1 /* $OpenBSD: auth-rh-rsa.c,v 1.43 2010/03/04 10:36:03 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Rhosts or /etc/hosts.equiv authentication combined with RSA host
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
18 #include <sys/types.h>
32 #include "pathnames.h"
38 #include "monitor_wrap.h"
41 extern ServerOptions options;
44 auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost,
48 HostStatus host_status;
50 if (blacklisted_key(client_host_key)) {
51 fp = key_fingerprint(client_host_key, SSH_FP_MD5, SSH_FP_HEX);
52 if (options.permit_blacklisted_keys)
53 logit("Public key %s blacklisted (see "
54 "ssh-vulnkey(1)); continuing anyway", fp);
56 logit("Public key %s blacklisted (see "
57 "ssh-vulnkey(1))", fp);
59 if (!options.permit_blacklisted_keys)
63 if (auth_key_is_revoked(client_host_key))
66 /* Check if we would accept it using rhosts authentication. */
67 if (!auth_rhosts(pw, cuser))
70 host_status = check_key_in_hostfiles(pw, client_host_key,
71 chost, _PATH_SSH_SYSTEM_HOSTFILE,
72 options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
74 return (host_status == HOST_OK);
78 * Tries to authenticate the user using the .rhosts file and the host using
79 * its host key. Returns true if authentication succeeds.
82 auth_rhosts_rsa(Authctxt *authctxt, char *cuser, Key *client_host_key)
85 struct passwd *pw = authctxt->pw;
87 debug("Trying rhosts with RSA host authentication for client user %.100s",
90 if (!authctxt->valid || client_host_key == NULL ||
91 client_host_key->rsa == NULL)
94 chost = (char *)get_canonical_hostname(options.use_dns);
95 debug("Rhosts RSA authentication: canonical host %.900s", chost);
97 if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) {
98 debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
99 packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
102 /* A matching host key was found and is known. */
104 /* Perform the challenge-response dialog with the client for the host key. */
105 if (!auth_rsa_challenge_dialog(client_host_key)) {
106 logit("Client on %.800s failed to respond correctly to host authentication.",
111 * We have authenticated the user using .rhosts or /etc/hosts.equiv,
112 * and the host using RSA. We accept the authentication.
115 verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
116 pw->pw_name, cuser, chost);
117 packet_send_debug("Rhosts with RSA host authentication accepted.");