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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 | */ | |
32 | struct 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 | */ | |
47 | struct 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 | |
8d23da22 | 74 | * @base: Common crypto API algorithm data structure |
4e5f2c40 SB |
75 | */ |
76 | struct 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 | /** | |
8d23da22 | 92 | * DOC: Generic Key-agreement Protocol Primitives API |
4e5f2c40 SB |
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 | */ | |
110 | struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask); | |
111 | ||
112 | static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm) | |
113 | { | |
114 | return &tfm->base; | |
115 | } | |
116 | ||
117 | static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg) | |
118 | { | |
119 | return container_of(alg, struct kpp_alg, base); | |
120 | } | |
121 | ||
122 | static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm) | |
123 | { | |
124 | return container_of(tfm, struct crypto_kpp, base); | |
125 | } | |
126 | ||
127 | static 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 | ||
132 | static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm) | |
133 | { | |
134 | return crypto_kpp_alg(tfm)->reqsize; | |
135 | } | |
136 | ||
137 | static 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 | ||
143 | static 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 | */ | |
153 | static 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 | */ | |
166 | static 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 | */ | |
183 | static 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 | */ | |
199 | static 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 | */ | |
218 | static 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 | */ | |
235 | static 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 | ||
243 | enum { | |
244 | CRYPTO_KPP_SECRET_TYPE_UNKNOWN, | |
802c7f1c | 245 | CRYPTO_KPP_SECRET_TYPE_DH, |
3c4b2390 | 246 | CRYPTO_KPP_SECRET_TYPE_ECDH, |
4e5f2c40 SB |
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 | */ | |
256 | struct 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 | |
8d23da22 SM |
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. | |
4e5f2c40 SB |
273 | * |
274 | * Return: zero on success; error code in case of error | |
275 | */ | |
276 | static 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 | |
8d23da22 SM |
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. | |
4e5f2c40 SB |
292 | * |
293 | * @req: kpp key request | |
294 | * | |
295 | * Return: zero on success; error code in case of error | |
296 | */ | |
297 | static 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 | */ | |
315 | static 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 | */ | |
332 | static 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 |