/****************************************************************************** * * swcipher.cpp - code for class 'SWCipher'- a driver class that * provides cipher utilities * * $Id: swcipher.cpp 3755 2020-07-19 18:43:07Z scribe $ * * Copyright 1999-2013 CrossWire Bible Society (http://www.crosswire.org) * CrossWire Bible Society * P. O. Box 2528 * Tempe, AZ 85280-2528 * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation version 2. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * */ #include #include #include #include namespace { char lats[] = { 'b', 'c', 'e', 'a', 'f', 'g', 'i', 'j', 'k', 'l', 'h', 'm', 'p', 'q', 'B', 'r', 'H', 'o', 's', 't', 'T', 'u', 'w', 'x', 'y', 'A', 'd', 'C', 'D', 'z', 'E', 'F', 'I', 'J', 'K', 'G', 'L', 'N', 'O', '7', 'P', 'Q', 'M', 'R', 'S', 'U', 'V', 'W', 'X', 'Y', '9', '0', '1', '2', 'Z', '3', '6', '4', 'n', '8', 'v', '5' }; } SWORD_NAMESPACE_START /****************************************************************************** * SWCipher Constructor - Initializes data for instance of SWCipher * */ SWCipher::SWCipher(unsigned char *key) { SWBuf cipherKey = personalize((const char *)key, false); master.initialize((unsigned char *)(const char *)cipherKey, cipherKey.size()); buf = 0; } /****************************************************************************** * SWCipher Destructor - Cleans up instance of SWCipher */ SWCipher::~SWCipher() { if (buf) free(buf); } void SWCipher::setUncipheredBuf(const char *ibuf, unsigned long ilen) { if (ibuf) { if (buf) free(buf); if (!ilen) { len = strlen(buf); ilen = len + 1; } else len = ilen; buf = (char *) malloc(ilen); memcpy(buf, ibuf, ilen); cipher = false; } decode(); } char *SWCipher::getUncipheredBuf() { decode(); return buf; } void SWCipher::setCipheredBuf(unsigned long *ilen, const char *ibuf) { if (ibuf) { if (buf) free(buf); buf = (char *) malloc(*ilen+1); memcpy(buf, ibuf, *ilen); len = *ilen; cipher = true; } encode(); *ilen = len; } char *SWCipher::getCipheredBuf(unsigned long *ilen) { encode(); if (ilen) *ilen = len; return buf; } /****************************************************************************** * SWCipher::encode - This function "encodes" the input stream into the * output stream. * The GetChars() and SendChars() functions are * used to separate this method from the actual * i/o. */ void SWCipher::encode(void) { if (!cipher) { work = master; for (unsigned long i = 0; i < len; i++) buf[i] = work.encrypt(buf[i]); cipher = true; } } /****************************************************************************** * SWCipher::decode - This function "decodes" the input stream into the * output stream. * The GetChars() and SendChars() functions are * used to separate this method from the actual * i/o. */ void SWCipher::decode(void) { if (cipher) { work = master; unsigned long i; for (i = 0; i < len; i++) buf[i] = work.decrypt(buf[i]); buf[i] = 0; cipher = false; } } /****************************************************************************** * SWCipher::setCipherKey - setter for a new CipherKey * */ void SWCipher::setCipherKey(const char *ikey) { SWBuf cipherKey = personalize(ikey, false); master.initialize((unsigned char *)(const char *)cipherKey, cipherKey.size()); } /****************************************************************************** * SWCipher::personalize - a simple personalization encoding * * encode - whether to encode or decode * */ SWBuf SWCipher::personalize(const SWBuf &buf, bool encode) { std::map charHash; for (int i = 0; i < 62; ++i) charHash[lats[i]] = i; SWBuf segs[5]; int segn = 0; for (unsigned int i = 0; i < buf.size() && segn < 5; ++i) { if (buf[i] == '-') ++segn; else segs[segn].append(buf[i]); } SWBuf result; SWBuf chkSum = segs[4]; if (segs[4].size() < 5) segs[4].size(4); for (int i = 0; i < 4; ++i) { int csum = 0; for (unsigned int j = 0; j < segs[i].size() && j < segs[0].size(); ++j) { char hash = charHash[segs[i][j]]; char obfusHash = charHash[segs[0][j%segs[0].size()]]; if (encode) { obfusHash = hash - (i ? obfusHash : 0); if (obfusHash < 0) obfusHash = (62 + obfusHash); } else { obfusHash = hash + (i ? obfusHash : 0); obfusHash %= 62; } if (i) segs[i][j] = lats[(long)obfusHash]; csum += (encode ? obfusHash : hash); } segs[4][i] = lats[csum%62]; if (result.size()) result += "-"; result += (!encode && !i ? "" : segs[i].c_str()); } if (encode) { result += "-"; result += segs[4]; } return (!encode && chkSum != segs[4]) ? buf : result; } SWORD_NAMESPACE_END