xref: /linux/crypto/sig.c (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
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 int sig_default_sign(struct crypto_sig *tfm,
88 			    const void *src, unsigned int slen,
89 			    void *dst, unsigned int dlen)
90 {
91 	return -ENOSYS;
92 }
93 
94 static int sig_default_verify(struct crypto_sig *tfm,
95 			      const void *src, unsigned int slen,
96 			      const void *dst, unsigned int dlen)
97 {
98 	return -ENOSYS;
99 }
100 
101 static int sig_default_set_key(struct crypto_sig *tfm,
102 			       const void *key, unsigned int keylen)
103 {
104 	return -ENOSYS;
105 }
106 
107 static int sig_prepare_alg(struct sig_alg *alg)
108 {
109 	struct crypto_alg *base = &alg->base;
110 
111 	if (!alg->sign)
112 		alg->sign = sig_default_sign;
113 	if (!alg->verify)
114 		alg->verify = sig_default_verify;
115 	if (!alg->set_priv_key)
116 		alg->set_priv_key = sig_default_set_key;
117 	if (!alg->set_pub_key)
118 		return -EINVAL;
119 	if (!alg->key_size)
120 		return -EINVAL;
121 	if (!alg->max_size)
122 		alg->max_size = alg->key_size;
123 	if (!alg->digest_size)
124 		alg->digest_size = alg->key_size;
125 
126 	base->cra_type = &crypto_sig_type;
127 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
128 	base->cra_flags |= CRYPTO_ALG_TYPE_SIG;
129 
130 	return 0;
131 }
132 
133 int crypto_register_sig(struct sig_alg *alg)
134 {
135 	struct crypto_alg *base = &alg->base;
136 	int err;
137 
138 	err = sig_prepare_alg(alg);
139 	if (err)
140 		return err;
141 
142 	return crypto_register_alg(base);
143 }
144 EXPORT_SYMBOL_GPL(crypto_register_sig);
145 
146 void crypto_unregister_sig(struct sig_alg *alg)
147 {
148 	crypto_unregister_alg(&alg->base);
149 }
150 EXPORT_SYMBOL_GPL(crypto_unregister_sig);
151 
152 int sig_register_instance(struct crypto_template *tmpl,
153 			  struct sig_instance *inst)
154 {
155 	int err;
156 
157 	if (WARN_ON(!inst->free))
158 		return -EINVAL;
159 
160 	err = sig_prepare_alg(&inst->alg);
161 	if (err)
162 		return err;
163 
164 	return crypto_register_instance(tmpl, sig_crypto_instance(inst));
165 }
166 EXPORT_SYMBOL_GPL(sig_register_instance);
167 
168 int crypto_grab_sig(struct crypto_sig_spawn *spawn,
169 		    struct crypto_instance *inst,
170 		    const char *name, u32 type, u32 mask)
171 {
172 	spawn->base.frontend = &crypto_sig_type;
173 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
174 }
175 EXPORT_SYMBOL_GPL(crypto_grab_sig);
176 
177 MODULE_LICENSE("GPL");
178 MODULE_DESCRIPTION("Public Key Signature Algorithms");
179