epicyon/webfinger.py

__filename__ = "webfinger.py"
__author__ = "Bob Mottram"
__license__ = "AGPL3+"
__version__ = "1.1.0"
__maintainer__ = "Bob Mottram"
__email__ = "bob@freedombone.net"
__status__ = "Production"

import base64
try:
    from Cryptodome.PublicKey import RSA
    from Cryptodome.Util import number
except ImportError:
    from Crypto.PublicKey import RSA
    from Crypto.Util import number
import os
from session import getJson
from cache import storeWebfingerInCache
from cache import getWebfingerFromCache
from utils import loadJson
from utils import loadJsonOnionify
from utils import saveJson


def parseHandle(handle: str) -> (str, str):
    if '.' not in handle:
        return None, None
    handleStr = handle.replace('https://', '').replace('http://', '')
    handleStr = handleStr.replace('dat://', '').replace('i2p://', '')
    if '/@' in handle:
        domain, nickname = handleStr.split('/@')
    else:
        if '/users/' in handle:
            domain, nickname = handleStr.split('/users/')
        else:
            if '@' in handle:
                nickname, domain = handle.split('@')
            else:
                return None, None
    return nickname, domain


def webfingerHandle(session, handle: str, httpPrefix: str,
                    cachedWebfingers: {},
                    fromDomain: str, projectVersion: str) -> {}:
    if not session:
        print('WARN: No session specified for webfingerHandle')
        return None

    nickname, domain = parseHandle(handle)
    if not nickname:
        return None
    wfDomain = domain
    if ':' in wfDomain:
        # wfPortStr=wfDomain.split(':')[1]
        # if wfPortStr.isdigit():
        #     wfPort=int(wfPortStr)
        # if wfPort==80 or wfPort==443:
        wfDomain = wfDomain.split(':')[0]
    wf = getWebfingerFromCache(nickname + '@' + wfDomain,
                               cachedWebfingers)
    if wf:
        return wf
    url = '{}://{}/.well-known/webfinger'.format(httpPrefix, domain)
    par = {
        'resource': 'acct:{}'.format(nickname + '@' + wfDomain)
    }
    hdr = {
        'Accept': 'application/jrd+json'
    }
    try:
        result = \
            getJson(session, url, hdr, par, projectVersion,
                    httpPrefix, fromDomain)
    except Exception as e:
        print("Unable to webfinger " + url)
        print('nickname: ' + str(nickname))
        print('domain: ' + str(wfDomain))
        print('headers: ' + str(hdr))
        print('params: ' + str(par))
        print(e)
        return None
    storeWebfingerInCache(nickname + '@' + wfDomain,
                          result, cachedWebfingers)
    return result


def generateMagicKey(publicKeyPem) -> str:
    """See magic_key method in
       https://github.com/tootsuite/mastodon/blob/
       707ddf7808f90e3ab042d7642d368c2ce8e95e6f/app/models/account.rb
    """
    privkey = RSA.importKey(publicKeyPem)
    modBytes = number.long_to_bytes(privkey.n)
    mod = base64.urlsafe_b64encode(modBytes).decode("utf-8")
    expBytes = number.long_to_bytes(privkey.e)
    pubexp = base64.urlsafe_b64encode(expBytes).decode("utf-8")
    return f"data:application/magic-public-key,RSA.{mod}.{pubexp}"


def storeWebfingerEndpoint(nickname: str, domain: str, port: int,
                           baseDir: str, wfJson: {}) -> bool:
    """Stores webfinger endpoint for a user to a file
    """
    originalDomain = domain
    if port:
        if port != 80 and port != 443:
            if ':' not in domain:
                domain = domain + ':' + str(port)
    handle = nickname + '@' + domain
    wfSubdir = '/wfendpoints'
    if not os.path.isdir(baseDir + wfSubdir):
        os.mkdir(baseDir + wfSubdir)
    filename = baseDir + wfSubdir + '/' + handle.lower() + '.json'
    saveJson(wfJson, filename)
    if nickname == 'inbox':
        handle = originalDomain + '@' + domain
        filename = baseDir + wfSubdir + '/' + handle.lower() + '.json'
        saveJson(wfJson, filename)
    return True


def createWebfingerEndpoint(nickname: str, domain: str, port: int,
                            httpPrefix: str, publicKeyPem) -> {}:
    """Creates a webfinger endpoint for a user
    """
    originalDomain = domain
    if port:
        if port != 80 and port != 443:
            if ':' not in domain:
                domain = domain + ':' + str(port)

    personName = nickname
    personId = httpPrefix + "://" + domain + "/users/" + personName
    subjectStr = "acct:" + personName + "@" + originalDomain
    profilePageHref = httpPrefix + "://" + domain + "/@" + nickname
    if nickname == 'inbox' or nickname == originalDomain:
        personName = 'actor'
        personId = httpPrefix + "://" + domain + "/" + personName
        subjectStr = "acct:" + originalDomain + "@" + originalDomain
        profilePageHref = httpPrefix + '://' + domain + \
            '/about/more?instance_actor=true'

    actor = httpPrefix + "://" + domain + "/users/" + nickname
    account = {
        "aliases": [
            httpPrefix + "://" + domain + "/@" + personName,
            personId
        ],
        "links": [
            {
                "href": profilePageHref,
                "rel": "http://webfinger.net/rel/profile-page",
                "type": "text/html"
            },
            {
                "href": actor + ".atom",
                "rel": "http://schemas.google.com/g/2010#updates-from",
                "type": "application/atom+xml"
            },
            {
                "href": personId,
                "rel": "self",
                "type": "application/activity+json"
            },
            {
                "href": generateMagicKey(publicKeyPem),
                "rel": "magic-public-key"
            }
        ],
        "subject": subjectStr
    }
    return account


def webfingerNodeInfo(httpPrefix: str, domainFull: str) -> {}:
    """ /.well-known/nodeinfo endpoint
    """
    nodeinfo = {
        'links': [
            {
                'href': httpPrefix + '://' + domainFull + '/nodeinfo/2.0',
                'rel': 'http://nodeinfo.diaspora.software/ns/schema/2.0'
            }
        ]
    }
    return nodeinfo


def webfingerMeta(httpPrefix: str, domainFull: str) -> str:
    """Return /.well-known/host-meta
    """
    metaStr = "<?xml version=’1.0' encoding=’UTF-8'?>"
    metaStr += "<XRD xmlns=’http://docs.oasis-open.org/ns/xri/xrd-1.0'"
    metaStr += " xmlns:hm=’http://host-meta.net/xrd/1.0'>"
    metaStr += ""
    metaStr += "<hm:Host>" + domainFull + "</hm:Host>"
    metaStr += ""
    metaStr += "<Link rel=’lrdd’"
    metaStr += " template=’" + httpPrefix + "://" + domainFull + \
        "/describe?uri={uri}'>"
    metaStr += " <Title>Resource Descriptor</Title>"
    metaStr += " </Link>"
    metaStr += "</XRD>"
    return metaStr


def webfingerLookup(path: str, baseDir: str,
                    domain: str, onionDomain: str,
                    port: int, debug: bool) -> {}:
    """Lookup the webfinger endpoint for an account
    """
    if not path.startswith('/.well-known/webfinger?'):
        return None
    handle = None
    if 'resource=acct:' in path:
        handle = path.split('resource=acct:')[1].strip()
        if debug:
            print('DEBUG: WEBFINGER handle ' + handle)
    else:
        if 'resource=acct%3A' in path:
            handle = path.split('resource=acct%3A')[1]
            handle = handle.replace('%40', '@', 1)
            handle = handle.replace('%3A', ':', 1).strip()
            if debug:
                print('DEBUG: WEBFINGER handle ' + handle)
    if not handle:
        if debug:
            print('DEBUG: WEBFINGER handle missing')
        return None
    if '&' in handle:
        handle = handle.split('&')[0].strip()
        if debug:
            print('DEBUG: WEBFINGER handle with & removed ' + handle)
    if '@' not in handle:
        if debug:
            print('DEBUG: WEBFINGER no @ in handle ' + handle)
        return None
    if port:
        if port != 80 and port != 443:
            if ':' not in handle:
                handle = handle + ':' + str(port)
    # convert @domain@domain to inbox@domain
    if '@' in handle:
        handleDomain = handle.split('@')[1]
        if handle.startswith(handleDomain + '@'):
            handle = 'inbox@' + handleDomain
    # if this is a lookup for a handle using its onion domain
    # then swap the onion domain for the clearnet version
    onionify = False
    if onionDomain:
        if onionDomain in handle:
            handle = handle.replace(onionDomain, domain)
            onionify = True
    filename = baseDir + '/wfendpoints/' + handle.lower() + '.json'
    if debug:
        print('DEBUG: WEBFINGER filename ' + filename)
    if not os.path.isfile(filename):
        if debug:
            print('DEBUG: WEBFINGER filename not found ' + filename)
        return None
    if not onionify:
        wfJson = loadJson(filename)
    else:
        print('Webfinger request for onionified ' + handle)
        wfJson = loadJsonOnionify(filename, domain, onionDomain)
    if not wfJson:
        wfJson = {"nickname": "unknown"}
    return wfJson