//Decrypt from Input Buffer to Output Buffer
//Returns false if n is multiple of 8
void BlowFish::Decrypt(const unsigned char* in, unsigned char* out, unsigned int n, int iMode)
{
//Check the buffer's length - should be > 0 and multiple of 8
if((n==0)||(n%8!=0))
//throw exception("Incorrect buffer length");
return;
SBlock work;
if(iMode == CBC) //CBC mode, using the Chain
{
SBlock crypt, chain(m_oChain);
for(; n >= 8; n -= 8, in += 8)
{
BytesToBlock(in, work);
crypt = work;
Decrypt(work);
work ^= chain;
chain = crypt;
BlockToBytes(work, out+=8);
}
}
else if(iMode == CFB) //CFB mode, using the Chain, not using Decrypt()
{
SBlock crypt, chain(m_oChain);
for(; n >= 8; n -= 8, in += 8)
{
BytesToBlock(in, work);
Encrypt(chain);
crypt = work;
work ^= chain;
chain = crypt;
BlockToBytes(work, out+=8);
}
}
else //ECB mode, not using the Chain
{
for(; n >= 8; n -= 8, in += 8)
{
BytesToBlock(in, work);
Decrypt(work);
BlockToBytes(work, out+=8);
}
}
}
//Decrypt Buffer in Place
//Returns false if n is multiple of 8
void CBlowFish::Decrypt(unsigned char* buf, size_t n, int iMode)
{
//Check the buffer's length - should be > 0 and multiple of 8
if((n==0)||(n%8!=0))
throw std::exception("Incorrect buffer length");
SBlock work;
if(iMode == CBC) //CBC mode, using the Chain
{
SBlock crypt, chain(m_oChain);
for(; n >= 8; n -= 8)
{
BytesToBlock(buf, work);
crypt = work;
Decrypt(work);
work ^= chain;
chain = crypt;
BlockToBytes(work, buf+=8);
}
}
else if(iMode == CFB) //CFB mode, using the Chain, not using Decrypt()
{
SBlock crypt, chain(m_oChain);
for(; n >= 8; n -= 8)
{
BytesToBlock(buf, work);
Encrypt(chain);
crypt = work;
work ^= chain;
chain = crypt;
BlockToBytes(work, buf+=8);
}
}
else //ECB mode, not using the Chain
{
for(; n >= 8; n -= 8)
{
BytesToBlock(buf, work);
Decrypt(work);
BlockToBytes(work, buf+=8);
}
}
}
//Encrypt Buffer in Place
//Returns false if n is multiple of 8
void BlowFish::Encrypt(unsigned char* buf, unsigned int n, int iMode)
{
//Check the buffer's length - should be > 0 and multiple of 8
if((n==0)||(n%8!=0))
//throw exception("Incorrect buffer length");
return;
SBlock work;
if(iMode == CBC) //CBC mode, using the Chain
{
SBlock chain(m_oChain);
for(; n >= 8; n -= 8)
{
BytesToBlock(buf, work);
work ^= chain;
Encrypt(work);
chain = work;
BlockToBytes(work, buf+=8);
}
}
else if(iMode == CFB) //CFB mode, using the Chain
{
SBlock chain(m_oChain);
for(; n >= 8; n -= 8)
{
Encrypt(chain);
BytesToBlock(buf, work);
work ^= chain;
chain = work;
BlockToBytes(work, buf+=8);
}
}
else //ECB mode, not using the Chain
{
for(; n >= 8; n -= 8)
{
BytesToBlock(buf, work);
Encrypt(work);
BlockToBytes(work, buf+=8);
}
}
}
