[deliverable/linux.git] / net / sunrpc / auth_gss / gss_krb5_unseal.c

/*
 *  linux/net/sunrpc/gss_krb5_unseal.c
 *
 *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.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.
 */

/*
 * Copyright (C) 1998 by the FundsXpress, INC.
 *
 * All rights reserved.
 *
 * Export of this software from the United States of America may require
 * a specific license from the United States Government.  It is the
 * responsibility of any person or organization contemplating export to
 * obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of FundsXpress. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  FundsXpress makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/crypto.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY        RPCDBG_AUTH
#endif


/* read_token is a mic token, and message_buffer is the data that the mic was
 * supposedly taken over. */

u32
gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
		struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
{
	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
	int			signalg;
	int			sealalg;
	s32			checksum_type;
	struct xdr_netobj	md5cksum = {.len = 0, .data = NULL};
	s32			now;
	int			direction;
	s32			seqnum;
	unsigned char		*ptr = (unsigned char *)read_token->data;
	int			bodysize;
	u32			ret = GSS_S_DEFECTIVE_TOKEN;

	dprintk("RPC:      krb5_read_token\n");

	if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
					read_token->len))
		goto out;

	if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) ||
	    (*ptr++ != ( KG_TOK_MIC_MSG    &0xff))   )
		goto out;

	/* XXX sanity-check bodysize?? */

	/* get the sign and seal algorithms */

	signalg = ptr[0] + (ptr[1] << 8);
	sealalg = ptr[2] + (ptr[3] << 8);

	/* Sanity checks */

	if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
		goto out;

	if (sealalg != 0xffff)
		goto out;

	/* there are several mappings of seal algorithms to sign algorithms,
	   but few enough that we can try them all. */

	if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) ||
	    (ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) ||
	    (ctx->sealalg == SEAL_ALG_DES3KD &&
	     signalg != SGN_ALG_HMAC_SHA1_DES3_KD))
		goto out;

	/* compute the checksum of the message */

	/* initialize the the cksum */
	switch (signalg) {
	case SGN_ALG_DES_MAC_MD5:
		checksum_type = CKSUMTYPE_RSA_MD5;
		break;
	default:
		ret = GSS_S_DEFECTIVE_TOKEN;
		goto out;
	}

	switch (signalg) {
	case SGN_ALG_DES_MAC_MD5:
		ret = make_checksum(checksum_type, ptr - 2, 8,
					 message_buffer, 0, &md5cksum);
		if (ret)
			goto out;

		ret = krb5_encrypt(ctx->seq, NULL, md5cksum.data,
				   md5cksum.data, 16);
		if (ret)
			goto out;

		if (memcmp(md5cksum.data + 8, ptr + 14, 8)) {
			ret = GSS_S_BAD_SIG;
			goto out;
		}
		break;
	default:
		ret = GSS_S_DEFECTIVE_TOKEN;
		goto out;
	}

	/* it got through unscathed.  Make sure the context is unexpired */

	now = get_seconds();

	ret = GSS_S_CONTEXT_EXPIRED;
	if (now > ctx->endtime)
		goto out;

	/* do sequencing checks */

	ret = GSS_S_BAD_SIG;
	if ((ret = krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction,
				    &seqnum)))
		goto out;

	if ((ctx->initiate && direction != 0xff) ||
	    (!ctx->initiate && direction != 0))
		goto out;

	ret = GSS_S_COMPLETE;
out:
	if (md5cksum.data) kfree(md5cksum.data);
	return ret;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/net/sunrpc/gss_krb5_unseal.c
	3	*
	4	* Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
	5	*
	6	* Copyright (c) 2000 The Regents of the University of Michigan.
	7	* All rights reserved.
	8	*
	9	* Andy Adamson <andros@umich.edu>
	10	*/
	11
	12	/*
	13	* Copyright 1993 by OpenVision Technologies, Inc.
	14	*
	15	* Permission to use, copy, modify, distribute, and sell this software
	16	* and its documentation for any purpose is hereby granted without fee,
	17	* provided that the above copyright notice appears in all copies and
	18	* that both that copyright notice and this permission notice appear in
	19	* supporting documentation, and that the name of OpenVision not be used
	20	* in advertising or publicity pertaining to distribution of the software
	21	* without specific, written prior permission. OpenVision makes no
	22	* representations about the suitability of this software for any
	23	* purpose. It is provided "as is" without express or implied warranty.
	24	*
	25	* OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	26	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	27	* EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	28	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
	29	* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
	30	* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
	31	* PERFORMANCE OF THIS SOFTWARE.
	32	*/
	33
	34	/*
	35	* Copyright (C) 1998 by the FundsXpress, INC.
	36	*
	37	* All rights reserved.
	38	*
	39	* Export of this software from the United States of America may require
	40	* a specific license from the United States Government. It is the
	41	* responsibility of any person or organization contemplating export to
	42	* obtain such a license before exporting.
	43	*
	44	* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
	45	* distribute this software and its documentation for any purpose and
	46	* without fee is hereby granted, provided that the above copyright
	47	* notice appear in all copies and that both that copyright notice and
	48	* this permission notice appear in supporting documentation, and that
	49	* the name of FundsXpress. not be used in advertising or publicity pertaining
	50	* to distribution of the software without specific, written prior
	51	* permission. FundsXpress makes no representations about the suitability of
	52	* this software for any purpose. It is provided "as is" without express
	53	* or implied warranty.
	54	*
	55	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	56	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	57	* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	58	*/
	59
	60	#include <linux/types.h>
	61	#include <linux/slab.h>
	62	#include <linux/jiffies.h>
	63	#include <linux/sunrpc/gss_krb5.h>
	64	#include <linux/crypto.h>
65
66	#ifdef RPC_DEBUG
67	# define RPCDBG_FACILITY RPCDBG_AUTH
68	#endif
69
70
bfa91516 BF	71	/* read_token is a mic token, and message_buffer is the data that the mic was
bfa91516 BF	72	* supposedly taken over. */
1da177e4	73
1da177e4	74	u32
a0857d03 BF	75	gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
a0857d03 BF	76	struct xdr_buf message_buffer, struct xdr_netobj read_token)
1da177e4	77	{
a0857d03	78	struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
1da177e4 LT	79	int signalg;
	80	int sealalg;
	81	s32 checksum_type;
	82	struct xdr_netobj md5cksum = {.len = 0, .data = NULL};
	83	s32 now;
	84	int direction;
	85	s32 seqnum;
	86	unsigned char ptr = (unsigned char )read_token->data;
	87	int bodysize;
	88	u32 ret = GSS_S_DEFECTIVE_TOKEN;
	89
	90	dprintk("RPC: krb5_read_token\n");
	91
	92	if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
	93	read_token->len))
	94	goto out;
	95
bfa91516 BF	96	if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) \|\|
bfa91516 BF	97	(*ptr++ != ( KG_TOK_MIC_MSG &0xff)) )
1da177e4 LT	98	goto out;
	99
	100	/* XXX sanity-check bodysize?? */
	101
1da177e4 LT	102	/* get the sign and seal algorithms */
	103
	104	signalg = ptr[0] + (ptr[1] << 8);
	105	sealalg = ptr[2] + (ptr[3] << 8);
	106
	107	/* Sanity checks */
	108
	109	if ((ptr[4] != 0xff) \|\| (ptr[5] != 0xff))
	110	goto out;
	111
bfa91516	112	if (sealalg != 0xffff)
1da177e4 LT	113	goto out;
	114
	115	/* there are several mappings of seal algorithms to sign algorithms,
	116	but few enough that we can try them all. */
	117
	118	if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) \|\|
	119	(ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) \|\|
	120	(ctx->sealalg == SEAL_ALG_DES3KD &&
	121	signalg != SGN_ALG_HMAC_SHA1_DES3_KD))
	122	goto out;
	123
	124	/* compute the checksum of the message */
	125
	126	/* initialize the the cksum */
	127	switch (signalg) {
	128	case SGN_ALG_DES_MAC_MD5:
	129	checksum_type = CKSUMTYPE_RSA_MD5;
	130	break;
	131	default:
	132	ret = GSS_S_DEFECTIVE_TOKEN;
	133	goto out;
	134	}
	135
	136	switch (signalg) {
	137	case SGN_ALG_DES_MAC_MD5:
	138	ret = make_checksum(checksum_type, ptr - 2, 8,
14ae162c	139	message_buffer, 0, &md5cksum);
1da177e4 LT	140	if (ret)
	141	goto out;
	142
	143	ret = krb5_encrypt(ctx->seq, NULL, md5cksum.data,
	144	md5cksum.data, 16);
	145	if (ret)
	146	goto out;
	147
	148	if (memcmp(md5cksum.data + 8, ptr + 14, 8)) {
	149	ret = GSS_S_BAD_SIG;
	150	goto out;
	151	}
	152	break;
	153	default:
	154	ret = GSS_S_DEFECTIVE_TOKEN;
	155	goto out;
	156	}
	157
	158	/* it got through unscathed. Make sure the context is unexpired */
	159
1da177e4 LT	160	now = get_seconds();
	161
	162	ret = GSS_S_CONTEXT_EXPIRED;
	163	if (now > ctx->endtime)
	164	goto out;
	165
	166	/* do sequencing checks */
	167
	168	ret = GSS_S_BAD_SIG;
	169	if ((ret = krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction,
	170	&seqnum)))
	171	goto out;
	172
	173	if ((ctx->initiate && direction != 0xff) \|\|
	174	(!ctx->initiate && direction != 0))
	175	goto out;
	176
	177	ret = GSS_S_COMPLETE;
	178	out:
	179	if (md5cksum.data) kfree(md5cksum.data);
	180	return ret;
	181	}