BLWSTRAW.CPP (7972B)
1 // 2 // Copyright 2020 Electronic Arts Inc. 3 // 4 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is free 5 // software: you can redistribute it and/or modify it under the terms of 6 // the GNU General Public License as published by the Free Software Foundation, 7 // either version 3 of the License, or (at your option) any later version. 8 9 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 10 // in the hope that it will be useful, but with permitted additional restrictions 11 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 12 // distributed with this program. You should have received a copy of the 13 // GNU General Public License along with permitted additional restrictions 14 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection 15 16 /* $Header: /CounterStrike/BLWSTRAW.CPP 1 3/03/97 10:24a Joe_bostic $ */ 17 /*********************************************************************************************** 18 *** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S *** 19 *********************************************************************************************** 20 * * 21 * Project Name : Command & Conquer * 22 * * 23 * File Name : BLWSTRAW.CPP * 24 * * 25 * Programmer : Joe L. Bostic * 26 * * 27 * Start Date : 07/02/96 * 28 * * 29 * Last Update : July 3, 1996 [JLB] * 30 * * 31 *---------------------------------------------------------------------------------------------* 32 * Functions: * 33 * BlowStraw::Get -- Fetch a block of data from the straw. * 34 * BlowStraw::Key -- Submit a key to the Blowfish straw. * 35 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 36 37 38 #include "blwstraw.h" 39 #include <string.h> 40 #include <assert.h> 41 42 43 /*********************************************************************************************** 44 * BlowStraw::Get -- Fetch a block of data from the straw. * 45 * * 46 * This routine will take a block of data from the straw and process it according to the * 47 * encrypt/decrypt flag and the key supplied. Prior to a key be supplied, the data passes * 48 * through this straw unchanged. * 49 * * 50 * INPUT: source -- Pointer to the buffer to hold the data being requested. * 51 * * 52 * length -- The length of the data being requested. * 53 * * 54 * OUTPUT: Returns with the actual number of bytes stored into the buffer. If the number * 55 * returned is less than the number requested, then this indicates that the data * 56 * source has been exhausted. * 57 * * 58 * WARNINGS: none * 59 * * 60 * HISTORY: * 61 * 07/03/1996 JLB : Created. * 62 *=============================================================================================*/ 63 int BlowStraw::Get(void * source, int slen) 64 { 65 /* 66 ** Verify the parameter for legality. 67 */ 68 if (source == NULL || slen <= 0) { 69 return(0); 70 } 71 72 /* 73 ** If there is no blowfish engine present, then merely pass the data through 74 ** unchanged. 75 */ 76 if (BF == NULL) { 77 return(Straw::Get(source, slen)); 78 } 79 80 int total = 0; 81 82 while (slen > 0) { 83 84 /* 85 ** If there are any left over bytes in the buffer, pass them 86 ** through first. 87 */ 88 if (Counter > 0) { 89 int sublen = (slen < Counter) ? slen : Counter; 90 memmove(source, &Buffer[sizeof(Buffer)-Counter], sublen); 91 Counter -= sublen; 92 source = ((char *)source) + sublen; 93 slen -= sublen; 94 total += sublen; 95 } 96 if (slen == 0) break; 97 98 /* 99 ** Fetch and encrypt/decrypt the next block. 100 */ 101 int incount = Straw::Get(Buffer, sizeof(Buffer)); 102 if (incount == 0) break; 103 104 /* 105 ** Only full blocks are processed. Partial blocks are 106 ** merely passed through unchanged. 107 */ 108 if (incount == sizeof(Buffer)) { 109 if (Control == DECRYPT) { 110 BF->Decrypt(Buffer, incount, Buffer); 111 } else { 112 BF->Encrypt(Buffer, incount, Buffer); 113 } 114 } else { 115 memmove(&Buffer[sizeof(Buffer)-incount], Buffer, incount); 116 } 117 Counter = incount; 118 } 119 120 /* 121 ** Return with the total number of bytes placed into the buffer. 122 */ 123 return(total); 124 } 125 126 127 /*********************************************************************************************** 128 * BlowStraw::Key -- Submit a key to the Blowfish straw. * 129 * * 130 * This will take the key specified and use it to process the data that flows through this * 131 * straw segment. Prior to a key being submitted, the data will flow through unchanged. * 132 * * 133 * INPUT: key -- Pointer to the key to submit. * 134 * * 135 * length-- The length of the key. The length must not exceed 56 bytes. * 136 * * 137 * OUTPUT: none * 138 * * 139 * WARNINGS: none * 140 * * 141 * HISTORY: * 142 * 07/03/1996 JLB : Created. * 143 *=============================================================================================*/ 144 void BlowStraw::Key(void const * key, int length) 145 { 146 /* 147 ** Create the blowfish engine if one isn't already present. 148 */ 149 if (BF == NULL) { 150 BF = new BlowfishEngine; 151 } 152 153 assert(BF != NULL); 154 155 if (BF != NULL) { 156 BF->Submit_Key(key, length); 157 } 158 }