xref: /openbmc/linux/crypto/sig.c (revision 7998abe6)
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 inline struct crypto_sig *__crypto_sig_tfm(struct crypto_tfm *tfm)
25 {
26 	return container_of(tfm, struct crypto_sig, base);
27 }
28 
29 static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
30 {
31 	if (tfm->__crt_alg->cra_type != &crypto_sig_type)
32 		return crypto_init_akcipher_ops_sig(tfm);
33 
34 	return 0;
35 }
36 
37 static void __maybe_unused crypto_sig_show(struct seq_file *m,
38 					   struct crypto_alg *alg)
39 {
40 	seq_puts(m, "type         : sig\n");
41 }
42 
43 static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
44 					    struct crypto_alg *alg)
45 {
46 	struct crypto_report_akcipher rsig = {};
47 
48 	strscpy(rsig.type, "sig", sizeof(rsig.type));
49 
50 	return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, sizeof(rsig), &rsig);
51 }
52 
53 static int __maybe_unused crypto_sig_report_stat(struct sk_buff *skb,
54 						 struct crypto_alg *alg)
55 {
56 	struct crypto_stat_akcipher rsig = {};
57 
58 	strscpy(rsig.type, "sig", sizeof(rsig.type));
59 
60 	return nla_put(skb, CRYPTOCFGA_STAT_AKCIPHER, sizeof(rsig), &rsig);
61 }
62 
63 static const struct crypto_type crypto_sig_type = {
64 	.extsize = crypto_alg_extsize,
65 	.init_tfm = crypto_sig_init_tfm,
66 #ifdef CONFIG_PROC_FS
67 	.show = crypto_sig_show,
68 #endif
69 #if IS_ENABLED(CONFIG_CRYPTO_USER)
70 	.report = crypto_sig_report,
71 #endif
72 #ifdef CONFIG_CRYPTO_STATS
73 	.report_stat = crypto_sig_report_stat,
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 int crypto_sig_maxsize(struct crypto_sig *tfm)
88 {
89 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
90 
91 	return crypto_akcipher_maxsize(*ctx);
92 }
93 EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
94 
95 int crypto_sig_sign(struct crypto_sig *tfm,
96 		    const void *src, unsigned int slen,
97 		    void *dst, unsigned int dlen)
98 {
99 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
100 	struct crypto_akcipher_sync_data data = {
101 		.tfm = *ctx,
102 		.src = src,
103 		.dst = dst,
104 		.slen = slen,
105 		.dlen = dlen,
106 	};
107 
108 	return crypto_akcipher_sync_prep(&data) ?:
109 	       crypto_akcipher_sync_post(&data,
110 					 crypto_akcipher_sign(data.req));
111 }
112 EXPORT_SYMBOL_GPL(crypto_sig_sign);
113 
114 int crypto_sig_verify(struct crypto_sig *tfm,
115 		      const void *src, unsigned int slen,
116 		      const void *digest, unsigned int dlen)
117 {
118 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
119 	struct crypto_akcipher_sync_data data = {
120 		.tfm = *ctx,
121 		.src = src,
122 		.slen = slen,
123 		.dlen = dlen,
124 	};
125 	int err;
126 
127 	err = crypto_akcipher_sync_prep(&data);
128 	if (err)
129 		return err;
130 
131 	memcpy(data.buf + slen, digest, dlen);
132 
133 	return crypto_akcipher_sync_post(&data,
134 					 crypto_akcipher_verify(data.req));
135 }
136 EXPORT_SYMBOL_GPL(crypto_sig_verify);
137 
138 int crypto_sig_set_pubkey(struct crypto_sig *tfm,
139 			  const void *key, unsigned int keylen)
140 {
141 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
142 
143 	return crypto_akcipher_set_pub_key(*ctx, key, keylen);
144 }
145 EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
146 
147 int crypto_sig_set_privkey(struct crypto_sig *tfm,
148 			  const void *key, unsigned int keylen)
149 {
150 	struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
151 
152 	return crypto_akcipher_set_priv_key(*ctx, key, keylen);
153 }
154 EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
155 
156 MODULE_LICENSE("GPL");
157 MODULE_DESCRIPTION("Public Key Signature Algorithms");
158