Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ECDSA P1363 signature encoding
4 *
5 * Copyright (c) 2024 Intel Corporation
6 */
7
8#include <linux/err.h>
9#include <linux/module.h>
10#include <crypto/algapi.h>
11#include <crypto/sig.h>
12#include <crypto/internal/ecc.h>
13#include <crypto/internal/sig.h>
14
15struct ecdsa_p1363_ctx {
16 struct crypto_sig *child;
17};
18
19static int ecdsa_p1363_verify(struct crypto_sig *tfm,
20 const void *src, unsigned int slen,
21 const void *digest, unsigned int dlen)
22{
23 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
24 unsigned int keylen = crypto_sig_keysize(ctx->child);
25 unsigned int ndigits = DIV_ROUND_UP(keylen, sizeof(u64));
26 struct ecdsa_raw_sig sig;
27
28 if (slen != 2 * keylen)
29 return -EINVAL;
30
31 ecc_digits_from_bytes(src, keylen, sig.r, ndigits);
32 ecc_digits_from_bytes(src + keylen, keylen, sig.s, ndigits);
33
34 return crypto_sig_verify(ctx->child, &sig, sizeof(sig), digest, dlen);
35}
36
37static unsigned int ecdsa_p1363_key_size(struct crypto_sig *tfm)
38{
39 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
40
41 return crypto_sig_keysize(ctx->child);
42}
43
44static unsigned int ecdsa_p1363_max_size(struct crypto_sig *tfm)
45{
46 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
47
48 return 2 * crypto_sig_keysize(ctx->child);
49}
50
51static unsigned int ecdsa_p1363_digest_size(struct crypto_sig *tfm)
52{
53 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
54
55 return crypto_sig_digestsize(ctx->child);
56}
57
58static int ecdsa_p1363_set_pub_key(struct crypto_sig *tfm,
59 const void *key, unsigned int keylen)
60{
61 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
62
63 return crypto_sig_set_pubkey(ctx->child, key, keylen);
64}
65
66static int ecdsa_p1363_init_tfm(struct crypto_sig *tfm)
67{
68 struct sig_instance *inst = sig_alg_instance(tfm);
69 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst);
70 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
71 struct crypto_sig *child_tfm;
72
73 child_tfm = crypto_spawn_sig(spawn);
74 if (IS_ERR(child_tfm))
75 return PTR_ERR(child_tfm);
76
77 ctx->child = child_tfm;
78
79 return 0;
80}
81
82static void ecdsa_p1363_exit_tfm(struct crypto_sig *tfm)
83{
84 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm);
85
86 crypto_free_sig(ctx->child);
87}
88
89static void ecdsa_p1363_free(struct sig_instance *inst)
90{
91 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst);
92
93 crypto_drop_sig(spawn);
94 kfree(inst);
95}
96
97static int ecdsa_p1363_create(struct crypto_template *tmpl, struct rtattr **tb)
98{
99 struct crypto_sig_spawn *spawn;
100 struct sig_instance *inst;
101 struct sig_alg *ecdsa_alg;
102 u32 mask;
103 int err;
104
105 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SIG, &mask);
106 if (err)
107 return err;
108
109 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
110 if (!inst)
111 return -ENOMEM;
112
113 spawn = sig_instance_ctx(inst);
114
115 err = crypto_grab_sig(spawn, sig_crypto_instance(inst),
116 crypto_attr_alg_name(tb[1]), 0, mask);
117 if (err)
118 goto err_free_inst;
119
120 ecdsa_alg = crypto_spawn_sig_alg(spawn);
121
122 err = -EINVAL;
123 if (strncmp(ecdsa_alg->base.cra_name, "ecdsa", 5) != 0)
124 goto err_free_inst;
125
126 err = crypto_inst_setname(sig_crypto_instance(inst), tmpl->name,
127 &ecdsa_alg->base);
128 if (err)
129 goto err_free_inst;
130
131 inst->alg.base.cra_priority = ecdsa_alg->base.cra_priority;
132 inst->alg.base.cra_ctxsize = sizeof(struct ecdsa_p1363_ctx);
133
134 inst->alg.init = ecdsa_p1363_init_tfm;
135 inst->alg.exit = ecdsa_p1363_exit_tfm;
136
137 inst->alg.verify = ecdsa_p1363_verify;
138 inst->alg.key_size = ecdsa_p1363_key_size;
139 inst->alg.max_size = ecdsa_p1363_max_size;
140 inst->alg.digest_size = ecdsa_p1363_digest_size;
141 inst->alg.set_pub_key = ecdsa_p1363_set_pub_key;
142
143 inst->free = ecdsa_p1363_free;
144
145 err = sig_register_instance(tmpl, inst);
146 if (err) {
147err_free_inst:
148 ecdsa_p1363_free(inst);
149 }
150 return err;
151}
152
153struct crypto_template ecdsa_p1363_tmpl = {
154 .name = "p1363",
155 .create = ecdsa_p1363_create,
156 .module = THIS_MODULE,
157};
158
159MODULE_ALIAS_CRYPTO("p1363");