[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 ([email protected])
 *
 *   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/string.h>
#include <keys/user-type.h>
#include <linux/key-type.h>
#include "cifsglob.h"
#include "cifs_spnego.h"
#include "cifs_debug.h"

/* create a new cifs key */
static int
cifs_spnego_key_instantiate(struct key *key, const void *data, size_t datalen)
{
	char *payload;
	int ret;

	ret = -ENOMEM;
	payload = kmalloc(datalen, GFP_KERNEL);
	if (!payload)
		goto error;

	/* attach the data */
	memcpy(payload, data, datalen);
	key->payload.data = payload;
	ret = 0;

error:
	return ret;
}

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


/*
 * keytype for CIFS spnego keys
 */
struct key_type cifs_spnego_key_type = {
	.name		= "cifs.spnego",
	.instantiate	= cifs_spnego_key_instantiate,
	.match		= user_match,
	.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

/* max possible addr len eg FEDC:BA98:7654:3210:FEDC:BA98:7654:3210/128 */
#define MAX_IPV6_ADDR_LEN	43

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

/* get a key struct with a SPNEGO security blob, suitable for session setup */
struct key *
cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
{
	struct TCP_Server_Info *server = sesInfo->server;
	char *description, *dp;
	size_t desc_len;
	struct key *spnego_key;
	const char *hostname = server->hostname;

	/* 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 + MAX_IPV6_ADDR_LEN +
		   MAX_MECH_STR_LEN +
		   UID_KEY_LEN + (sizeof(uid_t) * 2) +
		   USER_KEY_LEN + strlen(sesInfo->userName) + 1;

	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->addr.sockAddr.sin_family == AF_INET)
		sprintf(dp, "ip4=%pI4", &server->addr.sockAddr.sin_addr);
	else if (server->addr.sockAddr.sin_family == AF_INET6)
		sprintf(dp, "ip6=%pi6", &server->addr.sockAddr6.sin6_addr);
	else
		goto out;

	dp = description + strlen(description);

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

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

	dp = description + strlen(description);
	sprintf(dp, ";user=%s", sesInfo->userName);

	cFYI(1, ("key description = %s", description));
	spnego_key = request_key(&cifs_spnego_key_type, description, "");

#ifdef CONFIG_CIFS_DEBUG2
	if (cifsFYI && !IS_ERR(spnego_key)) {
		struct cifs_spnego_msg *msg = spnego_key->payload.data;
		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;
}
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 ([email protected])
	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>
	23	#include <linux/string.h>
	24	#include <keys/user-type.h>
	25	#include <linux/key-type.h>
	26	#include "cifsglob.h"
	27	#include "cifs_spnego.h"
	28	#include "cifs_debug.h"
	29
	30	/* create a new cifs key */
	31	static int
	32	cifs_spnego_key_instantiate(struct key key, const void data, size_t datalen)
	33	{
	34	char *payload;
	35	int ret;
	36
	37	ret = -ENOMEM;
	38	payload = kmalloc(datalen, GFP_KERNEL);
	39	if (!payload)
	40	goto error;
	41
	42	/* attach the data */
	43	memcpy(payload, data, datalen);
d9fb5c09	44	key->payload.data = payload;
f1d662a7 SF	45	ret = 0;
	46
	47	error:
	48	return ret;
	49	}
	50
	51	static void
	52	cifs_spnego_key_destroy(struct key *key)
	53	{
	54	kfree(key->payload.data);
	55	}
	56
	57
	58	/*
	59	* keytype for CIFS spnego keys
	60	*/
	61	struct key_type cifs_spnego_key_type = {
	62	.name = "cifs.spnego",
	63	.instantiate = cifs_spnego_key_instantiate,
	64	.match = user_match,
	65	.destroy = cifs_spnego_key_destroy,
	66	.describe = user_describe,
	67	};
	68
7c9c3760 SF	69	/* length of longest version string e.g. strlen("ver=0xFF") */
	70	#define MAX_VER_STR_LEN 8
	71
	72	/* length of longest security mechanism name, eg in future could have
	73	* strlen(";sec=ntlmsspi") */
	74	#define MAX_MECH_STR_LEN 13
	75
3ec332ef SF	76	/* max possible addr len eg FEDC:BA98:7654:3210:FEDC:BA98:7654:3210/128 */
3ec332ef SF	77	#define MAX_IPV6_ADDR_LEN 43
7c9c3760 SF	78
	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
	88	/* strlen of ";user=" */
	89	#define USER_KEY_LEN 6
	90
f1d662a7 SF	91	/* get a key struct with a SPNEGO security blob, suitable for session setup */
f1d662a7 SF	92	struct key *
d6c2e4d0	93	cifs_get_spnego_key(struct cifsSesInfo *sesInfo)
f1d662a7 SF	94	{
	95	struct TCP_Server_Info *server = sesInfo->server;
	96	char description, dp;
	97	size_t desc_len;
	98	struct key *spnego_key;
d6c2e4d0	99	const char *hostname = server->hostname;
f1d662a7	100
66b8bd3c JL	101	/* length of fields (with semicolons): ver=0xyz ip4=ipaddress
	102	host=hostname sec=mechanism uid=0xFF user=username */
	103	desc_len = MAX_VER_STR_LEN +
7c9c3760 SF	104	HOST_KEY_LEN + strlen(hostname) +
7c9c3760 SF	105	IP_KEY_LEN + MAX_IPV6_ADDR_LEN +
66b8bd3c	106	MAX_MECH_STR_LEN +
7c9c3760 SF	107	UID_KEY_LEN + (sizeof(uid_t) * 2) +
7c9c3760 SF	108	USER_KEY_LEN + strlen(sesInfo->userName) + 1;
66b8bd3c	109
f1d662a7 SF	110	spnego_key = ERR_PTR(-ENOMEM);
	111	description = kzalloc(desc_len, GFP_KERNEL);
	112	if (description == NULL)
	113	goto out;
	114
	115	dp = description;
	116	/* start with version and hostname portion of UNC string */
	117	spnego_key = ERR_PTR(-EINVAL);
68bf728a	118	sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,
f1d662a7 SF	119	hostname);
	120	dp = description + strlen(description);
	121
	122	/* add the server address */
	123	if (server->addr.sockAddr.sin_family == AF_INET)
be859405	124	sprintf(dp, "ip4=%pI4", &server->addr.sockAddr.sin_addr);
f1d662a7	125	else if (server->addr.sockAddr.sin_family == AF_INET6)
4b7a4274	126	sprintf(dp, "ip6=%pi6", &server->addr.sockAddr6.sin6_addr);
f1d662a7 SF	127	else
	128	goto out;
	129
	130	dp = description + strlen(description);
	131
c16fefa5	132	/* for now, only sec=krb5 and sec=mskrb5 are valid */
f1d662a7 SF	133	if (server->secType == Kerberos)
f1d662a7 SF	134	sprintf(dp, ";sec=krb5");
c16fefa5 SF	135	else if (server->secType == MSKerberos)
c16fefa5 SF	136	sprintf(dp, ";sec=mskrb5");
f1d662a7 SF	137	else
	138	goto out;
	139
9eae8a89 IM	140	dp = description + strlen(description);
	141	sprintf(dp, ";uid=0x%x", sesInfo->linux_uid);
	142
e4058245 IM	143	dp = description + strlen(description);
	144	sprintf(dp, ";user=%s", sesInfo->userName);
	145
f1d662a7 SF	146	cFYI(1, ("key description = %s", description));
	147	spnego_key = request_key(&cifs_spnego_key_type, description, "");
	148
05b3de63	149	#ifdef CONFIG_CIFS_DEBUG2
f1d662a7 SF	150	if (cifsFYI && !IS_ERR(spnego_key)) {
f1d662a7 SF	151	struct cifs_spnego_msg *msg = spnego_key->payload.data;
ead03e30	152	cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U,
05b3de63	153	msg->secblob_len + msg->sesskey_len));
f1d662a7	154	}
05b3de63	155	#endif /* CONFIG_CIFS_DEBUG2 */
f1d662a7 SF	156
	157	out:
	158	kfree(description);
	159	return spnego_key;
	160	}