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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/net/sunrpc/gss_generic_token.c
3 *
4 * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/generic/util_token.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.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -080014 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 * 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.
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -080024 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * 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#include <linux/types.h>
35#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/string.h>
37#include <linux/sunrpc/sched.h>
38#include <linux/sunrpc/gss_asn1.h>
39
40
Jeff Laytonf895b252014-11-17 16:58:04 -050041#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
Linus Torvalds1da177e2005-04-16 15:20:36 -070042# define RPCDBG_FACILITY RPCDBG_AUTH
43#endif
44
45
46/* TWRITE_STR from gssapiP_generic.h */
47#define TWRITE_STR(ptr, str, len) \
48 memcpy((ptr), (char *) (str), (len)); \
49 (ptr) += (len);
50
51/* XXXX this code currently makes the assumption that a mech oid will
52 never be longer than 127 bytes. This assumption is not inherent in
53 the interfaces, so the code can be fixed if the OSI namespace
54 balloons unexpectedly. */
55
56/* Each token looks like this:
57
580x60 tag for APPLICATION 0, SEQUENCE
59 (constructed, definite-length)
60 <length> possible multiple bytes, need to parse/generate
61 0x06 tag for OBJECT IDENTIFIER
62 <moid_length> compile-time constant string (assume 1 byte)
63 <moid_bytes> compile-time constant string
64 <inner_bytes> the ANY containing the application token
65 bytes 0,1 are the token type
66 bytes 2,n are the token data
67
68For the purposes of this abstraction, the token "header" consists of
69the sequence tag and length octets, the mech OID DER encoding, and the
70first two inner bytes, which indicate the token type. The token
71"body" consists of everything else.
72
73*/
74
75static int
76der_length_size( int length)
77{
78 if (length < (1<<7))
Eric Dumazeta02cec22010-09-22 20:43:57 +000079 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 else if (length < (1<<8))
Eric Dumazeta02cec22010-09-22 20:43:57 +000081 return 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#if (SIZEOF_INT == 2)
83 else
Eric Dumazeta02cec22010-09-22 20:43:57 +000084 return 3;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085#else
86 else if (length < (1<<16))
Eric Dumazeta02cec22010-09-22 20:43:57 +000087 return 3;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 else if (length < (1<<24))
Eric Dumazeta02cec22010-09-22 20:43:57 +000089 return 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 else
Eric Dumazeta02cec22010-09-22 20:43:57 +000091 return 5;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#endif
93}
94
95static void
96der_write_length(unsigned char **buf, int length)
97{
98 if (length < (1<<7)) {
99 *(*buf)++ = (unsigned char) length;
100 } else {
101 *(*buf)++ = (unsigned char) (der_length_size(length)+127);
102#if (SIZEOF_INT > 2)
103 if (length >= (1<<24))
104 *(*buf)++ = (unsigned char) (length>>24);
105 if (length >= (1<<16))
106 *(*buf)++ = (unsigned char) ((length>>16)&0xff);
107#endif
108 if (length >= (1<<8))
109 *(*buf)++ = (unsigned char) ((length>>8)&0xff);
110 *(*buf)++ = (unsigned char) (length&0xff);
111 }
112}
113
114/* returns decoded length, or < 0 on failure. Advances buf and
115 decrements bufsize */
116
117static int
118der_read_length(unsigned char **buf, int *bufsize)
119{
120 unsigned char sf;
121 int ret;
122
123 if (*bufsize < 1)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000124 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 sf = *(*buf)++;
126 (*bufsize)--;
127 if (sf & 0x80) {
128 if ((sf &= 0x7f) > ((*bufsize)-1))
Eric Dumazeta02cec22010-09-22 20:43:57 +0000129 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 if (sf > SIZEOF_INT)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000131 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 ret = 0;
133 for (; sf; sf--) {
134 ret = (ret<<8) + (*(*buf)++);
135 (*bufsize)--;
136 }
137 } else {
138 ret = sf;
139 }
140
Eric Dumazeta02cec22010-09-22 20:43:57 +0000141 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142}
143
144/* returns the length of a token, given the mech oid and the body size */
145
146int
147g_token_size(struct xdr_netobj *mech, unsigned int body_size)
148{
149 /* set body_size to sequence contents size */
Kevin Coffman4ab4b0b2008-03-31 10:31:44 -0400150 body_size += 2 + (int) mech->len; /* NEED overflow check */
Eric Dumazeta02cec22010-09-22 20:43:57 +0000151 return 1 + der_length_size(body_size) + body_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Trond Myklebust7bd88262008-12-23 15:21:32 -0500154EXPORT_SYMBOL_GPL(g_token_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156/* fills in a buffer with the token header. The buffer is assumed to
157 be the right size. buf is advanced past the token header */
158
159void
160g_make_token_header(struct xdr_netobj *mech, int body_size, unsigned char **buf)
161{
162 *(*buf)++ = 0x60;
Kevin Coffman4ab4b0b2008-03-31 10:31:44 -0400163 der_write_length(buf, 2 + mech->len + body_size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 *(*buf)++ = 0x06;
165 *(*buf)++ = (unsigned char) mech->len;
166 TWRITE_STR(*buf, mech->data, ((int) mech->len));
167}
168
Trond Myklebust7bd88262008-12-23 15:21:32 -0500169EXPORT_SYMBOL_GPL(g_make_token_header);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171/*
172 * Given a buffer containing a token, reads and verifies the token,
173 * leaving buf advanced past the token header, and setting body_size
174 * to the number of remaining bytes. Returns 0 on success,
175 * G_BAD_TOK_HEADER for a variety of errors, and G_WRONG_MECH if the
176 * mechanism in the token does not match the mech argument. buf and
177 * *body_size are left unmodified on error.
178 */
179u32
180g_verify_token_header(struct xdr_netobj *mech, int *body_size,
181 unsigned char **buf_in, int toksize)
182{
183 unsigned char *buf = *buf_in;
184 int seqsize;
185 struct xdr_netobj toid;
186 int ret = 0;
187
188 if ((toksize-=1) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000189 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 if (*buf++ != 0x60)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000191 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 if ((seqsize = der_read_length(&buf, &toksize)) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000194 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196 if (seqsize != toksize)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000197 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199 if ((toksize-=1) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000200 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 if (*buf++ != 0x06)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000202 return G_BAD_TOK_HEADER;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if ((toksize-=1) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000205 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 toid.len = *buf++;
207
208 if ((toksize-=toid.len) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000209 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 toid.data = buf;
211 buf+=toid.len;
212
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800213 if (! g_OID_equal(&toid, mech))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 ret = G_WRONG_MECH;
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 /* G_WRONG_MECH is not returned immediately because it's more important
217 to return G_BAD_TOK_HEADER if the token header is in fact bad */
218
219 if ((toksize-=2) < 0)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000220 return G_BAD_TOK_HEADER;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 if (ret)
Eric Dumazeta02cec22010-09-22 20:43:57 +0000223 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
225 if (!ret) {
226 *buf_in = buf;
227 *body_size = toksize;
228 }
229
Eric Dumazeta02cec22010-09-22 20:43:57 +0000230 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231}
232
Trond Myklebust7bd88262008-12-23 15:21:32 -0500233EXPORT_SYMBOL_GPL(g_verify_token_header);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234