// Copyright 2010 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Package des implements the Data Encryption Standard (DES) and the // Triple Data Encryption Algorithm (TDEA) as defined // in U.S. Federal Information Processing Standards Publication 46-3. // // DES is cryptographically broken and should not be used for secure // applications. package des // Used to perform an initial permutation of a 64-bit input block. var initialPermutation = [64]byte{ 6, 14, 22, 30, 38, 46, 54, 62, 4, 12, 20, 28, 36, 44, 52, 60, 2, 10, 18, 26, 34, 42, 50, 58, 0, 8, 16, 24, 32, 40, 48, 56, 7, 15, 23, 31, 39, 47, 55, 63, 5, 13, 21, 29, 37, 45, 53, 61, 3, 11, 19, 27, 35, 43, 51, 59, 1, 9, 17, 25, 33, 41, 49, 57, } // Used to perform a final permutation of a 4-bit preoutput block. This is the // inverse of initialPermutation var finalPermutation = [64]byte{ 24, 56, 16, 48, 8, 40, 0, 32, 25, 57, 17, 49, 9, 41, 1, 33, 26, 58, 18, 50, 10, 42, 2, 34, 27, 59, 19, 51, 11, 43, 3, 35, 28, 60, 20, 52, 12, 44, 4, 36, 29, 61, 21, 53, 13, 45, 5, 37, 30, 62, 22, 54, 14, 46, 6, 38, 31, 63, 23, 55, 15, 47, 7, 39, } // Used to expand an input block of 32 bits, producing an output block of 48 // bits. var expansionFunction = [48]byte{ 0, 31, 30, 29, 28, 27, 28, 27, 26, 25, 24, 23, 24, 23, 22, 21, 20, 19, 20, 19, 18, 17, 16, 15, 16, 15, 14, 13, 12, 11, 12, 11, 10, 9, 8, 7, 8, 7, 6, 5, 4, 3, 4, 3, 2, 1, 0, 31, } // Yields a 32-bit output from a 32-bit input var permutationFunction = [32]byte{ 16, 25, 12, 11, 3, 20, 4, 15, 31, 17, 9, 6, 27, 14, 1, 22, 30, 24, 8, 18, 0, 5, 29, 23, 13, 19, 2, 26, 10, 21, 28, 7, } // Used in the key schedule to select 56 bits // from a 64-bit input. var permutedChoice1 = [56]byte{ 7, 15, 23, 31, 39, 47, 55, 63, 6, 14, 22, 30, 38, 46, 54, 62, 5, 13, 21, 29, 37, 45, 53, 61, 4, 12, 20, 28, 1, 9, 17, 25, 33, 41, 49, 57, 2, 10, 18, 26, 34, 42, 50, 58, 3, 11, 19, 27, 35, 43, 51, 59, 36, 44, 52, 60, } // Used in the key schedule to produce each subkey by selecting 48 bits from // the 56-bit input var permutedChoice2 = [48]byte{ 42, 39, 45, 32, 55, 51, 53, 28, 41, 50, 35, 46, 33, 37, 44, 52, 30, 48, 40, 49, 29, 36, 43, 54, 15, 4, 25, 19, 9, 1, 26, 16, 5, 11, 23, 8, 12, 7, 17, 0, 22, 3, 10, 14, 6, 20, 27, 24, } // 8 S-boxes composed of 4 rows and 16 columns // Used in the DES cipher function var sBoxes = [8][4][16]uint8{ // S-box 1 { {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}, }, // S-box 2 { {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}, }, // S-box 3 { {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}, }, // S-box 4 { {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}, }, // S-box 5 { {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}, }, // S-box 6 { {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}, }, // S-box 7 { {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}, }, // S-box 8 { {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}, }, } // Size of left rotation per round in each half of the key schedule var ksRotations = [16]uint8{1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}