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
|
/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* Copyright (C) 2008 by the Massachusetts Institute of Technology.
* Copyright 1995 by Richard P. Basch. All Rights Reserved.
* Copyright 1995 by Lehman Brothers, 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 Richard P. Basch, Lehman Brothers and M.I.T. not be used
* in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. Richard P. Basch,
* Lehman Brothers and M.I.T. make no representations about the suitability
* of this software for any purpose. It is provided "as is" without
* express or implied warranty.
*/
#include "crypto_int.h"
#include "des_int.h"
#include "f_tables.h"
void
krb5int_des3_cbc_encrypt(krb5_crypto_iov *data, unsigned long num_data,
const mit_des_key_schedule ks1,
const mit_des_key_schedule ks2,
const mit_des_key_schedule ks3,
mit_des_cblock ivec)
{
unsigned DES_INT32 left, right;
const unsigned DES_INT32 *kp1, *kp2, *kp3;
const unsigned char *ip;
struct iov_cursor cursor;
unsigned char block[MIT_DES_BLOCK_LENGTH];
/* Get key pointers here. These won't need to be reinitialized. */
kp1 = (const unsigned DES_INT32 *)ks1;
kp2 = (const unsigned DES_INT32 *)ks2;
kp3 = (const unsigned DES_INT32 *)ks3;
/* Initialize left and right with the contents of the initial vector. */
ip = (ivec != NULL) ? ivec : mit_des_zeroblock;
left = load_32_be(ip);
right = load_32_be(ip + 4);
k5_iov_cursor_init(&cursor, data, num_data, MIT_DES_BLOCK_LENGTH, FALSE);
while (k5_iov_cursor_get(&cursor, block)) {
/* xor this block with the previous ciphertext. */
left ^= load_32_be(block);
right ^= load_32_be(block + 4);
/* Encrypt what we have and store it back into block. */
DES_DO_ENCRYPT(left, right, kp1);
DES_DO_DECRYPT(left, right, kp2);
DES_DO_ENCRYPT(left, right, kp3);
store_32_be(left, block);
store_32_be(right, block + 4);
k5_iov_cursor_put(&cursor, block);
}
if (ivec != NULL) {
store_32_be(left, ivec);
store_32_be(right, ivec + 4);
}
}
void
krb5int_des3_cbc_decrypt(krb5_crypto_iov *data, unsigned long num_data,
const mit_des_key_schedule ks1,
const mit_des_key_schedule ks2,
const mit_des_key_schedule ks3,
mit_des_cblock ivec)
{
unsigned DES_INT32 left, right;
const unsigned DES_INT32 *kp1, *kp2, *kp3;
const unsigned char *ip;
unsigned DES_INT32 ocipherl, ocipherr;
unsigned DES_INT32 cipherl, cipherr;
struct iov_cursor cursor;
unsigned char block[MIT_DES_BLOCK_LENGTH];
/* Get key pointers here. These won't need to be reinitialized. */
kp1 = (const unsigned DES_INT32 *)ks1;
kp2 = (const unsigned DES_INT32 *)ks2;
kp3 = (const unsigned DES_INT32 *)ks3;
/*
* Decrypting is harder than encrypting because of
* the necessity of remembering a lot more things.
* Should think about this a little more...
*/
/* Prime the old cipher with ivec.*/
ip = (ivec != NULL) ? ivec : mit_des_zeroblock;
ocipherl = load_32_be(ip);
ocipherr = load_32_be(ip + 4);
k5_iov_cursor_init(&cursor, data, num_data, MIT_DES_BLOCK_LENGTH, FALSE);
while (k5_iov_cursor_get(&cursor, block)) {
/* Split this block into left and right. */
cipherl = left = load_32_be(block);
cipherr = right = load_32_be(block + 4);
/* Decrypt and xor with the old cipher to get plain text. */
DES_DO_DECRYPT(left, right, kp3);
DES_DO_ENCRYPT(left, right, kp2);
DES_DO_DECRYPT(left, right, kp1);
left ^= ocipherl;
right ^= ocipherr;
/* Store the encrypted halves back into block. */
store_32_be(left, block);
store_32_be(right, block + 4);
/* Save current cipher block halves. */
ocipherl = cipherl;
ocipherr = cipherr;
k5_iov_cursor_put(&cursor, block);
}
if (ivec != NULL) {
store_32_be(ocipherl, ivec);
store_32_be(ocipherr, ivec + 4);
}
}
|
