Support IPv6 in http.cookiejar when deciding whether a string is a HDN or a IP addr

Ideas
1

Hi everyone.

in http.cookiejar we’ve got constant IPV4_RE which is widely used to decide whether a string is a HDN or a IP address

IPV4_RE = re.compile(r"\.\d+$", re.ASCII)

it is used like this:


def liberal_is_HDN(text):
    """Return True if text is a sort-of-like a host domain name.

    For accepting/blocking domains.

    """
    if IPV4_RE.search(text):
        return False
    return True

It seems like it only detects that whether the string ends with a dot and some number. Well IMO

  • Firstly, IPv4 shouldn’t be like 257.257.257.257 right? we could add number ranges in the regex.
  • Secondly, it does not support IPv6, address like 2001:db8::1 would be detected as a HDN which is completely wrong.

the author wrote that in func is_HDN:

    # XXX
    # This may well be wrong.  Which RFC is HDN defined in, if any (for
    #  the purposes of RFC 2965)?
    # For the current implementation, what about IPv6?  Remember to look
    #  at other uses of IPV4_RE also, if change this.

Since we’ve got stdlib ipaddress after 3.3, why couldn’t we just simply use

import ipaddress
def is_ip(text):
    try:
        ipaddress.ip_address(text)
        return True
    except ValueError:
        return False

to cope with the ip problem?

I want to create a PR about this (change IPV4_RE regex into is_ip()). Please let me know if you have any suggestions. I deeply appreciate it for your time!

3 Likes
2

How is it widely used? Just in this module, or in 3rd party code?

3

Just in this moudle, but in various functions

4

Thanks! This seems like a reasonable change to me, though I’ll include the caveat that I’ve never looked at the code.

1 Like
5

I’ve already created a issue and a PR (which is closed because it has already been there for a while tho lol, nvm, it can be reopened at anytime). Maybe I’ll reopen it after you review the codes? Thank you for your effort!

6

I’m not really the right person to look at it, but I’ll try to take a look as time allows.

1 Like