mirror of git://anongit.mindrot.org/openssh.git
115 lines
3.7 KiB
C
115 lines
3.7 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 1.21 2001/01/21 19:05:42 markus Exp $");
|
|
|
|
#include "packet.h"
|
|
#include "xmalloc.h"
|
|
#include "uidswap.h"
|
|
#include "log.h"
|
|
#include "servconf.h"
|
|
#include "key.h"
|
|
#include "hostfile.h"
|
|
#include "pathnames.h"
|
|
#include "auth.h"
|
|
#include "tildexpand.h"
|
|
#include "canohost.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, RSA *client_host_key)
|
|
{
|
|
extern ServerOptions options;
|
|
const char *canonical_hostname;
|
|
HostStatus host_status;
|
|
Key *client_key, *found;
|
|
|
|
debug("Trying rhosts with RSA host authentication for client user %.100s", client_user);
|
|
|
|
if (pw == NULL || client_host_key == NULL)
|
|
return 0;
|
|
|
|
/* 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);
|
|
|
|
/* wrap the RSA key into a 'generic' key */
|
|
client_key = key_new(KEY_RSA1);
|
|
BN_copy(client_key->rsa->e, client_host_key->e);
|
|
BN_copy(client_key->rsa->n, client_host_key->n);
|
|
found = key_new(KEY_RSA1);
|
|
|
|
/* Check if we know the host and its host key. */
|
|
host_status = check_host_in_hostfile(_PATH_SSH_SYSTEM_HOSTFILE, canonical_hostname,
|
|
client_key, found, NULL);
|
|
|
|
/* 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(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
|
|
/*
|
|
* Check file permissions of _PATH_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_key, found, NULL);
|
|
restore_uid();
|
|
}
|
|
xfree(user_hostfile);
|
|
}
|
|
key_free(client_key);
|
|
key_free(found);
|
|
|
|
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)) {
|
|
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;
|
|
}
|