1// (C) 1996-1998 Luigi Rizzo (luigi@iet.unipi.it) 2// 2009-2010 Jack Lloyd (lloyd@randombit.net) 3// 2011 Billy Brumley (billy.brumley@aalto.fi) 4// 2016-2017 Vivint, Inc. (jeff.wendling@vivint.com) 5// 6// Portions derived from code by Phil Karn (karn@ka9q.ampr.org), 7// Robert Morelos-Zaragoza (robert@spectra.eng.hawaii.edu) and Hari 8// Thirumoorthy (harit@spectra.eng.hawaii.edu), Aug 1995 9// 10// Redistribution and use in source and binary forms, with or without 11// modification, are permitted provided that the following conditions are 12// met: 13// 14// 1. Redistributions of source code must retain the above copyright 15// notice, this list of conditions and the following disclaimer. 16// 17// 2. Redistributions in binary form must reproduce the above copyright 18// notice, this list of conditions and the following disclaimer in the 19// documentation and/or other materials provided with the 20// distribution. 21// 22// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 23// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 24// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 25// DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, 26// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 27// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 28// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 30// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 31// IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32// POSSIBILITY OF SUCH DAMAGE. 33 34package infectious 35 36var ( 37 gf_exp = [510]byte{ 38 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1D, 0x3A, 0x74, 39 0xE8, 0xCD, 0x87, 0x13, 0x26, 0x4C, 0x98, 0x2D, 0x5A, 0xB4, 0x75, 40 0xEA, 0xC9, 0x8F, 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0x9D, 41 0x27, 0x4E, 0x9C, 0x25, 0x4A, 0x94, 0x35, 0x6A, 0xD4, 0xB5, 0x77, 42 0xEE, 0xC1, 0x9F, 0x23, 0x46, 0x8C, 0x05, 0x0A, 0x14, 0x28, 0x50, 43 0xA0, 0x5D, 0xBA, 0x69, 0xD2, 0xB9, 0x6F, 0xDE, 0xA1, 0x5F, 0xBE, 44 0x61, 0xC2, 0x99, 0x2F, 0x5E, 0xBC, 0x65, 0xCA, 0x89, 0x0F, 0x1E, 45 0x3C, 0x78, 0xF0, 0xFD, 0xE7, 0xD3, 0xBB, 0x6B, 0xD6, 0xB1, 0x7F, 46 0xFE, 0xE1, 0xDF, 0xA3, 0x5B, 0xB6, 0x71, 0xE2, 0xD9, 0xAF, 0x43, 47 0x86, 0x11, 0x22, 0x44, 0x88, 0x0D, 0x1A, 0x34, 0x68, 0xD0, 0xBD, 48 0x67, 0xCE, 0x81, 0x1F, 0x3E, 0x7C, 0xF8, 0xED, 0xC7, 0x93, 0x3B, 49 0x76, 0xEC, 0xC5, 0x97, 0x33, 0x66, 0xCC, 0x85, 0x17, 0x2E, 0x5C, 50 0xB8, 0x6D, 0xDA, 0xA9, 0x4F, 0x9E, 0x21, 0x42, 0x84, 0x15, 0x2A, 51 0x54, 0xA8, 0x4D, 0x9A, 0x29, 0x52, 0xA4, 0x55, 0xAA, 0x49, 0x92, 52 0x39, 0x72, 0xE4, 0xD5, 0xB7, 0x73, 0xE6, 0xD1, 0xBF, 0x63, 0xC6, 53 0x91, 0x3F, 0x7E, 0xFC, 0xE5, 0xD7, 0xB3, 0x7B, 0xF6, 0xF1, 0xFF, 54 0xE3, 0xDB, 0xAB, 0x4B, 0x96, 0x31, 0x62, 0xC4, 0x95, 0x37, 0x6E, 55 0xDC, 0xA5, 0x57, 0xAE, 0x41, 0x82, 0x19, 0x32, 0x64, 0xC8, 0x8D, 56 0x07, 0x0E, 0x1C, 0x38, 0x70, 0xE0, 0xDD, 0xA7, 0x53, 0xA6, 0x51, 57 0xA2, 0x59, 0xB2, 0x79, 0xF2, 0xF9, 0xEF, 0xC3, 0x9B, 0x2B, 0x56, 58 0xAC, 0x45, 0x8A, 0x09, 0x12, 0x24, 0x48, 0x90, 0x3D, 0x7A, 0xF4, 59 0xF5, 0xF7, 0xF3, 0xFB, 0xEB, 0xCB, 0x8B, 0x0B, 0x16, 0x2C, 0x58, 60 0xB0, 0x7D, 0xFA, 0xE9, 0xCF, 0x83, 0x1B, 0x36, 0x6C, 0xD8, 0xAD, 61 0x47, 0x8E, 62 63 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1D, 0x3A, 0x74, 64 0xE8, 0xCD, 0x87, 0x13, 0x26, 0x4C, 0x98, 0x2D, 0x5A, 0xB4, 0x75, 65 0xEA, 0xC9, 0x8F, 0x03, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC0, 0x9D, 66 0x27, 0x4E, 0x9C, 0x25, 0x4A, 0x94, 0x35, 0x6A, 0xD4, 0xB5, 0x77, 67 0xEE, 0xC1, 0x9F, 0x23, 0x46, 0x8C, 0x05, 0x0A, 0x14, 0x28, 0x50, 68 0xA0, 0x5D, 0xBA, 0x69, 0xD2, 0xB9, 0x6F, 0xDE, 0xA1, 0x5F, 0xBE, 69 0x61, 0xC2, 0x99, 0x2F, 0x5E, 0xBC, 0x65, 0xCA, 0x89, 0x0F, 0x1E, 70 0x3C, 0x78, 0xF0, 0xFD, 0xE7, 0xD3, 0xBB, 0x6B, 0xD6, 0xB1, 0x7F, 71 0xFE, 0xE1, 0xDF, 0xA3, 0x5B, 0xB6, 0x71, 0xE2, 0xD9, 0xAF, 0x43, 72 0x86, 0x11, 0x22, 0x44, 0x88, 0x0D, 0x1A, 0x34, 0x68, 0xD0, 0xBD, 73 0x67, 0xCE, 0x81, 0x1F, 0x3E, 0x7C, 0xF8, 0xED, 0xC7, 0x93, 0x3B, 74 0x76, 0xEC, 0xC5, 0x97, 0x33, 0x66, 0xCC, 0x85, 0x17, 0x2E, 0x5C, 75 0xB8, 0x6D, 0xDA, 0xA9, 0x4F, 0x9E, 0x21, 0x42, 0x84, 0x15, 0x2A, 76 0x54, 0xA8, 0x4D, 0x9A, 0x29, 0x52, 0xA4, 0x55, 0xAA, 0x49, 0x92, 77 0x39, 0x72, 0xE4, 0xD5, 0xB7, 0x73, 0xE6, 0xD1, 0xBF, 0x63, 0xC6, 78 0x91, 0x3F, 0x7E, 0xFC, 0xE5, 0xD7, 0xB3, 0x7B, 0xF6, 0xF1, 0xFF, 79 0xE3, 0xDB, 0xAB, 0x4B, 0x96, 0x31, 0x62, 0xC4, 0x95, 0x37, 0x6E, 80 0xDC, 0xA5, 0x57, 0xAE, 0x41, 0x82, 0x19, 0x32, 0x64, 0xC8, 0x8D, 81 0x07, 0x0E, 0x1C, 0x38, 0x70, 0xE0, 0xDD, 0xA7, 0x53, 0xA6, 0x51, 82 0xA2, 0x59, 0xB2, 0x79, 0xF2, 0xF9, 0xEF, 0xC3, 0x9B, 0x2B, 0x56, 83 0xAC, 0x45, 0x8A, 0x09, 0x12, 0x24, 0x48, 0x90, 0x3D, 0x7A, 0xF4, 84 0xF5, 0xF7, 0xF3, 0xFB, 0xEB, 0xCB, 0x8B, 0x0B, 0x16, 0x2C, 0x58, 85 0xB0, 0x7D, 0xFA, 0xE9, 0xCF, 0x83, 0x1B, 0x36, 0x6C, 0xD8, 0xAD, 86 0x47, 0x8E, 87 } 88 gf_log = [256]byte{ 89 0xFF, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1A, 0xC6, 0x03, 0xDF, 0x33, 90 0xEE, 0x1B, 0x68, 0xC7, 0x4B, 0x04, 0x64, 0xE0, 0x0E, 0x34, 0x8D, 91 0xEF, 0x81, 0x1C, 0xC1, 0x69, 0xF8, 0xC8, 0x08, 0x4C, 0x71, 0x05, 92 0x8A, 0x65, 0x2F, 0xE1, 0x24, 0x0F, 0x21, 0x35, 0x93, 0x8E, 0xDA, 93 0xF0, 0x12, 0x82, 0x45, 0x1D, 0xB5, 0xC2, 0x7D, 0x6A, 0x27, 0xF9, 94 0xB9, 0xC9, 0x9A, 0x09, 0x78, 0x4D, 0xE4, 0x72, 0xA6, 0x06, 0xBF, 95 0x8B, 0x62, 0x66, 0xDD, 0x30, 0xFD, 0xE2, 0x98, 0x25, 0xB3, 0x10, 96 0x91, 0x22, 0x88, 0x36, 0xD0, 0x94, 0xCE, 0x8F, 0x96, 0xDB, 0xBD, 97 0xF1, 0xD2, 0x13, 0x5C, 0x83, 0x38, 0x46, 0x40, 0x1E, 0x42, 0xB6, 98 0xA3, 0xC3, 0x48, 0x7E, 0x6E, 0x6B, 0x3A, 0x28, 0x54, 0xFA, 0x85, 99 0xBA, 0x3D, 0xCA, 0x5E, 0x9B, 0x9F, 0x0A, 0x15, 0x79, 0x2B, 0x4E, 100 0xD4, 0xE5, 0xAC, 0x73, 0xF3, 0xA7, 0x57, 0x07, 0x70, 0xC0, 0xF7, 101 0x8C, 0x80, 0x63, 0x0D, 0x67, 0x4A, 0xDE, 0xED, 0x31, 0xC5, 0xFE, 102 0x18, 0xE3, 0xA5, 0x99, 0x77, 0x26, 0xB8, 0xB4, 0x7C, 0x11, 0x44, 103 0x92, 0xD9, 0x23, 0x20, 0x89, 0x2E, 0x37, 0x3F, 0xD1, 0x5B, 0x95, 104 0xBC, 0xCF, 0xCD, 0x90, 0x87, 0x97, 0xB2, 0xDC, 0xFC, 0xBE, 0x61, 105 0xF2, 0x56, 0xD3, 0xAB, 0x14, 0x2A, 0x5D, 0x9E, 0x84, 0x3C, 0x39, 106 0x53, 0x47, 0x6D, 0x41, 0xA2, 0x1F, 0x2D, 0x43, 0xD8, 0xB7, 0x7B, 107 0xA4, 0x76, 0xC4, 0x17, 0x49, 0xEC, 0x7F, 0x0C, 0x6F, 0xF6, 0x6C, 108 0xA1, 0x3B, 0x52, 0x29, 0x9D, 0x55, 0xAA, 0xFB, 0x60, 0x86, 0xB1, 109 0xBB, 0xCC, 0x3E, 0x5A, 0xCB, 0x59, 0x5F, 0xB0, 0x9C, 0xA9, 0xA0, 110 0x51, 0x0B, 0xF5, 0x16, 0xEB, 0x7A, 0x75, 0x2C, 0xD7, 0x4F, 0xAE, 111 0xD5, 0xE9, 0xE6, 0xE7, 0xAD, 0xE8, 0x74, 0xD6, 0xF4, 0xEA, 0xA8, 112 0x50, 0x58, 0xAF, 113 } 114 gf_inverse = [256]byte{ 115 0x00, 0x01, 0x8E, 0xF4, 0x47, 0xA7, 0x7A, 0xBA, 0xAD, 0x9D, 0xDD, 116 0x98, 0x3D, 0xAA, 0x5D, 0x96, 0xD8, 0x72, 0xC0, 0x58, 0xE0, 0x3E, 117 0x4C, 0x66, 0x90, 0xDE, 0x55, 0x80, 0xA0, 0x83, 0x4B, 0x2A, 0x6C, 118 0xED, 0x39, 0x51, 0x60, 0x56, 0x2C, 0x8A, 0x70, 0xD0, 0x1F, 0x4A, 119 0x26, 0x8B, 0x33, 0x6E, 0x48, 0x89, 0x6F, 0x2E, 0xA4, 0xC3, 0x40, 120 0x5E, 0x50, 0x22, 0xCF, 0xA9, 0xAB, 0x0C, 0x15, 0xE1, 0x36, 0x5F, 121 0xF8, 0xD5, 0x92, 0x4E, 0xA6, 0x04, 0x30, 0x88, 0x2B, 0x1E, 0x16, 122 0x67, 0x45, 0x93, 0x38, 0x23, 0x68, 0x8C, 0x81, 0x1A, 0x25, 0x61, 123 0x13, 0xC1, 0xCB, 0x63, 0x97, 0x0E, 0x37, 0x41, 0x24, 0x57, 0xCA, 124 0x5B, 0xB9, 0xC4, 0x17, 0x4D, 0x52, 0x8D, 0xEF, 0xB3, 0x20, 0xEC, 125 0x2F, 0x32, 0x28, 0xD1, 0x11, 0xD9, 0xE9, 0xFB, 0xDA, 0x79, 0xDB, 126 0x77, 0x06, 0xBB, 0x84, 0xCD, 0xFE, 0xFC, 0x1B, 0x54, 0xA1, 0x1D, 127 0x7C, 0xCC, 0xE4, 0xB0, 0x49, 0x31, 0x27, 0x2D, 0x53, 0x69, 0x02, 128 0xF5, 0x18, 0xDF, 0x44, 0x4F, 0x9B, 0xBC, 0x0F, 0x5C, 0x0B, 0xDC, 129 0xBD, 0x94, 0xAC, 0x09, 0xC7, 0xA2, 0x1C, 0x82, 0x9F, 0xC6, 0x34, 130 0xC2, 0x46, 0x05, 0xCE, 0x3B, 0x0D, 0x3C, 0x9C, 0x08, 0xBE, 0xB7, 131 0x87, 0xE5, 0xEE, 0x6B, 0xEB, 0xF2, 0xBF, 0xAF, 0xC5, 0x64, 0x07, 132 0x7B, 0x95, 0x9A, 0xAE, 0xB6, 0x12, 0x59, 0xA5, 0x35, 0x65, 0xB8, 133 0xA3, 0x9E, 0xD2, 0xF7, 0x62, 0x5A, 0x85, 0x7D, 0xA8, 0x3A, 0x29, 134 0x71, 0xC8, 0xF6, 0xF9, 0x43, 0xD7, 0xD6, 0x10, 0x73, 0x76, 0x78, 135 0x99, 0x0A, 0x19, 0x91, 0x14, 0x3F, 0xE6, 0xF0, 0x86, 0xB1, 0xE2, 136 0xF1, 0xFA, 0x74, 0xF3, 0xB4, 0x6D, 0x21, 0xB2, 0x6A, 0xE3, 0xE7, 137 0xB5, 0xEA, 0x03, 0x8F, 0xD3, 0xC9, 0x42, 0xD4, 0xE8, 0x75, 0x7F, 138 0xFF, 0x7E, 0xFD, 139 } 140 gf_mul_table = [256][256]byte{} 141) 142 143func init() { 144 for i := 0; i < 256; i++ { 145 for j := 0; j < 256; j++ { 146 log_i := int(gf_log[i]) 147 log_j := int(gf_log[j]) 148 gf_mul_table[i][j] = gf_exp[(log_i+log_j)%255] 149 } 150 } 151 for i := 0; i < 256; i++ { 152 gf_mul_table[0][i], gf_mul_table[i][0] = 0, 0 153 } 154} 155