[thirdparty/linux.git] / fs / cifs / cifs_spnego.c

/*
 *   fs/cifs/cifs_spnego.c -- SPNEGO upcall management for CIFS
 *
 *   Copyright (c) 2007 Red Hat, Inc.
 *   Author(s): Jeff Layton (jlayton@redhat.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/list.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <keys/user-type.h>
#include <linux/key-type.h>
#include <linux/keyctl.h>
#include <linux/inet.h>
#include "cifsglob.h"
#include "cifs_spnego.h"
#include "cifs_debug.h"
#include "cifsproto.h"
static const struct cred *spnego_cred;

/* create a new cifs key */
static int
cifs_spnego_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
{
	char *payload;
	int ret;

	ret = -ENOMEM;
	payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL);
	if (!payload)
		goto error;

	/* attach the data */
	key->payload.data[0] = payload;
	ret = 0;

error:
	return ret;
}

static void
cifs_spnego_key_destroy(struct key *key)
{
	kfree(key->payload.data[0]);
}


/*
 * keytype for CIFS spnego keys
 */
struct key_type cifs_spnego_key_type = {
	.name		= "cifs.spnego",
	.instantiate	= cifs_spnego_key_instantiate,
	.destroy	= cifs_spnego_key_destroy,
	.describe	= user_describe,
};

/* length of longest version string e.g.  strlen("ver=0xFF") */
#define MAX_VER_STR_LEN		8

/* length of longest security mechanism name, eg in future could have
 * strlen(";sec=ntlmsspi") */
#define MAX_MECH_STR_LEN	13

/* strlen of "host=" */
#define HOST_KEY_LEN		5

/* strlen of ";ip4=" or ";ip6=" */
#define IP_KEY_LEN		5

/* strlen of ";uid=0x" */
#define UID_KEY_LEN		7

/* strlen of ";creduid=0x" */
#define CREDUID_KEY_LEN		11

/* strlen of ";user=" */
#define USER_KEY_LEN		6

/* strlen of ";pid=0x" */
#define PID_KEY_LEN		7

/* get a key struct with a SPNEGO security blob, suitable for session setup */
struct key *
cifs_get_spnego_key(struct cifs_ses *sesInfo)
{
	struct TCP_Server_Info *server = sesInfo->server;
	struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr;
	struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr;
	char *description, *dp;
	size_t desc_len;
	struct key *spnego_key;
	const char *hostname = server->hostname;
	const struct cred *saved_cred;

	/* length of fields (with semicolons): ver=0xyz ip4=ipaddress
	   host=hostname sec=mechanism uid=0xFF user=username */
	desc_len = MAX_VER_STR_LEN +
		   HOST_KEY_LEN + strlen(hostname) +
		   IP_KEY_LEN + INET6_ADDRSTRLEN +
		   MAX_MECH_STR_LEN +
		   UID_KEY_LEN + (sizeof(uid_t) * 2) +
		   CREDUID_KEY_LEN + (sizeof(uid_t) * 2) +
		   PID_KEY_LEN + (sizeof(pid_t) * 2) + 1;

	if (sesInfo->user_name)
		desc_len += USER_KEY_LEN + strlen(sesInfo->user_name);

	spnego_key = ERR_PTR(-ENOMEM);
	description = kzalloc(desc_len, GFP_KERNEL);
	if (description == NULL)
		goto out;

	dp = description;
	/* start with version and hostname portion of UNC string */
	spnego_key = ERR_PTR(-EINVAL);
	sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
		hostname);
	dp = description + strlen(description);

	/* add the server address */
	if (server->dstaddr.ss_family == AF_INET)
		sprintf(dp, "ip4=%pI4", &sa->sin_addr);
	else if (server->dstaddr.ss_family == AF_INET6)
		sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);
	else
		goto out;

	dp = description + strlen(description);

	/* for now, only sec=krb5 and sec=mskrb5 are valid */
	if (server->sec_kerberos)
		sprintf(dp, ";sec=krb5");
	else if (server->sec_mskerberos)
		sprintf(dp, ";sec=mskrb5");
	else
		goto out;

	dp = description + strlen(description);
	sprintf(dp, ";uid=0x%x",
		from_kuid_munged(&init_user_ns, sesInfo->linux_uid));

	dp = description + strlen(description);
	sprintf(dp, ";creduid=0x%x",
		from_kuid_munged(&init_user_ns, sesInfo->cred_uid));

	if (sesInfo->user_name) {
		dp = description + strlen(description);
		sprintf(dp, ";user=%s", sesInfo->user_name);
	}

	dp = description + strlen(description);
	sprintf(dp, ";pid=0x%x", current->pid);

	cifs_dbg(FYI, "key description = %s\n", description);
	saved_cred = override_creds(spnego_cred);
	spnego_key = request_key(&cifs_spnego_key_type, description, "");
	revert_creds(saved_cred);

#ifdef CONFIG_CIFS_DEBUG2
	if (cifsFYI && !IS_ERR(spnego_key)) {
		struct cifs_spnego_msg *msg = spnego_key->payload.data[0];
		cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U,
				msg->secblob_len + msg->sesskey_len));
	}
#endif /* CONFIG_CIFS_DEBUG2 */

out:
	kfree(description);
	return spnego_key;
}

int
init_cifs_spnego(void)
{
	struct cred *cred;
	struct key *keyring;
	int ret;

	cifs_dbg(FYI, "Registering the %s key type\n",
		 cifs_spnego_key_type.name);

	/*
	 * Create an override credential set with special thread keyring for
	 * spnego upcalls.
	 */

	cred = prepare_kernel_cred(NULL);
	if (!cred)
		return -ENOMEM;

	keyring = keyring_alloc(".cifs_spnego",
				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
				KEY_USR_VIEW | KEY_USR_READ,
				KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
	if (IS_ERR(keyring)) {
		ret = PTR_ERR(keyring);
		goto failed_put_cred;
	}

	ret = register_key_type(&cifs_spnego_key_type);
	if (ret < 0)
		goto failed_put_key;

	/*
	 * instruct request_key() to use this special keyring as a cache for
	 * the results it looks up
	 */
	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
	cred->thread_keyring = keyring;
	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
	spnego_cred = cred;

	cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring));
	return 0;

failed_put_key:
	key_put(keyring);
failed_put_cred:
	put_cred(cred);
	return ret;
}

void
exit_cifs_spnego(void)
{
	key_revoke(spnego_cred->thread_keyring);
	unregister_key_type(&cifs_spnego_key_type);
	put_cred(spnego_cred);
	cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name);
}
Commit	Line	Data
f1d662a7 SF	1	/*
	2	* fs/cifs/cifs_spnego.c -- SPNEGO upcall management for CIFS
	3	*
	4	* Copyright (c) 2007 Red Hat, Inc.
	5	* Author(s): Jeff Layton (jlayton@redhat.com)
	6	*
	7	* This library is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU Lesser General Public License as published
	9	* by the Free Software Foundation; either version 2.1 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This library is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
	15	* the GNU Lesser General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU Lesser General Public License
	18	* along with this library; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21
	22	#include <linux/list.h>
5a0e3ad6	23	#include <linux/slab.h>
f1d662a7 SF	24	#include <linux/string.h>
	25	#include <keys/user-type.h>
	26	#include <linux/key-type.h>
b74cb9a8	27	#include <linux/keyctl.h>
50b64e3b	28	#include <linux/inet.h>
f1d662a7 SF	29	#include "cifsglob.h"
	30	#include "cifs_spnego.h"
	31	#include "cifs_debug.h"
b74cb9a8 SP	32	#include "cifsproto.h"
b74cb9a8 SP	33	static const struct cred *spnego_cred;
f1d662a7 SF	34
	35	/* create a new cifs key */
	36	static int
cf7f601c	37	cifs_spnego_key_instantiate(struct key key, struct key_preparsed_payload prep)
f1d662a7 SF	38	{
	39	char *payload;
	40	int ret;
	41
	42	ret = -ENOMEM;
f7f7c185	43	payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL);
f1d662a7 SF	44	if (!payload)
	45	goto error;
	46
	47	/* attach the data */
146aa8b1	48	key->payload.data[0] = payload;
f1d662a7 SF	49	ret = 0;
	50
	51	error:
	52	return ret;
	53	}
	54
	55	static void
	56	cifs_spnego_key_destroy(struct key *key)
	57	{
146aa8b1	58	kfree(key->payload.data[0]);
f1d662a7 SF	59	}
	60
	61
	62	/*
	63	* keytype for CIFS spnego keys
	64	*/
	65	struct key_type cifs_spnego_key_type = {
	66	.name = "cifs.spnego",
	67	.instantiate = cifs_spnego_key_instantiate,
f1d662a7 SF	68	.destroy = cifs_spnego_key_destroy,
	69	.describe = user_describe,
	70	};
	71
7c9c3760 SF	72	/* length of longest version string e.g. strlen("ver=0xFF") */
	73	#define MAX_VER_STR_LEN 8
	74
	75	/* length of longest security mechanism name, eg in future could have
	76	* strlen(";sec=ntlmsspi") */
	77	#define MAX_MECH_STR_LEN 13
	78
7c9c3760 SF	79	/* strlen of "host=" */
	80	#define HOST_KEY_LEN 5
	81
	82	/* strlen of ";ip4=" or ";ip6=" */
	83	#define IP_KEY_LEN 5
	84
	85	/* strlen of ";uid=0x" */
	86	#define UID_KEY_LEN 7
	87
ba5dadbf JL	88	/* strlen of ";creduid=0x" */
	89	#define CREDUID_KEY_LEN 11
	90
7c9c3760 SF	91	/* strlen of ";user=" */
	92	#define USER_KEY_LEN 6
	93
c4c1bff6 JL	94	/* strlen of ";pid=0x" */
	95	#define PID_KEY_LEN 7
	96
f1d662a7 SF	97	/* get a key struct with a SPNEGO security blob, suitable for session setup */
f1d662a7 SF	98	struct key *
96daf2b0	99	cifs_get_spnego_key(struct cifs_ses *sesInfo)
f1d662a7 SF	100	{
f1d662a7 SF	101	struct TCP_Server_Info *server = sesInfo->server;
a9f1b85e PS	102	struct sockaddr_in sa = (struct sockaddr_in ) &server->dstaddr;
a9f1b85e PS	103	struct sockaddr_in6 sa6 = (struct sockaddr_in6 ) &server->dstaddr;
f1d662a7 SF	104	char description, dp;
	105	size_t desc_len;
	106	struct key *spnego_key;
d6c2e4d0	107	const char *hostname = server->hostname;
b74cb9a8	108	const struct cred *saved_cred;
f1d662a7	109
66b8bd3c JL	110	/* length of fields (with semicolons): ver=0xyz ip4=ipaddress
	111	host=hostname sec=mechanism uid=0xFF user=username */
	112	desc_len = MAX_VER_STR_LEN +
7c9c3760	113	HOST_KEY_LEN + strlen(hostname) +
50b64e3b	114	IP_KEY_LEN + INET6_ADDRSTRLEN +
66b8bd3c	115	MAX_MECH_STR_LEN +
7c9c3760	116	UID_KEY_LEN + (sizeof(uid_t) * 2) +
ba5dadbf	117	CREDUID_KEY_LEN + (sizeof(uid_t) * 2) +
c4c1bff6	118	PID_KEY_LEN + (sizeof(pid_t) * 2) + 1;
66b8bd3c	119
04febabc JL	120	if (sesInfo->user_name)
	121	desc_len += USER_KEY_LEN + strlen(sesInfo->user_name);
	122
f1d662a7 SF	123	spnego_key = ERR_PTR(-ENOMEM);
	124	description = kzalloc(desc_len, GFP_KERNEL);
	125	if (description == NULL)
	126	goto out;
	127
	128	dp = description;
	129	/* start with version and hostname portion of UNC string */
	130	spnego_key = ERR_PTR(-EINVAL);
68bf728a	131	sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
f1d662a7 SF	132	hostname);
	133	dp = description + strlen(description);
	134
	135	/* add the server address */
a9f1b85e PS	136	if (server->dstaddr.ss_family == AF_INET)
	137	sprintf(dp, "ip4=%pI4", &sa->sin_addr);
	138	else if (server->dstaddr.ss_family == AF_INET6)
	139	sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);
f1d662a7 SF	140	else
	141	goto out;
	142
	143	dp = description + strlen(description);
	144
c16fefa5	145	/* for now, only sec=krb5 and sec=mskrb5 are valid */
26efa0ba	146	if (server->sec_kerberos)
f1d662a7	147	sprintf(dp, ";sec=krb5");
26efa0ba	148	else if (server->sec_mskerberos)
c16fefa5	149	sprintf(dp, ";sec=mskrb5");
f1d662a7 SF	150	else
	151	goto out;
	152
9eae8a89	153	dp = description + strlen(description);
64ed39dd EB	154	sprintf(dp, ";uid=0x%x",
64ed39dd EB	155	from_kuid_munged(&init_user_ns, sesInfo->linux_uid));
9eae8a89	156
3e4b3e1f	157	dp = description + strlen(description);
64ed39dd EB	158	sprintf(dp, ";creduid=0x%x",
64ed39dd EB	159	from_kuid_munged(&init_user_ns, sesInfo->cred_uid));
3e4b3e1f	160
04febabc JL	161	if (sesInfo->user_name) {
	162	dp = description + strlen(description);
	163	sprintf(dp, ";user=%s", sesInfo->user_name);
	164	}
e4058245	165
c4c1bff6 JL	166	dp = description + strlen(description);
	167	sprintf(dp, ";pid=0x%x", current->pid);
	168
f96637be	169	cifs_dbg(FYI, "key description = %s\n", description);
b74cb9a8	170	saved_cred = override_creds(spnego_cred);
f1d662a7	171	spnego_key = request_key(&cifs_spnego_key_type, description, "");
b74cb9a8	172	revert_creds(saved_cred);
f1d662a7	173
05b3de63	174	#ifdef CONFIG_CIFS_DEBUG2
f1d662a7	175	if (cifsFYI && !IS_ERR(spnego_key)) {
146aa8b1	176	struct cifs_spnego_msg *msg = spnego_key->payload.data[0];
ead03e30	177	cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U,
05b3de63	178	msg->secblob_len + msg->sesskey_len));
f1d662a7	179	}
05b3de63	180	#endif /* CONFIG_CIFS_DEBUG2 */
f1d662a7 SF	181
	182	out:
	183	kfree(description);
	184	return spnego_key;
	185	}
b74cb9a8 SP	186
	187	int
	188	init_cifs_spnego(void)
	189	{
	190	struct cred *cred;
	191	struct key *keyring;
	192	int ret;
	193
	194	cifs_dbg(FYI, "Registering the %s key type\n",
	195	cifs_spnego_key_type.name);
	196
	197	/*
	198	* Create an override credential set with special thread keyring for
	199	* spnego upcalls.
	200	*/
	201
	202	cred = prepare_kernel_cred(NULL);
	203	if (!cred)
	204	return -ENOMEM;
	205
	206	keyring = keyring_alloc(".cifs_spnego",
	207	GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
	208	(KEY_POS_ALL & ~KEY_POS_SETATTR) \|
	209	KEY_USR_VIEW \| KEY_USR_READ,
	210	KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
	211	if (IS_ERR(keyring)) {
	212	ret = PTR_ERR(keyring);
	213	goto failed_put_cred;
	214	}
	215
	216	ret = register_key_type(&cifs_spnego_key_type);
	217	if (ret < 0)
	218	goto failed_put_key;
	219
	220	/*
	221	* instruct request_key() to use this special keyring as a cache for
	222	* the results it looks up
	223	*/
	224	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
	225	cred->thread_keyring = keyring;
	226	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
	227	spnego_cred = cred;
	228
	229	cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring));
	230	return 0;
	231
	232	failed_put_key:
	233	key_put(keyring);
	234	failed_put_cred:
	235	put_cred(cred);
	236	return ret;
	237	}
	238
	239	void
	240	exit_cifs_spnego(void)
	241	{
	242	key_revoke(spnego_cred->thread_keyring);
	243	unregister_key_type(&cifs_spnego_key_type);
	244	put_cred(spnego_cred);
	245	cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name);
	246	}