67 lines
1.9 KiB
Python
67 lines
1.9 KiB
Python
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#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""
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Created on Wed Feb 3 12:41:14 2021
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@author: pjoulaud
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"""
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CLE_PRIV_P = 53
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CLE_PRIV_Q = 97
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CLE_PUB_E = 7
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CLE_PUB_N = CLE_PRIV_P * CLE_PRIV_Q
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def conversion_message_en_nombre(chaine, bloc=3):
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nombre = ""
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for i in chaine :
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nombre += str(ord(i)-ord('A')+1)
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#print(nombre)
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while len(nombre)%bloc != 0 :
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nombre = '0' + nombre
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return nombre
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def chiffrement(chaine_num, bloc=3, e=CLE_PUB_E, n=CLE_PUB_N):
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code = ""
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for i in range(len(chaine_num)//bloc):
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morceau_chaine_num = chaine_num[i*bloc:(i+1)*bloc]
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#print(morceau_chaine_num)
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morceau_chaine_num = int(morceau_chaine_num)
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morceau_chaine_num = morceau_chaine_num**e
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morceau_chaine_num = morceau_chaine_num%n
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morceau_chaine_num = str(morceau_chaine_num)
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code += morceau_chaine_num
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code += ' '
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return code[:-1]
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def dechiffrement(chaine_num, bloc=2, e=CLE_PUB_E, n=CLE_PUB_N, p=CLE_PRIV_P, q=CLE_PRIV_Q):
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nombre = 1
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while nombre%e != 0 :
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nombre += (p-1)*(q-1)
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print(nombre)
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d = nombre//e
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liste_num = chaine_num.split(' ')
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print(liste_num)
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liste_decod = []
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for i in liste_num :
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decode = (int(i)**d) % n
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liste_decod.append(str(decode))
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print(liste_decod)
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chaine_decode = ''.join(liste_decod)
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print(chaine_decode)
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message = ""
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a_completer = len(chaine_decode)%bloc
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for i in range(a_completer):
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chaine_decode = '0' + chaine_decode
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for i in range(len(chaine_decode)//bloc):
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morceau_chaine_num = int(chaine_decode[i*bloc:(i+1)*bloc])
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message += chr(morceau_chaine_num+ord('A')-1)
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print(morceau_chaine_num, ' ',message)
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return message
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ma_chaine_num = conversion_message_en_nombre('BONJOUR')
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print(ma_chaine_num)
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mon_code = chiffrement(ma_chaine_num)
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print(mon_code)
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mon_message = dechiffrement(mon_code)
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print('message : ', mon_message)
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