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
|
/*
* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "krb_locl.h"
RCSID("$Id: mk_safe.c,v 1.21 1997/04/19 23:18:03 joda Exp $");
/* application include files */
#include "lsb_addr_comp.h"
/* from rd_safe.c */
extern int dqc_type;
void fixup_quad_cksum(void*, size_t, des_cblock*, void*, void*, int);
/*
* krb_mk_safe() constructs an AUTH_MSG_SAFE message. It takes some
* user data "in" of "length" bytes and creates a packet in "out"
* consisting of the user data, a timestamp, and the sender's network
* address, followed by a checksum computed on the above, using the
* given "key". The length of the resulting packet is returned.
*
* The "out" packet consists of:
*
* Size Variable Field
* ---- -------- -----
*
* 1 byte KRB_PROT_VERSION protocol version number
* 1 byte AUTH_MSG_SAFE | message type plus local
* HOST_BYTE_ORDER byte order in low bit
*
* ===================== begin checksum ================================
*
* 4 bytes length length of user data
* length in user data
* 1 byte msg_time_5ms timestamp milliseconds
* 4 bytes sender->sin.addr.s_addr sender's IP address
*
* 4 bytes msg_time_sec or timestamp seconds with
* -msg_time_sec direction in sign bit
*
* ======================= end checksum ================================
*
* 16 bytes big_cksum quadratic checksum of
* above using "key"
*/
int32_t
krb_mk_safe(void *in, void *out, u_int32_t length, des_cblock *key,
struct sockaddr_in *sender, struct sockaddr_in *receiver)
{
unsigned char * p = (unsigned char*)out;
struct timeval tv;
unsigned char *start;
u_int32_t src_addr;
p += krb_put_int(KRB_PROT_VERSION, p, 1);
p += krb_put_int(AUTH_MSG_SAFE, p, 1);
start = p;
p += krb_put_int(length, p, 4);
memcpy(p, in, length);
p += length;
gettimeofday(&tv, NULL);
*p++ = tv.tv_usec/5000; /* 5ms */
src_addr = sender->sin_addr.s_addr;
p += krb_put_address(src_addr, p);
p += krb_put_int(lsb_time(tv.tv_sec, sender, receiver), p, 4);
{
/* We are faking big endian mode, so we need to fix the
* checksum (that is byte order dependent). We always send a
* checksum of the new type, unless we know that we are
* talking to an old client (this requires a call to
* krb_rd_safe first).
*/
unsigned char new_checksum[16];
unsigned char old_checksum[16];
fixup_quad_cksum(start, p - start, key, new_checksum, old_checksum, 0);
if((dqc_type == DES_QUAD_GUESS && DES_QUAD_DEFAULT == DES_QUAD_OLD) ||
dqc_type == DES_QUAD_OLD)
memcpy(p, old_checksum, 16);
else
memcpy(p, new_checksum, 16);
}
p += 16;
return p - (unsigned char*)out;
}
|
