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
|
/*
* Copyright (c) 1999 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. Neither the name of KTH 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 KTH AND ITS 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 KTH OR ITS 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 "krb5_locl.h"
RCSID("$Id$");
static krb5_error_code
rr13(unsigned char *buf, size_t len)
{
unsigned char *tmp;
int bytes = (len + 7) / 8;
int i;
if(len == 0)
return 0;
{
const int bits = 13 % len;
const int lbit = len % 8;
tmp = malloc(bytes);
if (tmp == NULL)
return ENOMEM;
memcpy(tmp, buf, bytes);
if(lbit) {
/* pad final byte with inital bits */
tmp[bytes - 1] &= 0xff << (8 - lbit);
for(i = lbit; i < 8; i += len)
tmp[bytes - 1] |= buf[0] >> i;
}
for(i = 0; i < bytes; i++) {
int bb;
int b1, s1, b2, s2;
/* calculate first bit position of this byte */
bb = 8 * i - bits;
while(bb < 0)
bb += len;
/* byte offset and shift count */
b1 = bb / 8;
s1 = bb % 8;
if(bb + 8 > bytes * 8)
/* watch for wraparound */
s2 = (len + 8 - s1) % 8;
else
s2 = 8 - s1;
b2 = (b1 + 1) % bytes;
buf[i] = (tmp[b1] << s1) | (tmp[b2] >> s2);
}
free(tmp);
}
return 0;
}
/* Add `b' to `a', both being one's complement numbers. */
static void
add1(unsigned char *a, unsigned char *b, size_t len)
{
int i;
int carry = 0;
for(i = len - 1; i >= 0; i--){
int x = a[i] + b[i] + carry;
carry = x > 0xff;
a[i] = x & 0xff;
}
for(i = len - 1; carry && i >= 0; i--){
int x = a[i] + carry;
carry = x > 0xff;
a[i] = x & 0xff;
}
}
krb5_error_code KRB5_LIB_FUNCTION
_krb5_n_fold(const void *str, size_t len, void *key, size_t size)
{
/* if len < size we need at most N * len bytes, ie < 2 * size;
if len > size we need at most 2 * len */
krb5_error_code ret = 0;
size_t maxlen = 2 * max(size, len);
size_t l = 0;
unsigned char *tmp = malloc(maxlen);
unsigned char *buf = malloc(len);
if (tmp == NULL || buf == NULL)
return ENOMEM;
memcpy(buf, str, len);
memset(key, 0, size);
do {
memcpy(tmp + l, buf, len);
l += len;
ret = rr13(buf, len * 8);
if (ret)
goto out;
while(l >= size) {
add1(key, tmp, size);
l -= size;
if(l == 0)
break;
memmove(tmp, tmp + size, l);
}
} while(l != 0);
out:
memset(buf, 0, len);
free(buf);
memset(tmp, 0, maxlen);
free(tmp);
return ret;
}
|
