2 * Key-agreement Protocol Primitives (KPP)
4 * Copyright (c) 2016, Intel Corporation
5 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
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)
16 #include <linux/crypto.h>
21 * @base: Common attributes for async crypto requests
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
33 struct crypto_async_request base;
34 struct scatterlist *src;
35 struct scatterlist *dst;
38 void *__ctx[] CRYPTO_MINALIGN_ATTR;
42 * struct crypto_kpp - user-instantiated object which encapsulate
43 * algorithms and core processing logic
45 * @base: Common crypto API algorithm data structure
48 struct crypto_tfm base;
52 * struct kpp_alg - generic key-agreement protocol primitives
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 the 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
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
70 * @exit: Undo everything @init did.
72 * @reqsize: Request context size required by algorithm
74 * @base: Common crypto API algorithm data structure
77 int (*set_secret)(struct crypto_kpp *tfm, const void *buffer,
79 int (*generate_public_key)(struct kpp_request *req);
80 int (*compute_shared_secret)(struct kpp_request *req);
82 unsigned int (*max_size)(struct crypto_kpp *tfm);
84 int (*init)(struct crypto_kpp *tfm);
85 void (*exit)(struct crypto_kpp *tfm);
88 struct crypto_alg base;
92 * DOC: Generic Key-agreement Protocol Primitives API
94 * The KPP API is used with the algorithm type
95 * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto)
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
104 * Allocate a handle for kpp algorithm. The returned struct crypto_kpp
105 * is required for any following API invocation
107 * Return: allocated handle in case of success; IS_ERR() is true in case of
108 * an error, PTR_ERR() returns the error code.
110 struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask);
112 static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm)
117 static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg)
119 return container_of(alg, struct kpp_alg, base);
122 static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm)
124 return container_of(tfm, struct crypto_kpp, base);
127 static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm)
129 return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg);
132 static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm)
134 return crypto_kpp_alg(tfm)->reqsize;
137 static inline void kpp_request_set_tfm(struct kpp_request *req,
138 struct crypto_kpp *tfm)
140 req->base.tfm = crypto_kpp_tfm(tfm);
143 static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req)
145 return __crypto_kpp_tfm(req->base.tfm);
148 static inline u32 crypto_kpp_get_flags(struct crypto_kpp *tfm)
150 return crypto_tfm_get_flags(crypto_kpp_tfm(tfm));
153 static inline void crypto_kpp_set_flags(struct crypto_kpp *tfm, u32 flags)
155 crypto_tfm_set_flags(crypto_kpp_tfm(tfm), flags);
159 * crypto_free_kpp() - free KPP tfm handle
161 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
163 * If @tfm is a NULL or error pointer, this function does nothing.
165 static inline void crypto_free_kpp(struct crypto_kpp *tfm)
167 crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm));
171 * kpp_request_alloc() - allocates kpp request
173 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
174 * @gfp: allocation flags
176 * Return: allocated handle in case of success or NULL in case of an error.
178 static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm,
181 struct kpp_request *req;
183 req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp);
185 kpp_request_set_tfm(req, tfm);
191 * kpp_request_free() - zeroize and free kpp request
193 * @req: request to free
195 static inline void kpp_request_free(struct kpp_request *req)
201 * kpp_request_set_callback() - Sets an asynchronous callback.
203 * Callback will be called when an asynchronous operation on a given
204 * request is finished.
206 * @req: request that the callback will be set for
207 * @flgs: specify for instance if the operation may backlog
208 * @cmpl: callback which will be called
209 * @data: private data used by the caller
211 static inline void kpp_request_set_callback(struct kpp_request *req,
213 crypto_completion_t cmpl,
216 req->base.complete = cmpl;
217 req->base.data = data;
218 req->base.flags = flgs;
222 * kpp_request_set_input() - Sets input buffer
224 * Sets parameters required by generate_public_key
227 * @input: ptr to input scatter list
228 * @input_len: size of the input scatter list
230 static inline void kpp_request_set_input(struct kpp_request *req,
231 struct scatterlist *input,
232 unsigned int input_len)
235 req->src_len = input_len;
239 * kpp_request_set_output() - Sets output buffer
241 * Sets parameters required by kpp operation
244 * @output: ptr to output scatter list
245 * @output_len: size of the output scatter list
247 static inline void kpp_request_set_output(struct kpp_request *req,
248 struct scatterlist *output,
249 unsigned int output_len)
252 req->dst_len = output_len;
256 CRYPTO_KPP_SECRET_TYPE_UNKNOWN,
257 CRYPTO_KPP_SECRET_TYPE_DH,
258 CRYPTO_KPP_SECRET_TYPE_ECDH,
262 * struct kpp_secret - small header for packing secret buffer
264 * @type: define type of secret. Each kpp type will define its own
265 * @len: specify the len of the secret, include the header, that
274 * crypto_kpp_set_secret() - Invoke kpp operation
276 * Function invokes the specific kpp operation for a given alg.
279 * @buffer: Buffer holding the packet representation of the private
280 * key. The structure of the packet key depends on the particular
281 * KPP implementation. Packing and unpacking helpers are provided
282 * for ECDH and DH (see the respective header files for those
284 * @len: Length of the packet private key buffer.
286 * Return: zero on success; error code in case of error
288 static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm,
289 const void *buffer, unsigned int len)
291 struct kpp_alg *alg = crypto_kpp_alg(tfm);
293 return alg->set_secret(tfm, buffer, len);
297 * crypto_kpp_generate_public_key() - Invoke kpp operation
299 * Function invokes the specific kpp operation for generating the public part
300 * for a given kpp algorithm.
302 * To generate a private key, the caller should use a random number generator.
303 * The output of the requested length serves as the private key.
305 * @req: kpp key request
307 * Return: zero on success; error code in case of error
309 static inline int crypto_kpp_generate_public_key(struct kpp_request *req)
311 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
312 struct kpp_alg *alg = crypto_kpp_alg(tfm);
314 return alg->generate_public_key(req);
318 * crypto_kpp_compute_shared_secret() - Invoke kpp operation
320 * Function invokes the specific kpp operation for computing the shared secret
321 * for a given kpp algorithm.
323 * @req: kpp key request
325 * Return: zero on success; error code in case of error
327 static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req)
329 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
330 struct kpp_alg *alg = crypto_kpp_alg(tfm);
332 return alg->compute_shared_secret(req);
336 * crypto_kpp_maxsize() - Get len for output buffer
338 * Function returns the output buffer size required for a given key.
339 * Function assumes that the key is already set in the transformation. If this
340 * function is called without a setkey or with a failed setkey, you will end up
341 * in a NULL dereference.
343 * @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
345 static inline unsigned int crypto_kpp_maxsize(struct crypto_kpp *tfm)
347 struct kpp_alg *alg = crypto_kpp_alg(tfm);
349 return alg->max_size(tfm);