OpenVAS Libraries  9.0.3
arc4.c
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1 /*
2  Unix SMB/CIFS implementation.
3 
4  An implementation of arc4.
5 
6  Copyright (C) Jeremy Allison 2005.
7 
8  This program is free software; you can redistribute it and/or modify
9  it under the terms of the GNU General Public License as published by
10  the Free Software Foundation; either version 2 of the License, or
11  (at your option) any later version.
12 
13  This program is distributed in the hope that it will be useful,
14  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  GNU General Public License for more details.
17 
18  You should have received a copy of the GNU General Public License
19  along with this program; if not, write to the Free Software
20  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 */
22 
23 
24 #include <stdlib.h>
25 /*****************************************************************
26  Initialize state for an arc4 crypt/decrpyt.
27  arc4 state is 258 bytes - last 2 bytes are the index bytes.
28 *****************************************************************/
29 
30 void smb_arc4_init_ntlmssp(unsigned char arc4_state_out[258], const unsigned char *key, size_t keylen)
31 {
32  size_t ind;
33  unsigned char j = 0;
34 
35  for (ind = 0; ind < 256; ind++) {
36  arc4_state_out[ind] = (unsigned char)ind;
37  }
38 
39  for( ind = 0; ind < 256; ind++) {
40  unsigned char tc;
41 
42  j += (arc4_state_out[ind] + key[ind%keylen]);
43 
44  tc = arc4_state_out[ind];
45  arc4_state_out[ind] = arc4_state_out[j];
46  arc4_state_out[j] = tc;
47  }
48  arc4_state_out[256] = 0;
49  arc4_state_out[257] = 0;
50 }
51 
52 /*****************************************************************
53  Do the arc4 crypt/decrpyt.
54  arc4 state is 258 bytes - last 2 bytes are the index bytes.
55 *****************************************************************/
56 
57 void smb_arc4_crypt_ntlmssp(unsigned char arc4_state_inout[258], unsigned char *data, size_t len)
58 {
59  unsigned char index_i = arc4_state_inout[256];
60  unsigned char index_j = arc4_state_inout[257];
61  size_t ind;
62 
63  for( ind = 0; ind < len; ind++) {
64  unsigned char tc;
65  unsigned char t;
66 
67  index_i++;
68  index_j += arc4_state_inout[index_i];
69 
70  tc = arc4_state_inout[index_i];
71  arc4_state_inout[index_i] = arc4_state_inout[index_j];
72  arc4_state_inout[index_j] = tc;
73 
74  t = arc4_state_inout[index_i] + arc4_state_inout[index_j];
75  data[ind] = data[ind] ^ arc4_state_inout[t];
76  }
77 
78  arc4_state_inout[256] = index_i;
79  arc4_state_inout[257] = index_j;
80 }
void smb_arc4_crypt_ntlmssp(unsigned char arc4_state_inout[258], unsigned char *data, size_t len)
Definition: arc4.c:57
void smb_arc4_init_ntlmssp(unsigned char arc4_state_out[258], const unsigned char *key, size_t keylen)
Definition: arc4.c:30