xref: /linux/crypto/sig.c (revision 23717055a79981daf7fafa09a4b0d7566f8384aa)
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 
8 #include <crypto/internal/sig.h>
9 #include <linux/cryptouser.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/seq_file.h>
13 #include <linux/string.h>
14 #include <net/netlink.h>
15 
16 #include "internal.h"
17 
18 #define CRYPTO_ALG_TYPE_SIG_MASK	0x0000000e
19 
20 static void crypto_sig_exit_tfm(struct crypto_tfm *tfm)
21 {
22 	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
23 	struct sig_alg *alg = crypto_sig_alg(sig);
24 
25 	alg->exit(sig);
26 }
27 
28 static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
29 {
30 	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
31 	struct sig_alg *alg = crypto_sig_alg(sig);
32 
33 	if (alg->exit)
34 		sig->base.exit = crypto_sig_exit_tfm;
35 
36 	if (alg->init)
37 		return alg->init(sig);
38 
39 	return 0;
40 }
41 
42 static void crypto_sig_free_instance(struct crypto_instance *inst)
43 {
44 	struct sig_instance *sig = sig_instance(inst);
45 
46 	sig->free(sig);
47 }
48 
49 static void __maybe_unused crypto_sig_show(struct seq_file *m,
50 					   struct crypto_alg *alg)
51 {
52 	seq_puts(m, "type         : sig\n");
53 }
54 
55 static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
56 					    struct crypto_alg *alg)
57 {
58 	struct crypto_report_sig rsig = {};
59 
60 	strscpy(rsig.type, "sig", sizeof(rsig.type));
61 
62 	return nla_put(skb, CRYPTOCFGA_REPORT_SIG, sizeof(rsig), &rsig);
63 }
64 
65 static const struct crypto_type crypto_sig_type = {
66 	.extsize = crypto_alg_extsize,
67 	.init_tfm = crypto_sig_init_tfm,
68 	.free = crypto_sig_free_instance,
69 #ifdef CONFIG_PROC_FS
70 	.show = crypto_sig_show,
71 #endif
72 #if IS_ENABLED(CONFIG_CRYPTO_USER)
73 	.report = crypto_sig_report,
74 #endif
75 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
76 	.maskset = CRYPTO_ALG_TYPE_SIG_MASK,
77 	.type = CRYPTO_ALG_TYPE_SIG,
78 	.tfmsize = offsetof(struct crypto_sig, base),
79 };
80 
81 struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
82 {
83 	return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
84 }
85 EXPORT_SYMBOL_GPL(crypto_alloc_sig);
86 
87 static void sig_prepare_alg(struct sig_alg *alg)
88 {
89 	struct crypto_alg *base = &alg->base;
90 
91 	base->cra_type = &crypto_sig_type;
92 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
93 	base->cra_flags |= CRYPTO_ALG_TYPE_SIG;
94 }
95 
96 static int sig_default_sign(struct crypto_sig *tfm,
97 			    const void *src, unsigned int slen,
98 			    void *dst, unsigned int dlen)
99 {
100 	return -ENOSYS;
101 }
102 
103 static int sig_default_verify(struct crypto_sig *tfm,
104 			      const void *src, unsigned int slen,
105 			      const void *dst, unsigned int dlen)
106 {
107 	return -ENOSYS;
108 }
109 
110 static int sig_default_set_key(struct crypto_sig *tfm,
111 			       const void *key, unsigned int keylen)
112 {
113 	return -ENOSYS;
114 }
115 
116 int crypto_register_sig(struct sig_alg *alg)
117 {
118 	struct crypto_alg *base = &alg->base;
119 
120 	if (!alg->sign)
121 		alg->sign = sig_default_sign;
122 	if (!alg->verify)
123 		alg->verify = sig_default_verify;
124 	if (!alg->set_priv_key)
125 		alg->set_priv_key = sig_default_set_key;
126 	if (!alg->set_pub_key)
127 		return -EINVAL;
128 	if (!alg->key_size)
129 		return -EINVAL;
130 	if (!alg->max_size)
131 		alg->max_size = alg->key_size;
132 	if (!alg->digest_size)
133 		alg->digest_size = alg->key_size;
134 
135 	sig_prepare_alg(alg);
136 	return crypto_register_alg(base);
137 }
138 EXPORT_SYMBOL_GPL(crypto_register_sig);
139 
140 void crypto_unregister_sig(struct sig_alg *alg)
141 {
142 	crypto_unregister_alg(&alg->base);
143 }
144 EXPORT_SYMBOL_GPL(crypto_unregister_sig);
145 
146 int sig_register_instance(struct crypto_template *tmpl,
147 			  struct sig_instance *inst)
148 {
149 	if (WARN_ON(!inst->free))
150 		return -EINVAL;
151 	sig_prepare_alg(&inst->alg);
152 	return crypto_register_instance(tmpl, sig_crypto_instance(inst));
153 }
154 EXPORT_SYMBOL_GPL(sig_register_instance);
155 
156 int crypto_grab_sig(struct crypto_sig_spawn *spawn,
157 		    struct crypto_instance *inst,
158 		    const char *name, u32 type, u32 mask)
159 {
160 	spawn->base.frontend = &crypto_sig_type;
161 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
162 }
163 EXPORT_SYMBOL_GPL(crypto_grab_sig);
164 
165 MODULE_LICENSE("GPL");
166 MODULE_DESCRIPTION("Public Key Signature Algorithms");
167