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|
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Markus Friedl.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
RCSID("$OpenBSD: auth2.c,v 1.11 2000/06/19 00:50:11 markus Exp $");
#include <openssl/dsa.h>
#include <openssl/rsa.h>
#include <openssl/evp.h>
#include "xmalloc.h"
#include "rsa.h"
#include "ssh.h"
#include "pty.h"
#include "packet.h"
#include "buffer.h"
#include "cipher.h"
#include "servconf.h"
#include "compat.h"
#include "channels.h"
#include "bufaux.h"
#include "ssh2.h"
#include "auth.h"
#include "session.h"
#include "dispatch.h"
#include "auth.h"
#include "key.h"
#include "kex.h"
#include "dsa.h"
#include "uidswap.h"
#include "auth-options.h"
/* import */
extern ServerOptions options;
extern unsigned char *session_id2;
extern int session_id2_len;
/* protocol */
void input_service_request(int type, int plen);
void input_userauth_request(int type, int plen);
void protocol_error(int type, int plen);
/* auth */
int ssh2_auth_none(struct passwd *pw);
int ssh2_auth_password(struct passwd *pw);
int ssh2_auth_pubkey(struct passwd *pw, char *service);
/* helper */
struct passwd* auth_set_user(char *u, char *s);
int user_dsa_key_allowed(struct passwd *pw, Key *key);
typedef struct Authctxt Authctxt;
struct Authctxt {
char *user;
char *service;
struct passwd pw;
int valid;
};
static Authctxt *authctxt = NULL;
static int userauth_success = 0;
/*
* loop until userauth_success == TRUE
*/
void
do_authentication2()
{
/* turn off skey/kerberos, not supported by SSH2 */
#ifdef SKEY
options.skey_authentication = 0;
#endif
#ifdef KRB4
options.kerberos_authentication = 0;
#endif
dispatch_init(&protocol_error);
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
dispatch_run(DISPATCH_BLOCK, &userauth_success);
do_authenticated2();
}
void
protocol_error(int type, int plen)
{
log("auth: protocol error: type %d plen %d", type, plen);
packet_start(SSH2_MSG_UNIMPLEMENTED);
packet_put_int(0);
packet_send();
packet_write_wait();
}
void
input_service_request(int type, int plen)
{
unsigned int len;
int accept = 0;
char *service = packet_get_string(&len);
packet_done();
if (strcmp(service, "ssh-userauth") == 0) {
if (!userauth_success) {
accept = 1;
/* now we can handle user-auth requests */
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
}
}
/* XXX all other service requests are denied */
if (accept) {
packet_start(SSH2_MSG_SERVICE_ACCEPT);
packet_put_cstring(service);
packet_send();
packet_write_wait();
} else {
debug("bad service request %s", service);
packet_disconnect("bad service request %s", service);
}
xfree(service);
}
void
input_userauth_request(int type, int plen)
{
static void (*authlog) (const char *fmt,...) = verbose;
static int attempt = 0;
unsigned int len;
int authenticated = 0;
char *user, *service, *method, *authmsg = NULL;
struct passwd *pw;
#ifdef WITH_AIXAUTHENTICATE
extern char *aixloginmsg;
#endif /* WITH_AIXAUTHENTICATE */
user = packet_get_string(&len);
service = packet_get_string(&len);
method = packet_get_string(&len);
if (++attempt == AUTH_FAIL_MAX) {
#ifdef WITH_AIXAUTHENTICATE
loginfailed(user,get_canonical_hostname(),"ssh");
#endif /* WITH_AIXAUTHENTICATE */
packet_disconnect("too many failed userauth_requests");
}
debug("userauth-request for user %s service %s method %s", user, service, method);
/* XXX we only allow the ssh-connection service */
pw = auth_set_user(user, service);
if (pw && strcmp(service, "ssh-connection")==0) {
if (strcmp(method, "none") == 0) {
authenticated = ssh2_auth_none(pw);
} else if (strcmp(method, "password") == 0) {
authenticated = ssh2_auth_password(pw);
} else if (strcmp(method, "publickey") == 0) {
authenticated = ssh2_auth_pubkey(pw, service);
}
}
if (authenticated && pw && pw->pw_uid == 0 && !options.permit_root_login) {
authenticated = 0;
log("ROOT LOGIN REFUSED FROM %.200s",
get_canonical_hostname());
}
#ifdef USE_PAM
if (authenticated && !do_pam_account(pw->pw_name, NULL))
authenticated = 0;
#endif /* USE_PAM */
/* Raise logging level */
if (authenticated == 1 ||
attempt == AUTH_FAIL_LOG ||
strcmp(method, "password") == 0)
authlog = log;
/* Log before sending the reply */
if (authenticated == 1) {
authmsg = "Accepted";
} else if (authenticated == 0) {
authmsg = "Failed";
} else {
authmsg = "Postponed";
}
authlog("%s %s for %.200s from %.200s port %d ssh2",
authmsg,
method,
pw && pw->pw_uid == 0 ? "ROOT" : user,
get_remote_ipaddr(),
get_remote_port());
/* XXX todo: check if multiple auth methods are needed */
if (authenticated == 1) {
#ifdef WITH_AIXAUTHENTICATE
/* We don't have a pty yet, so just label the line as "ssh" */
if (loginsuccess(user,get_canonical_hostname(),"ssh",
&aixloginmsg) < 0)
aixloginmsg = NULL;
#endif /* WITH_AIXAUTHENTICATE */
/* turn off userauth */
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error);
packet_start(SSH2_MSG_USERAUTH_SUCCESS);
packet_send();
packet_write_wait();
/* now we can break out */
userauth_success = 1;
} else if (authenticated == 0) {
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring("publickey,password"); /* XXX dynamic */
packet_put_char(0); /* XXX partial success, unused */
packet_send();
packet_write_wait();
}
xfree(service);
xfree(user);
xfree(method);
}
int
ssh2_auth_none(struct passwd *pw)
{
packet_done();
#ifdef USE_PAM
return auth_pam_password(pw, "");
#else /* USE_PAM */
return auth_password(pw, "");
#endif /* USE_PAM */
}
int
ssh2_auth_password(struct passwd *
|