sig.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * Public Key Signature Algorithm
  4 *
  5 * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
  6 */
  7#ifndef _CRYPTO_SIG_H
  8#define _CRYPTO_SIG_H
  9
 10#include <linux/crypto.h>
 11
 12/**
 13 * struct crypto_sig - user-instantiated objects which encapsulate
 14 * algorithms and core processing logic
 15 *
 16 * @base:	Common crypto API algorithm data structure
 17 */
 18struct crypto_sig {
 19	struct crypto_tfm base;
 20};
 21
 22/**
 23 * struct sig_alg - generic public key signature algorithm
 24 *
 25 * @sign:	Function performs a sign operation as defined by public key
 26 *		algorithm. On success, the signature size is returned.
 27 *		Optional.
 28 * @verify:	Function performs a complete verify operation as defined by
 29 *		public key algorithm, returning verification status. Optional.
 30 * @set_pub_key: Function invokes the algorithm specific set public key
 31 *		function, which knows how to decode and interpret
 32 *		the BER encoded public key and parameters. Mandatory.
 33 * @set_priv_key: Function invokes the algorithm specific set private key
 34 *		function, which knows how to decode and interpret
 35 *		the BER encoded private key and parameters. Optional.
 36 * @key_size:	Function returns key size. Mandatory.
 37 * @digest_size: Function returns maximum digest size. Optional.
 38 * @max_size:	Function returns maximum signature size. Optional.
 39 * @init:	Initialize the cryptographic transformation object.
 40 *		This function is used to initialize the cryptographic
 41 *		transformation object. This function is called only once at
 42 *		the instantiation time, right after the transformation context
 43 *		was allocated. In case the cryptographic hardware has some
 44 *		special requirements which need to be handled by software, this
 45 *		function shall check for the precise requirement of the
 46 *		transformation and put any software fallbacks in place.
 47 * @exit:	Deinitialize the cryptographic transformation object. This is a
 48 *		counterpart to @init, used to remove various changes set in
 49 *		@init.
 50 *
 51 * @base:	Common crypto API algorithm data structure
 52 */
 53struct sig_alg {
 54	int (*sign)(struct crypto_sig *tfm,
 55		    const void *src, unsigned int slen,
 56		    void *dst, unsigned int dlen);
 57	int (*verify)(struct crypto_sig *tfm,
 58		      const void *src, unsigned int slen,
 59		      const void *digest, unsigned int dlen);
 60	int (*set_pub_key)(struct crypto_sig *tfm,
 61			   const void *key, unsigned int keylen);
 62	int (*set_priv_key)(struct crypto_sig *tfm,
 63			    const void *key, unsigned int keylen);
 64	unsigned int (*key_size)(struct crypto_sig *tfm);
 65	unsigned int (*digest_size)(struct crypto_sig *tfm);
 66	unsigned int (*max_size)(struct crypto_sig *tfm);
 67	int (*init)(struct crypto_sig *tfm);
 68	void (*exit)(struct crypto_sig *tfm);
 69
 70	struct crypto_alg base;
 71};
 72
 73/**
 74 * DOC: Generic Public Key Signature API
 75 *
 76 * The Public Key Signature API is used with the algorithms of type
 77 * CRYPTO_ALG_TYPE_SIG (listed as type "sig" in /proc/crypto)
 78 */
 79
 80/**
 81 * crypto_alloc_sig() - allocate signature tfm handle
 82 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the
 83 *	      signing algorithm e.g. "ecdsa"
 84 * @type: specifies the type of the algorithm
 85 * @mask: specifies the mask for the algorithm
 86 *
 87 * Allocate a handle for public key signature algorithm. The returned struct
 88 * crypto_sig is the handle that is required for any subsequent
 89 * API invocation for signature operations.
 90 *
 91 * Return: allocated handle in case of success; IS_ERR() is true in case
 92 *	   of an error, PTR_ERR() returns the error code.
 93 */
 94struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask);
 95
 96static inline struct crypto_tfm *crypto_sig_tfm(struct crypto_sig *tfm)
 97{
 98	return &tfm->base;
 99}
100
101static inline struct crypto_sig *__crypto_sig_tfm(struct crypto_tfm *tfm)
102{
103	return container_of(tfm, struct crypto_sig, base);
104}
105
106static inline struct sig_alg *__crypto_sig_alg(struct crypto_alg *alg)
107{
108	return container_of(alg, struct sig_alg, base);
109}
110
111static inline struct sig_alg *crypto_sig_alg(struct crypto_sig *tfm)
112{
113	return __crypto_sig_alg(crypto_sig_tfm(tfm)->__crt_alg);
114}
115
116/**
117 * crypto_free_sig() - free signature tfm handle
118 *
119 * @tfm: signature tfm handle allocated with crypto_alloc_sig()
120 *
121 * If @tfm is a NULL or error pointer, this function does nothing.
122 */
123static inline void crypto_free_sig(struct crypto_sig *tfm)
124{
125	crypto_destroy_tfm(tfm, crypto_sig_tfm(tfm));
126}
127
128/**
129 * crypto_sig_keysize() - Get key size
130 *
131 * Function returns the key size in bits.
132 * Function assumes that the key is already set in the transformation. If this
133 * function is called without a setkey or with a failed setkey, you may end up
134 * in a NULL dereference.
135 *
136 * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
137 */
138static inline unsigned int crypto_sig_keysize(struct crypto_sig *tfm)
139{
140	struct sig_alg *alg = crypto_sig_alg(tfm);
141
142	return alg->key_size(tfm);
143}
144
145/**
146 * crypto_sig_digestsize() - Get maximum digest size
147 *
148 * Function returns the maximum digest size in bytes.
149 * Function assumes that the key is already set in the transformation. If this
150 * function is called without a setkey or with a failed setkey, you may end up
151 * in a NULL dereference.
152 *
153 * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
154 */
155static inline unsigned int crypto_sig_digestsize(struct crypto_sig *tfm)
156{
157	struct sig_alg *alg = crypto_sig_alg(tfm);
158
159	return alg->digest_size(tfm);
160}
161
162/**
163 * crypto_sig_maxsize() - Get maximum signature size
164 *
165 * Function returns the maximum signature size in bytes.
166 * Function assumes that the key is already set in the transformation. If this
167 * function is called without a setkey or with a failed setkey, you may end up
168 * in a NULL dereference.
169 *
170 * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
171 */
172static inline unsigned int crypto_sig_maxsize(struct crypto_sig *tfm)
173{
174	struct sig_alg *alg = crypto_sig_alg(tfm);
175
176	return alg->max_size(tfm);
177}
178
179/**
180 * crypto_sig_sign() - Invoke signing operation
181 *
182 * Function invokes the specific signing operation for a given algorithm
183 *
184 * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
185 * @src:	source buffer
186 * @slen:	source length
187 * @dst:	destination obuffer
188 * @dlen:	destination length
189 *
190 * Return: signature size on success; error code in case of error
191 */
192static inline int crypto_sig_sign(struct crypto_sig *tfm,
193				  const void *src, unsigned int slen,
194				  void *dst, unsigned int dlen)
195{
196	struct sig_alg *alg = crypto_sig_alg(tfm);
197
198	return alg->sign(tfm, src, slen, dst, dlen);
199}
200
201/**
202 * crypto_sig_verify() - Invoke signature verification
203 *
204 * Function invokes the specific signature verification operation
205 * for a given algorithm.
206 *
207 * @tfm:	signature tfm handle allocated with crypto_alloc_sig()
208 * @src:	source buffer
209 * @slen:	source length
210 * @digest:	digest
211 * @dlen:	digest length
212 *
213 * Return: zero on verification success; error code in case of error.
214 */
215static inline int crypto_sig_verify(struct crypto_sig *tfm,
216				    const void *src, unsigned int slen,
217				    const void *digest, unsigned int dlen)
218{
219	struct sig_alg *alg = crypto_sig_alg(tfm);
220
221	return alg->verify(tfm, src, slen, digest, dlen);
222}
223
224/**
225 * crypto_sig_set_pubkey() - Invoke set public key operation
226 *
227 * Function invokes the algorithm specific set key function, which knows
228 * how to decode and interpret the encoded key and parameters
229 *
230 * @tfm:	tfm handle
231 * @key:	BER encoded public key, algo OID, paramlen, BER encoded
232 *		parameters
233 * @keylen:	length of the key (not including other data)
234 *
235 * Return: zero on success; error code in case of error
236 */
237static inline int crypto_sig_set_pubkey(struct crypto_sig *tfm,
238					const void *key, unsigned int keylen)
239{
240	struct sig_alg *alg = crypto_sig_alg(tfm);
241
242	return alg->set_pub_key(tfm, key, keylen);
243}
244
245/**
246 * crypto_sig_set_privkey() - Invoke set private key operation
247 *
248 * Function invokes the algorithm specific set key function, which knows
249 * how to decode and interpret the encoded key and parameters
250 *
251 * @tfm:	tfm handle
252 * @key:	BER encoded private key, algo OID, paramlen, BER encoded
253 *		parameters
254 * @keylen:	length of the key (not including other data)
255 *
256 * Return: zero on success; error code in case of error
257 */
258static inline int crypto_sig_set_privkey(struct crypto_sig *tfm,
259					 const void *key, unsigned int keylen)
260{
261	struct sig_alg *alg = crypto_sig_alg(tfm);
262
263	return alg->set_priv_key(tfm, key, keylen);
264}
265#endif