2 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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.
26 RCSID("$OpenBSD: ssh-rsa.c,v 1.17 2002/03/29 19:18:33 stevesk Exp $");
28 #include <openssl/evp.h>
29 #include <openssl/err.h>
40 /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
44 u_char **sigp, u_int *lenp,
45 u_char *data, u_int datalen)
49 u_char digest[EVP_MAX_MD_SIZE], *sig, *ret;
50 u_int slen, dlen, len;
54 if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
55 error("ssh_rsa_sign: no RSA key");
58 if (datafellows & SSH_BUG_SIGBLOB) {
59 error("ssh_rsa_sign: SSH_BUG_SIGBLOB not supported");
62 nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
63 if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
64 error("ssh_rsa_sign: EVP_get_digestbynid %d failed", nid);
67 EVP_DigestInit(&md, evp_md);
68 EVP_DigestUpdate(&md, data, datalen);
69 EVP_DigestFinal(&md, digest, &dlen);
71 slen = RSA_size(key->rsa);
74 ok = RSA_sign(nid, digest, dlen, sig, &len, key->rsa);
75 memset(digest, 'd', sizeof(digest));
78 int ecode = ERR_get_error();
79 error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL));
84 int diff = slen - len;
85 debug("slen %d > len %d", slen, len);
86 memmove(sig + diff, sig, len);
88 } else if (len > slen) {
89 error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
93 /* encode signature */
95 buffer_put_cstring(&b, "ssh-rsa");
96 buffer_put_string(&b, sig, slen);
99 memcpy(ret, buffer_ptr(&b), len);
101 memset(sig, 's', slen);
114 u_char *signature, u_int signaturelen,
115 u_char *data, u_int datalen)
118 const EVP_MD *evp_md;
121 u_char digest[EVP_MAX_MD_SIZE], *sigblob;
125 if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
126 error("ssh_rsa_verify: no RSA key");
129 if (datafellows & SSH_BUG_SIGBLOB) {
130 error("ssh_rsa_verify: SSH_BUG_SIGBLOB not supported");
133 if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
134 error("ssh_rsa_verify: n too small: %d bits",
135 BN_num_bits(key->rsa->n));
139 buffer_append(&b, signature, signaturelen);
140 ktype = buffer_get_string(&b, NULL);
141 if (strcmp("ssh-rsa", ktype) != 0) {
142 error("ssh_rsa_verify: cannot handle type %s", ktype);
148 sigblob = buffer_get_string(&b, &len);
149 rlen = buffer_len(&b);
152 error("ssh_rsa_verify: remaining bytes in signature %d", rlen);
156 nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
157 if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
158 error("ssh_rsa_verify: EVP_get_digestbynid %d failed", nid);
162 EVP_DigestInit(&md, evp_md);
163 EVP_DigestUpdate(&md, data, datalen);
164 EVP_DigestFinal(&md, digest, &dlen);
166 ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa);
167 memset(digest, 'd', sizeof(digest));
168 memset(sigblob, 's', len);
171 int ecode = ERR_get_error();
172 error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
174 debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");