xref: /linux/crypto/sig.c (revision f85f5ae45ad945270a8884261de8249431e8b5a6)
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/akcipher.h>
9 #include <crypto/internal/sig.h>
10 #include <linux/cryptouser.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/scatterlist.h>
14 #include <linux/seq_file.h>
15 #include <linux/string.h>
16 #include <net/netlink.h>
17 
18 #include "internal.h"
19 
20 #define CRYPTO_ALG_TYPE_SIG_MASK	0x0000000e
21 
22 static const struct crypto_type crypto_sig_type;
23 
24 static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
25 {
26 	if (tfm->__crt_alg->cra_type != &crypto_sig_type)
27 		return crypto_init_akcipher_ops_sig(tfm);
28 
29 	return 0;
30 }
31 
32 static void __maybe_unused crypto_sig_show(struct seq_file *m,
33 					   struct crypto_alg *alg)
34 {
35 	seq_puts(m, "type         : sig\n");
36 }
37 
38 static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
39 					    struct crypto_alg *alg)
40 {
41 	struct crypto_report_akcipher rsig = {};
42 
43 	strscpy(rsig.type, "sig", sizeof(rsig.type));
44 
45 	return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, sizeof(rsig), &rsig);
46 }
47 
48 static int __maybe_unused crypto_sig_report_stat(struct sk_buff *skb,
49 						 struct crypto_alg *alg)
50 {
51 	struct crypto_stat_akcipher rsig = {};
52 
53 	strscpy(rsig.type, "sig", sizeof(rsig.type));
54 
55 	return nla_put(skb, CRYPTOCFGA_STAT_AKCIPHER, sizeof(rsig), &rsig);
56 }
57 
58 static const struct crypto_type crypto_sig_type = {
59 	.extsize = crypto_alg_extsize,
60 	.init_tfm = crypto_sig_init_tfm,
61 #ifdef CONFIG_PROC_FS
62 	.show = crypto_sig_show,
63 #endif
64 #if IS_ENABLED(CONFIG_CRYPTO_USER)
65 	.report = crypto_sig_report,
66 #endif
67 #ifdef CONFIG_CRYPTO_STATS
68 	.report_stat = crypto_sig_report_stat,
69 #endif
70 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
71 	.maskset = CRYPTO_ALG_TYPE_SIG_MASK,
72 	.type = CRYPTO_ALG_TYPE_SIG,
73 	.tfmsize = offsetof(struct crypto_sig, base),
74 };
75 
76 struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
77 {
78 	return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
79 }
80 EXPORT_SYMBOL_GPL(crypto_alloc_sig);
81 
82 int crypto_sig_maxsize(struct crypto_sig *tfm)
83 {
84 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
85 
86 	return crypto_akcipher_maxsize(*ctx);
87 }
88 EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
89 
90 int crypto_sig_sign(struct crypto_sig *tfm,
91 		    const void *src, unsigned int slen,
92 		    void *dst, unsigned int dlen)
93 {
94 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
95 	struct crypto_akcipher_sync_data data = {
96 		.tfm = *ctx,
97 		.src = src,
98 		.dst = dst,
99 		.slen = slen,
100 		.dlen = dlen,
101 	};
102 
103 	return crypto_akcipher_sync_prep(&data) ?:
104 	       crypto_akcipher_sync_post(&data,
105 					 crypto_akcipher_sign(data.req));
106 }
107 EXPORT_SYMBOL_GPL(crypto_sig_sign);
108 
109 int crypto_sig_verify(struct crypto_sig *tfm,
110 		      const void *src, unsigned int slen,
111 		      const void *digest, unsigned int dlen)
112 {
113 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
114 	struct crypto_akcipher_sync_data data = {
115 		.tfm = *ctx,
116 		.src = src,
117 		.slen = slen,
118 		.dlen = dlen,
119 	};
120 	int err;
121 
122 	err = crypto_akcipher_sync_prep(&data);
123 	if (err)
124 		return err;
125 
126 	memcpy(data.buf + slen, digest, dlen);
127 
128 	return crypto_akcipher_sync_post(&data,
129 					 crypto_akcipher_verify(data.req));
130 }
131 EXPORT_SYMBOL_GPL(crypto_sig_verify);
132 
133 int crypto_sig_set_pubkey(struct crypto_sig *tfm,
134 			  const void *key, unsigned int keylen)
135 {
136 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
137 
138 	return crypto_akcipher_set_pub_key(*ctx, key, keylen);
139 }
140 EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
141 
142 int crypto_sig_set_privkey(struct crypto_sig *tfm,
143 			  const void *key, unsigned int keylen)
144 {
145 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
146 
147 	return crypto_akcipher_set_priv_key(*ctx, key, keylen);
148 }
149 EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
150 
151 MODULE_LICENSE("GPL");
152 MODULE_DESCRIPTION("Public Key Signature Algorithms");
153