aboutsummaryrefslogtreecommitdiffstats
path: root/net/sunrpc/auth_gss/gss_krb5_seal.c
blob: e1f0571843c8c700363bdade9b2282d91119e014 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
/*
 *  linux/net/sunrpc/gss_krb5_seal.c
 *
 *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.c
 *
 *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Andy Adamson	<andros@umich.edu>
 *  J. Bruce Fields	<bfields@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/jiffies.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/random.h>
#include <linux/crypto.h>
#include <linux/atomic.h>

#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY        RPCDBG_AUTH
#endif

DEFINE_SPINLOCK(krb5_seq_lock);

static void *
setup_token(struct krb5_ctx *ctx, struct xdr_netobj *token)
{
	u16 *ptr;
	void *krb5_hdr;
	int body_size = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;

	token->len = g_token_size(&ctx->mech_used, body_size);

	ptr = (u16 *)token->data;
	g_make_token_header(&ctx->mech_used, body_size, (unsigned char **)&ptr);

	/* ptr now at start of header described in rfc 1964, section 1.2.1: */
	krb5_hdr = ptr;
	*ptr++ = KG_TOK_MIC_MSG;
	/*
	 * signalg is stored as if it were converted from LE to host endian, even
	 * though it's an opaque pair of bytes according to the RFC.
	 */
	*ptr++ = (__force u16)cpu_to_le16(ctx->gk5e->signalg);
	*ptr++ = SEAL_ALG_NONE;
	*ptr = 0xffff;

	return krb5_hdr;
}

static void *
setup_token_v2(struct krb5_ctx *ctx, struct xdr_netobj *token)
{
	u16 *ptr;
	void *krb5_hdr;
	u8 *p, flags = 0x00;

	if ((ctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0)
		flags |= 0x01;
	if (ctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY)
		flags |= 0x04;

	/* Per rfc 4121, sec 4.2.6.1, there is no header,
	 * just start the token */
	krb5_hdr = ptr = (u16 *)token->data;

	*ptr++ = KG2_TOK_MIC;
	p = (u8 *)ptr;
	*p++ = flags;
	*p++ = 0xff;
	ptr = (u16 *)p;
	*ptr++ = 0xffff;
	*ptr = 0xffff;

	token->len = GSS_KRB5_TOK_HDR_LEN + ctx->gk5e->cksumlength;
	return krb5_hdr;
}

static u32
gss_get_mic_v1(struct krb5_ctx *ctx, struct xdr_buf *text,
		struct xdr_netobj *token)
{
	char			cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
	struct xdr_netobj	md5cksum = {.len = sizeof(cksumdata),
					    .data = cksumdata};
	void			*ptr;
	s32			now;
	u32			seq_send;
	u8			*cksumkey;

	dprintk("RPC:       %s\n", __func__);
	BUG_ON(ctx == NULL);

	now = get_seconds();

	ptr = setup_token(ctx, token);

	if (ctx->gk5e->keyed_cksum)
		cksumkey = ctx->cksum;
	else
		cksumkey = NULL;

	if (make_checksum(ctx, ptr, 8, text, 0, cksumkey,
			  KG_USAGE_SIGN, &md5cksum))
		return GSS_S_FAILURE;

	memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data, md5cksum.len);

	spin_lock(&krb5_seq_lock);
	seq_send = ctx->seq_send++;
	spin_unlock(&krb5_seq_lock);

	if (krb5_make_seq_num(ctx, ctx->seq, ctx->initiate ? 0 : 0xff,
			      seq_send, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8))
		return GSS_S_FAILURE;

	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
}

static u32
gss_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
		struct xdr_netobj *token)
{
	char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
	struct xdr_netobj cksumobj = { .len = sizeof(cksumdata),
				       .data = cksumdata};
	void *krb5_hdr;
	s32 now;
	u64 seq_send;
	u8 *cksumkey;
	unsigned int cksum_usage;
	__be64 seq_send_be64;

	dprintk("RPC:       %s\n", __func__);

	krb5_hdr = setup_token_v2(ctx, token);

	/* Set up the sequence number. Now 64-bits in clear
	 * text and w/o direction indicator */
	spin_lock(&krb5_seq_lock);
	seq_send = ctx->seq_send64++;
	spin_unlock(&krb5_seq_lock);

	seq_send_be64 = cpu_to_be64(seq_send);
	memcpy(krb5_hdr + 8, (char *) &seq_send_be64, 8);

	if (ctx->initiate) {
		cksumkey = ctx->initiator_sign;
		cksum_usage = KG_USAGE_INITIATOR_SIGN;
	} else {
		cksumkey = ctx->acceptor_sign;
		cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
	}

	if (make_checksum_v2(ctx, krb5_hdr, GSS_KRB5_TOK_HDR_LEN,
			     text, 0, cksumkey, cksum_usage, &cksumobj))
		return GSS_S_FAILURE;

	memcpy(krb5_hdr + GSS_KRB5_TOK_HDR_LEN, cksumobj.data, cksumobj.len);

	now = get_seconds();

	return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
}

u32
gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
		     struct xdr_netobj *token)
{
	struct krb5_ctx		*ctx = gss_ctx->internal_ctx_id;

	switch (ctx->enctype) {
	default:
		BUG();
	case ENCTYPE_DES_CBC_RAW:
	case ENCTYPE_DES3_CBC_RAW:
	case ENCTYPE_ARCFOUR_HMAC:
		return gss_get_mic_v1(ctx, text, token);
	case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
	case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
		return gss_get_mic_v2(ctx, text, token);
	}
}