mirror of
git://anongit.mindrot.org/openssh.git
synced 2024-12-17 23:54:35 +00:00
f4732f6475
[auth-krb5.c] Perform Kerberos calls even for invalid users to prevent leaking information about account validity. bz #975, patch originally from Senthil Kumar, sanity checked by Simon Wilkinson, tested by djm@, biorn@, ok markus@
240 lines
6.1 KiB
C
240 lines
6.1 KiB
C
/*
|
|
* Kerberos v5 authentication and ticket-passing routines.
|
|
*
|
|
* $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
|
|
*/
|
|
/*
|
|
* Copyright (c) 2002 Daniel Kouril. 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.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
RCSID("$OpenBSD: auth-krb5.c,v 1.16 2005/11/21 09:42:10 dtucker Exp $");
|
|
|
|
#include "ssh.h"
|
|
#include "ssh1.h"
|
|
#include "packet.h"
|
|
#include "xmalloc.h"
|
|
#include "log.h"
|
|
#include "servconf.h"
|
|
#include "uidswap.h"
|
|
#include "auth.h"
|
|
|
|
#ifdef KRB5
|
|
#include <krb5.h>
|
|
|
|
extern ServerOptions options;
|
|
|
|
static int
|
|
krb5_init(void *context)
|
|
{
|
|
Authctxt *authctxt = (Authctxt *)context;
|
|
krb5_error_code problem;
|
|
|
|
if (authctxt->krb5_ctx == NULL) {
|
|
problem = krb5_init_context(&authctxt->krb5_ctx);
|
|
if (problem)
|
|
return (problem);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
auth_krb5_password(Authctxt *authctxt, const char *password)
|
|
{
|
|
#ifndef HEIMDAL
|
|
krb5_creds creds;
|
|
krb5_principal server;
|
|
#endif
|
|
krb5_error_code problem;
|
|
krb5_ccache ccache = NULL;
|
|
int len;
|
|
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
problem = krb5_init(authctxt);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
|
|
&authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
#ifdef HEIMDAL
|
|
problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
|
|
authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
restore_uid();
|
|
|
|
problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
ccache, password, 1, NULL);
|
|
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
|
|
&authctxt->krb5_fwd_ccache);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
|
|
authctxt->krb5_fwd_ccache);
|
|
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
|
|
ccache = NULL;
|
|
if (problem)
|
|
goto out;
|
|
|
|
#else
|
|
problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
|
|
authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
|
|
KRB5_NT_SRV_HST, &server);
|
|
if (problem)
|
|
goto out;
|
|
|
|
restore_uid();
|
|
problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
|
|
NULL, NULL, NULL);
|
|
krb5_free_principal(authctxt->krb5_ctx, server);
|
|
temporarily_use_uid(authctxt->pw);
|
|
if (problem)
|
|
goto out;
|
|
|
|
if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
authctxt->pw->pw_name)) {
|
|
problem = -1;
|
|
goto out;
|
|
}
|
|
|
|
problem = ssh_krb5_cc_gen(authctxt->krb5_ctx, &authctxt->krb5_fwd_ccache);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
|
|
authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache,
|
|
&creds);
|
|
if (problem)
|
|
goto out;
|
|
#endif
|
|
|
|
authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
|
|
|
|
len = strlen(authctxt->krb5_ticket_file) + 6;
|
|
authctxt->krb5_ccname = xmalloc(len);
|
|
snprintf(authctxt->krb5_ccname, len, "FILE:%s",
|
|
authctxt->krb5_ticket_file);
|
|
|
|
#ifdef USE_PAM
|
|
if (options.use_pam)
|
|
do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
|
|
#endif
|
|
|
|
out:
|
|
restore_uid();
|
|
|
|
if (problem) {
|
|
if (ccache)
|
|
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
|
|
|
|
if (authctxt->krb5_ctx != NULL && problem!=-1)
|
|
debug("Kerberos password authentication failed: %s",
|
|
krb5_get_err_text(authctxt->krb5_ctx, problem));
|
|
else
|
|
debug("Kerberos password authentication failed: %d",
|
|
problem);
|
|
|
|
krb5_cleanup_proc(authctxt);
|
|
|
|
if (options.kerberos_or_local_passwd)
|
|
return (-1);
|
|
else
|
|
return (0);
|
|
}
|
|
return (authctxt->valid ? 1 : 0);
|
|
}
|
|
|
|
void
|
|
krb5_cleanup_proc(Authctxt *authctxt)
|
|
{
|
|
debug("krb5_cleanup_proc called");
|
|
if (authctxt->krb5_fwd_ccache) {
|
|
krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
|
|
authctxt->krb5_fwd_ccache = NULL;
|
|
}
|
|
if (authctxt->krb5_user) {
|
|
krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
|
|
authctxt->krb5_user = NULL;
|
|
}
|
|
if (authctxt->krb5_ctx) {
|
|
krb5_free_context(authctxt->krb5_ctx);
|
|
authctxt->krb5_ctx = NULL;
|
|
}
|
|
}
|
|
|
|
#ifndef HEIMDAL
|
|
krb5_error_code
|
|
ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
|
|
int tmpfd, ret;
|
|
char ccname[40];
|
|
mode_t old_umask;
|
|
|
|
ret = snprintf(ccname, sizeof(ccname),
|
|
"FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
|
|
if (ret < 0 || (size_t)ret >= sizeof(ccname))
|
|
return ENOMEM;
|
|
|
|
old_umask = umask(0177);
|
|
tmpfd = mkstemp(ccname + strlen("FILE:"));
|
|
umask(old_umask);
|
|
if (tmpfd == -1) {
|
|
logit("mkstemp(): %.100s", strerror(errno));
|
|
return errno;
|
|
}
|
|
|
|
if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
|
|
logit("fchmod(): %.100s", strerror(errno));
|
|
close(tmpfd);
|
|
return errno;
|
|
}
|
|
close(tmpfd);
|
|
|
|
return (krb5_cc_resolve(ctx, ccname, ccache));
|
|
}
|
|
#endif /* !HEIMDAL */
|
|
#endif /* KRB5 */
|