xorString.py

__author__ = 'moranned'

import argparse
import binascii

def printArray(s, key):
    b = bytearray(s)
    for i in range(len(b)):
        b[i] ^= key
    enc = binascii.hexlify(b)
    print '    $key%d = { %s }' %(key, enc)

def main():
    parser = argparse.ArgumentParser(description="Xor strings")
    parser.add_argument("-s", "--string", help="String to Encode")
    parser.add_argument("-r", "--rule", help="Rule name")
    args = parser.parse_args()
    if args.string and args.rule:
        print 'rule %s {' %args.rule
        print '  strings:'
        print '    $mz = { 4d5a }'
        print '    $str = "%s"' %args.string
        for key in range(1,256):
            printArray(args.string, key)
        print '  condition:'
        print '    ($mz at 0) and ($str or 1 of ($key*))'
        print '}'

if __name__ == '__main__':
    main()