Blowfish::Blowfish(const byte *key_string, unsigned int keylength, CipherDir dir)
: pbox(ROUNDS+2), sbox(4*256)
{
assert(keylength == KeyLength(keylength));
unsigned i, j=0, k;
word32 data, dspace[2] = {0, 0};
memcpy(pbox, p_init, sizeof(p_init));
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 (dir==DECRYPTION)
for (i=0; i<(ROUNDS+2)/2; i++)
std::swap(pbox[i], pbox[ROUNDS+1-i]);
}
void BlowfishSetKey (BF_KEY *key, int keylength, unsigned char *key_string)
{
unsigned i, j=0, k;
word32 data, dspace[2] = {0, 0};
word32 *sbox = key->sbox;
word32 *pbox = key->pbox;
memcpy(pbox, p_init, sizeof(p_init));
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(key, dspace, pbox);
for (i=0; i<ROUNDS; i+=2)
crypt_block(key, pbox+i, pbox+i+2);
crypt_block(key, pbox+ROUNDS, sbox);
for (i=0; i<4*256-2; i+=2)
crypt_block(key, sbox+i, sbox+i+2);
for (i=0; i < ROUNDS+2; i++)
key->pbox_dec[ROUNDS+1-i] = pbox[i];
}
void Blowfish::SetKey(const byte* key_string, word32 keylength, CipherDir dir)
{
assert(keylength >= 4 && keylength <= 56);
unsigned i, j=0, k;
word32 data, dspace[2] = {0, 0};
memcpy(pbox_, p_init_, sizeof(p_init_));
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 (dir==DECRYPTION)
for (i=0; i<(ROUNDS+2)/2; i++)
mySTL::swap(pbox_[i], pbox_[ROUNDS+1-i]);
}
