1 /* 2 * Copyright 2012 Jacek Caban for CodeWeavers 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Lesser General Public 6 * License as published by the Free Software Foundation; either 7 * version 2.1 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public 15 * License along with this library; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA 17 */ 18 19 #include "jscript.h" 20 21 #include "wine/debug.h" 22 23 WINE_DEFAULT_DEBUG_CHANNEL(jscript); 24 25 /* 26 * This file implements algorithm for decoding scripts encoded by 27 * screnc.exe. The 'secret' algorithm that's well documented here: 28 * http://www.virtualconspiracy.com/content/articles/breaking-screnc 29 */ 30 31 static const unsigned char pick_encoding[64] = { 32 1,2,0,1,2,0,2,0,0,2,0,2,1,0,2,0, 33 1,0,2,0,1,1,2,0,0,2,1,0,2,0,0,2, 34 1,1,0,2,0,2,0,1,0,1,1,2,0,1,0,2, 35 1,0,2,0,1,1,2,0,0,1,1,2,0,1,0,2}; 36 37 static const unsigned char dictionary[][3] = { 38 {0x00,0x00,0x00}, {0x01,0x01,0x01}, {0x02,0x02,0x02}, {0x03,0x03,0x03}, 39 {0x04,0x04,0x04}, {0x05,0x05,0x05}, {0x06,0x06,0x06}, {0x07,0x07,0x07}, 40 {0x08,0x08,0x08}, {0x7b,0x57,0x6e}, {0x0a,0x0a,0x0a}, {0x0b,0x0b,0x0b}, 41 {0x0c,0x0c,0x0c}, {0x0d,0x0d,0x0d}, {0x0e,0x0e,0x0e}, {0x0f,0x0f,0x0f}, 42 {0x10,0x10,0x10}, {0x11,0x11,0x11}, {0x12,0x12,0x12}, {0x13,0x13,0x13}, 43 {0x14,0x14,0x14}, {0x15,0x15,0x15}, {0x16,0x16,0x16}, {0x17,0x17,0x17}, 44 {0x18,0x18,0x18}, {0x19,0x19,0x19}, {0x1a,0x1a,0x1a}, {0x1b,0x1b,0x1b}, 45 {0x1c,0x1c,0x1c}, {0x1d,0x1d,0x1d}, {0x1e,0x1e,0x1e}, {0x1f,0x1f,0x1f}, 46 {0x32,0x2e,0x2d}, {0x30,0x47,0x75}, {0x21,0x7a,0x52}, {0x29,0x56,0x60}, 47 {0x5b,0x42,0x71}, {0x38,0x6a,0x5e}, {0x33,0x2f,0x49}, {0x3d,0x26,0x5c}, 48 {0x58,0x49,0x62}, {0x3a,0x41,0x7d}, {0x35,0x34,0x29}, {0x65,0x32,0x36}, 49 {0x39,0x5b,0x20}, {0x5c,0x76,0x7c}, {0x56,0x72,0x7a}, {0x73,0x43,0x7f}, 50 {0x66,0x38,0x6b}, {0x4e,0x39,0x63}, {0x45,0x70,0x33}, {0x6b,0x45,0x2b}, 51 {0x62,0x68,0x68}, {0x59,0x71,0x51}, {0x78,0x4f,0x66}, {0x5e,0x09,0x76}, 52 {0x7d,0x62,0x31}, {0x4a,0x44,0x64}, {0x6d,0x23,0x54}, {0x71,0x75,0x43}, 53 {0x00,0x00,0x00}, {0x60,0x7e,0x3a}, {0x00,0x00,0x00}, {0x53,0x5e,0x7e}, 54 {0x00,0x00,0x00}, {0x42,0x77,0x45}, {0x27,0x4a,0x2c}, {0x48,0x61,0x2a}, 55 {0x72,0x5d,0x74}, {0x75,0x22,0x27}, {0x31,0x4b,0x37}, {0x37,0x6f,0x44}, 56 {0x4d,0x4e,0x79}, {0x52,0x3b,0x59}, {0x22,0x4c,0x2f}, {0x54,0x50,0x6f}, 57 {0x6a,0x67,0x26}, {0x47,0x2a,0x72}, {0x64,0x7d,0x6a}, {0x2d,0x74,0x39}, 58 {0x20,0x54,0x7b}, {0x7f,0x2b,0x3f}, {0x2e,0x2d,0x38}, {0x4c,0x2c,0x77}, 59 {0x5d,0x30,0x67}, {0x7e,0x6e,0x53}, {0x6c,0x6b,0x47}, {0x6f,0x66,0x34}, 60 {0x79,0x35,0x78}, {0x74,0x25,0x5d}, {0x43,0x21,0x30}, {0x26,0x64,0x23}, 61 {0x76,0x4d,0x5a}, {0x25,0x52,0x5b}, {0x24,0x63,0x6c}, {0x2b,0x3f,0x48}, 62 {0x28,0x7b,0x55}, {0x23,0x78,0x70}, {0x41,0x29,0x69}, {0x34,0x28,0x2e}, 63 {0x09,0x73,0x4c}, {0x2a,0x59,0x21}, {0x44,0x33,0x24}, {0x3f,0x7f,0x4e}, 64 {0x77,0x6d,0x50}, {0x3b,0x55,0x09}, {0x55,0x53,0x56}, {0x69,0x7c,0x73}, 65 {0x61,0x3a,0x35}, {0x63,0x5f,0x61}, {0x50,0x65,0x4b}, {0x67,0x46,0x58}, 66 {0x51,0x58,0x3b}, {0x49,0x31,0x57}, {0x4f,0x69,0x22}, {0x46,0x6c,0x6d}, 67 {0x68,0x5a,0x4d}, {0x7c,0x48,0x25}, {0x36,0x27,0x28}, {0x70,0x5c,0x46}, 68 {0x6e,0x3d,0x4a}, {0x7a,0x24,0x32}, {0x2f,0x79,0x41}, {0x5f,0x37,0x3d}, 69 {0x4b,0x60,0x5f}, {0x5a,0x51,0x4f}, {0x2c,0x20,0x42}, {0x57,0x36,0x65}}; 70 71 static const int digits[] = { 72 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 73 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 74 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 75 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 76 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 77 0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, 78 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 79 0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 80 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 81 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 82 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 83 0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff, 84 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 85 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 86 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 87 0x31, 0x32, 0x33, 0xff, 0xff, 0xff, 0xff, 0xff}; 88 89 static BOOL decode_dword(const WCHAR *p, DWORD *ret) 90 { 91 DWORD i; 92 93 for(i=0; i<6; i++) { 94 if(p[i] >= sizeof(digits)/sizeof(*digits) || digits[p[i]] == 0xff) 95 return FALSE; 96 } 97 if(p[6] != '=' || p[7] != '=') 98 return FALSE; 99 100 *ret = (digits[p[0]] << 2) 101 + (digits[p[1]] >> 4) 102 + ((digits[p[1]] & 0xf) << 12) 103 + ((digits[p[2]] >> 2) << 8) 104 + ((digits[p[2]] & 0x3) << 22) 105 + (digits[p[3]] << 16) 106 + ((digits[p[4]] << 2) << 24) 107 + ((digits[p[5]] >> 4) << 24); 108 return TRUE; 109 } 110 111 HRESULT decode_source(WCHAR *code) 112 { 113 const WCHAR *src = code; 114 WCHAR *dst = code; 115 116 static const WCHAR decode_beginW[] = {'#','@','~','^'}; 117 static const WCHAR decode_endW[] = {'^','#','~','@'}; 118 119 while(*src) { 120 if(!strncmpW(src, decode_beginW, sizeof(decode_beginW)/sizeof(*decode_beginW))) { 121 DWORD len, i, j=0, csum, s=0; 122 123 src += sizeof(decode_beginW)/sizeof(*decode_beginW); 124 125 if(!decode_dword(src, &len)) 126 return JS_E_INVALID_CHAR; 127 128 src += 8; 129 130 for(i=0; i<len; i++) { 131 if (src[i] == '@') { 132 switch(src[++i]) { 133 case '#': 134 s += dst[j++] = '\r'; 135 break; 136 case '&': 137 s += dst[j++] = '\n'; 138 break; 139 case '!': 140 s += dst[j++] = '<'; 141 break; 142 case '*': 143 s += dst[j++] = '>'; 144 break; 145 case '$': 146 s += dst[j++] = '@'; 147 break; 148 default: 149 FIXME("unescape %c\n", src[i]); 150 return E_FAIL; 151 } 152 }else if (src[i] < 128) { 153 s += dst[j] = dictionary[src[i]][pick_encoding[j%64]]; 154 j++; 155 }else { 156 FIXME("Unsupported char %c\n", src[i]); 157 return E_FAIL; 158 } 159 } 160 161 src += len; 162 dst += j; 163 164 if(!decode_dword(src, &csum) || s != csum) 165 return JS_E_INVALID_CHAR; 166 src += 8; 167 168 if(strncmpW(src, decode_endW, sizeof(decode_endW)/sizeof(*decode_endW))) 169 return JS_E_INVALID_CHAR; 170 src += sizeof(decode_endW)/sizeof(*decode_endW); 171 }else { 172 *dst++ = *src++; 173 } 174 } 175 176 *dst = 0; 177 178 TRACE("decoded %s\n", debugstr_w(code)); 179 return S_OK; 180 } 181