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.
25static int pkey_ed25519_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) { return 1; }
26
27static 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 OPENSSL_PUT_ERROR(EVP, ERR_R_MALLOC_FAILURE);
31 return 0;
32 }
33
34 if (!EVP_PKEY_set_type(pkey, EVP_PKEY_ED25519)) {
35 OPENSSL_free(key);
36 return 0;
37 }
38
39 uint8_t pubkey_unused[32];
40 ED25519_keypair(pubkey_unused, key->key.priv);
41 key->has_private = 1;
42
43 OPENSSL_free(pkey->pkey.ptr);
44 pkey->pkey.ptr = key;
45 return 1;
46}
47
48static int pkey_ed25519_sign_message(EVP_PKEY_CTX *ctx, uint8_t *sig,
49 size_t *siglen, const uint8_t *tbs,
50 size_t tbslen) {
51 ED25519_KEY *key = ctx->pkey->pkey.ptr;
52 if (!key->has_private) {
53 OPENSSL_PUT_ERROR(EVP, EVP_R_NOT_A_PRIVATE_KEY);
54 return 0;
55 }
56
57 if (sig == NULL) {
58 *siglen = 64;
59 return 1;
60 }
61
62 if (*siglen < 64) {
63 OPENSSL_PUT_ERROR(EVP, EVP_R_BUFFER_TOO_SMALL);
64 return 0;
65 }
66
67 if (!ED25519_sign(sig, tbs, tbslen, key->key.priv)) {
68 return 0;
69 }
70
71 *siglen = 64;
72 return 1;
73}
74
75static int pkey_ed25519_verify_message(EVP_PKEY_CTX *ctx, const uint8_t *sig,
76 size_t siglen, const uint8_t *tbs,
77 size_t tbslen) {
78 ED25519_KEY *key = ctx->pkey->pkey.ptr;
79 if (siglen != 64 ||
80 !ED25519_verify(tbs, tbslen, sig, key->key.pub.value)) {
81 OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_SIGNATURE);
82 return 0;
83 }
84
85 return 1;
86}
87
88const EVP_PKEY_METHOD ed25519_pkey_meth = {
89 EVP_PKEY_ED25519,
90 NULL /* init */,
91 pkey_ed25519_copy,
92 NULL /* cleanup */,
93 pkey_ed25519_keygen,
94 NULL /* sign */,
95 pkey_ed25519_sign_message,
96 NULL /* verify */,
97 pkey_ed25519_verify_message,
98 NULL /* verify_recover */,
99 NULL /* encrypt */,
100 NULL /* decrypt */,
101 NULL /* derive */,
102 NULL /* paramgen */,
103 NULL /* ctrl */,
104};
105