Annotation of src/usr.bin/ssh/ssh-ed25519.c, Revision 1.3
1.3 ! djm 1: /* $OpenBSD: ssh-ed25519.c,v 1.2 2014/02/02 03:44:31 djm Exp $ */
1.1 markus 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:
18: #include <sys/types.h>
19:
20: #include "crypto_api.h"
21:
1.3 ! djm 22: #include <limits.h>
1.1 markus 23: #include <string.h>
24: #include <stdarg.h>
25:
26: #include "xmalloc.h"
27: #include "log.h"
28: #include "buffer.h"
29: #include "key.h"
30: #include "ssh.h"
31:
32: int
33: ssh_ed25519_sign(const Key *key, u_char **sigp, u_int *lenp,
34: const u_char *data, u_int datalen)
35: {
36: u_char *sig;
37: u_int slen, len;
38: unsigned long long smlen;
39: int ret;
40: Buffer b;
41:
42: if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
43: key->ed25519_sk == NULL) {
44: error("%s: no ED25519 key", __func__);
1.3 ! djm 45: return -1;
! 46: }
! 47:
! 48: if (datalen >= UINT_MAX - crypto_sign_ed25519_BYTES) {
! 49: error("%s: datalen %u too long", __func__, datalen);
1.1 markus 50: return -1;
51: }
52: smlen = slen = datalen + crypto_sign_ed25519_BYTES;
53: sig = xmalloc(slen);
54:
55: if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen,
56: key->ed25519_sk)) != 0 || smlen <= datalen) {
57: error("%s: crypto_sign_ed25519 failed: %d", __func__, ret);
58: free(sig);
59: return -1;
60: }
61: /* encode signature */
62: buffer_init(&b);
63: buffer_put_cstring(&b, "ssh-ed25519");
64: buffer_put_string(&b, sig, smlen - datalen);
65: len = buffer_len(&b);
66: if (lenp != NULL)
67: *lenp = len;
68: if (sigp != NULL) {
69: *sigp = xmalloc(len);
70: memcpy(*sigp, buffer_ptr(&b), len);
71: }
72: buffer_free(&b);
1.2 djm 73: explicit_bzero(sig, slen);
1.1 markus 74: free(sig);
75:
76: return 0;
77: }
78:
79: int
80: ssh_ed25519_verify(const Key *key, const u_char *signature, u_int signaturelen,
81: const u_char *data, u_int datalen)
82: {
83: Buffer b;
84: char *ktype;
85: u_char *sigblob, *sm, *m;
86: u_int len;
87: unsigned long long smlen, mlen;
88: int rlen, ret;
89:
90: if (key == NULL || key_type_plain(key->type) != KEY_ED25519 ||
91: key->ed25519_pk == NULL) {
92: error("%s: no ED25519 key", __func__);
93: return -1;
94: }
95: buffer_init(&b);
96: buffer_append(&b, signature, signaturelen);
97: ktype = buffer_get_cstring(&b, NULL);
98: if (strcmp("ssh-ed25519", ktype) != 0) {
99: error("%s: cannot handle type %s", __func__, ktype);
100: buffer_free(&b);
101: free(ktype);
102: return -1;
103: }
104: free(ktype);
105: sigblob = buffer_get_string(&b, &len);
106: rlen = buffer_len(&b);
107: buffer_free(&b);
108: if (rlen != 0) {
109: error("%s: remaining bytes in signature %d", __func__, rlen);
110: free(sigblob);
111: return -1;
112: }
113: if (len > crypto_sign_ed25519_BYTES) {
114: error("%s: len %u > crypto_sign_ed25519_BYTES %u", __func__,
115: len, crypto_sign_ed25519_BYTES);
116: free(sigblob);
117: return -1;
118: }
119: smlen = len + datalen;
120: sm = xmalloc(smlen);
121: memcpy(sm, sigblob, len);
122: memcpy(sm+len, data, datalen);
123: mlen = smlen;
124: m = xmalloc(mlen);
125: if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen,
126: key->ed25519_pk)) != 0) {
127: debug2("%s: crypto_sign_ed25519_open failed: %d",
128: __func__, ret);
129: }
130: if (ret == 0 && mlen != datalen) {
131: debug2("%s: crypto_sign_ed25519_open "
132: "mlen != datalen (%llu != %u)", __func__, mlen, datalen);
133: ret = -1;
134: }
135: /* XXX compare 'm' and 'data' ? */
136:
1.2 djm 137: explicit_bzero(sigblob, len);
138: explicit_bzero(sm, smlen);
139: explicit_bzero(m, smlen); /* NB. mlen may be invalid if ret != 0 */
1.1 markus 140: free(sigblob);
141: free(sm);
142: free(m);
143: debug("%s: signature %scorrect", __func__, (ret != 0) ? "in" : "");
144:
145: /* translate return code carefully */
146: return (ret == 0) ? 1 : -1;
147: }
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