407 lines
9.8 KiB
C
407 lines
9.8 KiB
C
/*
|
|
* Kerberos v5 authentication and ticket-passing routines.
|
|
*
|
|
* $xFreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp$
|
|
*/
|
|
/*
|
|
* 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 1.9 2002/09/09 06:48:06 itojun Exp $");
|
|
RCSID("$FreeBSD$");
|
|
|
|
#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>
|
|
#ifndef HEIMDAL
|
|
#define krb5_get_err_text(context,code) error_message(code)
|
|
#endif /* !HEIMDAL */
|
|
|
|
extern ServerOptions options;
|
|
|
|
static int
|
|
krb5_init(void *context)
|
|
{
|
|
Authctxt *authctxt = (Authctxt *)context;
|
|
krb5_error_code problem;
|
|
static int cleanup_registered = 0;
|
|
|
|
if (authctxt->krb5_ctx == NULL) {
|
|
problem = krb5_init_context(&authctxt->krb5_ctx);
|
|
if (problem)
|
|
return (problem);
|
|
krb5_init_ets(authctxt->krb5_ctx);
|
|
}
|
|
if (!cleanup_registered) {
|
|
fatal_add_cleanup(krb5_cleanup_proc, authctxt);
|
|
cleanup_registered = 1;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Try krb5 authentication. server_user is passed for logging purposes
|
|
* only, in auth is received ticket, in client is returned principal
|
|
* from the ticket
|
|
*/
|
|
int
|
|
auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply)
|
|
{
|
|
krb5_error_code problem;
|
|
krb5_principal server;
|
|
krb5_ticket *ticket;
|
|
int fd, ret;
|
|
|
|
ret = 0;
|
|
server = NULL;
|
|
ticket = NULL;
|
|
reply->length = 0;
|
|
|
|
problem = krb5_init(authctxt);
|
|
if (problem)
|
|
goto err;
|
|
|
|
problem = krb5_auth_con_init(authctxt->krb5_ctx,
|
|
&authctxt->krb5_auth_ctx);
|
|
if (problem)
|
|
goto err;
|
|
|
|
fd = packet_get_connection_in();
|
|
#ifdef HEIMDAL
|
|
problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
|
|
authctxt->krb5_auth_ctx, &fd);
|
|
#else
|
|
problem = krb5_auth_con_genaddrs(authctxt->krb5_ctx,
|
|
authctxt->krb5_auth_ctx,fd,
|
|
KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR |
|
|
KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR);
|
|
#endif
|
|
if (problem)
|
|
goto err;
|
|
|
|
problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
|
|
KRB5_NT_SRV_HST, &server);
|
|
if (problem)
|
|
goto err;
|
|
|
|
problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
|
|
auth, server, NULL, NULL, &ticket);
|
|
if (problem)
|
|
goto err;
|
|
|
|
#ifdef HEIMDAL
|
|
problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
|
|
&authctxt->krb5_user);
|
|
#else
|
|
problem = krb5_copy_principal(authctxt->krb5_ctx,
|
|
ticket->enc_part2->client,
|
|
&authctxt->krb5_user);
|
|
#endif
|
|
if (problem)
|
|
goto err;
|
|
|
|
/* if client wants mutual auth */
|
|
problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
|
|
reply);
|
|
if (problem)
|
|
goto err;
|
|
|
|
/* Check .k5login authorization now. */
|
|
if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
authctxt->pw->pw_name))
|
|
goto err;
|
|
|
|
if (client)
|
|
krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
client);
|
|
|
|
ret = 1;
|
|
err:
|
|
if (server)
|
|
krb5_free_principal(authctxt->krb5_ctx, server);
|
|
if (ticket)
|
|
krb5_free_ticket(authctxt->krb5_ctx, ticket);
|
|
if (!ret && reply->length) {
|
|
xfree(reply->data);
|
|
memset(reply, 0, sizeof(*reply));
|
|
}
|
|
|
|
if (problem) {
|
|
if (authctxt->krb5_ctx != NULL)
|
|
debug("Kerberos v5 authentication failed: %s",
|
|
krb5_get_err_text(authctxt->krb5_ctx, problem));
|
|
else
|
|
debug("Kerberos v5 authentication failed: %d",
|
|
problem);
|
|
}
|
|
|
|
return (ret);
|
|
}
|
|
|
|
int
|
|
auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
|
|
{
|
|
krb5_error_code problem;
|
|
krb5_ccache ccache = NULL;
|
|
char *pname;
|
|
krb5_creds **creds;
|
|
|
|
if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
|
|
return (0);
|
|
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
#ifdef HEIMDAL
|
|
problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
|
|
#else
|
|
{
|
|
char ccname[40];
|
|
int tmpfd;
|
|
|
|
snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
|
|
|
|
if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
|
|
log("mkstemp(): %.100s", strerror(errno));
|
|
problem = errno;
|
|
goto fail;
|
|
}
|
|
if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
|
|
log("fchmod(): %.100s", strerror(errno));
|
|
close(tmpfd);
|
|
problem = errno;
|
|
goto fail;
|
|
}
|
|
close(tmpfd);
|
|
problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &ccache);
|
|
}
|
|
#endif
|
|
if (problem)
|
|
goto fail;
|
|
|
|
problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
|
|
authctxt->krb5_user);
|
|
if (problem)
|
|
goto fail;
|
|
|
|
#ifdef HEIMDAL
|
|
problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
|
|
ccache, tgt);
|
|
if (problem)
|
|
goto fail;
|
|
#else
|
|
problem = krb5_rd_cred(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
|
|
tgt, &creds, NULL);
|
|
if (problem)
|
|
goto fail;
|
|
problem = krb5_cc_store_cred(authctxt->krb5_ctx, ccache, *creds);
|
|
if (problem)
|
|
goto fail;
|
|
#endif
|
|
|
|
authctxt->krb5_fwd_ccache = ccache;
|
|
ccache = NULL;
|
|
|
|
authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
|
|
|
|
problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
&pname);
|
|
if (problem)
|
|
goto fail;
|
|
|
|
debug("Kerberos v5 TGT accepted (%s)", pname);
|
|
|
|
restore_uid();
|
|
|
|
return (1);
|
|
|
|
fail:
|
|
if (problem)
|
|
debug("Kerberos v5 TGT passing failed: %s",
|
|
krb5_get_err_text(authctxt->krb5_ctx, problem));
|
|
if (ccache)
|
|
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
|
|
|
|
restore_uid();
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
auth_krb5_password(Authctxt *authctxt, const char *password)
|
|
{
|
|
#ifndef HEIMDAL
|
|
krb5_creds creds;
|
|
krb5_principal server;
|
|
char ccname[40];
|
|
int tmpfd;
|
|
#endif
|
|
krb5_error_code problem;
|
|
|
|
if (authctxt->pw == NULL)
|
|
return (0);
|
|
|
|
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,
|
|
&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;
|
|
|
|
restore_uid();
|
|
problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
authctxt->krb5_fwd_ccache, password, 1, NULL);
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
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;
|
|
}
|
|
|
|
snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());
|
|
|
|
if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) {
|
|
log("mkstemp(): %.100s", strerror(errno));
|
|
problem = errno;
|
|
goto out;
|
|
}
|
|
|
|
if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
|
|
log("fchmod(): %.100s", strerror(errno));
|
|
close(tmpfd);
|
|
problem = errno;
|
|
goto out;
|
|
}
|
|
close(tmpfd);
|
|
|
|
problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &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);
|
|
|
|
out:
|
|
restore_uid();
|
|
|
|
if (problem) {
|
|
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 (1);
|
|
}
|
|
|
|
void
|
|
krb5_cleanup_proc(void *context)
|
|
{
|
|
Authctxt *authctxt = (Authctxt *)context;
|
|
|
|
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_auth_ctx) {
|
|
krb5_auth_con_free(authctxt->krb5_ctx,
|
|
authctxt->krb5_auth_ctx);
|
|
authctxt->krb5_auth_ctx = NULL;
|
|
}
|
|
if (authctxt->krb5_ctx) {
|
|
krb5_free_context(authctxt->krb5_ctx);
|
|
authctxt->krb5_ctx = NULL;
|
|
}
|
|
}
|
|
|
|
#endif /* KRB5 */
|