python-webfinger/webfinger.py

import logging
import requests

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


class WebFingerClient(object):

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

    def jrd(self, host, resource, rel, raw=False):
        """ Load resource at given URL and attempt to parse either XRD or JRD
            based on HTTP response Content-Type header.
        """

        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 = resp.content
        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 content

        return resp.json()

    def finger(self, resource, rel=None):
        """ Perform a WebFinger query based on the given subject.
            The `rel` parameter, if specified, will be passed to the provider,
            but be aware that providers are not required to implement the
            rel filter.
        """
        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

        jrd = self.jrd(host, resource, rel)
        return WebFingerResponse(jrd)


def finger(resource, rel=None, timeout=None, official=False):
    """ Shortcut method for invoking WebFingerClient.
    """

    if ":" not in resource:
        raise WebFingerException("scheme is required in subject URI")

    client = WebFingerClient(timeout=timeout, official=official)
    return client.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)

    if args.rel:

        link = wf.find_link(args.rel)

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

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

    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")