Annotation of src/usr.bin/ssh/ssh-rsa.c, Revision 1.12
1.1 markus 1: /*
2: * Copyright (c) 2000 Markus Friedl. All rights reserved.
3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
24:
25: #include "includes.h"
1.12 ! markus 26: RCSID("$OpenBSD: ssh-rsa.c,v 1.11 2001/11/07 21:40:21 markus Exp $");
1.5 markus 27:
28: #include <openssl/evp.h>
29: #include <openssl/err.h>
1.1 markus 30:
31: #include "xmalloc.h"
1.5 markus 32: #include "log.h"
1.1 markus 33: #include "buffer.h"
34: #include "bufaux.h"
35: #include "key.h"
1.6 itojun 36: #include "ssh-rsa.h"
1.8 markus 37: #include "compat.h"
1.1 markus 38:
39: /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
40: int
41: ssh_rsa_sign(
42: Key *key,
1.2 markus 43: u_char **sigp, int *lenp,
44: u_char *data, int datalen)
1.1 markus 45: {
1.7 markus 46: const EVP_MD *evp_md;
1.1 markus 47: EVP_MD_CTX md;
1.2 markus 48: u_char *digest, *sig, *ret;
49: u_int slen, dlen, len;
1.7 markus 50: int ok, nid;
1.1 markus 51: Buffer b;
52:
53: if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
54: error("ssh_rsa_sign: no RSA key");
55: return -1;
56: }
1.11 markus 57: if (datafellows & SSH_BUG_SIGBLOB) {
58: error("ssh_rsa_sign: SSH_BUG_SIGBLOB not supported");
59: return -1;
60: }
1.8 markus 61: nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
1.7 markus 62: if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
63: error("ssh_rsa_sign: EVP_get_digestbynid %d failed", nid);
64: return -1;
65: }
1.1 markus 66: dlen = evp_md->md_size;
67: digest = xmalloc(dlen);
68: EVP_DigestInit(&md, evp_md);
69: EVP_DigestUpdate(&md, data, datalen);
70: EVP_DigestFinal(&md, digest, NULL);
71:
1.7 markus 72: slen = RSA_size(key->rsa);
73: sig = xmalloc(slen);
74:
75: ok = RSA_sign(nid, digest, dlen, sig, &len, key->rsa);
1.1 markus 76: memset(digest, 'd', dlen);
77: xfree(digest);
78:
79: if (ok != 1) {
80: int ecode = ERR_get_error();
81: error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL));
82: xfree(sig);
83: return -1;
84: }
85: if (len < slen) {
86: int diff = slen - len;
87: debug("slen %d > len %d", slen, len);
88: memmove(sig + diff, sig, len);
89: memset(sig, 0, diff);
90: } else if (len > slen) {
91: error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
92: xfree(sig);
93: return -1;
94: }
95: /* encode signature */
96: buffer_init(&b);
97: buffer_put_cstring(&b, "ssh-rsa");
98: buffer_put_string(&b, sig, slen);
99: len = buffer_len(&b);
100: ret = xmalloc(len);
101: memcpy(ret, buffer_ptr(&b), len);
102: buffer_free(&b);
103: memset(sig, 's', slen);
104: xfree(sig);
105:
106: if (lenp != NULL)
107: *lenp = len;
108: if (sigp != NULL)
109: *sigp = ret;
110: return 0;
111: }
112:
113: int
114: ssh_rsa_verify(
115: Key *key,
1.2 markus 116: u_char *signature, int signaturelen,
117: u_char *data, int datalen)
1.1 markus 118: {
119: Buffer b;
1.7 markus 120: const EVP_MD *evp_md;
1.1 markus 121: EVP_MD_CTX md;
122: char *ktype;
1.2 markus 123: u_char *sigblob, *digest;
124: u_int len, dlen;
1.7 markus 125: int rlen, ret, nid;
1.1 markus 126:
127: if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
128: error("ssh_rsa_verify: no RSA key");
1.11 markus 129: return -1;
130: }
131: if (datafellows & SSH_BUG_SIGBLOB) {
132: error("ssh_rsa_verify: SSH_BUG_SIGBLOB not supported");
1.4 markus 133: return -1;
134: }
135: if (BN_num_bits(key->rsa->n) < 768) {
136: error("ssh_rsa_verify: n too small: %d bits",
137: BN_num_bits(key->rsa->n));
1.1 markus 138: return -1;
139: }
140: buffer_init(&b);
1.10 stevesk 141: buffer_append(&b, signature, signaturelen);
1.1 markus 142: ktype = buffer_get_string(&b, NULL);
143: if (strcmp("ssh-rsa", ktype) != 0) {
144: error("ssh_rsa_verify: cannot handle type %s", ktype);
145: buffer_free(&b);
146: xfree(ktype);
147: return -1;
148: }
149: xfree(ktype);
1.10 stevesk 150: sigblob = buffer_get_string(&b, &len);
1.1 markus 151: rlen = buffer_len(&b);
152: buffer_free(&b);
153: if(rlen != 0) {
1.12 ! markus 154: error("ssh_rsa_verify: remaining bytes in signature %d", rlen);
1.7 markus 155: xfree(sigblob);
1.1 markus 156: return -1;
157: }
1.8 markus 158: nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
1.7 markus 159: if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
1.12 ! markus 160: error("ssh_rsa_verify: EVP_get_digestbynid %d failed", nid);
1.7 markus 161: xfree(sigblob);
162: return -1;
163: }
1.1 markus 164: dlen = evp_md->md_size;
165: digest = xmalloc(dlen);
166: EVP_DigestInit(&md, evp_md);
167: EVP_DigestUpdate(&md, data, datalen);
168: EVP_DigestFinal(&md, digest, NULL);
169:
1.7 markus 170: ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa);
1.1 markus 171: memset(digest, 'd', dlen);
172: xfree(digest);
173: memset(sigblob, 's', len);
174: xfree(sigblob);
175: if (ret == 0) {
176: int ecode = ERR_get_error();
177: error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
178: }
179: debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");
180: return ret;
181: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-rsa.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh