func expensiveBlowfishSetup(key []byte, cost uint32, salt []byte) (*blowfish.Cipher, error) {
csalt, err := base64Decode(salt)
if err != nil {
return nil, err
}
// Bug compatibility with C bcrypt implementations. They use the trailing
// NULL in the key string during expansion.
ckey := append(key, 0)
c, err := blowfish.NewSaltedCipher(ckey, csalt)
if err != nil {
return nil, err
}
var i, rounds uint64
rounds = 1 << cost
for i = 0; i < rounds; i++ {
blowfish.ExpandKey(ckey, c)
blowfish.ExpandKey(csalt, c)
}
return c, nil
}
func (e *Engine) blowfish_salt_ctr() error {
salt := e.stack.Pop()
return e.ctr(func(key []byte) (cipher.Block, error) { return blowfish.NewSaltedCipher(key, salt) })
}
