1 /* Copyright (c) 2017, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15 #include <openssl/evp.h>
16
17 #include <openssl/curve25519.h>
18 #include <openssl/err.h>
19 #include <openssl/mem.h>
20
21 #include "internal.h"
22
23
24 // Ed25519 has no parameters to copy.
pkey_ed25519_copy(EVP_PKEY_CTX * dst,EVP_PKEY_CTX * src)25 static int pkey_ed25519_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) { return 1; }
26
pkey_ed25519_keygen(EVP_PKEY_CTX * ctx,EVP_PKEY * pkey)27 static int pkey_ed25519_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
28 ED25519_KEY *key = OPENSSL_malloc(sizeof(ED25519_KEY));
29 if (key == NULL) {
30 return 0;
31 }
32
33 evp_pkey_set_method(pkey, &ed25519_asn1_meth);
34
35 uint8_t pubkey_unused[32];
36 ED25519_keypair(pubkey_unused, key->key);
37 key->has_private = 1;
38
39 OPENSSL_free(pkey->pkey);
40 pkey->pkey = key;
41 return 1;
42 }
43
pkey_ed25519_sign_message(EVP_PKEY_CTX * ctx,uint8_t * sig,size_t * siglen,const uint8_t * tbs,size_t tbslen)44 static int pkey_ed25519_sign_message(EVP_PKEY_CTX *ctx, uint8_t *sig,
45 size_t *siglen, const uint8_t *tbs,
46 size_t tbslen) {
47 const ED25519_KEY *key = ctx->pkey->pkey;
48 if (!key->has_private) {
49 OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
50 return 0;
51 }
52
53 if (sig == NULL) {
54 *siglen = 64;
55 return 1;
56 }
57
58 if (*siglen < 64) {
59 OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
60 return 0;
61 }
62
63 if (!ED25519_sign(sig, tbs, tbslen, key->key)) {
64 return 0;
65 }
66
67 *siglen = 64;
68 return 1;
69 }
70
pkey_ed25519_verify_message(EVP_PKEY_CTX * ctx,const uint8_t * sig,size_t siglen,const uint8_t * tbs,size_t tbslen)71 static int pkey_ed25519_verify_message(EVP_PKEY_CTX *ctx, const uint8_t *sig,
72 size_t siglen, const uint8_t *tbs,
73 size_t tbslen) {
74 const ED25519_KEY *key = ctx->pkey->pkey;
75 if (siglen != 64 ||
76 !ED25519_verify(tbs, tbslen, sig, key->key + ED25519_PUBLIC_KEY_OFFSET)) {
77 OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_SIGNATURE);
78 return 0;
79 }
80
81 return 1;
82 }
83
84 const EVP_PKEY_METHOD ed25519_pkey_meth = {
85 EVP_PKEY_ED25519,
86 NULL /* init */,
87 pkey_ed25519_copy,
88 NULL /* cleanup */,
89 pkey_ed25519_keygen,
90 NULL /* sign */,
91 pkey_ed25519_sign_message,
92 NULL /* verify */,
93 pkey_ed25519_verify_message,
94 NULL /* verify_recover */,
95 NULL /* encrypt */,
96 NULL /* decrypt */,
97 NULL /* derive */,
98 NULL /* paramgen */,
99 NULL /* ctrl */,
100 };
101