1/*
2 *  linux/net/sunrpc/gss_krb5_seal.c
3 *
4 *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.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 *  J. Bruce Fields	<bfields@umich.edu>
11 */
12
13/*
14 * Copyright 1993 by OpenVision Technologies, Inc.
15 *
16 * Permission to use, copy, modify, distribute, and sell this software
17 * and its documentation for any purpose is hereby granted without fee,
18 * provided that the above copyright notice appears in all copies and
19 * that both that copyright notice and this permission notice appear in
20 * supporting documentation, and that the name of OpenVision not be used
21 * in advertising or publicity pertaining to distribution of the software
22 * without specific, written prior permission. OpenVision makes no
23 * representations about the suitability of this software for any
24 * purpose.  It is provided "as is" without express or implied warranty.
25 *
26 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
27 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
28 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
29 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
30 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
31 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
32 * PERFORMANCE OF THIS SOFTWARE.
33 */
34
35/*
36 * Copyright (C) 1998 by the FundsXpress, INC.
37 *
38 * All rights reserved.
39 *
40 * Export of this software from the United States of America may require
41 * a specific license from the United States Government.  It is the
42 * responsibility of any person or organization contemplating export to
43 * obtain such a license before exporting.
44 *
45 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
46 * distribute this software and its documentation for any purpose and
47 * without fee is hereby granted, provided that the above copyright
48 * notice appear in all copies and that both that copyright notice and
49 * this permission notice appear in supporting documentation, and that
50 * the name of FundsXpress. not be used in advertising or publicity pertaining
51 * to distribution of the software without specific, written prior
52 * permission.  FundsXpress makes no representations about the suitability of
53 * this software for any purpose.  It is provided "as is" without express
54 * or implied warranty.
55 *
56 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
57 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
58 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
59 */
60
61#include <linux/types.h>
62#include <linux/slab.h>
63#include <linux/jiffies.h>
64#include <linux/sunrpc/gss_krb5.h>
65#include <linux/random.h>
66#include <asm/scatterlist.h>
67#include <linux/crypto.h>
68
69#ifdef RPC_DEBUG
70# define RPCDBG_FACILITY        RPCDBG_AUTH
71#endif
72
73DEFINE_SPINLOCK(krb5_seq_lock);
74
75u32
76gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
77		struct xdr_netobj *token)
78{
79	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;
80	char			cksumdata[16];
81	struct xdr_netobj	md5cksum = {.len = 0, .data = cksumdata};
82	unsigned char		*ptr, *krb5_hdr, *msg_start;
83	s32			now;
84	u32			seq_send;
85
86	dprintk("RPC:       gss_krb5_seal\n");
87
88	now = get_seconds();
89
90	token->len = g_token_size(&ctx->mech_used, 22);
91
92	ptr = token->data;
93	g_make_token_header(&ctx->mech_used, 22, &ptr);
94
95	*ptr++ = (unsigned char) ((KG_TOK_MIC_MSG>>8)&0xff);
96	*ptr++ = (unsigned char) (KG_TOK_MIC_MSG&0xff);
97
98	/* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
99	krb5_hdr = ptr - 2;
100	msg_start = krb5_hdr + 24;
101
102	*(__be16 *)(krb5_hdr + 2) = htons(SGN_ALG_DES_MAC_MD5);
103	memset(krb5_hdr + 4, 0xff, 4);
104
105	if (make_checksum("md5", krb5_hdr, 8, text, 0, &md5cksum))
106		return GSS_S_FAILURE;
107
108	if (krb5_encrypt(ctx->seq, NULL, md5cksum.data,
109			  md5cksum.data, md5cksum.len))
110		return GSS_S_FAILURE;
111
112	memcpy(krb5_hdr + 16, md5cksum.data + md5cksum.len - KRB5_CKSUM_LENGTH,
113	       KRB5_CKSUM_LENGTH);
114
115	spin_lock(&krb5_seq_lock);
116	seq_send = ctx->seq_send++;
117	spin_unlock(&krb5_seq_lock);
118
119	if (krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff,
120			       ctx->seq_send, krb5_hdr + 16, krb5_hdr + 8))
121		return GSS_S_FAILURE;
122
123	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
124}
125