python 通过正则表达式模式解析DNS。例如“克[O] {2} GL [AEO] .COM”

Posted 2021-05-09

#!/usr/bin/env python

import socket
import argparse
import sys
import re

def test_domain(domain_name):
    try:
        return bool(socket.gethostbyname(domain_name))
    except socket.gaierror, e:
        return False


RE_PARSE_EXPR = re.compile(r'\[([^\]]+)\](?:\{([0-9]+)\})?')


def gen_charset(expr_charset):
    results = []

    def genchars(char_range):
        start, end = char_range.group(1, 2)
        results.extend(range(ord(start), ord(end) +1))

    expr_charset = re.sub(r'(.)\-(.)', genchars, expr_charset)
    results.extend([ ord(i) for i in expr_charset ])
    return results



class Generator(object):

    def __init__(self, charsequences):
        self.charsequences = charsequences
        self.counts = [ len(q) for q in charsequences ]
        self.total_combinations = reduce(lambda x, y: x * y, self.counts)

    @property
    def significance(self):
        return reversed(list(enumerate(self.charsequences)))


    def selectIndexSequence(self, value):
        offset = 1
        for i, q in self.significance:
            index = ((value / offset) % len(q))
            offset = offset * len(q)
            yield q[index]



    def getValueAtIndex(self, index):
        return reversed(list(self.selectIndexSequence(index)))

    @property
    def maximum(self):
        return 0 + self.total_combinations

    @property
    def all(self):
        for i in range(0, self.maximum):
            yield list(self.getValueAtIndex(i))


def buildFormatter(expr):
    fields = []

    def repl(match):
        charset, howmany = match.group(1, 2)
        if howmany is None:
            howmany = 1
        fields.extend([gen_charset(charset)] * (int(howmany)))
        return ('%c') * int(howmany)

    result = RE_PARSE_EXPR.sub(repl, expr)
    return result, fields






def generateCombinations(values):
    return Generator(values).all


def generateResults(format_str, values):
    for combo in generateCombinations(values):
        yield (str(format_str) % tuple(combo))


def main(args):
    for expr_format in args.domain_format:
        _format, _fields = buildFormatter(expr_format)
        if not len(_fields):
            if not test_domain(_format):
                print "FAIL {0}".format(_format)
        else:
            for i in generateResults(_format, _fields):
                if not test_domain(i):
                    print "FAIL {0}".format(i)


def options(args):
    parser = argparse.ArgumentParser(description = 'domain resolver en-masse')
    parser.add_argument('domain_format', metavar='FORMAT', type=str, nargs='+')
    return parser.parse_args(args)

if __name__ == '__main__':
    main(options(sys.argv[1:]))