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
|
/* xsiemens.c */
/* Siemens service code generator */
/* (C) Ivan Gorinov, 30.09.2002 */
#include "chiffre.h"
unsigned char key1[4] = {0x57, 0xF9, 0x3A, 0xC1}; /* Level 1 key */
unsigned char key2[4] = {0xA4, 0xD3, 0x67, 0x9C}; /* Level 2 key */
/* 4-bit substitution boxes */
unsigned char sbox_h[0x10] =
{0x09, 0x02, 0x04, 0x06, 0x08, 0x07, 0x05, 0x03, 0x01, 0x00,
0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F};
unsigned char sbox_l[0x10] =
{0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F};
unsigned char sbox[0x100]; /* 8-bit substitution box */
char digit[] = "0123456789ABCDEF";
/* Convert hex digit to binary value */
int from_hex(int c)
{
int i;
for(i = 0; i < 0x10; i++) if(c == digit[i]) break;
if (i >= 0x10) i = -1;
return i;
}
/* Convert binary value to string (decimal) */
int bin2dec(char *s, int n, unsigned long l)
{
int c, i, j;
j = n;
s[j] = 0;
for(i = 0; i < n; i++) {
c = l % 10;
l /= 10;
c = digit[c];
s[--j] = c;
}
return j;
}
/* Convert two 4-bit boxes to one 8-bit */
int initbox(void)
{
int i, j, k, x;
k = 0;
for(i = 0; i < 0x10; i++) {
x = sbox_h[i] << 4;
for(j = 0; j < 0x10; j++) {
sbox[k] = sbox_l[j] | x;
k++;
}
}
return 0;
}
/* Substitution */
void subst(unsigned char *b, unsigned char *a, int n)
{
int i;
for(i = 0; i < n; i++) b[i] = sbox[a[i]];
}
/* Xor N bytes with Z, inverting every odd byte */
void xxstr(unsigned char *b, unsigned char *a, int n, int z)
{
int i;
for(i = 0; i < n; i++) {
if(i & 1) {
b[i] = (~a[i]) ^ z;
} else {
b[i] = a[i] ^ z;
}
}
}
/* Encryption (1 iteration) */
void ec_f(unsigned char *a, int n, int z)
{
unsigned char bc[0x20], bs[0x10], bx[0x10];
int n2, i;
for(i = 0; i < n; i++) bc[i] = a[i];
n2 = n >> 1;
subst(bs, a, n2);
xxstr(bx, bs, n2, z);
for(i = 0; i < n2; i++) {
a[i] = bx[i] ^ bc[i+n2];
a[i+n2] = bc[i];
}
}
void ec_f_bak(unsigned char *a, int n, int z)
{
unsigned char bc[0x20], bs[0x10], bx[0x10];
int n2, i;
n2 = n >> 1;
for(i = 0; i < n2; i++) bc[i+n2] = a[i];
subst(bs, bc + n2, n2);
xxstr(bx, bs, n2, z);
for(i = 0; i < n2; i++) bc[i] = bx[i] ^ a[i+n2];
for(i = 0; i < n; i++) a[i] = bc[i];
}
/* Decryption (1 iteration) */
void dc_f(unsigned char *a, int n, int z)
{
unsigned char bc[0x20], bs[0x10], bx[0x10];
int n2, i;
for(i = 0; i < n; i++) bc[i] = a[i];
n2 = n >> 1;
subst(bs, a + n2, n2);
xxstr(bx, bs, n2, z);
for(i = 0; i < n2; i++) {
a[i] = bc[i+n2];
a[i+n2] = bx[i] ^ bc[i];
}
}
/* Encryption (IMSI -> code) */
void ss_encrypt(unsigned char *a, int n, unsigned char *key)
{
int i;
for(i = 0; i < 4; i++) ec_f_bak(a, n, key[i]);
}
/* Decryption (code -> IMSI) */
void ss_decrypt(unsigned char *a, int n, unsigned char *key)
{
int i;
for(i = 0; i < 4; i++) dc_f(a, n, key[3-i]);
}
int siemens_code(char *str_imsi, char *str_code, int level)
{
unsigned char array[8];
unsigned char xcode[8];
unsigned char test[8];
unsigned long l0, l1;
unsigned char *key;
int x, c, i, j;
if(!str_code) return -1;
str_code[0] = 0;
initbox();
switch(level) {
case 1: key = key1; break;
case 2: key = key2; break;
default: return -1;
}
/* Check the length of IMSI */
for(i = 0; i < 32; i++) if(!str_imsi[i]) break;
if(i == 0) return -1;
if(i >= 32) return -1;
/* Convert last 12 digits to 6 bytes [2-7] */
for(j = 7; j >= 2; j--) {
if (i == 0) {
c = 0x0F;
} else {
c = str_imsi[--i];
c = from_hex(c);
if(c < 0) return -1;
}
x = c;
if(i == 0) {
c = 0x0F;
} else {
c = str_imsi[--i];
c = from_hex(c);
if(c < 0) return -1;
}
x = (x << 4) | c;
array[j] = x;
}
/* This byte is never checked by firmware */
array[1] = 0;
/* Byte [0] <- checksum */
x = 0;
for(i = 1; i < 8; i++) x ^= array[i];
array[0] = x;
for(i = 0; i < 8; i++) xcode[i] = array[i];
/* Make the code */
ss_encrypt(xcode, 8, key);
/* The test */
for(i = 0; i < 8; i++) test[i] = xcode[i];
ss_decrypt(test, 8, key);
for(i = 0; i < 8; i++) if(test[i] != array[i]) break;
if(i < 8) return -1;
/* Convert to strings */
l0 = 0;
for(i = 3; i >= 0; i--) l0 = (l0 << 8) | xcode[i];
l1 = 0;
for(i = 7; i >= 4; i--) l1 = (l1 << 8) | xcode[i];
bin2dec(str_code, 10, l0);
bin2dec(str_code + 10, 10, l1);
return 0;
}
|
