2 * Copyright (c) 2002 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.
25 RCSID("$OpenBSD: ssh-keysign.c,v 1.2 2002/05/31 10:30:33 markus Exp $");
27 #include <openssl/evp.h>
39 #include "pathnames.h"
42 valid_request(struct passwd *pw, char *host, Key **ret, u_char *data,
55 buffer_append(&b, data, datalen);
58 buffer_skip_string(&b);
59 if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
63 buffer_skip_string(&b);
66 p = buffer_get_string(&b, NULL);
67 if (strcmp("ssh-connection", p) != 0)
72 p = buffer_get_string(&b, NULL);
73 if (strcmp("hostbased", p) != 0)
78 pkalg = buffer_get_string(&b, NULL);
79 pkblob = buffer_get_string(&b, &blen);
81 pktype = key_type_from_name(pkalg);
82 if (pktype == KEY_UNSPEC)
84 else if ((key = key_from_blob(pkblob, blen)) == NULL)
86 else if (key->type != pktype)
91 /* client host name, handle trailing dot */
92 p = buffer_get_string(&b, &len);
93 debug2("valid_request: check expect chost %s got %s", host, p);
94 if (strlen(host) != len - 1)
96 else if (p[len - 1] != '.')
98 else if (strncasecmp(host, p, len - 1) != 0)
103 p = buffer_get_string(&b, NULL);
105 if (strcmp(pw->pw_name, p) != 0)
110 if (buffer_len(&b) != 0)
113 debug3("valid_request: fail %d", fail);
115 if (fail && key != NULL)
120 return (fail ? -1 : 0);
124 main(int argc, char **argv)
129 int key_fd[2], i, found, version = 2, fd;
130 u_char *signature, *data;
134 key_fd[0] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
135 key_fd[1] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
140 #ifdef DEBUG_SSH_KEYSIGN
141 log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
144 if (key_fd[0] == -1 && key_fd[1] == -1)
145 fatal("could not open any host key");
147 if ((pw = getpwuid(getuid())) == NULL)
148 fatal("getpwuid failed");
151 SSLeay_add_all_algorithms();
154 for (i = 0; i < 2; i++) {
158 keys[i] = key_load_private_pem(key_fd[i], KEY_UNSPEC,
165 fatal("no hostkey found");
168 if (msg_recv(STDIN_FILENO, &b) < 0)
169 fatal("msg_recv failed");
170 if (buffer_get_char(&b) != version)
171 fatal("bad version");
172 fd = buffer_get_int(&b);
173 if ((fd == STDIN_FILENO) || (fd == STDOUT_FILENO))
175 if ((host = get_local_name(fd)) == NULL)
176 fatal("cannot get sockname for fd");
178 data = buffer_get_string(&b, &dlen);
179 if (valid_request(pw, host, &key, data, dlen) < 0)
180 fatal("not a valid request");
185 for (i = 0; i < 2; i++) {
186 if (keys[i] != NULL &&
187 key_equal(key, keys[i])) {
193 fatal("no matching hostkey found");
195 if (key_sign(keys[i], &signature, &slen, data, dlen) != 0)
196 fatal("key_sign failed");
200 buffer_put_string(&b, signature, slen);
201 msg_send(STDOUT_FILENO, version, &b);