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(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(mem: 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
266