webfinger.py

from __future__ import print_function
import logging

__version__ = '1.0'

RELS = {
    'activity_streams': 'http://activitystrea.ms/spec/1.0',
    'avatar': 'http://webfinger.net/rel/avatar',
    'hcard': 'http://microformats.org/profile/hcard',
    'open_id': 'http://specs.openid.net/auth/2.0/provider',
    'opensocial': 'http://ns.opensocial.org/2008/opensocial/activitystreams',
    'portable_contacts': 'http://portablecontacts.net/spec/1.0',
    'profile': 'http://webfinger.net/rel/profile-page',
    'webfist': 'http://webfist.org/spec/rel',
    'xfn': 'http://gmpg.org/xfn/11',
}

WEBFINGER_TYPE = 'application/jrd+json'
LEGACY_WEBFINGER_TYPES = ['application/json']

UNOFFICIAL_ENDPOINTS = {
    'facebook.com': 'facebook-webfinger.appspot.com',
    'twitter.com': 'twitter-webfinger.appspot.com',
}

logger = logging.getLogger("webfinger")


class WebFingerException(Exception):
    pass


class WebFingerResponse(object):
    """ Response that wraps an RD object. It provides attribute-style access
        to links for specific rels, responding with the href attribute
        of the matched element.
    """

    def __init__(self, jrd):
        self.jrd = jrd

    def __getattr__(self, name):
        if name in RELS:
            return self.rel(RELS[name])
        return getattr(self.jrd, name)

    @property
    def subject(self):
        return self.jrd.get('subject')

    @property
    def aliases(self):
        return self.jrd.get('aliases', [])

    @property
    def properties(self):
        return self.jrd.get('properties', {})

    @property
    def links(self):
        return self.jrd.get('links', [])

    def rel(self, relation, attr='href'):
        for link in self.links:
            if link.get('rel') == relation:
                if attr:
                    return link.get(attr)
                return link


class WebFingerClient(object):

    def __init__(self, timeout=None, official=False):
        self.official = official
        self.timeout = timeout

    def _parse_host(self, resource):

        host = resource.split("@")[-1]

        if host in UNOFFICIAL_ENDPOINTS and not self.official:
            unofficial_host = UNOFFICIAL_ENDPOINTS[host]
            logging.debug('host %s is not supported, using unofficial endpoint %s' % (host, unofficial_host))
            host = unofficial_host

        return host

    def finger(self, resource, host=None, rel=None, raw=False):

        import requests

        if not host:
            host = self._parse_host(resource)

        url = "https://%s/.well-known/webfinger" % host

        headers = {
            'User-Agent': 'python-webfinger/%s' % __version__,
            'Accept': WEBFINGER_TYPE,
        }

        params = {'resource': resource}
        if rel:
            params['rel'] = rel

        resp = requests.get(url, params=params, headers=headers, timeout=self.timeout, verify=True)
        logging.debug('fetching JRD from %s' % resp.url)

        content_type = resp.headers.get('Content-Type', '').split(';', 1)[0].strip()
        logging.debug('response content type: %s' % content_type)

        if content_type != WEBFINGER_TYPE and content_type not in LEGACY_WEBFINGER_TYPES:
            raise WebFingerException('Invalid response type from server')

        if raw:
            return resp.json()

        return WebFingerResponse(resp.json())


def finger(resource, rel=None):
    """ Convenience method for invoking WebFingerClient.
    """
    return WebFingerClient().finger(resource, rel=rel)


if __name__ == '__main__':

    import argparse

    parser = argparse.ArgumentParser(description="Simple webfinger client.")
    parser.add_argument("acct", metavar="URI", help="account URI")
    parser.add_argument("-d", "--debug", dest="debug", action="store_true", help="print debug logging output to console")
    parser.add_argument("-r", "--rel", metavar="REL", dest="rel", help="desired relation")

    args = parser.parse_args()

    if args.debug:
        logging.basicConfig(level=logging.DEBUG)

    wf = finger(args.acct, rel=args.rel)

    print("--- %s ---" % wf.subject)

    if args.rel:

        link = wf.rel(args.rel)

        if link is None:
            print("*** Link not found for rel=%s" % args.rel)

        print("%s:\n\t%s" % (args.rel, link))

    else:

        print("Activity Streams:  ", wf.activity_streams)
        print("Avatar:            ", wf.avatar)
        print("HCard:             ", wf.hcard)
        print("OpenID:            ", wf.open_id)
        print("Open Social:       ", wf.opensocial)
        print("Portable Contacts: ", wf.portable_contacts)
        print("Profile:           ", wf.profile)
        print("WebFist:           ", wf.webfist)
        print("XFN:               ", wf.rel("http://gmpg.org/xfn/11"))