test2.py

#!/usr/bin/python3

# Since Google's switch from Hangouts to Google Chat,
# the endpoints and behaviour of codes has chasnged.
# This should work with the latest version.
#
# Since: 2020-10-01T00:00Z

# Expected exit codes:
# 0:    Meeting space successfully resolved
# 1:    Exception thrown
# 6:    Lookup code did not resolve to a meeting
# 7:    Meeting does not exist
# 8:    Meeting space ended
# 9:    Meeting space is private
# 128:  Incorrect invocation

import sys
from requests import get, post
from urllib.parse import urlparse
from base64 import b64decode
from re import match, findall
from os import getenv
from time import time
from http.cookies import SimpleCookie
from hashlib import sha1
from blackboxprotobuf import protobuf_to_json, protobuf_from_json
from json import loads as loadsJSON
from json import dumps as dumpsJSON


SERIALIZATION_DELIM = ':\t'


class RequestError(Exception):
    def __init__(self, msg, rl, rh, rd, r):
        self.msg = msg
        self.rl = rl
        self.rh = rh
        self.rd = rd
        self.r = r
        print("REQUEST:")
        print(' '.join(['POST', repr(rl)]))
        print(repr(rh))
        print(repr(rd))

        print()

        print("RESPONSE:")
        print(repr(r), r.status_code)
        print(repr(r.headers))
        print(repr(r.text))

        print()
        super().__init__(self.msg)


def generate_sapisidhash():
    cookie = SimpleCookie()
    cookie.load(getenv('COOKIE'))
    cookie = dict(cookie.items())
    t = str(int(time()))
    return ' '.join([
        "SAPISIDHASH",
        '_'.join([
            t,
            sha1(' '.join([
                t,
                cookie['SAPISID'].coded_value,
                'https://meet.google.com'
            ]).encode()).hexdigest()
        ])
    ])


def get_idtype(idcode):
    if match(r"^([a-z]{3}-[a-z]{4}-[a-z]{3})$", idcode):
        # Meeting code provided
        return "MEETING_CODE"
    elif match(r"^([a-zA-Z0-9]+)$", idcode):
        # (likely) Lookup code provided
        return "LOOKUP_CODE"
    else:
        print(SERIALIZATION_DELIM.join(('error', "Unrecognized identifier.",)))
        exit(1)


def validate_meeting_code(meetcode):
    idtype = get_idtype(meetcode)
    if idtype != "LOOKUP_CODE":
        return
    rl = "https://meet.google.com/lookup/%s?authuser=%s" % (meetcode, getenv('COOKIE_AUTHUSER'))
    rh = {
        "cookie": getenv('COOKIE'),
        "user-agent": getenv("CLIENT_USER_AGENT")
    }
    r = get(
        rl,
        headers=rh,
        allow_redirects=False
    )
    if r.status_code != 302:
        raise RequestError("Meeting code validation returned unexpected %s status code." % r.status_code, rl, rh, '', r)
    redirect = urlparse(r.headers['Location'])
    if redirect.hostname == 'accounts.google.com' and redirect.path.lstrip('/') == 'AccountChooser':
        raise Exception('Cookies bad format: lookup resolution request got redirected to account chooser.')
    if redirect.hostname != 'meet.google.com':
        raise Exception('Lookup resolution request got redirected to unknown domain %s.' % redirect.hostname)
    if redirect.path.split('/')[1:3] == ['_meet', 'whoops']:
        return False
    else:
        return redirect.path.lstrip('/')


def resolve_meeting_code(meetcode):
    # print(repr(get_requestdata_template(code)[1].format(code)))
    rl = "https://meet.google.com/$rpc/google.rtc.meetings.v1.MeetingSpaceService/ResolveMeetingSpace"
    rh = {
        "content-type": "application/x-protobuf",
        "cookie": getenv('COOKIE'),
        "authorization": generate_sapisidhash(),
        "x-goog-api-key": getenv('GAPIKEY'),
        "x-goog-authuser": getenv('COOKIE_AUTHUSER'),
        "x-goog-encode-response-if-executable": "base64",
        "x-origin": "https://meet.google.com"
    }
    rd = protobuf_from_json(
        dumpsJSON({
            '1': meetcode,
            '6': 1
        }),
        {
            '1': {
                'type': 'bytes',
                'name': ''
            },
            '6': {
                'type': 'int',
                'name': ''
            }
        }
    )
    r = post(
        rl,
        headers=rh,
        data=rd
    )

    if r.status_code != 200:
        # print(repr(r.status_code), repr(r.text))
        if r.status_code == 401 and "Request had invalid authentication credentials." in r.text:
            raise RequestError("Authentication failed.", rl, rh, rd, r)
        if r.status_code == 403 and "The request is missing a valid API key." in r.text:
            raise RequestError("API key invalid.", rl, rh, rd, r)
        if r.status_code == 400 and "Request contains an invalid argument." in r.text:
            raise RequestError("Invalid argument during request.", rl, rh, rd, r)
        if r.status_code == 400 and "The conference is gone" in r.text:
            print(SERIALIZATION_DELIM.join(('result', "Meeting space ended.",)))
            exit(8)
        if r.status_code == 404 and "Requested meeting space does not exist." in r.text:
            print(SERIALIZATION_DELIM.join(('result', "No such meeting code.",)))
            exit(7)
        if r.status_code == 403 and "The requester cannot resolve this meeting" in r.text:
            exit(9)
        raise RequestError("Unknown error.", rl, rh, rd, r)

    p = protobuf_to_json(b64decode(r.text))
    if getenv("PROTOBUF_DEBUG_LOG_ENDPOINT") is not None:
        post(
            getenv("PROTOBUF_DEBUG_LOG_ENDPOINT"),
            json={"content": "```\n{}\n```\n```json\n{}\n```".format(r.text, p[0])}
        )

    p = loadsJSON(p[0])

    spacecode = p['1']
    meetcode = p['2'] if type(p['2']) is str else findall(r"https?://meet\.google\.com/(?:_meet/)?(\w{3}-\w{4}-\w{3})(?:\?.*)?$", p['3'])[0]
    meeturl = p['3']
    lookupcode = p.get('7', None)
    gmeettoken = r.headers.get('x-goog-meeting-token', None)

    details = p.get('6')
    organization = None
    maxparticipants = None
    if details:
        organization = details.get('4')
        maxparticipants = details.get('6')

    return (spacecode, meetcode, meeturl, gmeettoken, lookupcode, organization, maxparticipants)


if __name__ == '__main__':
    try:
        code = sys.argv[1].lower()
    except IndexError:
        print(SERIALIZATION_DELIM.join(('error', "No meeting identifier passed to script.",)))
        exit(128)
    idtype = get_idtype(code)
    if idtype == 'LOOKUP_CODE':
        code = validate_meeting_code(code)
    if code is False:
        print(SERIALIZATION_DELIM.join(('result', "Unable to validate lookup code.",)))
        exit(6)
    else:
        print(SERIALIZATION_DELIM.join(('resolved', code,)))
    ret = resolve_meeting_code(code)
    ret = zip(('spacecode', 'meetcode', 'meeturl', 'gmeettoken', 'lookupcode', 'organization', 'maxmeetsize',), ret)
    for field, value in ret:
        if value is not None and all([t is str for t in map(type, (field, value))]):
            print(SERIALIZATION_DELIM.join([field, value]))