auth-rh-rsa.c revision 92559 
1/*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 *                    All rights reserved
5 * Rhosts or /etc/hosts.equiv authentication combined with RSA host
6 * authentication.
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose.  Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 */
14
15#include "includes.h"
16RCSID("$OpenBSD: auth-rh-rsa.c,v 1.29 2002/03/04 12:43:06 markus Exp $");
17RCSID("$FreeBSD: head/crypto/openssh/auth-rh-rsa.c 92559 2002-03-18 10:09:43Z des $");
18
19#include "packet.h"
20#include "uidswap.h"
21#include "log.h"
22#include "servconf.h"
23#include "key.h"
24#include "hostfile.h"
25#include "pathnames.h"
26#include "auth.h"
27#include "canohost.h"
28
29/*
30 * Tries to authenticate the user using the .rhosts file and the host using
31 * its host key.  Returns true if authentication succeeds.
32 */
33
34int
35auth_rhosts_rsa(struct passwd *pw, const char *client_user, Key *client_host_key)
36{
37	extern ServerOptions options;
38	const char *canonical_hostname;
39	HostStatus host_status;
40
41	debug("Trying rhosts with RSA host authentication for client user %.100s", client_user);
42
43	if (pw == NULL || client_host_key == NULL || client_host_key->rsa == NULL)
44		return 0;
45
46	/* Check if we would accept it using rhosts authentication. */
47	if (!auth_rhosts(pw, client_user))
48		return 0;
49
50	canonical_hostname = get_canonical_hostname(
51	    options.verify_reverse_mapping);
52
53	debug("Rhosts RSA authentication: canonical host %.900s", canonical_hostname);
54
55	host_status = check_key_in_hostfiles(pw, client_host_key,
56	    canonical_hostname, _PATH_SSH_SYSTEM_HOSTFILE,
57	    options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
58
59	if (host_status != HOST_OK) {
60		debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
61		packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
62		return 0;
63	}
64	/* A matching host key was found and is known. */
65
66	/* Perform the challenge-response dialog with the client for the host key. */
67	if (!auth_rsa_challenge_dialog(client_host_key->rsa)) {
68		log("Client on %.800s failed to respond correctly to host authentication.",
69		    canonical_hostname);
70		return 0;
71	}
72	/*
73	 * We have authenticated the user using .rhosts or /etc/hosts.equiv,
74	 * and the host using RSA. We accept the authentication.
75	 */
76
77	verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
78	   pw->pw_name, client_user, canonical_hostname);
79	packet_send_debug("Rhosts with RSA host authentication accepted.");
80	return 1;
81}
82