69 lines
1.7 KiB
C#
69 lines
1.7 KiB
C#
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// This code is derived from jcifs smb client library <jcifs at samba dot org>
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// Ported by J. Arturo <webmaster at komodosoft dot net>
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 2.1 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License along with this library; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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namespace SharpCifs.Util
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{
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public class Rc4
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{
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internal byte[] S;
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internal int I;
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internal int J;
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public Rc4()
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{
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}
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public Rc4(byte[] key)
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{
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Init(key, 0, key.Length);
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}
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public virtual void Init(byte[] key, int ki, int klen)
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{
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S = new byte[256];
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for (I = 0; I < 256; I++)
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{
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S[I] = unchecked((byte)I);
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}
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for (I = J = 0; I < 256; I++)
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{
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J = (J + key[ki + I % klen] + S[I]) & unchecked(0xff);
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byte t = S[I];
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S[I] = S[J];
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S[J] = t;
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}
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I = J = 0;
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}
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public virtual void Update(byte[] src, int soff, int slen, byte[] dst, int doff)
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{
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int slim;
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slim = soff + slen;
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while (soff < slim)
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{
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I = (I + 1) & unchecked(0xff);
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J = (J + S[I]) & unchecked(0xff);
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byte t = S[I];
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S[I] = S[J];
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S[J] = t;
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dst[doff++] = unchecked((byte)(src[soff++] ^ S[(S[I] + S[J]) & unchecked(0xff)]));
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}
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}
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}
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}
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