#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Wed Feb  3 12:41:14 2021

@author: pjoulaud
"""

CLE_PRIV_P = 53
CLE_PRIV_Q = 97
CLE_PUB_E = 7
CLE_PUB_N = CLE_PRIV_P * CLE_PRIV_Q


def conversion_message_en_nombre(chaine, bloc=3):
    nombre = ""
    for i in chaine :
        nombre += str(ord(i)-ord('A')+1)
        #print(nombre)
    while len(nombre)%bloc != 0 :
        nombre = '0' + nombre
    return nombre

def chiffrement(chaine_num, bloc=3, e=CLE_PUB_E, n=CLE_PUB_N):
    code = ""
    for i in range(len(chaine_num)//bloc):
        morceau_chaine_num = chaine_num[i*bloc:(i+1)*bloc]
        #print(morceau_chaine_num)
        morceau_chaine_num = int(morceau_chaine_num)
        morceau_chaine_num = morceau_chaine_num**e
        morceau_chaine_num = morceau_chaine_num%n
        morceau_chaine_num = str(morceau_chaine_num)
        code += morceau_chaine_num
        code += ' '
    return code[:-1]
    
def dechiffrement(chaine_num, bloc=2, e=CLE_PUB_E, n=CLE_PUB_N, p=CLE_PRIV_P, q=CLE_PRIV_Q):
    nombre = 1
    while nombre%e != 0 :
        nombre += (p-1)*(q-1)
        print(nombre)
    d = nombre//e
    liste_num = chaine_num.split(' ')
    print(liste_num)
    liste_decod = []
    for i in liste_num :
        decode = (int(i)**d) % n
        liste_decod.append(str(decode))
    print(liste_decod)
    chaine_decode = ''.join(liste_decod)
    print(chaine_decode)
    message = ""
    a_completer = len(chaine_decode)%bloc
    for i in range(a_completer):
        chaine_decode = '0' + chaine_decode
    for i in range(len(chaine_decode)//bloc):
        morceau_chaine_num = int(chaine_decode[i*bloc:(i+1)*bloc])
        message += chr(morceau_chaine_num+ord('A')-1)
        print(morceau_chaine_num, ' ',message)
    return message

ma_chaine_num = conversion_message_en_nombre('BONJOUR')
print(ma_chaine_num)
mon_code = chiffrement(ma_chaine_num)
print(mon_code)
mon_message = dechiffrement(mon_code)
print('message : ', mon_message)