|author||Guy Harris <email@example.com>||2002-12-03 00:37:27 +0000|
|committer||Guy Harris <firstname.lastname@example.org>||2002-12-03 00:37:27 +0000|
From Devin Heitmueller:
add MD4 and RC4 crypto support; use it to decrypt the NT password encryption block in UnicodeChangePassword2. svn path=/trunk/; revision=6727
Diffstat (limited to 'crypt-rc4.c')
1 files changed, 81 insertions, 0 deletions
diff --git a/crypt-rc4.c b/crypt-rc4.c
new file mode 100644
@@ -0,0 +1,81 @@
+ Unix SMB/CIFS implementation.
+ a partial implementation of RC4 designed for use in the
+ SMB authentication protocol
+ Copyright (C) Andrew Tridgell 1998
+ $Id: crypt-rc4.c,v 1.1 2002/12/03 00:37:27 guy Exp $
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+# include "config.h"
+/* Perform RC4 on a block of data using specified key. "data" is a pointer
+ to the block to be processed. Output is written to same memory as input,
+ so caller may need to make a copy before calling this function, since
+ the input will be overwritten. "val" specifies length of data buffer.
+ "key" is assumed to be a 16 octets in length
+ Taken from Samba source code. In the long term, it might be nice to have
+ the input and output buffer differ, have a length specifier for the key,
+ and separate the initialization function from the process function (as is
+ done with the Alleged-RC4 implementation).
+void crypt_rc4( unsigned char *data, const unsigned char *key, int val)
+ unsigned char s_box;
+ unsigned char index_i = 0;
+ unsigned char index_j = 0;
+ unsigned char j = 0;
+ int ind;
+ for (ind = 0; ind < 256; ind++)
+ s_box[ind] = (unsigned char)ind;
+ for( ind = 0; ind < 256; ind++)
+ unsigned char tc;
+ j += (s_box[ind] + key[ind%16]);
+ tc = s_box[ind];
+ s_box[ind] = s_box[j];
+ s_box[j] = tc;
+ for( ind = 0; ind < val; ind++)
+ unsigned char tc;
+ unsigned char t;
+ index_j += s_box[index_i];
+ tc = s_box[index_i];
+ s_box[index_i] = s_box[index_j];
+ s_box[index_j] = tc;
+ t = s_box[index_i] + s_box[index_j];
+ data[ind] = data[ind] ^ s_box[t];