BlockCipher.cpp

00001 #include "BlockCipher.h"
00002 #include <string.h>
00003 
00004 BlockCipher::BlockCipher(uint32_t bs, BLOCK_CIPHER_MODE m, uint8_t *iv):
00005 Cipher(),
00006 blockSize(bs),
00007 mode(m),
00008 IV(0)
00009 {
00010     if(mode == CBC_MODE)
00011     {
00012         IV = new uint8_t[blockSize];
00013         memcpy(IV, iv, blockSize); 
00014     }
00015 }
00016 
00017 BlockCipher::~BlockCipher()
00018 {
00019     if(IV != 0)
00020         delete[] IV;
00021 }
00022 
00023 CIPHER_TYPE BlockCipher::getType() const
00024 {
00025     return BLOCK_CIPHER;
00026 }
00027 
00028 uint32_t BlockCipher::getBlockSize() const
00029 {
00030     return blockSize;
00031 }
00032 
00033 void BlockCipher::encrypt(uint8_t *out, uint8_t *in, uint32_t length)
00034 {
00035     uint8_t *tmp = 0;
00036     if(mode == CBC_MODE)
00037         tmp = new uint8_t[getBlockSize()];
00038     for(uint32_t i = 0; i < length; i += getBlockSize())
00039     {
00040         if(mode == CBC_MODE)
00041         {
00042             memcpy(tmp, &in[i], getBlockSize());
00043             for(int j = 0; j < (int)getBlockSize(); ++j)
00044                 tmp[j] ^= IV[j];
00045                 
00046             encryptBlock(&out[i], tmp);
00047         
00048             memcpy(IV, &out[i], getBlockSize());
00049         }
00050         else        
00051             encryptBlock(&out[i], &in[i]);
00052     }
00053     if(mode == CBC_MODE)
00054         delete[] tmp;
00055 }
00056 
00057 void BlockCipher::decrypt(uint8_t *out, uint8_t *in, uint32_t length)
00058 {
00059     for(uint32_t i = 0; i < length; i += getBlockSize())
00060     {
00061         if(mode == CBC_MODE)
00062         {
00063             decryptBlock(&out[i], &in[i]);
00064             for(int j = 0; j < (int)getBlockSize(); ++j)
00065                 out[i+j] ^= IV[j];
00066         
00067             memcpy(IV, &in[i], getBlockSize());
00068         }
00069         else        
00070             decryptBlock(&out[i], &in[i]);
00071     }
00072 }