/*****************************************************************************/ /* CascDecrypt.cpp Copyright (c) Ladislav Zezula 2015 */ /*---------------------------------------------------------------------------*/ /* Decryption functions for CascLib */ /*---------------------------------------------------------------------------*/ /* Date Ver Who Comment */ /* -------- ---- --- ------- */ /* 31.10.15 1.00 Lad The first version of CascDecrypt.cpp */ /*****************************************************************************/ #define __CASCLIB_SELF__ #include "CascLib.h" #include "CascCommon.h" //----------------------------------------------------------------------------- // Local structures typedef struct _CASC_ENCRYPTION_KEY { ULONGLONG KeyName; // "Name" of the key BYTE Key[0x10]; // The key itself } CASC_ENCRYPTION_KEY, *PCASC_ENCRYPTION_KEY; typedef struct _CASC_SALSA20 { DWORD Key[0x10]; DWORD dwRounds; } CASC_SALSA20, *PCASC_SALSA20; //----------------------------------------------------------------------------- // Known encryption keys. See https://wowdev.wiki/CASC for updates static CASC_ENCRYPTION_KEY CascKeys[] = { // Key Name Encryption key Seen in // ---------------------- ------------------------------------------------------------------------------------------------ ----------- // Battle.net app {0x2C547F26A2613E01ULL, {0x37, 0xC5, 0x0C, 0x10, 0x2D, 0x4C, 0x9E, 0x3A, 0x5A, 0xC0, 0x69, 0xF0, 0x72, 0xB1, 0x41, 0x7D}}, // Battle.net App Alpha 1.5.0 // Overwatch {0xFB680CB6A8BF81F3ULL, {0x62, 0xD9, 0x0E, 0xFA, 0x7F, 0x36, 0xD7, 0x1C, 0x39, 0x8A, 0xE2, 0xF1, 0xFE, 0x37, 0xBD, 0xB9}}, // 0.8.0.24919_retailx64 (hardcoded) {0x402CD9D8D6BFED98ULL, {0xAE, 0xB0, 0xEA, 0xDE, 0xA4, 0x76, 0x12, 0xFE, 0x6C, 0x04, 0x1A, 0x03, 0x95, 0x8D, 0xF2, 0x41}}, // 0.8.0.24919_retailx64 (hardcoded) {0xDBD3371554F60306ULL, {0x34, 0xE3, 0x97, 0xAC, 0xE6, 0xDD, 0x30, 0xEE, 0xFD, 0xC9, 0x8A, 0x2A, 0xB0, 0x93, 0xCD, 0x3C}}, // 0.8.0.24919_retailx64 (streamed from server) {0x11A9203C9881710AULL, {0x2E, 0x2C, 0xB8, 0xC3, 0x97, 0xC2, 0xF2, 0x4E, 0xD0, 0xB5, 0xE4, 0x52, 0xF1, 0x8D, 0xC2, 0x67}}, // 0.8.0.24919_retailx64 (streamed from server) {0xA19C4F859F6EFA54ULL, {0x01, 0x96, 0xCB, 0x6F, 0x5E, 0xCB, 0xAD, 0x7C, 0xB5, 0x28, 0x38, 0x91, 0xB9, 0x71, 0x2B, 0x4B}}, // 0.8.0.24919_retailx64 (streamed from server) {0x87AEBBC9C4E6B601ULL, {0x68, 0x5E, 0x86, 0xC6, 0x06, 0x3D, 0xFD, 0xA6, 0xC9, 0xE8, 0x52, 0x98, 0x07, 0x6B, 0x3D, 0x42}}, // 0.8.0.24919_retailx64 (streamed from server) {0xDEE3A0521EFF6F03ULL, {0xAD, 0x74, 0x0C, 0xE3, 0xFF, 0xFF, 0x92, 0x31, 0x46, 0x81, 0x26, 0x98, 0x57, 0x08, 0xE1, 0xB9}}, // 0.8.0.24919_retailx64 (streamed from server) {0x8C9106108AA84F07ULL, {0x53, 0xD8, 0x59, 0xDD, 0xA2, 0x63, 0x5A, 0x38, 0xDC, 0x32, 0xE7, 0x2B, 0x11, 0xB3, 0x2F, 0x29}}, // 0.8.0.24919_retailx64 (streamed from server) {0x49166D358A34D815ULL, {0x66, 0x78, 0x68, 0xCD, 0x94, 0xEA, 0x01, 0x35, 0xB9, 0xB1, 0x6C, 0x93, 0xB1, 0x12, 0x4A, 0xBA}}, // 0.8.0.24919_retailx64 (streamed from server) {0x1463A87356778D14ULL, {0x69, 0xBD, 0x2A, 0x78, 0xD0, 0x5C, 0x50, 0x3E, 0x93, 0x99, 0x49, 0x59, 0xB3, 0x0E, 0x5A, 0xEC}}, // (streamed from server) {0x5E152DE44DFBEE01ULL, {0xE4, 0x5A, 0x17, 0x93, 0xB3, 0x7E, 0xE3, 0x1A, 0x8E, 0xB8, 0x5C, 0xEE, 0x0E, 0xEE, 0x1B, 0x68}}, // (streamed from server) {0x9B1F39EE592CA415ULL, {0x54, 0xA9, 0x9F, 0x08, 0x1C, 0xAD, 0x0D, 0x08, 0xF7, 0xE3, 0x36, 0xF4, 0x36, 0x8E, 0x89, 0x4C}}, // (streamed from server) {0x24C8B75890AD5917ULL, {0x31, 0x10, 0x0C, 0x00, 0xFD, 0xE0, 0xCE, 0x18, 0xBB, 0xB3, 0x3F, 0x3A, 0xC1, 0x5B, 0x30, 0x9F}}, // (included in game) {0xEA658B75FDD4890FULL, {0xDE, 0xC7, 0xA4, 0xE7, 0x21, 0xF4, 0x25, 0xD1, 0x33, 0x03, 0x98, 0x95, 0xC3, 0x60, 0x36, 0xF8}}, // (included in game) {0x026FDCDF8C5C7105ULL, {0x8F, 0x41, 0x80, 0x9D, 0xA5, 0x53, 0x66, 0xAD, 0x41, 0x6D, 0x3C, 0x33, 0x74, 0x59, 0xEE, 0xE3}}, // (included in game) {0xCAE3FAC925F20402ULL, {0x98, 0xB7, 0x8E, 0x87, 0x74, 0xBF, 0x27, 0x50, 0x93, 0xCB, 0x1B, 0x5F, 0xC7, 0x14, 0x51, 0x1B}}, // (included in game) {0x061581CA8496C80CULL, {0xDA, 0x2E, 0xF5, 0x05, 0x2D, 0xB9, 0x17, 0x38, 0x0B, 0x8A, 0xA6, 0xEF, 0x7A, 0x5F, 0x8E, 0x6A}}, // {0xBE2CB0FAD3698123ULL, {0x90, 0x2A, 0x12, 0x85, 0x83, 0x6C, 0xE6, 0xDA, 0x58, 0x95, 0x02, 0x0D, 0xD6, 0x03, 0xB0, 0x65}}, // {0x57A5A33B226B8E0AULL, {0xFD, 0xFC, 0x35, 0xC9, 0x9B, 0x9D, 0xB1, 0x1A, 0x32, 0x62, 0x60, 0xCA, 0x24, 0x6A, 0xCB, 0x41}}, // 1.1.0.0.30200 (Ana) {0x42B9AB1AF5015920ULL, {0xC6, 0x87, 0x78, 0x82, 0x3C, 0x96, 0x4C, 0x6F, 0x24, 0x7A, 0xCC, 0x0F, 0x4A, 0x25, 0x84, 0xF8}}, // 1.2.0.1.30684 (Summer Games) {0x4F0FE18E9FA1AC1AULL, {0x89, 0x38, 0x1C, 0x74, 0x8F, 0x65, 0x31, 0xBB, 0xFC, 0xD9, 0x77, 0x53, 0xD0, 0x6C, 0xC3, 0xCD}}, // 1.2.0.1.30684 {0x7758B2CF1E4E3E1BULL, {0x3D, 0xE6, 0x0D, 0x37, 0xC6, 0x64, 0x72, 0x35, 0x95, 0xF2, 0x7C, 0x5C, 0xDB, 0xF0, 0x8B, 0xFA}}, // 1.2.0.1.30684 {0xE5317801B3561125ULL, {0x7D, 0xD0, 0x51, 0x19, 0x9F, 0x84, 0x01, 0xF9, 0x5E, 0x4C, 0x03, 0xC8, 0x84, 0xDC, 0xEA, 0x33}}, // 1.4.0.2.32143 (Halloween Terror) {0x16B866D7BA3A8036ULL, {0x13, 0x95, 0xE8, 0x82, 0xBF, 0x25, 0xB4, 0x81, 0xF6, 0x1A, 0x4D, 0x62, 0x11, 0x41, 0xDA, 0x6E}}, // 1.4.1.0.31804 (Bastion Blizzcon 2016 skin) {0x11131FFDA0D18D30ULL, {0xC3, 0x2A, 0xD1, 0xB8, 0x25, 0x28, 0xE0, 0xA4, 0x56, 0x89, 0x7B, 0x3C, 0xE1, 0xC2, 0xD2, 0x7E}}, // 1.5.0.1.32795 (Sombra) {0xCAC6B95B2724144AULL, {0x73, 0xE4, 0xBE, 0xA1, 0x45, 0xDF, 0x2B, 0x89, 0xB6, 0x5A, 0xEF, 0x02, 0xF8, 0x3F, 0xA2, 0x60}}, // 1.5.0.1.32795 (Ecopoint: Antarctica) {0xB7DBC693758A5C36ULL, {0xBC, 0x3A, 0x92, 0xBF, 0xE3, 0x02, 0x51, 0x8D, 0x91, 0xCC, 0x30, 0x79, 0x06, 0x71, 0xBF, 0x10}}, // 1.5.0.1.32795 (Genji Oni skin) {0xFA505078126ACB3EULL, {0xBD, 0xC5, 0x18, 0x62, 0xAB, 0xED, 0x79, 0xB2, 0xDE, 0x48, 0xC8, 0xE7, 0xE6, 0x6C, 0x62, 0x00}}, // 15 WOW-20740patch7.0.1_Beta {0xFF813F7D062AC0BCULL, {0xAA, 0x0B, 0x5C, 0x77, 0xF0, 0x88, 0xCC, 0xC2, 0xD3, 0x90, 0x49, 0xBD, 0x26, 0x7F, 0x06, 0x6D}}, // 25 WOW-20740patch7.0.1_Beta (streamed from server) {0xD1E9B5EDF9283668ULL, {0x8E, 0x4A, 0x25, 0x79, 0x89, 0x4E, 0x38, 0xB4, 0xAB, 0x90, 0x58, 0xBA, 0x5C, 0x73, 0x28, 0xEE}}, // 39 WOW-20740patch7.0.1_Beta (streamed from server) {0xB76729641141CB34ULL, {0x98, 0x49, 0xD1, 0xAA, 0x7B, 0x1F, 0xD0, 0x98, 0x19, 0xC5, 0xC6, 0x62, 0x83, 0xA3, 0x26, 0xEC}}, // 40 WOW-20740patch7.0.1_Beta (streamed from server) {0xFFB9469FF16E6BF8ULL, {0xD5, 0x14, 0xBD, 0x19, 0x09, 0xA9, 0xE5, 0xDC, 0x87, 0x03, 0xF4, 0xB8, 0xBB, 0x1D, 0xFD, 0x9A}}, // 41 WOW-20740patch7.0.1_Beta (streamed from server) {0x23C5B5DF837A226CULL, {0x14, 0x06, 0xE2, 0xD8, 0x73, 0xB6, 0xFC, 0x99, 0x21, 0x7A, 0x18, 0x08, 0x81, 0xDA, 0x8D, 0x62}}, // 42 WOW-20740patch7.0.1_Beta (streamed from server) // {0x3AE403EF40AC3037ULL, {0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??}}, // 51 {0xE2854509C471C554ULL, {0x43, 0x32, 0x65, 0xF0, 0xCD, 0xEB, 0x2F, 0x4E, 0x65, 0xC0, 0xEE, 0x70, 0x08, 0x71, 0x4D, 0x9E}}, // 52 Warcraft movie items {0x8EE2CB82178C995AULL, {0xDA, 0x6A, 0xFC, 0x98, 0x9E, 0xD6, 0xCA, 0xD2, 0x79, 0x88, 0x59, 0x92, 0xC0, 0x37, 0xA8, 0xEE}}, // 55 BlizzCon 2016 Murlocs {0x5813810F4EC9B005ULL, {0x01, 0xBE, 0x8B, 0x43, 0x14, 0x2D, 0xD9, 0x9A, 0x9E, 0x69, 0x0F, 0xAD, 0x28, 0x8B, 0x60, 0x82}}, // 56 Fel Kitten {0x7F9E217166ED43EAULL, {0x05, 0xFC, 0x92, 0x7B, 0x9F, 0x4F, 0x5B, 0x05, 0x56, 0x81, 0x42, 0x91, 0x2A, 0x05, 0x2B, 0x0F}}, // 57 WOW-21531patch7.0.3_Beta {0xC4A8D364D23793F7ULL, {0xD1, 0xAC, 0x20, 0xFD, 0x14, 0x95, 0x7F, 0xAB, 0xC2, 0x71, 0x96, 0xE9, 0xF6, 0xE7, 0x02, 0x4A}}, // 58 WOW-21691patch7.0.3_Beta Demon Hunter #1 cinematic (legion_dh1) {0x40A234AEBCF2C6E5ULL, {0xC6, 0xC5, 0xF6, 0xC7, 0xF7, 0x35, 0xD7, 0xD9, 0x4C, 0x87, 0x26, 0x7F, 0xA4, 0x99, 0x4D, 0x45}}, // 59 WOW-21691patch7.0.3_Beta Demon Hunter #2 cinematic (legion_dh2) {0x9CF7DFCFCBCE4AE5ULL, {0x72, 0xA9, 0x7A, 0x24, 0xA9, 0x98, 0xE3, 0xA5, 0x50, 0x0F, 0x38, 0x71, 0xF3, 0x76, 0x28, 0xC0}}, // 60 WOW-21691patch7.0.3_Beta Val'sharah #1 cinematic (legion_val_yd) {0x4E4BDECAB8485B4FULL, {0x38, 0x32, 0xD7, 0xC4, 0x2A, 0xAC, 0x92, 0x68, 0xF0, 0x0B, 0xE7, 0xB6, 0xB4, 0x8E, 0xC9, 0xAF}}, // 61 WOW-21691patch7.0.3_Beta Val'sharah #2 cinematic (legion_val_yx) {0x94A50AC54EFF70E4ULL, {0xC2, 0x50, 0x1A, 0x72, 0x65, 0x4B, 0x96, 0xF8, 0x63, 0x50, 0xC5, 0xA9, 0x27, 0x96, 0x2F, 0x7A}}, // 62 WOW-21691patch7.0.3_Beta Sylvanas warchief cinematic (legion_org_vs) {0xBA973B0E01DE1C2CULL, {0xD8, 0x3B, 0xBC, 0xB4, 0x6C, 0xC4, 0x38, 0xB1, 0x7A, 0x48, 0xE7, 0x6C, 0x4F, 0x56, 0x54, 0xA3}}, // 63 WOW-21691patch7.0.3_Beta Stormheim Sylvanas vs Greymane cinematic (legion_sth) {0x494A6F8E8E108BEFULL, {0xF0, 0xFD, 0xE1, 0xD2, 0x9B, 0x27, 0x4F, 0x6E, 0x7D, 0xBD, 0xB7, 0xFF, 0x81, 0x5F, 0xE9, 0x10}}, // 64 WOW-21691patch7.0.3_Beta Harbingers Gul'dan video (legion_hrb_g) {0x918D6DD0C3849002ULL, {0x85, 0x70, 0x90, 0xD9, 0x26, 0xBB, 0x28, 0xAE, 0xDA, 0x4B, 0xF0, 0x28, 0xCA, 0xCC, 0x4B, 0xA3}}, // 65 WOW-21691patch7.0.3_Beta Harbingers Khadgar video (legion_hrb_k) {0x0B5F6957915ADDCAULL, {0x4D, 0xD0, 0xDC, 0x82, 0xB1, 0x01, 0xC8, 0x0A, 0xBA, 0xC0, 0xA4, 0xD5, 0x7E, 0x67, 0xF8, 0x59}}, // 66 WOW-21691patch7.0.3_Beta Harbingers Illidan video (legion_hrb_i) {0x794F25C6CD8AB62BULL, {0x76, 0x58, 0x3B, 0xDA, 0xCD, 0x52, 0x57, 0xA3, 0xF7, 0x3D, 0x15, 0x98, 0xA2, 0xCA, 0x2D, 0x99}}, // 67 WOW-21846patch7.0.3_Beta Suramar cinematic (legion_su_i) {0xA9633A54C1673D21ULL, {0x1F, 0x8D, 0x46, 0x7F, 0x5D, 0x6D, 0x41, 0x1F, 0x8A, 0x54, 0x8B, 0x63, 0x29, 0xA5, 0x08, 0x7E}}, // 68 WOW-21846patch7.0.3_Beta legion_su_r cinematic {0x5E5D896B3E163DEAULL, {0x8A, 0xCE, 0x8D, 0xB1, 0x69, 0xE2, 0xF9, 0x8A, 0xC3, 0x6A, 0xD5, 0x2C, 0x08, 0x8E, 0x77, 0xC1}}, // 69 WOW-21846patch7.0.3_Beta Broken Shore intro cinematic (legion_bs_i) {0x0EBE36B5010DFD7FULL, {0x9A, 0x89, 0xCC, 0x7E, 0x3A, 0xCB, 0x29, 0xCF, 0x14, 0xC6, 0x0B, 0xC1, 0x3B, 0x1E, 0x46, 0x16}}, // 70 WOW-21846patch7.0.3_Beta Alliance Broken Shore cinematic (legion_bs_a) {0x01E828CFFA450C0FULL, {0x97, 0x2B, 0x6E, 0x74, 0x42, 0x0E, 0xC5, 0x19, 0xE6, 0xF9, 0xD9, 0x7D, 0x59, 0x4A, 0xA3, 0x7C}}, // 71 WOW-21846patch7.0.3_Beta Horde Broken Shore cinematic (legion_bs_h) {0x4A7BD170FE18E6AEULL, {0xAB, 0x55, 0xAE, 0x1B, 0xF0, 0xC7, 0xC5, 0x19, 0xAF, 0xF0, 0x28, 0xC1, 0x56, 0x10, 0xA4, 0x5B}}, // 72 WOW-21846patch7.0.3_Beta Khadgar & Light's Heart cinematic (legion_iq_lv) {0x69549CB975E87C4FULL, {0x7B, 0x6F, 0xA3, 0x82, 0xE1, 0xFA, 0xD1, 0x46, 0x5C, 0x85, 0x1E, 0x3F, 0x47, 0x34, 0xA1, 0xB3}}, // 73 WOW-21846patch7.0.3_Beta legion_iq_id cinematic {0x460C92C372B2A166ULL, {0x94, 0x6D, 0x56, 0x59, 0xF2, 0xFA, 0xF3, 0x27, 0xC0, 0xB7, 0xEC, 0x82, 0x8B, 0x74, 0x8A, 0xDB}}, // 74 WOW-21952patch7.0.3_Beta Stormheim Alliance cinematic (legion_g_a_sth) {0x8165D801CCA11962ULL, {0xCD, 0x0C, 0x0F, 0xFA, 0xAD, 0x93, 0x63, 0xEC, 0x14, 0xDD, 0x25, 0xEC, 0xDD, 0x2A, 0x5B, 0x62}}, // 75 WOW-21952patch7.0.3_Beta Stormheim Horde cinematic (legion_g_h_sth) // {0xA3F1C999090ADAC9ULL, {0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??}}, // 81 WOW-22578patch7.1.0_PTR Firecat Mount // {0x18AFDF5191923610ULL, {0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??}}, // 82 WOW-22578patch7.1.0_PTR {0, {0}} }; static const char * szKeyConstant16 = "expand 16-byte k"; static const char * szKeyConstant32 = "expand 32-byte k"; //----------------------------------------------------------------------------- // Local functions static DWORD Rol32(DWORD dwValue, DWORD dwRolCount) { return (dwValue << dwRolCount) | (dwValue >> (32 - dwRolCount)); } static LPBYTE FindCascKey(ULONGLONG KeyName) { // Search the known keys for(size_t i = 0; CascKeys[i].KeyName != 0; i++) { if(CascKeys[i].KeyName == KeyName) return CascKeys[i].Key; } // Key not found return NULL; } static void Initialize(PCASC_SALSA20 pState, LPBYTE pbKey, DWORD cbKeyLength, LPBYTE pbVector) { const char * szConstants = (cbKeyLength == 32) ? szKeyConstant32 : szKeyConstant16; DWORD KeyIndex = cbKeyLength - 0x10; memset(pState, 0, sizeof(CASC_SALSA20)); pState->Key[0] = *(PDWORD)(szConstants + 0x00); pState->Key[1] = *(PDWORD)(pbKey + 0x00); pState->Key[2] = *(PDWORD)(pbKey + 0x04); pState->Key[3] = *(PDWORD)(pbKey + 0x08); pState->Key[4] = *(PDWORD)(pbKey + 0x0C); pState->Key[5] = *(PDWORD)(szConstants + 0x04); pState->Key[6] = *(PDWORD)(pbVector + 0x00); pState->Key[7] = *(PDWORD)(pbVector + 0x04); pState->Key[8] = 0; pState->Key[9] = 0; pState->Key[10] = *(PDWORD)(szConstants + 0x08); pState->Key[11] = *(PDWORD)(pbKey + KeyIndex + 0x00); pState->Key[12] = *(PDWORD)(pbKey + KeyIndex + 0x04); pState->Key[13] = *(PDWORD)(pbKey + KeyIndex + 0x08); pState->Key[14] = *(PDWORD)(pbKey + KeyIndex + 0x0C); pState->Key[15] = *(PDWORD)(szConstants + 0x0C); pState->dwRounds = 20; } static int Decrypt(PCASC_SALSA20 pState, LPBYTE pbOutBuffer, LPBYTE pbInBuffer, size_t cbInBuffer) { LPBYTE pbXorValue; DWORD KeyMirror[0x10]; DWORD XorValue[0x10]; DWORD BlockSize; DWORD i; // Repeat until we have data to read while(cbInBuffer > 0) { // Create the copy of the key memcpy(KeyMirror, pState->Key, sizeof(KeyMirror)); // Shuffle the key for(i = 0; i < pState->dwRounds; i += 2) { KeyMirror[0x04] ^= Rol32((KeyMirror[0x00] + KeyMirror[0x0C]), 0x07); KeyMirror[0x08] ^= Rol32((KeyMirror[0x04] + KeyMirror[0x00]), 0x09); KeyMirror[0x0C] ^= Rol32((KeyMirror[0x08] + KeyMirror[0x04]), 0x0D); KeyMirror[0x00] ^= Rol32((KeyMirror[0x0C] + KeyMirror[0x08]), 0x12); KeyMirror[0x09] ^= Rol32((KeyMirror[0x05] + KeyMirror[0x01]), 0x07); KeyMirror[0x0D] ^= Rol32((KeyMirror[0x09] + KeyMirror[0x05]), 0x09); KeyMirror[0x01] ^= Rol32((KeyMirror[0x0D] + KeyMirror[0x09]), 0x0D); KeyMirror[0x05] ^= Rol32((KeyMirror[0x01] + KeyMirror[0x0D]), 0x12); KeyMirror[0x0E] ^= Rol32((KeyMirror[0x0A] + KeyMirror[0x06]), 0x07); KeyMirror[0x02] ^= Rol32((KeyMirror[0x0E] + KeyMirror[0x0A]), 0x09); KeyMirror[0x06] ^= Rol32((KeyMirror[0x02] + KeyMirror[0x0E]), 0x0D); KeyMirror[0x0A] ^= Rol32((KeyMirror[0x06] + KeyMirror[0x02]), 0x12); KeyMirror[0x03] ^= Rol32((KeyMirror[0x0F] + KeyMirror[0x0B]), 0x07); KeyMirror[0x07] ^= Rol32((KeyMirror[0x03] + KeyMirror[0x0F]), 0x09); KeyMirror[0x0B] ^= Rol32((KeyMirror[0x07] + KeyMirror[0x03]), 0x0D); KeyMirror[0x0F] ^= Rol32((KeyMirror[0x0B] + KeyMirror[0x07]), 0x12); KeyMirror[0x01] ^= Rol32((KeyMirror[0x00] + KeyMirror[0x03]), 0x07); KeyMirror[0x02] ^= Rol32((KeyMirror[0x01] + KeyMirror[0x00]), 0x09); KeyMirror[0x03] ^= Rol32((KeyMirror[0x02] + KeyMirror[0x01]), 0x0D); KeyMirror[0x00] ^= Rol32((KeyMirror[0x03] + KeyMirror[0x02]), 0x12); KeyMirror[0x06] ^= Rol32((KeyMirror[0x05] + KeyMirror[0x04]), 0x07); KeyMirror[0x07] ^= Rol32((KeyMirror[0x06] + KeyMirror[0x05]), 0x09); KeyMirror[0x04] ^= Rol32((KeyMirror[0x07] + KeyMirror[0x06]), 0x0D); KeyMirror[0x05] ^= Rol32((KeyMirror[0x04] + KeyMirror[0x07]), 0x12); KeyMirror[0x0B] ^= Rol32((KeyMirror[0x0A] + KeyMirror[0x09]), 0x07); KeyMirror[0x08] ^= Rol32((KeyMirror[0x0B] + KeyMirror[0x0A]), 0x09); KeyMirror[0x09] ^= Rol32((KeyMirror[0x08] + KeyMirror[0x0B]), 0x0D); KeyMirror[0x0A] ^= Rol32((KeyMirror[0x09] + KeyMirror[0x08]), 0x12); KeyMirror[0x0C] ^= Rol32((KeyMirror[0x0F] + KeyMirror[0x0E]), 0x07); KeyMirror[0x0D] ^= Rol32((KeyMirror[0x0C] + KeyMirror[0x0F]), 0x09); KeyMirror[0x0E] ^= Rol32((KeyMirror[0x0D] + KeyMirror[0x0C]), 0x0D); KeyMirror[0x0F] ^= Rol32((KeyMirror[0x0E] + KeyMirror[0x0D]), 0x12); } // Set the number of remaining bytes pbXorValue = (LPBYTE)XorValue; BlockSize = (DWORD)CASCLIB_MIN(cbInBuffer, 0x40); // Prepare the XOR constants for(i = 0; i < 16; i++) { XorValue[i] = KeyMirror[i] + pState->Key[i]; } // Decrypt the block for(i = 0; i < BlockSize; i++) { pbOutBuffer[i] = pbInBuffer[i] ^ pbXorValue[i]; } pState->Key[8] = pState->Key[8] + 1; if(pState->Key[8] == 0) pState->Key[9] = pState->Key[9] + 1; // Adjust buffers pbOutBuffer += BlockSize; pbInBuffer += BlockSize; cbInBuffer -= BlockSize; } return ERROR_SUCCESS; } static int Decrypt_Salsa20(LPBYTE pbOutBuffer, LPBYTE pbInBuffer, size_t cbInBuffer, LPBYTE pbKey, DWORD cbKeySize, LPBYTE pbVector) { CASC_SALSA20 SalsaState; Initialize(&SalsaState, pbKey, cbKeySize, pbVector); return Decrypt(&SalsaState, pbOutBuffer, pbInBuffer, cbInBuffer); } //----------------------------------------------------------------------------- // Public functions int CascDecrypt(LPBYTE pbOutBuffer, PDWORD pcbOutBuffer, LPBYTE pbInBuffer, DWORD cbInBuffer, DWORD dwFrameIndex) { ULONGLONG KeyName = 0; LPBYTE pbBufferEnd = pbInBuffer + cbInBuffer; LPBYTE pbKey; DWORD KeyNameSize; DWORD dwShift = 0; DWORD IVSize; BYTE Vector[0x08]; BYTE EncryptionType; int nError; // Verify and retrieve the key name size if(pbInBuffer >= pbBufferEnd) return ERROR_FILE_CORRUPT; if(pbInBuffer[0] != 0 && pbInBuffer[0] != 8) return ERROR_NOT_SUPPORTED; KeyNameSize = *pbInBuffer++; // Copy the key name if((pbInBuffer + KeyNameSize) >= pbBufferEnd) return ERROR_FILE_CORRUPT; memcpy(&KeyName, pbInBuffer, KeyNameSize); pbInBuffer += KeyNameSize; // Verify and retrieve the Vector size if(pbInBuffer >= pbBufferEnd) return ERROR_FILE_CORRUPT; if(pbInBuffer[0] != 4 && pbInBuffer[0] != 8) return ERROR_NOT_SUPPORTED; IVSize = *pbInBuffer++; // Copy the initialization vector if((pbInBuffer + IVSize) >= pbBufferEnd) return ERROR_FILE_CORRUPT; memset(Vector, 0, sizeof(Vector)); memcpy(Vector, pbInBuffer, IVSize); pbInBuffer += IVSize; // Verify and retrieve the encryption type if(pbInBuffer >= pbBufferEnd) return ERROR_FILE_CORRUPT; if(pbInBuffer[0] != 'S' && pbInBuffer[0] != 'A') return ERROR_NOT_SUPPORTED; EncryptionType = *pbInBuffer++; // Do we have enough space in the output buffer? if((DWORD)(pbBufferEnd - pbInBuffer) > pcbOutBuffer[0]) return ERROR_INSUFFICIENT_BUFFER; // Check if we know the key pbKey = FindCascKey(KeyName); if(pbKey == NULL) return ERROR_FILE_ENCRYPTED; // Shuffle the Vector with the block index // Note that there's no point to go beyond 32 bits, unless the file has // more than 0xFFFFFFFF frames. for(int i = 0; i < sizeof(dwFrameIndex); i++) { Vector[i] = Vector[i] ^ (BYTE)((dwFrameIndex >> dwShift) & 0xFF); dwShift += 8; } // Perform the decryption-specific action switch(EncryptionType) { case 'S': // Salsa20 nError = Decrypt_Salsa20(pbOutBuffer, pbInBuffer, (pbBufferEnd - pbInBuffer), pbKey, 0x10, Vector); if(nError != ERROR_SUCCESS) return nError; // Supply the size of the output buffer pcbOutBuffer[0] = (DWORD)(pbBufferEnd - pbInBuffer); return ERROR_SUCCESS; // case 'A': // return ERROR_NOT_SUPPORTED; } assert(false); return ERROR_NOT_SUPPORTED; } int CascDirectCopy(LPBYTE pbOutBuffer, PDWORD pcbOutBuffer, LPBYTE pbInBuffer, DWORD cbInBuffer) { // Check the buffer size if((cbInBuffer - 1) > pcbOutBuffer[0]) return ERROR_INSUFFICIENT_BUFFER; // Copy the data memcpy(pbOutBuffer, pbInBuffer, cbInBuffer); pcbOutBuffer[0] = cbInBuffer; return ERROR_SUCCESS; }