openssh/auth-rh-rsa.c
Damien Miller 95def09838 - Merged very large OpenBSD source code reformat
- OpenBSD CVS updates
   - [channels.c cipher.c compat.c log-client.c scp.c serverloop.c]
     [ssh.h sshd.8 sshd.c]
     syslog changes:
     * Unified Logmessage for all auth-types, for success and for failed
     * Standard connections get only ONE line in the LOG when level==LOG:
       Auth-attempts are logged only, if authentication is:
          a) successfull or
          b) with passwd or
          c) we had more than AUTH_FAIL_LOG failues
     * many log() became verbose()
     * old behaviour with level=VERBOSE
   - [readconf.c readconf.h ssh.1 ssh.h sshconnect.c sshd.c]
     tranfer s/key challenge/response data in SSH_SMSG_AUTH_TIS_CHALLENGE
     messages. allows use of s/key in windows (ttssh, securecrt) and
     ssh-1.2.27 clients without 'ssh -v', ok: niels@
   - [sshd.8]
     -V, for fallback to openssh in SSH2 compatibility mode
   - [sshd.c]
     fix sigchld race; cjc5@po.cwru.edu
1999-11-25 00:26:21 +11:00

102 lines
3.2 KiB
C

/*
*
* auth-rh-rsa.c
*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* Created: Sun May 7 03:08:06 1995 ylo
*
* Rhosts or /etc/hosts.equiv authentication combined with RSA host
* authentication.
*
*/
#include "includes.h"
RCSID("$Id: auth-rh-rsa.c,v 1.6 1999/11/24 13:26:21 damien Exp $");
#include "packet.h"
#include "ssh.h"
#include "xmalloc.h"
#include "uidswap.h"
#include "servconf.h"
/* 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, const char *client_user,
BIGNUM *client_host_key_e, BIGNUM *client_host_key_n)
{
extern ServerOptions options;
const char *canonical_hostname;
HostStatus host_status;
BIGNUM *ke, *kn;
debug("Trying rhosts with RSA host authentication for %.100s", client_user);
/* Check if we would accept it using rhosts authentication. */
if (!auth_rhosts(pw, client_user))
return 0;
canonical_hostname = get_canonical_hostname();
debug("Rhosts RSA authentication: canonical host %.900s",
canonical_hostname);
/* Check if we know the host and its host key. */
ke = BN_new();
kn = BN_new();
host_status = check_host_in_hostfile(SSH_SYSTEM_HOSTFILE, canonical_hostname,
client_host_key_e, client_host_key_n,
ke, kn);
/* Check user host file unless ignored. */
if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
struct stat st;
char *user_hostfile = tilde_expand_filename(SSH_USER_HOSTFILE, pw->pw_uid);
/* Check file permissions of SSH_USER_HOSTFILE, auth_rsa()
did already check pw->pw_dir, but there is a race XXX */
if (options.strict_modes &&
(stat(user_hostfile, &st) == 0) &&
((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
(st.st_mode & 022) != 0)) {
log("Rhosts RSA authentication refused for %.100s: bad owner or modes for %.200s",
pw->pw_name, user_hostfile);
} else {
/* XXX race between stat and the following open() */
temporarily_use_uid(pw->pw_uid);
host_status = check_host_in_hostfile(user_hostfile, canonical_hostname,
client_host_key_e, client_host_key_n,
ke, kn);
restore_uid();
}
xfree(user_hostfile);
}
BN_free(ke);
BN_free(kn);
if (host_status != HOST_OK) {
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_e, client_host_key_n)) {
log("Client on %.800s failed to respond correctly to host authentication.",
canonical_hostname);
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, client_user, canonical_hostname);
packet_send_debug("Rhosts with RSA host authentication accepted.");
return 1;
}