415 *
416 * @tfm: tfm handle
417 * @key: BER encoded private key, algo OID, paramlen, BER encoded
418 * parameters
419 * @keylen: length of the key (not including other data)
420 *
421 * Return: zero on success; error code in case of error
422 */
423 static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
424 const void *key,
425 unsigned int keylen)
426 {
427 struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
428
429 return alg->set_priv_key(tfm, key, keylen);
430 }
431 #endif
432
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