[deliverable/linux.git] / drivers / staging / lustre / lustre / ptlrpc / gss / gss_generic_token.c

/*
 * Modifications for Lustre
 *
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * Copyright (c) 2011, Intel Corporation.
 *
 * Author: Eric Mei <ericm@clusterfs.com>
 */

/*
 *  linux/net/sunrpc/gss_generic_token.c
 *
 *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/generic/util_token.c
 *
 *  Copyright (c) 2000 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Andy Adamson   <andros@umich.edu>
 */

/*
 * Copyright 1993 by OpenVision Technologies, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of OpenVision not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. OpenVision makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#define DEBUG_SUBSYSTEM S_SEC
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mutex.h>

#include <obd.h>
#include <obd_class.h>
#include <obd_support.h>
#include <lustre/lustre_idl.h>
#include <lustre_net.h>
#include <lustre_import.h>
#include <lustre_sec.h>

#include "gss_err.h"
#include "gss_internal.h"
#include "gss_api.h"
#include "gss_krb5.h"
#include "gss_asn1.h"


/* TWRITE_STR from gssapiP_generic.h */
#define TWRITE_STR(ptr, str, len) \
	memcpy((ptr), (char *) (str), (len)); \
	(ptr) += (len);

/* XXXX this code currently makes the assumption that a mech oid will
   never be longer than 127 bytes.  This assumption is not inherent in
   the interfaces, so the code can be fixed if the OSI namespace
   balloons unexpectedly. */

/* Each token looks like this:

0x60				tag for APPLICATION 0, SEQUENCE
					(constructed, definite-length)
	<length>		possible multiple bytes, need to parse/generate
	0x06			tag for OBJECT IDENTIFIER
		<moid_length>	compile-time constant string (assume 1 byte)
		<moid_bytes>	compile-time constant string
	<inner_bytes>		the ANY containing the application token
					bytes 0,1 are the token type
					bytes 2,n are the token data

For the purposes of this abstraction, the token "header" consists of
the sequence tag and length octets, the mech OID DER encoding, and the
first two inner bytes, which indicate the token type.  The token
"body" consists of everything else.

*/

static
int der_length_size(int length)
{
	if (length < (1 << 7))
		return 1;
	else if (length < (1 << 8))
		return 2;
#if (SIZEOF_INT == 2)
	else
		return 3;
#else
	else if (length < (1 << 16))
		return 3;
	else if (length < (1 << 24))
		return 4;
	else
		return 5;
#endif
}

static
void der_write_length(unsigned char **buf, int length)
{
	if (length < (1 << 7)) {
		*(*buf)++ = (unsigned char) length;
	} else {
		*(*buf)++ = (unsigned char) (der_length_size(length) + 127);
#if (SIZEOF_INT > 2)
		if (length >= (1 << 24))
			*(*buf)++ = (unsigned char) (length >> 24);
		if (length >= (1 << 16))
			*(*buf)++ = (unsigned char) ((length >> 16) & 0xff);
#endif
		if (length >= (1 << 8))
			*(*buf)++ = (unsigned char) ((length >> 8) & 0xff);
		*(*buf)++ = (unsigned char) (length & 0xff);
	}
}

/*
 * returns decoded length, or < 0 on failure.  Advances buf and
 * decrements bufsize
 */
static
int der_read_length(unsigned char **buf, int *bufsize)
{
	unsigned char sf;
	int ret;

	if (*bufsize < 1)
		return -1;
	sf = *(*buf)++;
	(*bufsize)--;
	if (sf & 0x80) {
		if ((sf &= 0x7f) > ((*bufsize) - 1))
			return -1;
		if (sf > SIZEOF_INT)
			return -1;
		ret = 0;
		for (; sf; sf--) {
			ret = (ret << 8) + (*(*buf)++);
			(*bufsize)--;
		}
	} else {
		ret = sf;
	}

	return ret;
}

/*
 * returns the length of a token, given the mech oid and the body size
 */
int g_token_size(rawobj_t *mech, unsigned int body_size)
{
	/* set body_size to sequence contents size */
	body_size += 4 + (int) mech->len; /* NEED overflow check */
	return (1 + der_length_size(body_size) + body_size);
}

/*
 * fills in a buffer with the token header.  The buffer is assumed to
 * be the right size.  buf is advanced past the token header
 */
void g_make_token_header(rawobj_t *mech, int body_size, unsigned char **buf)
{
	*(*buf)++ = 0x60;
	der_write_length(buf, 4 + mech->len + body_size);
	*(*buf)++ = 0x06;
	*(*buf)++ = (unsigned char) mech->len;
	TWRITE_STR(*buf, mech->data, ((int) mech->len));
}

/*
 * Given a buffer containing a token, reads and verifies the token,
 * leaving buf advanced past the token header, and setting body_size
 * to the number of remaining bytes.  Returns 0 on success,
 * G_BAD_TOK_HEADER for a variety of errors, and G_WRONG_MECH if the
 * mechanism in the token does not match the mech argument.  buf and
 * *body_size are left unmodified on error.
 */
__u32 g_verify_token_header(rawobj_t *mech, int *body_size,
			    unsigned char **buf_in, int toksize)
{
	unsigned char *buf = *buf_in;
	int seqsize;
	rawobj_t toid;
	int ret = 0;

	if ((toksize -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	if (*buf++ != 0x60)
		return (G_BAD_TOK_HEADER);

	if ((seqsize = der_read_length(&buf, &toksize)) < 0)
		return(G_BAD_TOK_HEADER);

	if (seqsize != toksize)
		return (G_BAD_TOK_HEADER);

	if ((toksize -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	if (*buf++ != 0x06)
		return (G_BAD_TOK_HEADER);

	if ((toksize -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	toid.len = *buf++;

	if ((toksize -= toid.len) < 0)
		return (G_BAD_TOK_HEADER);
	toid.data = buf;
	buf += toid.len;

	if (!g_OID_equal(&toid, mech))
		ret = G_WRONG_MECH;

	/* G_WRONG_MECH is not returned immediately because it's more
	 * important to return G_BAD_TOK_HEADER if the token header is
	 * in fact bad
	 */
	if ((toksize -= 2) < 0)
		return (G_BAD_TOK_HEADER);

	if (ret)
		return (ret);

	if (!ret) {
		*buf_in = buf;
		*body_size = toksize;
	}

	return (ret);
}

/*
 * Given a buffer containing a token, returns a copy of the mech oid in
 * the parameter mech.
 */
__u32 g_get_mech_oid(rawobj_t *mech, rawobj_t *in_buf)
{
	unsigned char *buf = in_buf->data;
	int len = in_buf->len;
	int ret = 0;
	int seqsize;

	if ((len -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	if (*buf++ != 0x60)
		return (G_BAD_TOK_HEADER);

	if ((seqsize = der_read_length(&buf, &len)) < 0)
		return (G_BAD_TOK_HEADER);

	if ((len -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	if (*buf++ != 0x06)
		return (G_BAD_TOK_HEADER);

	if ((len -= 1) < 0)
		return (G_BAD_TOK_HEADER);
	mech->len = *buf++;

	if ((len -= mech->len) < 0)
		return (G_BAD_TOK_HEADER);
	OBD_ALLOC_LARGE(mech->data, mech->len);
	if (!mech->data)
		return (G_BUFFER_ALLOC);
	memcpy(mech->data, buf, mech->len);

	return ret;
}
Commit	Line	Data
d7e09d03 PT	1	/*
	2	* Modifications for Lustre
	3	*
	4	* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
	5	*
	6	* Copyright (c) 2011, Intel Corporation.
	7	*
	8	* Author: Eric Mei <ericm@clusterfs.com>
	9	*/
	10
	11	/*
	12	* linux/net/sunrpc/gss_generic_token.c
	13	*
	14	* Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/generic/util_token.c
	15	*
	16	* Copyright (c) 2000 The Regents of the University of Michigan.
	17	* All rights reserved.
	18	*
	19	* Andy Adamson <andros@umich.edu>
	20	*/
	21
	22	/*
	23	* Copyright 1993 by OpenVision Technologies, Inc.
	24	*
	25	* Permission to use, copy, modify, distribute, and sell this software
	26	* and its documentation for any purpose is hereby granted without fee,
	27	* provided that the above copyright notice appears in all copies and
	28	* that both that copyright notice and this permission notice appear in
	29	* supporting documentation, and that the name of OpenVision not be used
	30	* in advertising or publicity pertaining to distribution of the software
	31	* without specific, written prior permission. OpenVision makes no
	32	* representations about the suitability of this software for any
	33	* purpose. It is provided "as is" without express or implied warranty.
	34	*
	35	* OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	36	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	37	* EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	38	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
	39	* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
	40	* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
	41	* PERFORMANCE OF THIS SOFTWARE.
	42	*/
	43
	44	#define DEBUG_SUBSYSTEM S_SEC
d7e09d03 PT	45	#include <linux/module.h>
	46	#include <linux/slab.h>
	47	#include <linux/mutex.h>
	48
	49	#include <obd.h>
	50	#include <obd_class.h>
	51	#include <obd_support.h>
	52	#include <lustre/lustre_idl.h>
	53	#include <lustre_net.h>
	54	#include <lustre_import.h>
	55	#include <lustre_sec.h>
	56
	57	#include "gss_err.h"
	58	#include "gss_internal.h"
	59	#include "gss_api.h"
	60	#include "gss_krb5.h"
	61	#include "gss_asn1.h"
	62
	63
	64	/* TWRITE_STR from gssapiP_generic.h */
	65	#define TWRITE_STR(ptr, str, len) \
	66	memcpy((ptr), (char *) (str), (len)); \
	67	(ptr) += (len);
	68
	69	/* XXXX this code currently makes the assumption that a mech oid will
	70	never be longer than 127 bytes. This assumption is not inherent in
	71	the interfaces, so the code can be fixed if the OSI namespace
	72	balloons unexpectedly. */
	73
	74	/* Each token looks like this:
	75
	76	0x60 tag for APPLICATION 0, SEQUENCE
	77	(constructed, definite-length)
	78	<length> possible multiple bytes, need to parse/generate
	79	0x06 tag for OBJECT IDENTIFIER
	80	<moid_length> compile-time constant string (assume 1 byte)
	81	<moid_bytes> compile-time constant string
	82	<inner_bytes> the ANY containing the application token
	83	bytes 0,1 are the token type
	84	bytes 2,n are the token data
	85
	86	For the purposes of this abstraction, the token "header" consists of
	87	the sequence tag and length octets, the mech OID DER encoding, and the
	88	first two inner bytes, which indicate the token type. The token
	89	"body" consists of everything else.
	90
	91	*/
	92
	93	static
	94	int der_length_size(int length)
	95	{
	96	if (length < (1 << 7))
	97	return 1;
	98	else if (length < (1 << 8))
	99	return 2;
	100	#if (SIZEOF_INT == 2)
	101	else
	102	return 3;
	103	#else
	104	else if (length < (1 << 16))
	105	return 3;
	106	else if (length < (1 << 24))
	107	return 4;
	108	else
109	return 5;
110	#endif
111	}
112
113	static
114	void der_write_length(unsigned char **buf, int length)
115	{
116	if (length < (1 << 7)) {
117	(buf)++ = (unsigned char) length;
118	} else {
119	(buf)++ = (unsigned char) (der_length_size(length) + 127);
120	#if (SIZEOF_INT > 2)
121	if (length >= (1 << 24))
122	(buf)++ = (unsigned char) (length >> 24);
123	if (length >= (1 << 16))
124	(buf)++ = (unsigned char) ((length >> 16) & 0xff);
125	#endif
126	if (length >= (1 << 8))
127	(buf)++ = (unsigned char) ((length >> 8) & 0xff);
128	(buf)++ = (unsigned char) (length & 0xff);
129	}
130	}
131
132	/*
133	* returns decoded length, or < 0 on failure. Advances buf and
134	* decrements bufsize
135	*/
136	static
137	int der_read_length(unsigned char *buf, int bufsize)
138	{
139	unsigned char sf;
140	int ret;
141
142	if (*bufsize < 1)
143	return -1;
144	sf = (buf)++;
145	(*bufsize)--;
146	if (sf & 0x80) {
147	if ((sf &= 0x7f) > ((*bufsize) - 1))
148	return -1;
149	if (sf > SIZEOF_INT)
150	return -1;
151	ret = 0;
152	for (; sf; sf--) {
153	ret = (ret << 8) + ((buf)++);
154	(*bufsize)--;
155	}
156	} else {
157	ret = sf;
158	}
159
160	return ret;
161	}
162
163	/*
164	* returns the length of a token, given the mech oid and the body size
165	*/
166	int g_token_size(rawobj_t *mech, unsigned int body_size)
167	{
168	/* set body_size to sequence contents size */
169	body_size += 4 + (int) mech->len; /* NEED overflow check */
170	return (1 + der_length_size(body_size) + body_size);
171	}
172
173	/*
174	* fills in a buffer with the token header. The buffer is assumed to
175	* be the right size. buf is advanced past the token header
176	*/
177	void g_make_token_header(rawobj_t mech, int body_size, unsigned char *buf)
178	{
179	(buf)++ = 0x60;
180	der_write_length(buf, 4 + mech->len + body_size);
181	(buf)++ = 0x06;
182	(buf)++ = (unsigned char) mech->len;
183	TWRITE_STR(*buf, mech->data, ((int) mech->len));
184	}
185
186	/*
187	* Given a buffer containing a token, reads and verifies the token,
188	* leaving buf advanced past the token header, and setting body_size
189	* to the number of remaining bytes. Returns 0 on success,
190	* G_BAD_TOK_HEADER for a variety of errors, and G_WRONG_MECH if the
191	* mechanism in the token does not match the mech argument. buf and
192	* *body_size are left unmodified on error.
193	*/
194	__u32 g_verify_token_header(rawobj_t mech, int body_size,
195	unsigned char **buf_in, int toksize)
196	{
197	unsigned char buf = buf_in;
198	int seqsize;
199	rawobj_t toid;
200	int ret = 0;
201
202	if ((toksize -= 1) < 0)
203	return (G_BAD_TOK_HEADER);
204	if (*buf++ != 0x60)
205	return (G_BAD_TOK_HEADER);
206
207	if ((seqsize = der_read_length(&buf, &toksize)) < 0)
208	return(G_BAD_TOK_HEADER);
209
210	if (seqsize != toksize)
211	return (G_BAD_TOK_HEADER);
212
213	if ((toksize -= 1) < 0)
214	return (G_BAD_TOK_HEADER);
215	if (*buf++ != 0x06)
216	return (G_BAD_TOK_HEADER);
217
218	if ((toksize -= 1) < 0)
219	return (G_BAD_TOK_HEADER);
220	toid.len = *buf++;
221
222	if ((toksize -= toid.len) < 0)
223	return (G_BAD_TOK_HEADER);
224	toid.data = buf;
225	buf += toid.len;
226
227	if (!g_OID_equal(&toid, mech))
228	ret = G_WRONG_MECH;
229
230	/* G_WRONG_MECH is not returned immediately because it's more
231	* important to return G_BAD_TOK_HEADER if the token header is
232	* in fact bad
233	*/
234	if ((toksize -= 2) < 0)
235	return (G_BAD_TOK_HEADER);
236
237	if (ret)
238	return (ret);
239
240	if (!ret) {
241	*buf_in = buf;
242	*body_size = toksize;
243	}
244
245	return (ret);
246	}
247
248	/*
249	* Given a buffer containing a token, returns a copy of the mech oid in
250	* the parameter mech.
251	*/
252	__u32 g_get_mech_oid(rawobj_t mech, rawobj_t in_buf)
253	{
254	unsigned char *buf = in_buf->data;
255	int len = in_buf->len;
256	int ret = 0;
257	int seqsize;
258
259	if ((len -= 1) < 0)
260	return (G_BAD_TOK_HEADER);
261	if (*buf++ != 0x60)
262	return (G_BAD_TOK_HEADER);
263
264	if ((seqsize = der_read_length(&buf, &len)) < 0)
265	return (G_BAD_TOK_HEADER);
266
267	if ((len -= 1) < 0)
268	return (G_BAD_TOK_HEADER);
269	if (*buf++ != 0x06)
270	return (G_BAD_TOK_HEADER);
271
272	if ((len -= 1) < 0)
273	return (G_BAD_TOK_HEADER);
274	mech->len = *buf++;
275
276	if ((len -= mech->len) < 0)
277	return (G_BAD_TOK_HEADER);
278	OBD_ALLOC_LARGE(mech->data, mech->len);
279	if (!mech->data)
280	return (G_BUFFER_ALLOC);
281	memcpy(mech->data, buf, mech->len);
282
283	return ret;
284	}