Modified version of https://gist.github.com/zekesonxx/dd9b06cdf09dbfddd4ea to make it work under Python 3.4

bitcoin-otc.py

import hexchat
from subprocess import Popen, PIPE
import urllib.request
import re

# HexChat #bitcoin-otc IRC Plugin
# Copyright (C) 2015 Zeke Sonxx <github.com/zekesonxx>
# License: MIT - choosealicense.com/licenses/mit/

# ### Features ###
# - Adds the /ident command
# (just a shortcut for getting gribble ident)
# - Adds the /otcauth command
# Kicks off a gribble login

# Based on https://github.com/TingPing/plugins/blob/master/HexChat/twitch.py

__module_name__ = 'bitcoin-otc'
__module_author__ = 'Zeke Sonxx'
__module_version__ = '0.0.1'
__module_description__ = 'Utilites for #bitcoin-otc in HexChat'

identhandle = None
otcauthhandle = None
otphandle = None


def otcOnly(func):
    """Only execute in the #bitcoin-otc channel"""
    def if_ec(*args, **kwargs):
        channel = hexchat.get_info('channel')
        if channel and (channel == '#bitcoin-otc'):
            return func(*args, **kwargs)
        else:
            return hexchat.EAT_NONE
    return if_ec


def ident_cb(word, word_eol, userdata):
    """Passthrough command for /msg gribble ident <user>"""
    if len(word) < 2:
        hexchat.prnt("/ident <user> Gets the user's current otc identity")
        return hexchat.EAT_ALL
    hexchat.command("query gribble ident "+word[1])
    return hexchat.EAT_ALL


def otcauth_cb(word, word_eol, userdata):
    """Passthrough command for /msg gribble eauth <user>"""
    if len(word) < 2:
        hexchat.prnt("/otcauth <username> GPG authenticate with gribble")
        return hexchat.EAT_ALL
    otcuser = word[1]
    hexchat.command("msg gribble gpg eauth "+otcuser)
    return hexchat.EAT_ALL


def otp_cb(word, word_eol, userdata):
    """Catches a gribble gpg challenge and completes it"""
    if hexchat.nickcmp(word[0][:9], ':gribble!') != 0:
        # not gribble
        return hexchat.EAT_NONE

    results = re.search("Get your encrypted OTP from (http://[^$ ]+)",
                        word_eol[3])

    if results is None or len(results.group(1)) == 0:
        # Not a challenge message
        return hexchat.EAT_NONE
    otpurl = results.group(1)
    challenge = urllib.request.urlopen(otpurl).read()

    p = Popen(["gpg2", "--decrypt"], stdin=PIPE, stdout=PIPE, stderr=PIPE)
    stdout, stderr = p.communicate(challenge)
    otp = hexchat.strip(stdout.decode('utf-8').strip())

    hexchat.command("msg gribble everify "+otp+" ")

    return hexchat.EAT_ALL


def hexchatisapileofshit(userdata):
    # So that you have a higher chance of not crashing when reloading.
    # You'll still probably crash. It's hexchat's fault.
    global identhandle
    global otcauthhandle
    global otphandle
    global finishauthhandle
    if identhandle is not None:
        hexchat.unhook(identhandle)
        identhandle = None
    if otcauthhandle is not None:
        hexchat.unhook(otcauthhandle)
        otcauthhandle = None
    if otphandle is not None:
        hexchat.unhook(otphandle)
        otphandle = None
    pass

identhandle = hexchat.hook_command("ident", ident_cb)
otcauthhandle = hexchat.hook_command("otcauth", otcauth_cb)
otphandle = hexchat.hook_server("PRIVMSG", otp_cb)

hexchat.hook_unload(hexchatisapileofshit)