1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Public Key Signature Algorithm
4  *
5  * Copyright (c) 2023 Herbert Xu <[email protected]>
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 
crypto_sig_exit_tfm(struct crypto_tfm * tfm)18 static void crypto_sig_exit_tfm(struct crypto_tfm *tfm)
19 {
20 	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
21 	struct sig_alg *alg = crypto_sig_alg(sig);
22 
23 	alg->exit(sig);
24 }
25 
crypto_sig_init_tfm(struct crypto_tfm * tfm)26 static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
27 {
28 	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
29 	struct sig_alg *alg = crypto_sig_alg(sig);
30 
31 	if (alg->exit)
32 		sig->base.exit = crypto_sig_exit_tfm;
33 
34 	if (alg->init)
35 		return alg->init(sig);
36 
37 	return 0;
38 }
39 
crypto_sig_free_instance(struct crypto_instance * inst)40 static void crypto_sig_free_instance(struct crypto_instance *inst)
41 {
42 	struct sig_instance *sig = sig_instance(inst);
43 
44 	sig->free(sig);
45 }
46 
crypto_sig_show(struct seq_file * m,struct crypto_alg * alg)47 static void __maybe_unused crypto_sig_show(struct seq_file *m,
48 					   struct crypto_alg *alg)
49 {
50 	seq_puts(m, "type         : sig\n");
51 }
52 
crypto_sig_report(struct sk_buff * skb,struct crypto_alg * alg)53 static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
54 					    struct crypto_alg *alg)
55 {
56 	struct crypto_report_sig rsig = {};
57 
58 	strscpy(rsig.type, "sig", sizeof(rsig.type));
59 
60 	return nla_put(skb, CRYPTOCFGA_REPORT_SIG, 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 	.free = crypto_sig_free_instance,
67 #ifdef CONFIG_PROC_FS
68 	.show = crypto_sig_show,
69 #endif
70 #if IS_ENABLED(CONFIG_CRYPTO_USER)
71 	.report = crypto_sig_report,
72 #endif
73 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
74 	.maskset = CRYPTO_ALG_TYPE_MASK,
75 	.type = CRYPTO_ALG_TYPE_SIG,
76 	.tfmsize = offsetof(struct crypto_sig, base),
77 };
78 
crypto_alloc_sig(const char * alg_name,u32 type,u32 mask)79 struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
80 {
81 	return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
82 }
83 EXPORT_SYMBOL_GPL(crypto_alloc_sig);
84 
sig_default_sign(struct crypto_sig * tfm,const void * src,unsigned int slen,void * dst,unsigned int dlen)85 static int sig_default_sign(struct crypto_sig *tfm,
86 			    const void *src, unsigned int slen,
87 			    void *dst, unsigned int dlen)
88 {
89 	return -ENOSYS;
90 }
91 
sig_default_verify(struct crypto_sig * tfm,const void * src,unsigned int slen,const void * dst,unsigned int dlen)92 static int sig_default_verify(struct crypto_sig *tfm,
93 			      const void *src, unsigned int slen,
94 			      const void *dst, unsigned int dlen)
95 {
96 	return -ENOSYS;
97 }
98 
sig_default_set_key(struct crypto_sig * tfm,const void * key,unsigned int keylen)99 static int sig_default_set_key(struct crypto_sig *tfm,
100 			       const void *key, unsigned int keylen)
101 {
102 	return -ENOSYS;
103 }
104 
sig_prepare_alg(struct sig_alg * alg)105 static int sig_prepare_alg(struct sig_alg *alg)
106 {
107 	struct crypto_alg *base = &alg->base;
108 
109 	if (!alg->sign)
110 		alg->sign = sig_default_sign;
111 	if (!alg->verify)
112 		alg->verify = sig_default_verify;
113 	if (!alg->set_priv_key)
114 		alg->set_priv_key = sig_default_set_key;
115 	if (!alg->set_pub_key)
116 		return -EINVAL;
117 	if (!alg->key_size)
118 		return -EINVAL;
119 	if (!alg->max_size)
120 		alg->max_size = alg->key_size;
121 	if (!alg->digest_size)
122 		alg->digest_size = alg->key_size;
123 
124 	base->cra_type = &crypto_sig_type;
125 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
126 	base->cra_flags |= CRYPTO_ALG_TYPE_SIG;
127 
128 	return 0;
129 }
130 
crypto_register_sig(struct sig_alg * alg)131 int crypto_register_sig(struct sig_alg *alg)
132 {
133 	struct crypto_alg *base = &alg->base;
134 	int err;
135 
136 	err = sig_prepare_alg(alg);
137 	if (err)
138 		return err;
139 
140 	return crypto_register_alg(base);
141 }
142 EXPORT_SYMBOL_GPL(crypto_register_sig);
143 
crypto_unregister_sig(struct sig_alg * alg)144 void crypto_unregister_sig(struct sig_alg *alg)
145 {
146 	crypto_unregister_alg(&alg->base);
147 }
148 EXPORT_SYMBOL_GPL(crypto_unregister_sig);
149 
sig_register_instance(struct crypto_template * tmpl,struct sig_instance * inst)150 int sig_register_instance(struct crypto_template *tmpl,
151 			  struct sig_instance *inst)
152 {
153 	int err;
154 
155 	if (WARN_ON(!inst->free))
156 		return -EINVAL;
157 
158 	err = sig_prepare_alg(&inst->alg);
159 	if (err)
160 		return err;
161 
162 	return crypto_register_instance(tmpl, sig_crypto_instance(inst));
163 }
164 EXPORT_SYMBOL_GPL(sig_register_instance);
165 
crypto_grab_sig(struct crypto_sig_spawn * spawn,struct crypto_instance * inst,const char * name,u32 type,u32 mask)166 int crypto_grab_sig(struct crypto_sig_spawn *spawn,
167 		    struct crypto_instance *inst,
168 		    const char *name, u32 type, u32 mask)
169 {
170 	spawn->base.frontend = &crypto_sig_type;
171 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
172 }
173 EXPORT_SYMBOL_GPL(crypto_grab_sig);
174 
175 MODULE_LICENSE("GPL");
176 MODULE_DESCRIPTION("Public Key Signature Algorithms");
177