2014-03-22 15:23:38 +00:00
|
|
|
/* $OpenBSD: auth2.c,v 1.130 2014/01/29 06:18:35 djm Exp $ */
|
2000-05-15 04:37:24 +00:00
|
|
|
/*
|
|
|
|
* 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.
|
|
|
|
*
|
|
|
|
* 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.
|
|
|
|
*/
|
2000-09-10 08:31:17 +00:00
|
|
|
|
2000-05-15 04:37:24 +00:00
|
|
|
#include "includes.h"
|
|
|
|
|
2006-09-30 13:29:51 +00:00
|
|
|
#include <sys/types.h>
|
2008-07-23 09:33:08 +00:00
|
|
|
#include <sys/stat.h>
|
|
|
|
#include <sys/uio.h>
|
2006-09-30 13:29:51 +00:00
|
|
|
|
2008-07-23 09:33:08 +00:00
|
|
|
#include <fcntl.h>
|
2006-09-30 13:29:51 +00:00
|
|
|
#include <pwd.h>
|
|
|
|
#include <stdarg.h>
|
|
|
|
#include <string.h>
|
2008-07-23 09:33:08 +00:00
|
|
|
#include <unistd.h>
|
2006-09-30 13:29:51 +00:00
|
|
|
|
2008-07-23 09:33:08 +00:00
|
|
|
#include "atomicio.h"
|
2009-10-01 15:19:37 +00:00
|
|
|
#include "xmalloc.h"
|
2006-09-30 13:29:51 +00:00
|
|
|
#include "ssh2.h"
|
2000-05-15 04:37:24 +00:00
|
|
|
#include "packet.h"
|
2001-05-04 03:57:05 +00:00
|
|
|
#include "log.h"
|
2006-09-30 13:29:51 +00:00
|
|
|
#include "buffer.h"
|
2000-05-15 04:37:24 +00:00
|
|
|
#include "servconf.h"
|
|
|
|
#include "compat.h"
|
2006-09-30 13:29:51 +00:00
|
|
|
#include "key.h"
|
|
|
|
#include "hostfile.h"
|
2000-05-15 04:37:24 +00:00
|
|
|
#include "auth.h"
|
|
|
|
#include "dispatch.h"
|
2001-05-04 03:57:05 +00:00
|
|
|
#include "pathnames.h"
|
2005-06-05 15:40:50 +00:00
|
|
|
#include "buffer.h"
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2004-01-07 11:10:17 +00:00
|
|
|
#ifdef GSSAPI
|
|
|
|
#include "ssh-gss.h"
|
|
|
|
#endif
|
2006-09-30 13:29:51 +00:00
|
|
|
#include "monitor_wrap.h"
|
2004-01-07 11:10:17 +00:00
|
|
|
|
2000-05-15 04:37:24 +00:00
|
|
|
/* import */
|
|
|
|
extern ServerOptions options;
|
2001-05-04 03:57:05 +00:00
|
|
|
extern u_char *session_id2;
|
2004-01-07 11:10:17 +00:00
|
|
|
extern u_int session_id2_len;
|
2005-06-05 15:40:50 +00:00
|
|
|
extern Buffer loginmsg;
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2002-06-23 14:01:54 +00:00
|
|
|
/* methods */
|
|
|
|
|
|
|
|
extern Authmethod method_none;
|
|
|
|
extern Authmethod method_pubkey;
|
|
|
|
extern Authmethod method_passwd;
|
|
|
|
extern Authmethod method_kbdint;
|
|
|
|
extern Authmethod method_hostbased;
|
2004-01-07 11:10:17 +00:00
|
|
|
#ifdef GSSAPI
|
|
|
|
extern Authmethod method_gssapi;
|
|
|
|
#endif
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2002-06-23 14:01:54 +00:00
|
|
|
Authmethod *authmethods[] = {
|
|
|
|
&method_none,
|
|
|
|
&method_pubkey,
|
2004-01-07 11:10:17 +00:00
|
|
|
#ifdef GSSAPI
|
|
|
|
&method_gssapi,
|
|
|
|
#endif
|
2002-06-23 14:01:54 +00:00
|
|
|
&method_passwd,
|
|
|
|
&method_kbdint,
|
|
|
|
&method_hostbased,
|
|
|
|
NULL
|
2000-12-05 02:20:19 +00:00
|
|
|
};
|
|
|
|
|
2000-05-15 04:37:24 +00:00
|
|
|
/* protocol */
|
|
|
|
|
2002-03-18 09:55:03 +00:00
|
|
|
static void input_service_request(int, u_int32_t, void *);
|
|
|
|
static void input_userauth_request(int, u_int32_t, void *);
|
2000-05-15 04:37:24 +00:00
|
|
|
|
|
|
|
/* helper */
|
2013-03-22 11:19:48 +00:00
|
|
|
static Authmethod *authmethod_lookup(Authctxt *, const char *);
|
|
|
|
static char *authmethods_get(Authctxt *authctxt);
|
2013-09-18 17:27:38 +00:00
|
|
|
|
|
|
|
#define MATCH_NONE 0 /* method or submethod mismatch */
|
|
|
|
#define MATCH_METHOD 1 /* method matches (no submethod specified) */
|
|
|
|
#define MATCH_BOTH 2 /* method and submethod match */
|
|
|
|
#define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */
|
|
|
|
static int list_starts_with(const char *, const char *, const char *);
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2008-07-23 09:33:08 +00:00
|
|
|
char *
|
|
|
|
auth2_read_banner(void)
|
|
|
|
{
|
|
|
|
struct stat st;
|
|
|
|
char *banner = NULL;
|
|
|
|
size_t len, n;
|
|
|
|
int fd;
|
|
|
|
|
|
|
|
if ((fd = open(options.banner, O_RDONLY)) == -1)
|
|
|
|
return (NULL);
|
|
|
|
if (fstat(fd, &st) == -1) {
|
|
|
|
close(fd);
|
|
|
|
return (NULL);
|
|
|
|
}
|
2012-08-29 15:46:01 +00:00
|
|
|
if (st.st_size <= 0 || st.st_size > 1*1024*1024) {
|
2008-07-23 09:33:08 +00:00
|
|
|
close(fd);
|
|
|
|
return (NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
len = (size_t)st.st_size; /* truncate */
|
|
|
|
banner = xmalloc(len + 1);
|
|
|
|
n = atomicio(read, fd, banner, len);
|
|
|
|
close(fd);
|
|
|
|
|
|
|
|
if (n != len) {
|
2013-09-18 17:27:38 +00:00
|
|
|
free(banner);
|
2008-07-23 09:33:08 +00:00
|
|
|
return (NULL);
|
|
|
|
}
|
|
|
|
banner[n] = '\0';
|
|
|
|
|
|
|
|
return (banner);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
userauth_send_banner(const char *msg)
|
|
|
|
{
|
|
|
|
if (datafellows & SSH_BUG_BANNER)
|
|
|
|
return;
|
|
|
|
|
|
|
|
packet_start(SSH2_MSG_USERAUTH_BANNER);
|
|
|
|
packet_put_cstring(msg);
|
|
|
|
packet_put_cstring(""); /* language, unused */
|
|
|
|
packet_send();
|
|
|
|
debug("%s: sent", __func__);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
userauth_banner(void)
|
|
|
|
{
|
|
|
|
char *banner = NULL;
|
|
|
|
|
|
|
|
if (options.banner == NULL ||
|
|
|
|
strcasecmp(options.banner, "none") == 0 ||
|
|
|
|
(datafellows & SSH_BUG_BANNER) != 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
|
|
|
|
goto done;
|
|
|
|
userauth_send_banner(banner);
|
|
|
|
|
|
|
|
done:
|
2013-09-18 17:27:38 +00:00
|
|
|
free(banner);
|
2008-07-23 09:33:08 +00:00
|
|
|
}
|
|
|
|
|
2000-05-15 04:37:24 +00:00
|
|
|
/*
|
2000-12-05 02:20:19 +00:00
|
|
|
* loop until authctxt->success == TRUE
|
2000-05-15 04:37:24 +00:00
|
|
|
*/
|
2004-02-26 10:38:49 +00:00
|
|
|
void
|
|
|
|
do_authentication2(Authctxt *authctxt)
|
2000-05-15 04:37:24 +00:00
|
|
|
{
|
2002-03-18 09:55:03 +00:00
|
|
|
dispatch_init(&dispatch_protocol_error);
|
2000-05-15 04:37:24 +00:00
|
|
|
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
|
2000-12-05 02:20:19 +00:00
|
|
|
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
|
|
|
|
2006-09-30 13:29:51 +00:00
|
|
|
/*ARGSUSED*/
|
2002-03-18 09:55:03 +00:00
|
|
|
static void
|
|
|
|
input_service_request(int type, u_int32_t seq, void *ctxt)
|
2000-05-15 04:37:24 +00:00
|
|
|
{
|
2000-12-05 02:20:19 +00:00
|
|
|
Authctxt *authctxt = ctxt;
|
2001-05-04 03:57:05 +00:00
|
|
|
u_int len;
|
2002-10-29 09:43:00 +00:00
|
|
|
int acceptit = 0;
|
2011-02-17 11:47:40 +00:00
|
|
|
char *service = packet_get_cstring(&len);
|
2002-03-18 09:55:03 +00:00
|
|
|
packet_check_eom();
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2000-12-05 02:20:19 +00:00
|
|
|
if (authctxt == NULL)
|
|
|
|
fatal("input_service_request: no authctxt");
|
|
|
|
|
2000-05-15 04:37:24 +00:00
|
|
|
if (strcmp(service, "ssh-userauth") == 0) {
|
2000-12-05 02:20:19 +00:00
|
|
|
if (!authctxt->success) {
|
2002-10-29 09:43:00 +00:00
|
|
|
acceptit = 1;
|
2000-05-15 04:37:24 +00:00
|
|
|
/* now we can handle user-auth requests */
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/* XXX all other service requests are denied */
|
|
|
|
|
2002-10-29 09:43:00 +00:00
|
|
|
if (acceptit) {
|
2000-05-15 04:37:24 +00:00
|
|
|
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);
|
|
|
|
}
|
2013-09-18 17:27:38 +00:00
|
|
|
free(service);
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
|
|
|
|
2006-09-30 13:29:51 +00:00
|
|
|
/*ARGSUSED*/
|
2002-03-18 09:55:03 +00:00
|
|
|
static void
|
|
|
|
input_userauth_request(int type, u_int32_t seq, void *ctxt)
|
2000-05-15 04:37:24 +00:00
|
|
|
{
|
2000-12-05 02:20:19 +00:00
|
|
|
Authctxt *authctxt = ctxt;
|
|
|
|
Authmethod *m = NULL;
|
2001-05-04 03:57:05 +00:00
|
|
|
char *user, *service, *method, *style = NULL;
|
2000-05-15 04:37:24 +00:00
|
|
|
int authenticated = 0;
|
|
|
|
|
2000-12-05 02:20:19 +00:00
|
|
|
if (authctxt == NULL)
|
|
|
|
fatal("input_userauth_request: no authctxt");
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2011-02-17 11:47:40 +00:00
|
|
|
user = packet_get_cstring(NULL);
|
|
|
|
service = packet_get_cstring(NULL);
|
|
|
|
method = packet_get_cstring(NULL);
|
2000-05-15 04:37:24 +00:00
|
|
|
debug("userauth-request for user %s service %s method %s", user, service, method);
|
2001-05-04 03:57:05 +00:00
|
|
|
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2001-05-04 03:57:05 +00:00
|
|
|
if ((style = strchr(user, ':')) != NULL)
|
|
|
|
*style++ = 0;
|
|
|
|
|
|
|
|
if (authctxt->attempt++ == 0) {
|
2000-12-05 02:20:19 +00:00
|
|
|
/* setup auth context */
|
2002-06-23 14:01:54 +00:00
|
|
|
authctxt->pw = PRIVSEP(getpwnamallow(user));
|
2004-04-20 09:35:04 +00:00
|
|
|
authctxt->user = xstrdup(user);
|
2002-06-23 14:01:54 +00:00
|
|
|
if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
|
2000-12-05 02:20:19 +00:00
|
|
|
authctxt->valid = 1;
|
|
|
|
debug2("input_userauth_request: setting up authctxt for %s", user);
|
|
|
|
} else {
|
2004-10-28 16:03:53 +00:00
|
|
|
logit("input_userauth_request: invalid user %s", user);
|
2004-01-07 11:10:17 +00:00
|
|
|
authctxt->pw = fakepw();
|
2005-06-05 15:40:50 +00:00
|
|
|
#ifdef SSH_AUDIT_EVENTS
|
|
|
|
PRIVSEP(audit_event(SSH_INVALID_USER));
|
2002-06-27 22:31:32 +00:00
|
|
|
#endif
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
2006-03-22 19:46:12 +00:00
|
|
|
#ifdef USE_PAM
|
|
|
|
if (options.use_pam)
|
|
|
|
PRIVSEP(start_pam(authctxt));
|
|
|
|
#endif
|
2004-10-28 16:03:53 +00:00
|
|
|
setproctitle("%s%s", authctxt->valid ? user : "unknown",
|
2002-06-23 14:01:54 +00:00
|
|
|
use_privsep ? " [net]" : "");
|
2000-12-05 02:20:19 +00:00
|
|
|
authctxt->service = xstrdup(service);
|
2002-03-18 09:55:03 +00:00
|
|
|
authctxt->style = style ? xstrdup(style) : NULL;
|
2002-06-23 14:01:54 +00:00
|
|
|
if (use_privsep)
|
|
|
|
mm_inform_authserv(service, style);
|
2008-07-23 09:33:08 +00:00
|
|
|
userauth_banner();
|
2013-03-22 11:19:48 +00:00
|
|
|
if (auth2_setup_methods_lists(authctxt) != 0)
|
|
|
|
packet_disconnect("no authentication methods enabled");
|
2002-03-18 09:55:03 +00:00
|
|
|
} else if (strcmp(user, authctxt->user) != 0 ||
|
|
|
|
strcmp(service, authctxt->service) != 0) {
|
|
|
|
packet_disconnect("Change of username or service not allowed: "
|
|
|
|
"(%s,%s) -> (%s,%s)",
|
|
|
|
authctxt->user, authctxt->service, user, service);
|
2000-12-05 02:20:19 +00:00
|
|
|
}
|
2001-05-04 03:57:05 +00:00
|
|
|
/* reset state */
|
2002-03-18 09:55:03 +00:00
|
|
|
auth2_challenge_stop(authctxt);
|
2004-01-07 11:10:17 +00:00
|
|
|
|
|
|
|
#ifdef GSSAPI
|
2009-02-24 18:49:27 +00:00
|
|
|
/* XXX move to auth2_gssapi_stop() */
|
2004-01-07 11:10:17 +00:00
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
|
|
|
|
#endif
|
|
|
|
|
2001-05-04 03:57:05 +00:00
|
|
|
authctxt->postponed = 0;
|
2011-09-28 08:14:41 +00:00
|
|
|
authctxt->server_caused_failure = 0;
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2001-05-04 03:57:05 +00:00
|
|
|
/* try to authenticate user */
|
2013-03-22 11:19:48 +00:00
|
|
|
m = authmethod_lookup(authctxt, method);
|
2008-07-23 09:33:08 +00:00
|
|
|
if (m != NULL && authctxt->failures < options.max_authtries) {
|
2000-12-05 02:20:19 +00:00
|
|
|
debug2("input_userauth_request: try method %s", method);
|
|
|
|
authenticated = m->userauth(authctxt);
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
2013-03-22 11:19:48 +00:00
|
|
|
userauth_finish(authctxt, authenticated, method, NULL);
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2013-09-18 17:27:38 +00:00
|
|
|
free(service);
|
|
|
|
free(user);
|
|
|
|
free(method);
|
2000-12-05 02:20:19 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
void
|
2013-03-22 11:19:48 +00:00
|
|
|
userauth_finish(Authctxt *authctxt, int authenticated, const char *method,
|
|
|
|
const char *submethod)
|
2000-12-05 02:20:19 +00:00
|
|
|
{
|
2002-03-18 09:55:03 +00:00
|
|
|
char *methods;
|
2013-03-22 11:19:48 +00:00
|
|
|
int partial = 0;
|
2002-03-18 09:55:03 +00:00
|
|
|
|
2001-05-04 03:57:05 +00:00
|
|
|
if (!authctxt->valid && authenticated)
|
|
|
|
fatal("INTERNAL ERROR: authenticated invalid user %s",
|
|
|
|
authctxt->user);
|
2013-03-22 11:19:48 +00:00
|
|
|
if (authenticated && authctxt->postponed)
|
|
|
|
fatal("INTERNAL ERROR: authenticated and postponed");
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2001-05-04 03:57:05 +00:00
|
|
|
/* Special handling for root */
|
2003-04-23 16:53:02 +00:00
|
|
|
if (authenticated && authctxt->pw->pw_uid == 0 &&
|
2005-06-05 15:40:50 +00:00
|
|
|
!auth_root_allowed(method)) {
|
2001-05-04 03:57:05 +00:00
|
|
|
authenticated = 0;
|
2005-06-05 15:40:50 +00:00
|
|
|
#ifdef SSH_AUDIT_EVENTS
|
|
|
|
PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
|
|
|
|
#endif
|
|
|
|
}
|
2000-05-15 04:37:24 +00:00
|
|
|
|
2013-03-22 11:19:48 +00:00
|
|
|
if (authenticated && options.num_auth_methods != 0) {
|
2013-09-18 17:27:38 +00:00
|
|
|
if (!auth2_update_methods_lists(authctxt, method, submethod)) {
|
2013-03-22 11:19:48 +00:00
|
|
|
authenticated = 0;
|
|
|
|
partial = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Log before sending the reply */
|
2013-09-18 17:27:38 +00:00
|
|
|
auth_log(authctxt, authenticated, partial, method, submethod);
|
2013-03-22 11:19:48 +00:00
|
|
|
|
|
|
|
if (authctxt->postponed)
|
|
|
|
return;
|
|
|
|
|
2002-06-27 22:31:32 +00:00
|
|
|
#ifdef USE_PAM
|
2005-06-05 15:40:50 +00:00
|
|
|
if (options.use_pam && authenticated) {
|
|
|
|
if (!PRIVSEP(do_pam_account())) {
|
|
|
|
/* if PAM returned a message, send it to the user */
|
|
|
|
if (buffer_len(&loginmsg) > 0) {
|
|
|
|
buffer_append(&loginmsg, "\0", 1);
|
|
|
|
userauth_send_banner(buffer_ptr(&loginmsg));
|
|
|
|
packet_write_wait();
|
|
|
|
}
|
|
|
|
fatal("Access denied for user %s by PAM account "
|
2005-09-03 06:59:33 +00:00
|
|
|
"configuration", authctxt->user);
|
2005-06-05 15:40:50 +00:00
|
|
|
}
|
|
|
|
}
|
2004-01-07 11:10:17 +00:00
|
|
|
#endif
|
2002-06-27 22:31:32 +00:00
|
|
|
|
2002-10-29 09:43:00 +00:00
|
|
|
#ifdef _UNICOS
|
|
|
|
if (authenticated && cray_access_denied(authctxt->user)) {
|
|
|
|
authenticated = 0;
|
2013-03-22 11:19:48 +00:00
|
|
|
fatal("Access denied for user %s.", authctxt->user);
|
2002-10-29 09:43:00 +00:00
|
|
|
}
|
|
|
|
#endif /* _UNICOS */
|
|
|
|
|
2002-03-18 09:55:03 +00:00
|
|
|
if (authenticated == 1) {
|
|
|
|
/* turn off userauth */
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
|
|
|
|
packet_start(SSH2_MSG_USERAUTH_SUCCESS);
|
|
|
|
packet_send();
|
|
|
|
packet_write_wait();
|
|
|
|
/* now we can break out */
|
|
|
|
authctxt->success = 1;
|
|
|
|
} else {
|
2008-07-23 09:33:08 +00:00
|
|
|
|
|
|
|
/* Allow initial try of "none" auth without failure penalty */
|
2011-09-28 08:14:41 +00:00
|
|
|
if (!authctxt->server_caused_failure &&
|
|
|
|
(authctxt->attempt > 1 || strcmp(method, "none") != 0))
|
2008-07-23 09:33:08 +00:00
|
|
|
authctxt->failures++;
|
|
|
|
if (authctxt->failures >= options.max_authtries) {
|
2005-06-05 15:40:50 +00:00
|
|
|
#ifdef SSH_AUDIT_EVENTS
|
|
|
|
PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
|
|
|
|
#endif
|
2002-03-18 09:55:03 +00:00
|
|
|
packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
|
2005-06-05 15:40:50 +00:00
|
|
|
}
|
2013-03-22 11:19:48 +00:00
|
|
|
methods = authmethods_get(authctxt);
|
|
|
|
debug3("%s: failure partial=%d next methods=\"%s\"", __func__,
|
|
|
|
partial, methods);
|
2002-03-18 09:55:03 +00:00
|
|
|
packet_start(SSH2_MSG_USERAUTH_FAILURE);
|
|
|
|
packet_put_cstring(methods);
|
2013-03-22 11:19:48 +00:00
|
|
|
packet_put_char(partial);
|
2002-03-18 09:55:03 +00:00
|
|
|
packet_send();
|
|
|
|
packet_write_wait();
|
2013-09-18 17:27:38 +00:00
|
|
|
free(methods);
|
2002-03-18 09:55:03 +00:00
|
|
|
}
|
2001-05-04 03:57:05 +00:00
|
|
|
}
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2013-03-22 11:19:48 +00:00
|
|
|
/*
|
|
|
|
* Checks whether method is allowed by at least one AuthenticationMethods
|
|
|
|
* methods list. Returns 1 if allowed, or no methods lists configured.
|
|
|
|
* 0 otherwise.
|
|
|
|
*/
|
2013-09-18 17:27:38 +00:00
|
|
|
int
|
|
|
|
auth2_method_allowed(Authctxt *authctxt, const char *method,
|
|
|
|
const char *submethod)
|
2013-03-22 11:19:48 +00:00
|
|
|
{
|
|
|
|
u_int i;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* NB. authctxt->num_auth_methods might be zero as a result of
|
|
|
|
* auth2_setup_methods_lists(), so check the configuration.
|
|
|
|
*/
|
|
|
|
if (options.num_auth_methods == 0)
|
|
|
|
return 1;
|
|
|
|
for (i = 0; i < authctxt->num_auth_methods; i++) {
|
2013-09-18 17:27:38 +00:00
|
|
|
if (list_starts_with(authctxt->auth_methods[i], method,
|
|
|
|
submethod) != MATCH_NONE)
|
2013-03-22 11:19:48 +00:00
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2002-03-18 09:55:03 +00:00
|
|
|
static char *
|
2013-03-22 11:19:48 +00:00
|
|
|
authmethods_get(Authctxt *authctxt)
|
2000-05-15 04:37:24 +00:00
|
|
|
{
|
2002-03-18 09:55:03 +00:00
|
|
|
Buffer b;
|
2000-12-05 02:20:19 +00:00
|
|
|
char *list;
|
2013-03-22 11:19:48 +00:00
|
|
|
u_int i;
|
2000-12-05 02:20:19 +00:00
|
|
|
|
2002-03-18 09:55:03 +00:00
|
|
|
buffer_init(&b);
|
2002-06-23 14:01:54 +00:00
|
|
|
for (i = 0; authmethods[i] != NULL; i++) {
|
|
|
|
if (strcmp(authmethods[i]->name, "none") == 0)
|
2000-12-05 02:20:19 +00:00
|
|
|
continue;
|
2013-03-22 11:19:48 +00:00
|
|
|
if (authmethods[i]->enabled == NULL ||
|
|
|
|
*(authmethods[i]->enabled) == 0)
|
|
|
|
continue;
|
2013-09-18 17:27:38 +00:00
|
|
|
if (!auth2_method_allowed(authctxt, authmethods[i]->name,
|
|
|
|
NULL))
|
2013-03-22 11:19:48 +00:00
|
|
|
continue;
|
|
|
|
if (buffer_len(&b) > 0)
|
|
|
|
buffer_append(&b, ",", 1);
|
|
|
|
buffer_append(&b, authmethods[i]->name,
|
|
|
|
strlen(authmethods[i]->name));
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
2002-03-18 09:55:03 +00:00
|
|
|
buffer_append(&b, "\0", 1);
|
|
|
|
list = xstrdup(buffer_ptr(&b));
|
|
|
|
buffer_free(&b);
|
2000-12-05 02:20:19 +00:00
|
|
|
return list;
|
|
|
|
}
|
|
|
|
|
2002-03-18 09:55:03 +00:00
|
|
|
static Authmethod *
|
2013-03-22 11:19:48 +00:00
|
|
|
authmethod_lookup(Authctxt *authctxt, const char *name)
|
2000-12-05 02:20:19 +00:00
|
|
|
{
|
2002-06-23 14:01:54 +00:00
|
|
|
int i;
|
|
|
|
|
2000-12-05 02:20:19 +00:00
|
|
|
if (name != NULL)
|
2002-06-23 14:01:54 +00:00
|
|
|
for (i = 0; authmethods[i] != NULL; i++)
|
|
|
|
if (authmethods[i]->enabled != NULL &&
|
|
|
|
*(authmethods[i]->enabled) != 0 &&
|
2013-03-22 11:19:48 +00:00
|
|
|
strcmp(name, authmethods[i]->name) == 0 &&
|
2013-09-18 17:27:38 +00:00
|
|
|
auth2_method_allowed(authctxt,
|
|
|
|
authmethods[i]->name, NULL))
|
2002-06-23 14:01:54 +00:00
|
|
|
return authmethods[i];
|
|
|
|
debug2("Unrecognized authentication method name: %s",
|
|
|
|
name ? name : "NULL");
|
2000-12-05 02:20:19 +00:00
|
|
|
return NULL;
|
2000-05-15 04:37:24 +00:00
|
|
|
}
|
2008-07-23 09:33:08 +00:00
|
|
|
|
2013-03-22 11:19:48 +00:00
|
|
|
/*
|
|
|
|
* Check a comma-separated list of methods for validity. Is need_enable is
|
|
|
|
* non-zero, then also require that the methods are enabled.
|
|
|
|
* Returns 0 on success or -1 if the methods list is invalid.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
auth2_methods_valid(const char *_methods, int need_enable)
|
|
|
|
{
|
2013-09-18 17:27:38 +00:00
|
|
|
char *methods, *omethods, *method, *p;
|
2013-03-22 11:19:48 +00:00
|
|
|
u_int i, found;
|
|
|
|
int ret = -1;
|
|
|
|
|
|
|
|
if (*_methods == '\0') {
|
|
|
|
error("empty authentication method list");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
omethods = methods = xstrdup(_methods);
|
|
|
|
while ((method = strsep(&methods, ",")) != NULL) {
|
|
|
|
for (found = i = 0; !found && authmethods[i] != NULL; i++) {
|
2013-09-18 17:27:38 +00:00
|
|
|
if ((p = strchr(method, ':')) != NULL)
|
|
|
|
*p = '\0';
|
2013-03-22 11:19:48 +00:00
|
|
|
if (strcmp(method, authmethods[i]->name) != 0)
|
|
|
|
continue;
|
|
|
|
if (need_enable) {
|
|
|
|
if (authmethods[i]->enabled == NULL ||
|
|
|
|
*(authmethods[i]->enabled) == 0) {
|
|
|
|
error("Disabled method \"%s\" in "
|
|
|
|
"AuthenticationMethods list \"%s\"",
|
|
|
|
method, _methods);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
found = 1;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
if (!found) {
|
|
|
|
error("Unknown authentication method \"%s\" in list",
|
|
|
|
method);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
out:
|
|
|
|
free(omethods);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Prune the AuthenticationMethods supplied in the configuration, removing
|
|
|
|
* any methods lists that include disabled methods. Note that this might
|
|
|
|
* leave authctxt->num_auth_methods == 0, even when multiple required auth
|
|
|
|
* has been requested. For this reason, all tests for whether multiple is
|
|
|
|
* enabled should consult options.num_auth_methods directly.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
auth2_setup_methods_lists(Authctxt *authctxt)
|
|
|
|
{
|
|
|
|
u_int i;
|
|
|
|
|
|
|
|
if (options.num_auth_methods == 0)
|
|
|
|
return 0;
|
|
|
|
debug3("%s: checking methods", __func__);
|
|
|
|
authctxt->auth_methods = xcalloc(options.num_auth_methods,
|
|
|
|
sizeof(*authctxt->auth_methods));
|
|
|
|
authctxt->num_auth_methods = 0;
|
|
|
|
for (i = 0; i < options.num_auth_methods; i++) {
|
|
|
|
if (auth2_methods_valid(options.auth_methods[i], 1) != 0) {
|
|
|
|
logit("Authentication methods list \"%s\" contains "
|
|
|
|
"disabled method, skipping",
|
|
|
|
options.auth_methods[i]);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
debug("authentication methods list %d: %s",
|
|
|
|
authctxt->num_auth_methods, options.auth_methods[i]);
|
|
|
|
authctxt->auth_methods[authctxt->num_auth_methods++] =
|
|
|
|
xstrdup(options.auth_methods[i]);
|
|
|
|
}
|
|
|
|
if (authctxt->num_auth_methods == 0) {
|
|
|
|
error("No AuthenticationMethods left after eliminating "
|
|
|
|
"disabled methods");
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
2013-09-18 17:27:38 +00:00
|
|
|
list_starts_with(const char *methods, const char *method,
|
|
|
|
const char *submethod)
|
2013-03-22 11:19:48 +00:00
|
|
|
{
|
|
|
|
size_t l = strlen(method);
|
2013-09-18 17:27:38 +00:00
|
|
|
int match;
|
|
|
|
const char *p;
|
2013-03-22 11:19:48 +00:00
|
|
|
|
|
|
|
if (strncmp(methods, method, l) != 0)
|
2013-09-18 17:27:38 +00:00
|
|
|
return MATCH_NONE;
|
|
|
|
p = methods + l;
|
|
|
|
match = MATCH_METHOD;
|
|
|
|
if (*p == ':') {
|
|
|
|
if (!submethod)
|
|
|
|
return MATCH_PARTIAL;
|
|
|
|
l = strlen(submethod);
|
|
|
|
p += 1;
|
|
|
|
if (strncmp(submethod, p, l))
|
|
|
|
return MATCH_NONE;
|
|
|
|
p += l;
|
|
|
|
match = MATCH_BOTH;
|
|
|
|
}
|
|
|
|
if (*p != ',' && *p != '\0')
|
|
|
|
return MATCH_NONE;
|
|
|
|
return match;
|
2013-03-22 11:19:48 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Remove method from the start of a comma-separated list of methods.
|
|
|
|
* Returns 0 if the list of methods did not start with that method or 1
|
|
|
|
* if it did.
|
|
|
|
*/
|
|
|
|
static int
|
2013-09-18 17:27:38 +00:00
|
|
|
remove_method(char **methods, const char *method, const char *submethod)
|
2013-03-22 11:19:48 +00:00
|
|
|
{
|
2013-09-18 17:27:38 +00:00
|
|
|
char *omethods = *methods, *p;
|
2013-03-22 11:19:48 +00:00
|
|
|
size_t l = strlen(method);
|
2013-09-18 17:27:38 +00:00
|
|
|
int match;
|
2013-03-22 11:19:48 +00:00
|
|
|
|
2013-09-18 17:27:38 +00:00
|
|
|
match = list_starts_with(omethods, method, submethod);
|
|
|
|
if (match != MATCH_METHOD && match != MATCH_BOTH)
|
2013-03-22 11:19:48 +00:00
|
|
|
return 0;
|
2013-09-18 17:27:38 +00:00
|
|
|
p = omethods + l;
|
|
|
|
if (submethod && match == MATCH_BOTH)
|
|
|
|
p += 1 + strlen(submethod); /* include colon */
|
|
|
|
if (*p == ',')
|
|
|
|
p++;
|
|
|
|
*methods = xstrdup(p);
|
2013-03-22 11:19:48 +00:00
|
|
|
free(omethods);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Called after successful authentication. Will remove the successful method
|
|
|
|
* from the start of each list in which it occurs. If it was the last method
|
|
|
|
* in any list, then authentication is deemed successful.
|
|
|
|
* Returns 1 if the method completed any authentication list or 0 otherwise.
|
|
|
|
*/
|
|
|
|
int
|
2013-09-18 17:27:38 +00:00
|
|
|
auth2_update_methods_lists(Authctxt *authctxt, const char *method,
|
|
|
|
const char *submethod)
|
2013-03-22 11:19:48 +00:00
|
|
|
{
|
|
|
|
u_int i, found = 0;
|
|
|
|
|
|
|
|
debug3("%s: updating methods list after \"%s\"", __func__, method);
|
|
|
|
for (i = 0; i < authctxt->num_auth_methods; i++) {
|
2013-09-18 17:27:38 +00:00
|
|
|
if (!remove_method(&(authctxt->auth_methods[i]), method,
|
|
|
|
submethod))
|
2013-03-22 11:19:48 +00:00
|
|
|
continue;
|
|
|
|
found = 1;
|
|
|
|
if (*authctxt->auth_methods[i] == '\0') {
|
|
|
|
debug2("authentication methods list %d complete", i);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
debug3("authentication methods list %d remaining: \"%s\"",
|
|
|
|
i, authctxt->auth_methods[i]);
|
|
|
|
}
|
|
|
|
/* This should not happen, but would be bad if it did */
|
|
|
|
if (!found)
|
|
|
|
fatal("%s: method not in AuthenticationMethods", __func__);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
|