Description of De-crypter

Description of the Main Raptor’s Cryptographic Algorithm

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Algorithm

This is the main solver algorithm program. It allow us to decrypt datas slices crypted with the version 1 of the Raptor Cryptographic Algorithm. To solve I need thse following variables :

• raw_txt : The input crypted string storage

• Basemin : The minimum Base index

• Basemax : The maximum Base index

• table2 : The list of list containing the Base Table

• testkey : The key of the algorithm, the decrypting process absolutely need this key.

The solving procedure is ruled by the following steps:

• Generating the Base Table and store it into my table2 variable

• Getting inputs known as crypted string and his associated key.

• Organize data slice removing separators via the slurps methods

• Decrypting process using the decrypt_procedure method (see documentation)

• Store and return the results of decrypting process

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Source Code

import sys
import math as m
import random as r

represent=''
table2 = []
dic = {}
main_dic={}
choice = ' '
chaine=''

if(len(sys.argv)!=4):
        Basemin = 2
        Basemax = 37
        Range   = 36**2
else :
        Basemin = int(sys.argv[1])
        Basemax = int(sys.argv[2])
        Range   = int(sys.argv[3])

if(Basemin<2 or Basemax>37):
        print("Affichage impossible veuillez selectionner une plage de valeure contenue dans [2,36]")
        exit(0)

maxi=Basemax-Basemin

for i in range(Basemin,Basemax):
        table2.append(table(i,0,Range,1))

for i in range (0,len(table2)):
        table2[i]=splitTable(table2[i])

for j in range (0,len(table2)):
        table2[j]=rec_table_construct_lvl1(table2[j],j+2,1,0)
        for k in range(0,j+2):
                table2[j][k]=(str(0)+table2[j][k])
table2=rec_manage(table2)

long_chaine = []
long_crypt  = []
longi=0
seuil = 20
seuil_lvl2=70
choice = ''
userchoice=0
sep=['!','"','#','$','%','&','(',')','*','+',',','-','.','/']
sep_lvl2=[":",";","<","=",">","?","@"]
sep_lvl3=['A','B','C','D','E','F','G','H','I','J','K','L']
mesquin=['M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

long_long_chaine = []
tmp_long_chaine  = []
long_chaine   = []
long_crypt    = []
testc         = []
testk         = []
int_chaine    = []
lvl2_key_miam = []
tmp_crypt     = []


while(choice!='q'):
        # init_all()
        current_sep_lvl3 =  "A"
        current_sep_lvl2 =  ":"
        long_chaine[:]   = []
        long_crypt[:]    = []
        long_long_crypt  = []
        testc[:]         = []
        testk[:]         = []
        int_chaine[:]    = []
        lvl2_key_miam[:] = []
        long_long_chaine[:] = []
        tmp_long_chaine[:]  = []
        tmp_crypt        = ()
        testkey=''
        raw_txt=''
        clean_txt = ''
        longi = 0
        longii= 0

        res = ()
        raw_txt=input("Chaine cryptée : \n")
        testkey=input("Clé unique : \n")
        if(len(raw_txt)/5>=seuil and len(raw_txt)/5<seuil_lvl2):
                longi+=1
        if(len(raw_txt)/5>=seuil_lvl2):
                longii+=1
        raw_txt = slurp3(raw_txt)
        testkey = slurp3(testkey)
        if(not longi and not longii):
                testkey=miam(testkey)
                clean_txt = decrypt_procedure(raw_txt,testkey,table2)
        else:
                if(longi):
                        lvl2_liste = []
                        lvl2_key   = []
                        lvl2_liste = slurp2(raw_txt)
                        lvl2_key   = slurp2(testkey)
                        lvl2_key_miam = []
                        for i in range (0,len(lvl2_key)):
                                lvl2_key_miam.append(miam(lvl2_key[i]))
                        for i in range (0,len(lvl2_liste)-1):
                                clean_txt+= decrypt_procedure(lvl2_liste[i],lvl2_key_miam[i],table2)

                if(longii):
                        lvl3_liste = []
                        lvl3_key   = []
                        lvl3_liste = slurp4(raw_txt)
                        lvl3_key   = slurp4(testkey)
                        lvl2_liste = []
                        lvl2_key   = []
                        lvl2_key_miam = []
                        final_key  = []
                        for i in range (0,len(lvl3_key)):
                                lvl2_key.append(slurp2(lvl3_key[i]))
                        for i in range (0,len(lvl3_liste)-1):
                                lvl2_liste.append(slurp2(lvl3_liste[i]))
                        for i in range(0,len(lvl2_key)-1):
                                lvl2_key_miam[:] = []
                                for j in range (0,len(lvl2_key[i])):
                                        lvl2_key_miam.append(miam(lvl2_key[i][j]))
                                del lvl2_key_miam[-1]
                                final_key.append(lvl2_key_miam)
                                for k in range (0,len(lvl2_liste[i])-1):
                                        clean_txt+=decrypt_procedure(lvl2_liste[i][k],final_key[0][k],table2)

        print("Chaine décryptée : \n")
        print(clean_txt)
        choice=input("c)ontinuer ou q)uitter")
        if(choice!='q'):
                userchoice+=1