File indexing completed on 2024-06-16 03:53:03

 /*
     This file is part of the KDE project
     SPDX-FileCopyrightText: 2001 George Staikos <staikos@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 // FIXME: should we unroll some loops?  Optimization can be done here.
 
 /* Implementation of 16 rounds blowfish as described in:
  * _Applied_Cryptography_ (c) Bruce Schneier, 1996.
  */
 
 #include "blowfish.h"
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
 #include "blowfishtables.h"
 
 // DO NOT INCLUDE THIS. IT BREAKS KWALLET.
 // We need to live with -Wundef until someone really figures out the problem.
 //#include <QtCore/qglobal.h> // for Q_BYTE_ORDER and friends
 // Workaround for -Wundef
 #define Q_BIG_ENDIAN 1
 #define Q_BYTE_ORDER Q_BIG_ENDIAN
 
 BlowFish::BlowFish()
 {
     _blksz = 8;
     m_key = nullptr;
     m_initialized = false;
 }
 
 bool BlowFish::init()
 {
     // Initialize the sboxes
     for (int i = 0; i < 256; i++) {
         m_S[0][i] = ks0[i];
         m_S[1][i] = ks1[i];
         m_S[2][i] = ks2[i];
         m_S[3][i] = ks3[i];
     }
 
     uint32_t datal = 0;
     uint32_t datar = 0;
     uint32_t data = 0;
     int j = 0;
 
     // Update the sboxes and pbox.
     for (int i = 0; i < 18; i++) {
         data = 0;
         for (int k = 0; k < 4; ++k) {
             data = (data << 8) | ((unsigned char *)m_key)[j++];
             if (j >= m_keylen / 8) {
                 j = 0;
             }
         }
         m_P[i] = P[i] ^ data;
     }
 
     for (int i = 0; i < 18; i += 2) {
         encipher(&datal, &datar);
         m_P[i] = datal;
         m_P[i + 1] = datar;
     }
 
     for (int j = 0; j < 4; j++) {
         for (int i = 0; i < 256; i += 2) {
             encipher(&datal, &datar);
             m_S[j][i] = datal;
             m_S[j][i + 1] = datar;
         }
     }
 
     // Nice code from gpg's implementation...
     //     check to see if the key is weak and return error if so
     for (int i = 0; i < 255; i++) {
         for (int j = i + 1; j < 256; j++) {
             if ((m_S[0][i] == m_S[0][j]) || (m_S[1][i] == m_S[1][j]) ||
                     (m_S[2][i] == m_S[2][j]) || (m_S[3][i] == m_S[3][j])) {
                 return false;
             }
         }
     }
 
     m_initialized = true;
 
     return true;
 }
 
 BlowFish::~BlowFish()
 {
     delete[](unsigned char *)m_key;
     m_key = nullptr;
 }
 
 int BlowFish::keyLen() const
 {
     return 448;
 }
 
 bool BlowFish::variableKeyLen() const
 {
     return true;
 }
 
 bool BlowFish::readyToGo() const
 {
     return m_initialized;
 }
 
 bool BlowFish::setKey(void *key, int bitlength)
 {
     if (bitlength <= 0 || bitlength > 448 || bitlength % 8 != 0) {
         return false;
     }
 
     delete[](unsigned char *)m_key;
 
     m_key = new unsigned char[bitlength / 8];
     memcpy(m_key, key, bitlength / 8);
     m_keylen = bitlength;
 
     return init();
 }
 // clang-format off
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
 #define shuffle(x) do {             \
         uint32_t r = x;             \
         x  = (r & 0xff000000) >> 24;    \
         x |= (r & 0x00ff0000) >>  8;    \
         x |= (r & 0x0000ff00) <<  8;    \
         x |= (r & 0x000000ff) << 24;    \
     } while (0)
 #endif
 // clang-format on
 
 int BlowFish::encrypt(void *block, int len)
 {
     uint32_t *d = (uint32_t *)block;
 
     if (!m_initialized || len % _blksz != 0) {
         return -1;
     }
 
     for (int i = 0; i < len / _blksz; i++) {
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
         shuffle(*d);
         shuffle(*(d + 1));
 #endif
         encipher(d, d + 1);
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
         shuffle(*d);
         shuffle(*(d + 1));
 #endif
         d += 2;
     }
 
     return len;
 }
 
 int BlowFish::decrypt(void *block, int len)
 {
     uint32_t *d = (uint32_t *)block;
 
     if (!m_initialized || len % _blksz != 0) {
         return -1;
     }
 
     for (int i = 0; i < len / _blksz; i++) {
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
         shuffle(*d);
         shuffle(*(d + 1));
 #endif
         decipher(d, d + 1);
 #if Q_BYTE_ORDER == Q_BIG_ENDIAN
         shuffle(*d);
         shuffle(*(d + 1));
 #endif
         d += 2;
     }
 
     return len;
 }
 
 uint32_t BlowFish::F(uint32_t x)
 {
     unsigned short a;
     unsigned short b;
     unsigned short c;
     unsigned short d;
     uint32_t y;
 
     d = x & 0x000000ff;
     x >>= 8;
     c = x & 0x000000ff;
     x >>= 8;
     b = x & 0x000000ff;
     x >>= 8;
     a = x & 0x000000ff;
 
     y = m_S[0][a] + m_S[1][b];
     y ^= m_S[2][c];
     y += m_S[3][d];
 
     return y;
 }
 
 void BlowFish::encipher(uint32_t *xl, uint32_t *xr)
 {
     uint32_t Xl = *xl;
     uint32_t Xr = *xr;
     uint32_t temp;
 
     for (int i = 0; i < 16; ++i) {
         Xl ^= m_P[i];
         Xr ^= F(Xl);
         // Exchange
         temp = Xl; Xl = Xr; Xr = temp;
     }
 
     // Exchange
     temp = Xl; Xl = Xr; Xr = temp;
 
     Xr ^= m_P[16];
     Xl ^= m_P[17];
 
     *xl = Xl;
     *xr = Xr;
 }
 
 void BlowFish::decipher(uint32_t *xl, uint32_t *xr)
 {
     uint32_t Xl = *xl;
     uint32_t Xr = *xr;
     uint32_t temp;
 
     for (int i = 17; i > 1; --i) {
         Xl ^= m_P[i];
         Xr ^= F(Xl);
         // Exchange
         temp = Xl; Xl = Xr; Xr = temp;
     }
 
     // Exchange
     temp = Xl; Xl = Xr; Xr = temp;
 
     Xr ^= m_P[1];
     Xl ^= m_P[0];
 
     *xl = Xl;
     *xr = Xr;
 }