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 if (!EVP_PKEY_set_type(pkey, EVP_PKEY_ED25519)) {
34 OPENSSL_free(key);
35 return 0;
36 }
37
38 uint8_t pubkey_unused[32];
39 ED25519_keypair(pubkey_unused, key->key);
40 key->has_private = 1;
41
42 OPENSSL_free(pkey->pkey);
43 pkey->pkey = key;
44 return 1;
45 }
46
pkey_ed25519_sign_message(EVP_PKEY_CTX * ctx,uint8_t * sig,size_t * siglen,const uint8_t * tbs,size_t tbslen)47 static int pkey_ed25519_sign_message(EVP_PKEY_CTX *ctx, uint8_t *sig,
48 size_t *siglen, const uint8_t *tbs,
49 size_t tbslen) {
50 const ED25519_KEY *key = ctx->pkey->pkey;
51 if (!key->has_private) {
52 OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
53 return 0;
54 }
55
56 if (sig == NULL) {
57 *siglen = 64;
58 return 1;
59 }
60
61 if (*siglen < 64) {
62 OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
63 return 0;
64 }
65
66 if (!ED25519_sign(sig, tbs, tbslen, key->key)) {
67 return 0;
68 }
69
70 *siglen = 64;
71 return 1;
72 }
73
pkey_ed25519_verify_message(EVP_PKEY_CTX * ctx,const uint8_t * sig,size_t siglen,const uint8_t * tbs,size_t tbslen)74 static int pkey_ed25519_verify_message(EVP_PKEY_CTX *ctx, const uint8_t *sig,
75 size_t siglen, const uint8_t *tbs,
76 size_t tbslen) {
77 const ED25519_KEY *key = ctx->pkey->pkey;
78 if (siglen != 64 ||
79 !ED25519_verify(tbs, tbslen, sig, key->key + ED25519_PUBLIC_KEY_OFFSET)) {
80 OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_SIGNATURE);
81 return 0;
82 }
83
84 return 1;
85 }
86
87 const EVP_PKEY_METHOD ed25519_pkey_meth = {
88 EVP_PKEY_ED25519,
89 NULL /* init */,
90 pkey_ed25519_copy,
91 NULL /* cleanup */,
92 pkey_ed25519_keygen,
93 NULL /* sign */,
94 pkey_ed25519_sign_message,
95 NULL /* verify */,
96 pkey_ed25519_verify_message,
97 NULL /* verify_recover */,
98 NULL /* encrypt */,
99 NULL /* decrypt */,
100 NULL /* derive */,
101 NULL /* paramgen */,
102 NULL /* ctrl */,
103 };
104