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 1.5 2001/01/21 19:05:58 markus Exp $");
28 #include <openssl/evp.h>
29 #include <openssl/err.h>
37 /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
41 u_char **sigp, int *lenp,
42 u_char *data, int datalen)
44 EVP_MD *evp_md = EVP_sha1();
46 u_char *digest, *sig, *ret;
47 u_int slen, dlen, len;
51 if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
52 error("ssh_rsa_sign: no RSA key");
55 slen = RSA_size(key->rsa);
58 dlen = evp_md->md_size;
59 digest = xmalloc(dlen);
60 EVP_DigestInit(&md, evp_md);
61 EVP_DigestUpdate(&md, data, datalen);
62 EVP_DigestFinal(&md, digest, NULL);
64 ok = RSA_sign(NID_sha1, digest, dlen, sig, &len, key->rsa);
65 memset(digest, 'd', dlen);
69 int ecode = ERR_get_error();
70 error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL));
75 int diff = slen - len;
76 debug("slen %d > len %d", slen, len);
77 memmove(sig + diff, sig, len);
79 } else if (len > slen) {
80 error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
84 /* encode signature */
86 buffer_put_cstring(&b, "ssh-rsa");
87 buffer_put_string(&b, sig, slen);
90 memcpy(ret, buffer_ptr(&b), len);
92 memset(sig, 's', slen);
99 debug2("ssh_rsa_sign: done");
106 u_char *signature, int signaturelen,
107 u_char *data, int datalen)
110 EVP_MD *evp_md = EVP_sha1();
113 u_char *sigblob, *digest;
118 if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
119 error("ssh_rsa_verify: no RSA key");
122 if (BN_num_bits(key->rsa->n) < 768) {
123 error("ssh_rsa_verify: n too small: %d bits",
124 BN_num_bits(key->rsa->n));
128 buffer_append(&b, (char *) signature, signaturelen);
129 ktype = buffer_get_string(&b, NULL);
130 if (strcmp("ssh-rsa", ktype) != 0) {
131 error("ssh_rsa_verify: cannot handle type %s", ktype);
137 sigblob = (u_char *)buffer_get_string(&b, &len);
138 rlen = buffer_len(&b);
141 error("ssh_rsa_verify: remaining bytes in signature %d", rlen);
145 dlen = evp_md->md_size;
146 digest = xmalloc(dlen);
147 EVP_DigestInit(&md, evp_md);
148 EVP_DigestUpdate(&md, data, datalen);
149 EVP_DigestFinal(&md, digest, NULL);
151 ret = RSA_verify(NID_sha1, digest, dlen, sigblob, len, key->rsa);
152 memset(digest, 'd', dlen);
154 memset(sigblob, 's', len);
157 int ecode = ERR_get_error();
158 error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
160 debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");