jsg@openbsd.org | d5ba1c0 | 2020-02-26 13:40:09 +0000 | [diff] [blame] | 1 | /* $OpenBSD: ssh-ed25519.c,v 1.8 2020/02/26 13:40:09 jsg Exp $ */ |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2013 Markus Friedl <markus@openbsd.org> |
| 4 | * |
| 5 | * Permission to use, copy, modify, and distribute this software for any |
| 6 | * purpose with or without fee is hereby granted, provided that the above |
| 7 | * copyright notice and this permission notice appear in all copies. |
| 8 | * |
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 16 | */ |
| 17 | |
Damien Miller | f104da2 | 2013-12-07 12:37:53 +1100 | [diff] [blame] | 18 | #include "includes.h" |
| 19 | |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 20 | #include <sys/types.h> |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 21 | #include <limits.h> |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 22 | |
| 23 | #include "crypto_api.h" |
| 24 | |
| 25 | #include <string.h> |
| 26 | #include <stdarg.h> |
| 27 | |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 28 | #include "log.h" |
markus@openbsd.org | 3c4726f | 2015-01-15 21:38:50 +0000 | [diff] [blame] | 29 | #include "sshbuf.h" |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 30 | #define SSHKEY_INTERNAL |
| 31 | #include "sshkey.h" |
| 32 | #include "ssherr.h" |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 33 | #include "ssh.h" |
| 34 | |
| 35 | int |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 36 | ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp, |
| 37 | const u_char *data, size_t datalen, u_int compat) |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 38 | { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 39 | u_char *sig = NULL; |
| 40 | size_t slen = 0, len; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 41 | unsigned long long smlen; |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 42 | int r, ret; |
| 43 | struct sshbuf *b = NULL; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 44 | |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 45 | if (lenp != NULL) |
| 46 | *lenp = 0; |
| 47 | if (sigp != NULL) |
| 48 | *sigp = NULL; |
Damien Miller | bee3a23 | 2014-02-24 15:57:22 +1100 | [diff] [blame] | 49 | |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 50 | if (key == NULL || |
| 51 | sshkey_type_plain(key->type) != KEY_ED25519 || |
| 52 | key->ed25519_sk == NULL || |
| 53 | datalen >= INT_MAX - crypto_sign_ed25519_BYTES) |
| 54 | return SSH_ERR_INVALID_ARGUMENT; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 55 | smlen = slen = datalen + crypto_sign_ed25519_BYTES; |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 56 | if ((sig = malloc(slen)) == NULL) |
| 57 | return SSH_ERR_ALLOC_FAIL; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 58 | |
| 59 | if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen, |
| 60 | key->ed25519_sk)) != 0 || smlen <= datalen) { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 61 | r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */ |
| 62 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 63 | } |
| 64 | /* encode signature */ |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 65 | if ((b = sshbuf_new()) == NULL) { |
| 66 | r = SSH_ERR_ALLOC_FAIL; |
| 67 | goto out; |
| 68 | } |
| 69 | if ((r = sshbuf_put_cstring(b, "ssh-ed25519")) != 0 || |
| 70 | (r = sshbuf_put_string(b, sig, smlen - datalen)) != 0) |
| 71 | goto out; |
| 72 | len = sshbuf_len(b); |
| 73 | if (sigp != NULL) { |
| 74 | if ((*sigp = malloc(len)) == NULL) { |
| 75 | r = SSH_ERR_ALLOC_FAIL; |
| 76 | goto out; |
| 77 | } |
| 78 | memcpy(*sigp, sshbuf_ptr(b), len); |
| 79 | } |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 80 | if (lenp != NULL) |
| 81 | *lenp = len; |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 82 | /* success */ |
| 83 | r = 0; |
| 84 | out: |
| 85 | sshbuf_free(b); |
jsg@openbsd.org | d5ba1c0 | 2020-02-26 13:40:09 +0000 | [diff] [blame] | 86 | if (sig != NULL) |
| 87 | freezero(sig, slen); |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 88 | |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 89 | return r; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 90 | } |
| 91 | |
| 92 | int |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 93 | ssh_ed25519_verify(const struct sshkey *key, |
| 94 | const u_char *signature, size_t signaturelen, |
| 95 | const u_char *data, size_t datalen, u_int compat) |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 96 | { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 97 | struct sshbuf *b = NULL; |
| 98 | char *ktype = NULL; |
| 99 | const u_char *sigblob; |
| 100 | u_char *sm = NULL, *m = NULL; |
| 101 | size_t len; |
| 102 | unsigned long long smlen = 0, mlen = 0; |
| 103 | int r, ret; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 104 | |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 105 | if (key == NULL || |
| 106 | sshkey_type_plain(key->type) != KEY_ED25519 || |
| 107 | key->ed25519_pk == NULL || |
djm@openbsd.org | b6e0140 | 2016-04-21 06:08:02 +0000 | [diff] [blame] | 108 | datalen >= INT_MAX - crypto_sign_ed25519_BYTES || |
| 109 | signature == NULL || signaturelen == 0) |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 110 | return SSH_ERR_INVALID_ARGUMENT; |
| 111 | |
| 112 | if ((b = sshbuf_from(signature, signaturelen)) == NULL) |
| 113 | return SSH_ERR_ALLOC_FAIL; |
| 114 | if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 || |
| 115 | (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0) |
| 116 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 117 | if (strcmp("ssh-ed25519", ktype) != 0) { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 118 | r = SSH_ERR_KEY_TYPE_MISMATCH; |
| 119 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 120 | } |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 121 | if (sshbuf_len(b) != 0) { |
| 122 | r = SSH_ERR_UNEXPECTED_TRAILING_DATA; |
| 123 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 124 | } |
| 125 | if (len > crypto_sign_ed25519_BYTES) { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 126 | r = SSH_ERR_INVALID_FORMAT; |
| 127 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 128 | } |
daniel@openbsd.org | 165bc87 | 2014-10-14 03:09:59 +0000 | [diff] [blame] | 129 | if (datalen >= SIZE_MAX - len) { |
| 130 | r = SSH_ERR_INVALID_ARGUMENT; |
| 131 | goto out; |
| 132 | } |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 133 | smlen = len + datalen; |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 134 | mlen = smlen; |
markus@openbsd.org | 3c4726f | 2015-01-15 21:38:50 +0000 | [diff] [blame] | 135 | if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) { |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 136 | r = SSH_ERR_ALLOC_FAIL; |
| 137 | goto out; |
| 138 | } |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 139 | memcpy(sm, sigblob, len); |
| 140 | memcpy(sm+len, data, datalen); |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 141 | if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen, |
| 142 | key->ed25519_pk)) != 0) { |
| 143 | debug2("%s: crypto_sign_ed25519_open failed: %d", |
| 144 | __func__, ret); |
| 145 | } |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 146 | if (ret != 0 || mlen != datalen) { |
| 147 | r = SSH_ERR_SIGNATURE_INVALID; |
| 148 | goto out; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 149 | } |
| 150 | /* XXX compare 'm' and 'data' ? */ |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 151 | /* success */ |
| 152 | r = 0; |
| 153 | out: |
jsg@openbsd.org | d5ba1c0 | 2020-02-26 13:40:09 +0000 | [diff] [blame] | 154 | if (sm != NULL) |
| 155 | freezero(sm, smlen); |
| 156 | if (m != NULL) |
| 157 | freezero(m, smlen); /* NB mlen may be invalid if r != 0 */ |
Damien Miller | 8668706 | 2014-07-02 15:28:02 +1000 | [diff] [blame] | 158 | sshbuf_free(b); |
| 159 | free(ktype); |
| 160 | return r; |
Damien Miller | 5be9d9e | 2013-12-07 11:24:01 +1100 | [diff] [blame] | 161 | } |