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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Key-agreement Protocol Primitives (KPP)
4 *
5 * Copyright (c) 2016, Intel Corporation
6 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
7 */
8
9#ifndef _CRYPTO_KPP_
10#define _CRYPTO_KPP_
11
12#include <linux/atomic.h>
13#include <linux/container_of.h>
14#include <linux/crypto.h>
15#include <linux/slab.h>
16
17/**
18 * struct kpp_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. In case of error where the dst sgl size was insufficient,
28 * it will be updated to the size required for the operation.
29 * @__ctx: Start of private context data
30 */
31struct kpp_request {
32 struct crypto_async_request base;
33 struct scatterlist *src;
34 struct scatterlist *dst;
35 unsigned int src_len;
36 unsigned int dst_len;
37 void *__ctx[] CRYPTO_MINALIGN_ATTR;
38};
39
40/**
41 * struct crypto_kpp - user-instantiated object which encapsulate
42 * algorithms and core processing logic
43 *
44 * @reqsize: Request context size required by algorithm
45 * implementation
46 * @base: Common crypto API algorithm data structure
47 */
48struct crypto_kpp {
49 unsigned int reqsize;
50
51 struct crypto_tfm base;
52};
53
54/*
55 * struct crypto_istat_kpp - statistics for KPP algorithm
56 * @setsecret_cnt: number of setsecrey operation
57 * @generate_public_key_cnt: number of generate_public_key operation
58 * @compute_shared_secret_cnt: number of compute_shared_secret operation
59 * @err_cnt: number of error for KPP requests
60 */
61struct crypto_istat_kpp {
62 atomic64_t setsecret_cnt;
63 atomic64_t generate_public_key_cnt;
64 atomic64_t compute_shared_secret_cnt;
65 atomic64_t err_cnt;
66};
67
68/**
69 * struct kpp_alg - generic key-agreement protocol primitives
70 *
71 * @set_secret: Function invokes the protocol specific function to
72 * store the secret private key along with parameters.
73 * The implementation knows how to decode the buffer
74 * @generate_public_key: Function generate the public key to be sent to the
75 * counterpart. In case of error, where output is not big
76 * enough req->dst_len will be updated to the size
77 * required
78 * @compute_shared_secret: Function compute the shared secret as defined by
79 * the algorithm. The result is given back to the user.
80 * In case of error, where output is not big enough,
81 * req->dst_len will be updated to the size required
82 * @max_size: Function returns the size of the output buffer
83 * @init: Initialize the object. This is called only once at
84 * instantiation time. In case the cryptographic hardware
85 * needs to be initialized. Software fallback should be
86 * put in place here.
87 * @exit: Undo everything @init did.
88 *
89 * @base: Common crypto API algorithm data structure
90 * @stat: Statistics for KPP algorithm
91 */
92struct kpp_alg {
93 int (*set_secret)(struct crypto_kpp *tfm, const void *buffer,
94 unsigned int len);
95 int (*generate_public_key)(struct kpp_request *req);
96 int (*compute_shared_secret)(struct kpp_request *req);
97
98 unsigned int (*max_size)(struct crypto_kpp *tfm);
99
100 int (*init)(struct crypto_kpp *tfm);
101 void (*exit)(struct crypto_kpp *tfm);
102
103#ifdef CONFIG_CRYPTO_STATS
104 struct crypto_istat_kpp stat;
105#endif
106
107 struct crypto_alg base;
108};
109
110/**
111 * DOC: Generic Key-agreement Protocol Primitives API
112 *
113 * The KPP API is used with the algorithm type
114 * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto)
115 */
116
117/**
118 * crypto_alloc_kpp() - allocate KPP tfm handle
119 * @alg_name: is the name of the kpp algorithm (e.g. "dh", "ecdh")
120 * @type: specifies the type of the algorithm
121 * @mask: specifies the mask for the algorithm
122 *
123 * Allocate a handle for kpp algorithm. The returned struct crypto_kpp
124 * is required for any following API invocation
125 *
126 * Return: allocated handle in case of success; IS_ERR() is true in case of
127 * an error, PTR_ERR() returns the error code.
128 */
129struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask);
130
131int crypto_has_kpp(const char *alg_name, u32 type, u32 mask);
132
133static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm)
134{
135 return &tfm->base;
136}
137
138static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg)
139{
140 return container_of(alg, struct kpp_alg, base);
141}
142
143static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm)
144{
145 return container_of(tfm, struct crypto_kpp, base);
146}
147
148static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm)
149{
150 return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg);
151}
152
153static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm)
154{
155 return tfm->reqsize;
156}
157
158static inline void kpp_request_set_tfm(struct kpp_request *req,
159 struct crypto_kpp *tfm)
160{
161 req->base.tfm = crypto_kpp_tfm(tfm);
162}
163
164static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req)
165{
166 return __crypto_kpp_tfm(req->base.tfm);
167}
168
169static inline u32 crypto_kpp_get_flags(struct crypto_kpp *tfm)
170{
171 return crypto_tfm_get_flags(crypto_kpp_tfm(tfm));
172}
173
174static inline void crypto_kpp_set_flags(struct crypto_kpp *tfm, u32 flags)
175{
176 crypto_tfm_set_flags(crypto_kpp_tfm(tfm), flags);
177}
178
179/**
180 * crypto_free_kpp() - free KPP tfm handle
181 *
182 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
183 *
184 * If @tfm is a NULL or error pointer, this function does nothing.
185 */
186static inline void crypto_free_kpp(struct crypto_kpp *tfm)
187{
188 crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm));
189}
190
191/**
192 * kpp_request_alloc() - allocates kpp request
193 *
194 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
195 * @gfp: allocation flags
196 *
197 * Return: allocated handle in case of success or NULL in case of an error.
198 */
199static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm,
200 gfp_t gfp)
201{
202 struct kpp_request *req;
203
204 req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp);
205 if (likely(req))
206 kpp_request_set_tfm(req, tfm);
207
208 return req;
209}
210
211/**
212 * kpp_request_free() - zeroize and free kpp request
213 *
214 * @req: request to free
215 */
216static inline void kpp_request_free(struct kpp_request *req)
217{
218 kfree_sensitive(req);
219}
220
221/**
222 * kpp_request_set_callback() - Sets an asynchronous callback.
223 *
224 * Callback will be called when an asynchronous operation on a given
225 * request is finished.
226 *
227 * @req: request that the callback will be set for
228 * @flgs: specify for instance if the operation may backlog
229 * @cmpl: callback which will be called
230 * @data: private data used by the caller
231 */
232static inline void kpp_request_set_callback(struct kpp_request *req,
233 u32 flgs,
234 crypto_completion_t cmpl,
235 void *data)
236{
237 req->base.complete = cmpl;
238 req->base.data = data;
239 req->base.flags = flgs;
240}
241
242/**
243 * kpp_request_set_input() - Sets input buffer
244 *
245 * Sets parameters required by generate_public_key
246 *
247 * @req: kpp request
248 * @input: ptr to input scatter list
249 * @input_len: size of the input scatter list
250 */
251static inline void kpp_request_set_input(struct kpp_request *req,
252 struct scatterlist *input,
253 unsigned int input_len)
254{
255 req->src = input;
256 req->src_len = input_len;
257}
258
259/**
260 * kpp_request_set_output() - Sets output buffer
261 *
262 * Sets parameters required by kpp operation
263 *
264 * @req: kpp request
265 * @output: ptr to output scatter list
266 * @output_len: size of the output scatter list
267 */
268static inline void kpp_request_set_output(struct kpp_request *req,
269 struct scatterlist *output,
270 unsigned int output_len)
271{
272 req->dst = output;
273 req->dst_len = output_len;
274}
275
276enum {
277 CRYPTO_KPP_SECRET_TYPE_UNKNOWN,
278 CRYPTO_KPP_SECRET_TYPE_DH,
279 CRYPTO_KPP_SECRET_TYPE_ECDH,
280};
281
282/**
283 * struct kpp_secret - small header for packing secret buffer
284 *
285 * @type: define type of secret. Each kpp type will define its own
286 * @len: specify the len of the secret, include the header, that
287 * follows the struct
288 */
289struct kpp_secret {
290 unsigned short type;
291 unsigned short len;
292};
293
294static inline struct crypto_istat_kpp *kpp_get_stat(struct kpp_alg *alg)
295{
296#ifdef CONFIG_CRYPTO_STATS
297 return &alg->stat;
298#else
299 return NULL;
300#endif
301}
302
303static inline int crypto_kpp_errstat(struct kpp_alg *alg, int err)
304{
305 if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
306 return err;
307
308 if (err && err != -EINPROGRESS && err != -EBUSY)
309 atomic64_inc(&kpp_get_stat(alg)->err_cnt);
310
311 return err;
312}
313
314/**
315 * crypto_kpp_set_secret() - Invoke kpp operation
316 *
317 * Function invokes the specific kpp operation for a given alg.
318 *
319 * @tfm: tfm handle
320 * @buffer: Buffer holding the packet representation of the private
321 * key. The structure of the packet key depends on the particular
322 * KPP implementation. Packing and unpacking helpers are provided
323 * for ECDH and DH (see the respective header files for those
324 * implementations).
325 * @len: Length of the packet private key buffer.
326 *
327 * Return: zero on success; error code in case of error
328 */
329static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm,
330 const void *buffer, unsigned int len)
331{
332 struct kpp_alg *alg = crypto_kpp_alg(tfm);
333
334 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
335 atomic64_inc(&kpp_get_stat(alg)->setsecret_cnt);
336
337 return crypto_kpp_errstat(alg, alg->set_secret(tfm, buffer, len));
338}
339
340/**
341 * crypto_kpp_generate_public_key() - Invoke kpp operation
342 *
343 * Function invokes the specific kpp operation for generating the public part
344 * for a given kpp algorithm.
345 *
346 * To generate a private key, the caller should use a random number generator.
347 * The output of the requested length serves as the private key.
348 *
349 * @req: kpp key request
350 *
351 * Return: zero on success; error code in case of error
352 */
353static inline int crypto_kpp_generate_public_key(struct kpp_request *req)
354{
355 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
356 struct kpp_alg *alg = crypto_kpp_alg(tfm);
357
358 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
359 atomic64_inc(&kpp_get_stat(alg)->generate_public_key_cnt);
360
361 return crypto_kpp_errstat(alg, alg->generate_public_key(req));
362}
363
364/**
365 * crypto_kpp_compute_shared_secret() - Invoke kpp operation
366 *
367 * Function invokes the specific kpp operation for computing the shared secret
368 * for a given kpp algorithm.
369 *
370 * @req: kpp key request
371 *
372 * Return: zero on success; error code in case of error
373 */
374static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req)
375{
376 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
377 struct kpp_alg *alg = crypto_kpp_alg(tfm);
378
379 if (IS_ENABLED(CONFIG_CRYPTO_STATS))
380 atomic64_inc(&kpp_get_stat(alg)->compute_shared_secret_cnt);
381
382 return crypto_kpp_errstat(alg, alg->compute_shared_secret(req));
383}
384
385/**
386 * crypto_kpp_maxsize() - Get len for output buffer
387 *
388 * Function returns the output buffer size required for a given key.
389 * Function assumes that the key is already set in the transformation. If this
390 * function is called without a setkey or with a failed setkey, you will end up
391 * in a NULL dereference.
392 *
393 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
394 */
395static inline unsigned int crypto_kpp_maxsize(struct crypto_kpp *tfm)
396{
397 struct kpp_alg *alg = crypto_kpp_alg(tfm);
398
399 return alg->max_size(tfm);
400}
401
402#endif
1/*
2 * Key-agreement Protocol Primitives (KPP)
3 *
4 * Copyright (c) 2016, Intel Corporation
5 * Authors: Salvatore Benedetto <salvatore.benedetto@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
14#ifndef _CRYPTO_KPP_
15#define _CRYPTO_KPP_
16#include <linux/crypto.h>
17
18/**
19 * struct kpp_request
20 *
21 * @base: Common attributes for async crypto requests
22 * @src: Source data
23 * @dst: Destination data
24 * @src_len: Size of the input buffer
25 * @dst_len: Size of the output buffer. It needs to be at least
26 * as big as the expected result depending on the operation
27 * After operation it will be updated with the actual size of the
28 * result. 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 kpp_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_kpp - user-instantiated object which encapsulate
43 * algorithms and core processing logic
44 *
45 * @base: Common crypto API algorithm data structure
46 */
47struct crypto_kpp {
48 struct crypto_tfm base;
49};
50
51/**
52 * struct kpp_alg - generic key-agreement protocol primitives
53 *
54 * @set_secret: Function invokes the protocol specific function to
55 * store the secret private key along with parameters.
56 * The implementation knows how to decode thie buffer
57 * @generate_public_key: Function generate the public key to be sent to the
58 * counterpart. In case of error, where output is not big
59 * enough req->dst_len will be updated to the size
60 * required
61 * @compute_shared_secret: Function compute the shared secret as defined by
62 * the algorithm. The result is given back to the user.
63 * In case of error, where output is not big enough,
64 * req->dst_len will be updated to the size required
65 * @max_size: Function returns the size of the output buffer
66 * @init: Initialize the object. This is called only once at
67 * instantiation time. In case the cryptographic hardware
68 * needs to be initialized. Software fallback should be
69 * put in place here.
70 * @exit: Undo everything @init did.
71 *
72 * @reqsize: Request context size required by algorithm
73 * implementation
74 * @base: Common crypto API algorithm data structure
75 */
76struct kpp_alg {
77 int (*set_secret)(struct crypto_kpp *tfm, void *buffer,
78 unsigned int len);
79 int (*generate_public_key)(struct kpp_request *req);
80 int (*compute_shared_secret)(struct kpp_request *req);
81
82 int (*max_size)(struct crypto_kpp *tfm);
83
84 int (*init)(struct crypto_kpp *tfm);
85 void (*exit)(struct crypto_kpp *tfm);
86
87 unsigned int reqsize;
88 struct crypto_alg base;
89};
90
91/**
92 * DOC: Generic Key-agreement Protocol Primitives API
93 *
94 * The KPP API is used with the algorithm type
95 * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto)
96 */
97
98/**
99 * crypto_alloc_kpp() - allocate KPP tfm handle
100 * @alg_name: is the name of the kpp algorithm (e.g. "dh", "ecdh")
101 * @type: specifies the type of the algorithm
102 * @mask: specifies the mask for the algorithm
103 *
104 * Allocate a handle for kpp algorithm. The returned struct crypto_kpp
105 * is requeried for any following API invocation
106 *
107 * Return: allocated handle in case of success; IS_ERR() is true in case of
108 * an error, PTR_ERR() returns the error code.
109 */
110struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask);
111
112static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm)
113{
114 return &tfm->base;
115}
116
117static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg)
118{
119 return container_of(alg, struct kpp_alg, base);
120}
121
122static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm)
123{
124 return container_of(tfm, struct crypto_kpp, base);
125}
126
127static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm)
128{
129 return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg);
130}
131
132static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm)
133{
134 return crypto_kpp_alg(tfm)->reqsize;
135}
136
137static inline void kpp_request_set_tfm(struct kpp_request *req,
138 struct crypto_kpp *tfm)
139{
140 req->base.tfm = crypto_kpp_tfm(tfm);
141}
142
143static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req)
144{
145 return __crypto_kpp_tfm(req->base.tfm);
146}
147
148/**
149 * crypto_free_kpp() - free KPP tfm handle
150 *
151 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
152 */
153static inline void crypto_free_kpp(struct crypto_kpp *tfm)
154{
155 crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm));
156}
157
158/**
159 * kpp_request_alloc() - allocates kpp request
160 *
161 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
162 * @gfp: allocation flags
163 *
164 * Return: allocated handle in case of success or NULL in case of an error.
165 */
166static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm,
167 gfp_t gfp)
168{
169 struct kpp_request *req;
170
171 req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp);
172 if (likely(req))
173 kpp_request_set_tfm(req, tfm);
174
175 return req;
176}
177
178/**
179 * kpp_request_free() - zeroize and free kpp request
180 *
181 * @req: request to free
182 */
183static inline void kpp_request_free(struct kpp_request *req)
184{
185 kzfree(req);
186}
187
188/**
189 * kpp_request_set_callback() - Sets an asynchronous callback.
190 *
191 * Callback will be called when an asynchronous operation on a given
192 * request is finished.
193 *
194 * @req: request that the callback will be set for
195 * @flgs: specify for instance if the operation may backlog
196 * @cmpl: callback which will be called
197 * @data: private data used by the caller
198 */
199static inline void kpp_request_set_callback(struct kpp_request *req,
200 u32 flgs,
201 crypto_completion_t cmpl,
202 void *data)
203{
204 req->base.complete = cmpl;
205 req->base.data = data;
206 req->base.flags = flgs;
207}
208
209/**
210 * kpp_request_set_input() - Sets input buffer
211 *
212 * Sets parameters required by generate_public_key
213 *
214 * @req: kpp request
215 * @input: ptr to input scatter list
216 * @input_len: size of the input scatter list
217 */
218static inline void kpp_request_set_input(struct kpp_request *req,
219 struct scatterlist *input,
220 unsigned int input_len)
221{
222 req->src = input;
223 req->src_len = input_len;
224}
225
226/**
227 * kpp_request_set_output() - Sets output buffer
228 *
229 * Sets parameters required by kpp operation
230 *
231 * @req: kpp request
232 * @output: ptr to output scatter list
233 * @output_len: size of the output scatter list
234 */
235static inline void kpp_request_set_output(struct kpp_request *req,
236 struct scatterlist *output,
237 unsigned int output_len)
238{
239 req->dst = output;
240 req->dst_len = output_len;
241}
242
243enum {
244 CRYPTO_KPP_SECRET_TYPE_UNKNOWN,
245 CRYPTO_KPP_SECRET_TYPE_DH,
246 CRYPTO_KPP_SECRET_TYPE_ECDH,
247};
248
249/**
250 * struct kpp_secret - small header for packing secret buffer
251 *
252 * @type: define type of secret. Each kpp type will define its own
253 * @len: specify the len of the secret, include the header, that
254 * follows the struct
255 */
256struct kpp_secret {
257 unsigned short type;
258 unsigned short len;
259};
260
261/**
262 * crypto_kpp_set_secret() - Invoke kpp operation
263 *
264 * Function invokes the specific kpp operation for a given alg.
265 *
266 * @tfm: tfm handle
267 * @buffer: Buffer holding the packet representation of the private
268 * key. The structure of the packet key depends on the particular
269 * KPP implementation. Packing and unpacking helpers are provided
270 * for ECDH and DH (see the respective header files for those
271 * implementations).
272 * @len: Length of the packet private key buffer.
273 *
274 * Return: zero on success; error code in case of error
275 */
276static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm, void *buffer,
277 unsigned int len)
278{
279 struct kpp_alg *alg = crypto_kpp_alg(tfm);
280
281 return alg->set_secret(tfm, buffer, len);
282}
283
284/**
285 * crypto_kpp_generate_public_key() - Invoke kpp operation
286 *
287 * Function invokes the specific kpp operation for generating the public part
288 * for a given kpp algorithm.
289 *
290 * To generate a private key, the caller should use a random number generator.
291 * The output of the requested length serves as the private key.
292 *
293 * @req: kpp key request
294 *
295 * Return: zero on success; error code in case of error
296 */
297static inline int crypto_kpp_generate_public_key(struct kpp_request *req)
298{
299 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
300 struct kpp_alg *alg = crypto_kpp_alg(tfm);
301
302 return alg->generate_public_key(req);
303}
304
305/**
306 * crypto_kpp_compute_shared_secret() - Invoke kpp operation
307 *
308 * Function invokes the specific kpp operation for computing the shared secret
309 * for a given kpp algorithm.
310 *
311 * @req: kpp key request
312 *
313 * Return: zero on success; error code in case of error
314 */
315static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req)
316{
317 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
318 struct kpp_alg *alg = crypto_kpp_alg(tfm);
319
320 return alg->compute_shared_secret(req);
321}
322
323/**
324 * crypto_kpp_maxsize() - Get len for output buffer
325 *
326 * Function returns the output buffer size required
327 *
328 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
329 *
330 * Return: minimum len for output buffer or error code if key hasn't been set
331 */
332static inline int crypto_kpp_maxsize(struct crypto_kpp *tfm)
333{
334 struct kpp_alg *alg = crypto_kpp_alg(tfm);
335
336 return alg->max_size(tfm);
337}
338
339#endif