blob: 6cd930f3678fb21384fc91e8927d0e49901af108 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/net/sunrpc/gss_krb5_unseal.c
3 *
4 * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
5 *
Kevin Coffman81d4a432010-03-17 13:02:51 -04006 * Copyright (c) 2000-2008 The Regents of the University of Michigan.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * 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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#include <linux/jiffies.h>
62#include <linux/sunrpc/gss_krb5.h>
63#include <linux/crypto.h>
64
65#ifdef RPC_DEBUG
66# define RPCDBG_FACILITY RPCDBG_AUTH
67#endif
68
69
J. Bruce Fieldsbfa91512005-10-13 16:55:08 -040070/* read_token is a mic token, and message_buffer is the data that the mic was
71 * supposedly taken over. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Kevin Coffman1ac37192010-03-17 13:02:49 -040073static u32
74gss_verify_mic_v1(struct krb5_ctx *ctx,
J. Bruce Fieldsa0857d02005-10-13 16:55:23 -040075 struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
77 int signalg;
78 int sealalg;
Kevin Coffman81d4a432010-03-17 13:02:51 -040079 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
80 struct xdr_netobj md5cksum = {.len = sizeof(cksumdata),
81 .data = cksumdata};
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 s32 now;
83 int direction;
Kevin Coffman5743d652008-03-31 10:31:33 -040084 u32 seqnum;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 unsigned char *ptr = (unsigned char *)read_token->data;
86 int bodysize;
Kevin Coffmane1f6c072010-03-17 13:02:52 -040087 u8 *cksumkey;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Chuck Lever8885cb32007-01-31 12:14:05 -050089 dprintk("RPC: krb5_read_token\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91 if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
92 read_token->len))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -050093 return GSS_S_DEFECTIVE_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
Kevin Coffmand00953a2008-04-30 12:45:53 -040095 if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) ||
96 (ptr[1] != (KG_TOK_MIC_MSG & 0xff)))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -050097 return GSS_S_DEFECTIVE_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 /* XXX sanity-check bodysize?? */
100
Kevin Coffmand00953a2008-04-30 12:45:53 -0400101 signalg = ptr[2] + (ptr[3] << 8);
Kevin Coffman81d4a432010-03-17 13:02:51 -0400102 if (signalg != ctx->gk5e->signalg)
J. Bruce Fields94efa932006-12-04 20:22:42 -0500103 return GSS_S_DEFECTIVE_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
Kevin Coffmand00953a2008-04-30 12:45:53 -0400105 sealalg = ptr[4] + (ptr[5] << 8);
J. Bruce Fields94efa932006-12-04 20:22:42 -0500106 if (sealalg != SEAL_ALG_NONE)
107 return GSS_S_DEFECTIVE_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
Kevin Coffmand00953a2008-04-30 12:45:53 -0400109 if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500110 return GSS_S_DEFECTIVE_TOKEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Kevin Coffmane1f6c072010-03-17 13:02:52 -0400112 if (ctx->gk5e->keyed_cksum)
113 cksumkey = ctx->cksum;
114 else
115 cksumkey = NULL;
116
117 if (make_checksum(ctx, ptr, 8, message_buffer, 0,
Kevin Coffman8b237072010-03-17 13:03:02 -0400118 cksumkey, KG_USAGE_SIGN, &md5cksum))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500119 return GSS_S_FAILURE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Kevin Coffmane1f6c072010-03-17 13:02:52 -0400121 if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
Kevin Coffman81d4a432010-03-17 13:02:51 -0400122 ctx->gk5e->cksumlength))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500123 return GSS_S_BAD_SIG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 /* it got through unscathed. Make sure the context is unexpired */
126
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 now = get_seconds();
128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 if (now > ctx->endtime)
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500130 return GSS_S_CONTEXT_EXPIRED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132 /* do sequencing checks */
133
Kevin Coffman1dbd9022010-03-17 13:03:04 -0400134 if (krb5_get_seq_num(ctx, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8,
135 &direction, &seqnum))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500136 return GSS_S_FAILURE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
138 if ((ctx->initiate && direction != 0xff) ||
139 (!ctx->initiate && direction != 0))
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500140 return GSS_S_BAD_SIG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
J. Bruce Fields39a21dd2006-12-04 20:22:39 -0500142 return GSS_S_COMPLETE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
Kevin Coffman1ac37192010-03-17 13:02:49 -0400144
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400145static u32
146gss_verify_mic_v2(struct krb5_ctx *ctx,
147 struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
148{
149 char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
150 struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
151 .data = cksumdata};
152 s32 now;
153 u64 seqnum;
154 u8 *ptr = read_token->data;
155 u8 *cksumkey;
156 u8 flags;
157 int i;
Kevin Coffman8b237072010-03-17 13:03:02 -0400158 unsigned int cksum_usage;
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400159
160 dprintk("RPC: %s\n", __func__);
161
162 if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_MIC)
163 return GSS_S_DEFECTIVE_TOKEN;
164
165 flags = ptr[2];
166 if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
167 (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
168 return GSS_S_BAD_SIG;
169
170 if (flags & KG2_TOKEN_FLAG_SEALED) {
171 dprintk("%s: token has unexpected sealed flag\n", __func__);
172 return GSS_S_FAILURE;
173 }
174
175 for (i = 3; i < 8; i++)
176 if (ptr[i] != 0xff)
177 return GSS_S_DEFECTIVE_TOKEN;
178
Kevin Coffman8b237072010-03-17 13:03:02 -0400179 if (ctx->initiate) {
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400180 cksumkey = ctx->acceptor_sign;
Kevin Coffman8b237072010-03-17 13:03:02 -0400181 cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
182 } else {
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400183 cksumkey = ctx->initiator_sign;
Kevin Coffman8b237072010-03-17 13:03:02 -0400184 cksum_usage = KG_USAGE_INITIATOR_SIGN;
185 }
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400186
187 if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0,
Kevin Coffman8b237072010-03-17 13:03:02 -0400188 cksumkey, cksum_usage, &cksumobj))
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400189 return GSS_S_FAILURE;
190
191 if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
192 ctx->gk5e->cksumlength))
193 return GSS_S_BAD_SIG;
194
195 /* it got through unscathed. Make sure the context is unexpired */
196 now = get_seconds();
197 if (now > ctx->endtime)
198 return GSS_S_CONTEXT_EXPIRED;
199
200 /* do sequencing checks */
201
202 seqnum = be64_to_cpup((__be64 *)ptr + 8);
203
204 return GSS_S_COMPLETE;
205}
206
Kevin Coffman1ac37192010-03-17 13:02:49 -0400207u32
208gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
209 struct xdr_buf *message_buffer,
210 struct xdr_netobj *read_token)
211{
212 struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
213
214 switch (ctx->enctype) {
215 default:
216 BUG();
217 case ENCTYPE_DES_CBC_RAW:
Kevin Coffman958142e2010-03-17 13:02:55 -0400218 case ENCTYPE_DES3_CBC_RAW:
Kevin Coffmanfffdaef2010-03-17 13:03:06 -0400219 case ENCTYPE_ARCFOUR_HMAC:
Kevin Coffman1ac37192010-03-17 13:02:49 -0400220 return gss_verify_mic_v1(ctx, message_buffer, read_token);
Kevin Coffmande9c17e2010-03-17 13:02:59 -0400221 case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
222 case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
223 return gss_verify_mic_v2(ctx, message_buffer, read_token);
Kevin Coffman1ac37192010-03-17 13:02:49 -0400224 }
225}
226