a858.py

#!/usr/bin/env python2
# A04 Decoder Logic by monocle with modifications from tuankiet65

import hashlib
import sys
from subprocess import check_output

f=open(sys.argv[1] + ".txt", 'r')
string = f.read()
f.close()
qr = check_output(['zbarimg', '--raw', '-q', sys.argv[1]+'.png'])
key = qr.replace('\n', '')

string = string.replace('\n', ' ')
string = string.replace('\r', ' ')
string = string.replace('  ', ' ')

asci = " aeiouqwrtypsdfghjxklzcvbnm1234567890',.?!@/"
#print string
string = string.split(" ")
decoded = ""
strlen = len(string)
swap = True
for x in string:
    notFound = True;
    print "Decoding", x
    for i in asci:
        #print "Matching", string[(strlen - 1) - i], "to", string[(strlen - 2) - i]
        for a in asci:
            if swap:
                m = hashlib.sha1();
                m.update(i+a+key);

                if m.hexdigest()[:20] == x:
                    print "Unswapped\t", m.hexdigest(), i, a
                    #print "D3"
                    #print "Found match:", string[strlen - i], "=", a;
                    decoded = decoded + i + a;
                    swap = False
                    notFound = False
                    break # r.i.p semicolon
            else:
                m = hashlib.sha1();
                m.update(i+a+key);
                if m.hexdigest()[20:] == x:
                    print "Swapped\t", m.hexdigest(), i, a
                    #print "D3"
                    #print "Found match:", string[strlen - i], "=", a;
                    decoded =decoded +  i + a;
                    swap = True
                    notFound = False
                    break;
    if notFound:
        decoded = i + a + decoded

for i in asci:
    decoded = decoded.replace(i+i, i)

decoded = decoded.replace("/", "");

print sys.argv[1]+" message: ",decoded