openssh/auth-rh-rsa.c
Damien Miller 3a961dc0d3 - (djm) OpenBSD CVS Sync
- markus@cvs.openbsd.org 2003/06/02 09:17:34
     [auth2-hostbased.c auth.c auth-options.c auth-rhosts.c auth-rh-rsa.c]
     [canohost.c monitor.c servconf.c servconf.h session.c sshd_config]
     [sshd_config.5]
     deprecate VerifyReverseMapping since it's dangerous if combined
     with IP based access control as noted by Mike Harding; replace with
     a UseDNS option, UseDNS is on by default and includes the
     VerifyReverseMapping check; with itojun@, provos@, jakob@ and deraadt@
     ok deraadt@, djm@
 - (djm) Fix portable-specific uses of verify_reverse_mapping too
2003-06-03 10:25:48 +10:00

92 lines
2.8 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Rhosts or /etc/hosts.equiv authentication combined with RSA host
* authentication.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
RCSID("$OpenBSD: auth-rh-rsa.c,v 1.36 2003/06/02 09:17:34 markus Exp $");
#include "packet.h"
#include "uidswap.h"
#include "log.h"
#include "servconf.h"
#include "key.h"
#include "hostfile.h"
#include "pathnames.h"
#include "auth.h"
#include "canohost.h"
#include "monitor_wrap.h"
/* import */
extern ServerOptions options;
int
auth_rhosts_rsa_key_allowed(struct passwd *pw, char *cuser, char *chost,
Key *client_host_key)
{
HostStatus host_status;
/* Check if we would accept it using rhosts authentication. */
if (!auth_rhosts(pw, cuser))
return 0;
host_status = check_key_in_hostfiles(pw, client_host_key,
chost, _PATH_SSH_SYSTEM_HOSTFILE,
options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
return (host_status == HOST_OK);
}
/*
* Tries to authenticate the user using the .rhosts file and the host using
* its host key. Returns true if authentication succeeds.
*/
int
auth_rhosts_rsa(struct passwd *pw, char *cuser, Key *client_host_key)
{
char *chost;
debug("Trying rhosts with RSA host authentication for client user %.100s",
cuser);
if (pw == NULL || client_host_key == NULL ||
client_host_key->rsa == NULL)
return 0;
chost = (char *)get_canonical_hostname(options.use_dns);
debug("Rhosts RSA authentication: canonical host %.900s", chost);
if (!PRIVSEP(auth_rhosts_rsa_key_allowed(pw, cuser, chost, client_host_key))) {
debug("Rhosts with RSA host authentication denied: unknown or invalid host key");
packet_send_debug("Your host key cannot be verified: unknown or invalid host key.");
return 0;
}
/* A matching host key was found and is known. */
/* Perform the challenge-response dialog with the client for the host key. */
if (!auth_rsa_challenge_dialog(client_host_key)) {
logit("Client on %.800s failed to respond correctly to host authentication.",
chost);
return 0;
}
/*
* We have authenticated the user using .rhosts or /etc/hosts.equiv,
* and the host using RSA. We accept the authentication.
*/
verbose("Rhosts with RSA host authentication accepted for %.100s, %.100s on %.700s.",
pw->pw_name, cuser, chost);
packet_send_debug("Rhosts with RSA host authentication accepted.");
return 1;
}