blowfish.cpp
// blowfish.cpp - originally written and placed in the public domain by Wei Dai
#include "pch.h"
#include "blowfish.h"
#include "misc.h"
NAMESPACE_BEGIN(CryptoPP)
void Blowfish::Base::UncheckedSetKey(const byte *key_string, unsigned int keylength, const NameValuePairs &)
{
AssertValidKeyLength(keylength);
unsigned i, j=0, k;
word32 data, dspace[2] = {0, 0};
std::memcpy(pbox, p_init, sizeof(p_init));
std::memcpy(sbox, s_init, sizeof(s_init));
// Xor key string into encryption key vector
for (i=0 ; i<ROUNDS+2 ; ++i)
{
data = 0 ;
for (k=0 ; k<4 ; ++k )
data = (data << 8) | key_string[j++ % keylength];
pbox[i] ^= data;
}
crypt_block(dspace, pbox);
for (i=0; i<ROUNDS; i+=2)
crypt_block(pbox+i, pbox+i+2);
crypt_block(pbox+ROUNDS, sbox);
for (i=0; i<4*256-2; i+=2)
crypt_block(sbox+i, sbox+i+2);
if (!IsForwardTransformation())
for (i=0; i<(ROUNDS+2)/2; i++)
std::swap(pbox[i], pbox[ROUNDS+1-i]);
}
// this version is only used to make pbox and sbox
void Blowfish::Base::crypt_block(const word32 in[2], word32 out[2]) const
{
word32 left = in[0];
word32 right = in[1];
const word32 *const s=sbox;
const word32 *p=pbox;
left ^= p[0];
for (unsigned i=0; i<ROUNDS/2; i++)
{
right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
^ p[2*i+1];
left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
^ p[2*i+2];
}
right ^= p[ROUNDS+1];
out[0] = right;
out[1] = left;
}
void Blowfish::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
typedef BlockGetAndPut<word32, BigEndian> Block;
word32 left, right;
Block::Get(inBlock)(left)(right);
const word32 *const s=sbox;
const word32 *p=pbox;
left ^= p[0];
for (unsigned i=0; i<ROUNDS/2; i++)
{
right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
^ p[2*i+1];
left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
^ p[2*i+2];
}
right ^= p[ROUNDS+1];
Block::Put(xorBlock, outBlock)(right)(left);
}
NAMESPACE_END
blowfish.h
Classes for the Blowfish block cipher.
FixedRounds< 16 >::ROUNDS
static const int ROUNDS
Definition seckey.h:56
NameValuePairs
Interface for retrieving values given their names.
Definition cryptlib.h:327
word32
unsigned int word32
32-bit unsigned datatype
Definition config_int.h:72
misc.h
Utility functions for the Crypto++ library.
CryptoPP
Crypto++ library namespace.
pch.h
Precompiled header file.