[openssh.git] / auth-krb5.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 $
 * $OpenBSD: auth-krb5.c,v 1.2 2001/11/12 01:47:09 dugsong Exp $
 */

#include "includes.h"
#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)
		debug("Kerberos v5 authentication failed: %s",
		    krb5_get_err_text(authctxt->krb5_ctx, 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;
	
	problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
	    authctxt->krb5_fwd_ccache, password, 1, NULL);
	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) {
		debug("Kerberos password authentication failed: %s",
		    krb5_get_err_text(authctxt->krb5_ctx, 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 */
Commit	Line	Data
aa9f6a6e	1	/*
	2	* Kerberos v5 authentication and ticket-passing routines.
	3	*
	4	* $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
ede8cea6	5	* $OpenBSD: auth-krb5.c,v 1.2 2001/11/12 01:47:09 dugsong Exp $
aa9f6a6e	6	*/
	7
	8	#include "includes.h"
	9	#include "ssh.h"
	10	#include "ssh1.h"
	11	#include "packet.h"
	12	#include "xmalloc.h"
	13	#include "log.h"
	14	#include "servconf.h"
	15	#include "uidswap.h"
	16	#include "auth.h"
	17
	18	#ifdef KRB5
	19	#include <krb5.h>
	20
	21	extern ServerOptions options;
	22
	23	static int
	24	krb5_init(void *context)
	25	{
	26	Authctxt authctxt = (Authctxt )context;
	27	krb5_error_code problem;
	28	static int cleanup_registered = 0;
	29
	30	if (authctxt->krb5_ctx == NULL) {
	31	problem = krb5_init_context(&authctxt->krb5_ctx);
	32	if (problem)
	33	return (problem);
	34	krb5_init_ets(authctxt->krb5_ctx);
	35	}
	36	if (!cleanup_registered) {
	37	fatal_add_cleanup(krb5_cleanup_proc, authctxt);
	38	cleanup_registered = 1;
	39	}
	40	return (0);
	41	}
	42
	43	/*
	44	* Try krb5 authentication. server_user is passed for logging purposes
	45	* only, in auth is received ticket, in client is returned principal
	46	* from the ticket
	47	*/
	48	int
	49	auth_krb5(Authctxt authctxt, krb5_data auth, char **client)
	50	{
	51	krb5_error_code problem;
	52	krb5_principal server;
	53	krb5_data reply;
	54	krb5_ticket *ticket;
ede8cea6	55	int fd, ret;
	56
	57	ret = 0;
aa9f6a6e	58	server = NULL;
	59	ticket = NULL;
	60	reply.length = 0;
	61
	62	problem = krb5_init(authctxt);
	63	if (problem)
	64	goto err;
	65
	66	problem = krb5_auth_con_init(authctxt->krb5_ctx,
	67	&authctxt->krb5_auth_ctx);
	68	if (problem)
	69	goto err;
	70
	71	fd = packet_get_connection_in();
	72	problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
	73	authctxt->krb5_auth_ctx, &fd);
	74	if (problem)
	75	goto err;
	76
	77	problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
	78	KRB5_NT_SRV_HST, &server);
	79	if (problem)
	80	goto err;
	81
	82	problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
	83	auth, server, NULL, NULL, &ticket);
	84	if (problem)
	85	goto err;
	86
	87	problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
	88	&authctxt->krb5_user);
	89	if (problem)
	90	goto err;
	91
	92	/* if client wants mutual auth */
	93	problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
	94	&reply);
	95	if (problem)
	96	goto err;
	97
	98	/* Check .k5login authorization now. */
	99	if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
	100	authctxt->pw->pw_name))
	101	goto err;
	102
	103	if (client)
	104	krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
	105	client);
	106
	107	packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE);
	108	packet_put_string((char *) reply.data, reply.length);
	109	packet_send();
	110	packet_write_wait();
ede8cea6	111
ede8cea6	112	ret = 1;
aa9f6a6e	113	err:
	114	if (server)
	115	krb5_free_principal(authctxt->krb5_ctx, server);
	116	if (ticket)
	117	krb5_free_ticket(authctxt->krb5_ctx, ticket);
	118	if (reply.length)
	119	xfree(reply.data);
	120
ede8cea6	121	if (problem)
aa9f6a6e	122	debug("Kerberos v5 authentication failed: %s",
aa9f6a6e	123	krb5_get_err_text(authctxt->krb5_ctx, problem));
ede8cea6	124
ede8cea6	125	return (ret);
aa9f6a6e	126	}
	127
	128	int
	129	auth_krb5_tgt(Authctxt authctxt, krb5_data tgt)
	130	{
	131	krb5_error_code problem;
	132	krb5_ccache ccache = NULL;
	133	char *pname;
	134
	135	if (authctxt->pw == NULL \|\| authctxt->krb5_user == NULL)
	136	return (0);
	137
	138	temporarily_use_uid(authctxt->pw);
	139
	140	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
	141	if (problem)
	142	goto fail;
	143
	144	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
	145	authctxt->krb5_user);
	146	if (problem)
	147	goto fail;
	148
	149	problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
	150	ccache, tgt);
	151	if (problem)
	152	goto fail;
	153
	154	authctxt->krb5_fwd_ccache = ccache;
	155	ccache = NULL;
	156
	157	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
	158
	159	problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
	160	&pname);
	161	if (problem)
	162	goto fail;
	163
	164	debug("Kerberos v5 TGT accepted (%s)", pname);
	165
	166	restore_uid();
	167
	168	return (1);
	169
	170	fail:
	171	if (problem)
	172	debug("Kerberos v5 TGT passing failed: %s",
	173	krb5_get_err_text(authctxt->krb5_ctx, problem));
	174	if (ccache)
	175	krb5_cc_destroy(authctxt->krb5_ctx, ccache);
	176
	177	restore_uid();
	178
	179	return (0);
	180	}
	181
	182	int
	183	auth_krb5_password(Authctxt authctxt, const char password)
	184	{
	185	krb5_error_code problem;
	186
	187	if (authctxt->pw == NULL)
	188	return (0);
	189
190	temporarily_use_uid(authctxt->pw);
191
192	problem = krb5_init(authctxt);
193	if (problem)
194	goto out;
195
196	problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
197	&authctxt->krb5_user);
198	if (problem)
199	goto out;
200
201	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
202	&authctxt->krb5_fwd_ccache);
203	if (problem)
204	goto out;
205
206	problem = krb5_cc_initialize(authctxt->krb5_ctx,
207	authctxt->krb5_fwd_ccache, authctxt->krb5_user);
208	if (problem)
209	goto out;
210
211	problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
212	authctxt->krb5_fwd_ccache, password, 1, NULL);
213	if (problem)
214	goto out;
215
216	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
217
218	out:
219	restore_uid();
220
221	if (problem) {
222	debug("Kerberos password authentication failed: %s",
223	krb5_get_err_text(authctxt->krb5_ctx, problem));
224
225	krb5_cleanup_proc(authctxt);
226
227	if (options.kerberos_or_local_passwd)
228	return (-1);
229	else
230	return (0);
231	}
232	return (1);
233	}
234
235	void
236	krb5_cleanup_proc(void *context)
237	{
238	Authctxt authctxt = (Authctxt )context;
239
240	debug("krb5_cleanup_proc called");
241	if (authctxt->krb5_fwd_ccache) {
242	krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
243	authctxt->krb5_fwd_ccache = NULL;
244	}
245	if (authctxt->krb5_user) {
246	krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
247	authctxt->krb5_user = NULL;
248	}
249	if (authctxt->krb5_auth_ctx) {
250	krb5_auth_con_free(authctxt->krb5_ctx,
251	authctxt->krb5_auth_ctx);
252	authctxt->krb5_auth_ctx = NULL;
253	}
254	if (authctxt->krb5_ctx) {
255	krb5_free_context(authctxt->krb5_ctx);
256	authctxt->krb5_ctx = NULL;
257	}
258	}
259
260	#endif /* KRB5 */