{*_* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Author: Franois PIETTE Creation: Sep 03, 2004 Version: 1.00 Description: DES encryption Credit: Implementation of the Data Encryption Standard (DES) as described in the book: Schneier, B., "Applied Cryptography - Protocols Algorithms, and source code in C", John Wiley & Sons, Inc. 1994. Original turbo-pascal implementation by Menno Victor van der Star . His code is available at http://www.geocities.com/SiliconValley/2926/tpsrc/despas.txt F. Piette updated the code to use typed parameters. EMail: http://www.overbyte.be http://www.rtfm.be/fpiette francois.piette@overbyte.be francois.piette@rtfm.be francois.piette@pophost.eunet.be Support: Use the mailing list twsocket@elists.org Follow "support" link at http://www.overbyte.be for subscription. Legal issues: Copyright (C) 2004-2005 by Franois PIETTE Rue de Grady 24, 4053 Embourg, Belgium. Fax: +32-4-365.74.56 This software is provided 'as-is', without any express or implied warranty. In no event will the author be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented, you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. 4. You must register this software by sending a picture postcard to the author. Use a nice stamp and mention your name, street address, EMail address and any comment you like to say. History: * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} unit IcsDES; {$R-} {$Q-} {$I ICSDEFS.INC} interface const IcsDESVersion = 100; CopyRight : String = ' IcsDES (c) 2004-2005 F. Piette V1.00 '; type TArrayOf8Bytes = array [0..7] of Byte; PArrayOf8Bytes = ^TArrayOf8Bytes; procedure DES( { Function encrypt/decrypt data using DES algotithm } const Input : TArrayOf8Bytes; { 64 bit of input } var Output : TArrayOf8Bytes; { 64 bit output from DES algorithm } const Key : TArrayOf8Bytes; { 64 bit key for DES algorithm } Encrypt : Boolean); { TRUE to encrypt, FALSE to decrypt } implementation type TArrayOf16Bytes = array [1..16] of Byte; TArrayOf28Bytes = array [1..28] of Byte; TArrayOf32Bytes = array [1..32] of Byte; TArrayOf48Bytes = array [1..48] of Byte; TArrayOf56Bytes = array [1..56] of Byte; TArrayOf64Bytes = array [1..64] of Byte; TDesData = record InputValue : TArrayOf64Bytes; OutputValue : TArrayOf64Bytes; RoundKeys : array [1..16] of TArrayOf48Bytes; L, R : TArrayOf32Bytes; FunctionResult : TArrayOf32Bytes; C, D : TArrayOf28Bytes; end; const { Initial Permutation } IP : TArrayOf64Bytes = (58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7); { Final Permutation } InvIP : TArrayOf64Bytes = (40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25); { Expansion Permutation } E : TArrayOf48Bytes = (32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1); { P-Box permutation } P : TArrayOf32Bytes = (16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25); { Key Permutation } PC_1 : TArrayOf56Bytes = (57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4); { Compression Permutation } PC_2 : TArrayOf48Bytes = (14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32); { Number of key bits shifted per round } ST : TArrayOf16Bytes = ( 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1); { S-Boxes } SBoxes : array [1..8, 0..3, 0..15] of Byte = (((14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7), ( 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8), ( 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0), (15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13)), ((15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10), ( 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5), ( 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15), (13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9)), ((10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8), (13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1), (13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7), ( 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12)), ((7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15), (13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9), (10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4), ( 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14)), ((2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9), (14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6), ( 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14), (11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3)), ((12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11), (10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8), ( 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6), ( 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13)), ((4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1), (13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6), ( 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2), ( 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12)), ((13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7), ( 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2), ( 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8), ( 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11))); {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} function GetBit(const Bits: TArrayOf8Bytes; Index: Byte): Byte; begin Dec(Index); if Bits[Index div 8] and (128 shr(Index mod 8)) > 0 then Result := 1 else Result := 0; end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} procedure SetBit(var Bits: TArrayOf8Bytes; Index, Value : Byte); var Bit: Byte; begin Dec(Index); Bit := 128 shr(Index mod 8); case Value of 0: Bits[Index div 8] := Bits[Index div 8] and (not Bit); 1: Bits[Index div 8] := Bits[Index div 8] or Bit; end; end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} procedure F( var FR : TArrayOf32Bytes; var FK : TArrayOf48Bytes; var TotalOut : TArrayOf32Bytes); var Temp1 : TArrayOf48Bytes; Temp2 : TArrayOf32Bytes; n, h, i, j, Row, Column : Integer; begin for n := 1 to 48 do Temp1[n] := FR[E[n]] xor FK[n]; for n := 1 to 8 do begin i := (n - 1) * 6; j := (n - 1) * 4; Row := Temp1[i + 1] * 2 + Temp1[i + 6]; Column := Temp1[i + 2] * 8 + Temp1[i + 3] * 4 + Temp1[i + 4] * 2 + Temp1[i + 5]; for h := 1 to 4 Do begin case h of 1: Temp2[j + h] := (SBoxes[n, Row, Column] and 8) div 8; 2: Temp2[j + h] := (SBoxes[n, Row, Column] and 4) div 4; 3: Temp2[j + h] := (SBoxes[n, Row, Column] and 2) div 2; 4: Temp2[j + h] := (SBoxes[n, Row, Column] and 1); end; end; end; for n := 1 to 32 do TotalOut[n] := Temp2[P[n]]; end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} procedure Shift(var SubKeyPart : TArrayOf28Bytes); var n, b: Byte; begin b := SubKeyPart[1]; for n := 1 to 27 do SubKeyPart[n] := SubKeyPart[n + 1]; SubKeyPart[28] := b; end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} procedure SubKey( var DesData : TDesData; Round : Byte; var SubKey : TArrayOf48Bytes); var n, b : Byte; begin for n := 1 to ST[Round] do begin Shift(DesData.C); Shift(DesData.D); end; for n := 1 to 48 do begin b := PC_2[n]; if b <= 28 then SubKey[n] := DesData.C[b] else SubKey[n] := DesData.D[b - 28]; end; end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *} procedure DES( const Input : TArrayOf8Bytes; var Output : TArrayOf8Bytes; const Key : TArrayOf8Bytes; Encrypt : Boolean); var n, b, Round : Byte; DesData : TDesData; begin for n := 1 to 64 do DesData.InputValue[n] := GetBit(Input, n); for n := 1 to 28 do begin DesData.C[n] := GetBit(Key, PC_1[n]); DesData.D[n] := GetBit(Key, PC_1[n + 28]); end; for n := 1 to 16 do SubKey(DesData, n, DesData.RoundKeys[n]); for n := 1 to 64 do begin if n <= 32 then DesData.L[n] := DesData.InputValue[IP[n]] else DesData.R[n - 32] := DesData.InputValue[IP[n]]; end; for Round := 1 to 16 do begin if Encrypt then F(DesData.R, DesData.RoundKeys[Round], DesData.FunctionResult) else F(DesData.R, DesData.RoundKeys[17 - Round], DesData.FunctionResult); for n := 1 to 32 do DesData.FunctionResult[n] := DesData.FunctionResult[n] xor DesData.L[n]; DesData.L := DesData.R; DesData.R := DesData.FunctionResult; end; for n := 1 to 64 do begin b := InvIP[n]; if b <= 32 then DesData.OutputValue[n] := DesData.R[b] else DesData.OutputValue[n] := DesData.L[b-32]; end; for n := 1 to 64 do SetBit(Output, n, DesData.OutputValue[n]); end; {* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}