Annotation of src/usr.bin/ssh/ssh-ecdsa.c, Revision 1.5
1.5 ! miod 1: /* $OpenBSD: ssh-ecdsa.c,v 1.4 2010/09/10 01:04:10 djm Exp $ */
1.1 djm 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
4: * Copyright (c) 2010 Damien Miller. All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #include <sys/types.h>
28:
29: #include <openssl/bn.h>
30: #include <openssl/ec.h>
31: #include <openssl/ecdsa.h>
32: #include <openssl/evp.h>
33:
34: #include <string.h>
35:
36: #include "xmalloc.h"
37: #include "buffer.h"
38: #include "compat.h"
39: #include "log.h"
40: #include "key.h"
41:
42: int
43: ssh_ecdsa_sign(const Key *key, u_char **sigp, u_int *lenp,
44: const u_char *data, u_int datalen)
45: {
46: ECDSA_SIG *sig;
1.3 djm 47: const EVP_MD *evp_md;
1.1 djm 48: EVP_MD_CTX md;
49: u_char digest[EVP_MAX_MD_SIZE];
50: u_int len, dlen;
51: Buffer b, bb;
52:
53: if (key == NULL || key->ecdsa == NULL ||
54: (key->type != KEY_ECDSA && key->type != KEY_ECDSA_CERT)) {
55: error("%s: no ECDSA key", __func__);
56: return -1;
57: }
1.3 djm 58: evp_md = key_ec_nid_to_evpmd(key->ecdsa_nid);
1.1 djm 59: EVP_DigestInit(&md, evp_md);
60: EVP_DigestUpdate(&md, data, datalen);
61: EVP_DigestFinal(&md, digest, &dlen);
62:
63: sig = ECDSA_do_sign(digest, dlen, key->ecdsa);
64: memset(digest, 'd', sizeof(digest));
65:
66: if (sig == NULL) {
67: error("%s: sign failed", __func__);
68: return -1;
69: }
70:
71: buffer_init(&bb);
72: buffer_put_bignum2(&bb, sig->r);
73: buffer_put_bignum2(&bb, sig->s);
74: ECDSA_SIG_free(sig);
75:
76: buffer_init(&b);
77: buffer_put_cstring(&b, key_ssh_name_plain(key));
78: buffer_put_string(&b, buffer_ptr(&bb), buffer_len(&bb));
79: buffer_free(&bb);
80: len = buffer_len(&b);
81: if (lenp != NULL)
82: *lenp = len;
83: if (sigp != NULL) {
84: *sigp = xmalloc(len);
85: memcpy(*sigp, buffer_ptr(&b), len);
86: }
87: buffer_free(&b);
88:
89: return 0;
90: }
91: int
92: ssh_ecdsa_verify(const Key *key, const u_char *signature, u_int signaturelen,
93: const u_char *data, u_int datalen)
94: {
95: ECDSA_SIG *sig;
1.3 djm 96: const EVP_MD *evp_md;
1.1 djm 97: EVP_MD_CTX md;
98: u_char digest[EVP_MAX_MD_SIZE], *sigblob;
99: u_int len, dlen;
100: int rlen, ret;
101: Buffer b, bb;
1.2 deraadt 102: char *ktype;
1.1 djm 103:
104: if (key == NULL || key->ecdsa == NULL ||
105: (key->type != KEY_ECDSA && key->type != KEY_ECDSA_CERT)) {
106: error("%s: no ECDSA key", __func__);
107: return -1;
108: }
1.3 djm 109: evp_md = key_ec_nid_to_evpmd(key->ecdsa_nid);
1.1 djm 110:
111: /* fetch signature */
112: buffer_init(&b);
113: buffer_append(&b, signature, signaturelen);
114: ktype = buffer_get_string(&b, NULL);
115: if (strcmp(key_ssh_name_plain(key), ktype) != 0) {
116: error("%s: cannot handle type %s", __func__, ktype);
117: buffer_free(&b);
118: xfree(ktype);
119: return -1;
120: }
121: xfree(ktype);
122: sigblob = buffer_get_string(&b, &len);
123: rlen = buffer_len(&b);
124: buffer_free(&b);
125: if (rlen != 0) {
126: error("%s: remaining bytes in signature %d", __func__, rlen);
127: xfree(sigblob);
128: return -1;
129: }
130:
131: /* parse signature */
132: if ((sig = ECDSA_SIG_new()) == NULL)
133: fatal("%s: ECDSA_SIG_new failed", __func__);
134: if ((sig->r = BN_new()) == NULL ||
135: (sig->s = BN_new()) == NULL)
136: fatal("%s: BN_new failed", __func__);
137:
138: buffer_init(&bb);
139: buffer_append(&bb, sigblob, len);
140: buffer_get_bignum2(&bb, sig->r);
141: buffer_get_bignum2(&bb, sig->s);
142: if (buffer_len(&bb) != 0)
143: fatal("%s: remaining bytes in inner sigblob", __func__);
1.5 ! miod 144: buffer_free(&bb);
1.1 djm 145:
146: /* clean up */
147: memset(sigblob, 0, len);
148: xfree(sigblob);
149:
150: /* hash the data */
151: EVP_DigestInit(&md, evp_md);
152: EVP_DigestUpdate(&md, data, datalen);
153: EVP_DigestFinal(&md, digest, &dlen);
154:
155: ret = ECDSA_do_verify(digest, dlen, sig, key->ecdsa);
156: memset(digest, 'd', sizeof(digest));
157:
158: ECDSA_SIG_free(sig);
159:
160: debug("%s: signature %s", __func__,
161: ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
162: return ret;
163: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-ecdsa.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh