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