def s_des_encrypt(bitstring, key1, key2, decrypt=False):
if decrypt:
key2,key1=key1,key2
bitstring=gf.permute_key(bitstring, pa.en_IP)
left,right=complex_function(bitstring[:4], bitstring[4:], key1)
left,right=complex_function(right, left, key2)
return gf.permute_key(left+right, pa.en_IP_inverse)
def MappingF(input_bitstring, keystring):
expanded_bitstring=gf.permute_key(input_bitstring, pa.mp_EP)
bitstring=bin(int(expanded_bitstring, 2)^int(keystring, 2))[2:].zfill(8)
left_bits=bitstring[:4]
right_bits=bitstring[4:]
left_out=SBox(left_bits, pa.mp_matrix_s0)
right_out=SBox(right_bits, pa.mp_matrix_s1)
return gf.permute_key(left_out+right_out, pa.mp_P4)
def s_des_keygen(key):
primary_key=gf.create_keystring(key, 10)
primary_key=gf.permute_key(primary_key, pa.kg_P10)
primary_key=gf.left_shift(primary_key[:5], 1) + gf.left_shift(primary_key[5:], 1)
key1=gf.permute_key(primary_key, pa.kg_P8)
primary_key=gf.left_shift(primary_key[:5], 2) + gf.left_shift(primary_key[5:], 2)
key2=gf.permute_key(primary_key, pa.kg_P8)
return key1,key2