void decode(KviCString & szText, unsigned char ** buf, int *len)
{
// make sure its length is multiple of 12 (eventually pad with zeroes)
if(szText.len() % 12)
{
int oldL = szText.len();
szText.setLen(szText.len() + (12 - (szText.len() % 12)));
char * padB = szText.ptr() + oldL;
char * padE = szText.ptr() + szText.len();
while(padB < padE)*padB++ = 0;
}
*len = (int)(szText.len() * 2) / 3;
*buf = (unsigned char *)KviMemory::allocate(*len);
unsigned char * p = (unsigned char *)szText.ptr();
unsigned char * e = p + szText.len();
int i;
unsigned char * bufp = *buf;
while(p < e)
{
quint32 * dw1 = (quint32 *)bufp;
bufp += 4;
quint32 * dw2 = (quint32 *)bufp;
bufp += 4;
*dw2 = 0;
for(i=0;i < 6;i++)*dw2 |= (fake_base64dec(*p++)) << (i * 6);
*dw1 = 0;
for(i=0;i < 6;i++)*dw1 |= (fake_base64dec(*p++)) << (i * 6);
}
// FIXME: this is probably needed only on LittleEndian machines!
byteswap_buffer(*buf,*len);
}
bool KviMircryptionEngine::doEncryptCBC(KviCString & plain, KviCString & encoded)
{
// make sure it is a multiple of 8 bytes (eventually pad with zeroes)
if(plain.len() % 8)
{
int oldL = plain.len();
plain.setLen(plain.len() + (8 - (plain.len() % 8)));
char * padB = plain.ptr() + oldL;
char * padE = plain.ptr() + plain.len();
while(padB < padE)
*padB++ = 0;
}
int ll = plain.len() + 8;
unsigned char * in = (unsigned char *)KviMemory::allocate(ll);
InitVectorEngine::fillRandomIV(in, 8);
KviMemory::copy(in + 8, plain.ptr(), plain.len());
// encrypt
unsigned char * out = (unsigned char *)KviMemory::allocate(ll);
BlowFish bf((unsigned char *)m_szEncryptKey.ptr(), m_szEncryptKey.len());
bf.ResetChain();
bf.Encrypt(in, out, ll, BlowFish::CBC);
KviMemory::free(in);
encoded.bufferToBase64((const char *)out, ll);
KviMemory::free(out);
encoded.prepend('*'); // prepend the signature
return true;
}
bool KviFile::load(KviCString & szData)
{
kvi_u32_t iLen;
if(!load(iLen))
return false;
szData.setLen(iLen);
return (read((char *)(szData.ptr()), iLen) == iLen);
}
bool KviMircryptionEngine::doDecryptECB(KviCString & encoded, KviCString & plain)
{
unsigned char * buf = nullptr;
int len;
UglyBase64::decode(encoded, &buf, &len);
plain.setLen(len);
BlowFish bf((unsigned char *)m_szDecryptKey.ptr(), m_szDecryptKey.len());
bf.ResetChain();
bf.Decrypt(buf, (unsigned char *)plain.ptr(), len, BlowFish::ECB);
KviMemory::free(buf);
return true;
}
bool KviMircryptionEngine::doEncryptECB(KviCString & plain, KviCString & encoded)
{
// make sure it is a multiple of 8 bytes (eventually pad with zeroes)
if(plain.len() % 8)
{
int oldL = plain.len();
plain.setLen(plain.len() + (8 - (plain.len() % 8)));
char * padB = plain.ptr() + oldL;
char * padE = plain.ptr() + plain.len();
while(padB < padE)
*padB++ = 0;
}
unsigned char * out = (unsigned char *)KviMemory::allocate(plain.len()); // we use this to avoid endiannes problems
BlowFish bf((unsigned char *)m_szEncryptKey.ptr(), m_szEncryptKey.len());
bf.ResetChain();
bf.Encrypt((unsigned char *)plain.ptr(), out, plain.len(), BlowFish::ECB);
UglyBase64::encode(out, plain.len(), encoded);
KviMemory::free(out);
return true;
}
bool KviMircryptionEngine::doDecryptCBC(KviCString & encoded, KviCString & plain)
{
if(*(encoded.ptr()) != '*')
{
qDebug("WARNING: specified a CBC key but the incoming message doesn't seem to be a CBC one");
return doDecryptECB(encoded, plain);
}
encoded.cutLeft(1);
char * tmpBuf;
int len = encoded.base64ToBuffer(&tmpBuf, false);
if(len < 0)
{
setLastError(__tr2qs("The message is not a base64 string: this is not my stuff"));
return false;
}
if((len < 8) || (len % 8))
{
setLastError(__tr2qs("The message doesn't seem to be encoded with CBC Mircryption"));
if(len > 0)
KviCString::freeBuffer(tmpBuf);
return false;
}
plain.setLen(len);
BlowFish bf((unsigned char *)m_szDecryptKey.ptr(), m_szDecryptKey.len());
bf.ResetChain();
bf.Decrypt((unsigned char *)tmpBuf, (unsigned char *)plain.ptr(), len, BlowFish::CBC);
// kill the first 8 bytes (random IV)
plain.cutLeft(8);
KviCString::freeBuffer(tmpBuf);
return true;
}
