auth-krb5.c - platform/external/openssh - Gitiles

 /*
  *    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 1.8 2002/03/19 10:49:35 markus 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;
 	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_error_code problem;
 	krb5_principal server;
 	krb5_data reply;
 	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();
 	problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
 	    authctxt->krb5_auth_ctx, &fd);
 	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;

 	problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
 	    &authctxt->krb5_user);
 	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);

 	packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
 	packet_put_string((char *) reply.data, reply.length);
 	packet_send();
 	packet_write_wait();

 	ret = 1;
  err:
 	if (server)
 		krb5_free_principal(authctxt->krb5_ctx, server);
 	if (ticket)
 		krb5_free_ticket(authctxt->krb5_ctx, ticket);
 	if (reply.length)
 		xfree(reply.data);

 	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;

 	if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
 		return (0);

 	temporarily_use_uid(authctxt->pw);

 	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
 	if (problem)
 		goto fail;

 	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
 	    authctxt->krb5_user);
 	if (problem)
 		goto fail;

 	problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
 	    ccache, tgt);
 	if (problem)
 		goto fail;

 	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)
 {
 	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;

 	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;

 	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)
 			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 */
	/*
	* 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 1.8 2002/03/19 10:49:35 markus 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;
	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_error_code problem;
	krb5_principal server;
	krb5_data reply;
	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();
	problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
	authctxt->krb5_auth_ctx, &fd);
	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;

	problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
	&authctxt->krb5_user);
	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);

	packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
	packet_put_string((char *) reply.data, reply.length);
	packet_send();
	packet_write_wait();

	ret = 1;
	err:
	if (server)
	krb5_free_principal(authctxt->krb5_ctx, server);
	if (ticket)
	krb5_free_ticket(authctxt->krb5_ctx, ticket);
	if (reply.length)
	xfree(reply.data);

	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;

	if (authctxt->pw == NULL \|\| authctxt->krb5_user == NULL)
	return (0);

	temporarily_use_uid(authctxt->pw);

	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
	if (problem)
	goto fail;

	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
	authctxt->krb5_user);
	if (problem)
	goto fail;

	problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
	ccache, tgt);
	if (problem)
	goto fail;

	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)
	{
	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;

	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;

	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)
	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 */