# -*- test-case-name: openid.test.server -*- """OpenID server protocol and logic. Overview ======== An OpenID server must perform three tasks: 1. Examine the incoming request to determine its nature and validity. 2. Make a decision about how to respond to this request. 3. Format the response according to the protocol. The first and last of these tasks may performed by the L{decodeRequest} and L{encodeResponse} methods of the L{Server} object. Who gets to do the intermediate task -- deciding how to respond to the request -- will depend on what type of request it is. If it's a request to authenticate a user (a X{C{checkid_setup}} or X{C{checkid_immediate}} request), you need to decide if you will assert that this user may claim the identity in question. Exactly how you do that is a matter of application policy, but it generally involves making sure the user has an account with your system and is logged in, checking to see if that identity is hers to claim, and verifying with the user that she does consent to releasing that information to the party making the request. Examine the properties of the L{CheckIDRequest} object, and if and when you've come to a decision, form a response by calling L{CheckIDRequest.answer}. Other types of requests relate to establishing associations between client and server and verifying the authenticity of previous communications. L{Server} contains all the logic and data necessary to respond to such requests; just pass it to L{Server.handleRequest}. OpenID Extensions ================= Do you want to provide other information for your users in addition to authentication? Version 1.2 of the OpenID protocol allows consumers to add extensions to their requests. For example, with sites using the U{Simple Registration Extension}, a user can agree to have their nickname and e-mail address sent to a site when they sign up. Since extensions do not change the way OpenID authentication works, code to handle extension requests may be completely separate from the L{OpenIDRequest} class here. But you'll likely want data sent back by your extension to be signed. L{OpenIDResponse} provides methods with which you can add data to it which can be signed with the other data in the OpenID signature. For example:: # when request is a checkid_* request response = request.answer(True) # this will a signed 'openid.sreg.timezone' parameter to the response response.addField('sreg', 'timezone', 'America/Los_Angeles') Stores ====== The OpenID server needs to maintain state between requests in order to function. Its mechanism for doing this is called a store. The store interface is defined in C{L{openid.store.interface.OpenIDStore}}. Additionally, several concrete store implementations are provided, so that most sites won't need to implement a custom store. For a store backed by flat files on disk, see C{L{openid.store.filestore.FileOpenIDStore}}. For stores based on MySQL or SQLite, see the C{L{openid.store.sqlstore}} module. Upgrading ========= The keys by which a server looks up associations in its store have changed in version 1.2 of this library. If your store has entries created from version 1.0 code, you should empty it. @group Requests: OpenIDRequest, AssociateRequest, CheckIDRequest, CheckAuthRequest @group Responses: OpenIDResponse @group HTTP Codes: HTTP_OK, HTTP_REDIRECT, HTTP_ERROR @group Response Encodings: ENCODE_KVFORM, ENCODE_URL """ import time from copy import deepcopy from openid import cryptutil from openid import kvform from openid import oidutil from openid.dh import DiffieHellman from openid.server.trustroot import TrustRoot from openid.association import Association HTTP_OK = 200 HTTP_REDIRECT = 302 HTTP_ERROR = 400 BROWSER_REQUEST_MODES = ['checkid_setup', 'checkid_immediate'] OPENID_PREFIX = 'openid.' ENCODE_KVFORM = ('kvform',) ENCODE_URL = ('URL/redirect',) class OpenIDRequest(object): """I represent an incoming OpenID request. @cvar mode: the C{X{openid.mode}} of this request. @type mode: str """ mode = None class CheckAuthRequest(OpenIDRequest): """A request to verify the validity of a previous response. @cvar mode: "X{C{check_authentication}}" @type mode: str @ivar assoc_handle: The X{association handle} the response was signed with. @type assoc_handle: str @ivar sig: The signature to check. @type sig: str @ivar signed: The ordered list of signed items you want to check. @type signed: list of pairs @ivar invalidate_handle: An X{association handle} the client is asking about the validity of. Optional, may be C{None}. @type invalidate_handle: str @see: U{OpenID Specs, Mode: check_authentication } """ mode = "check_authentication" def __init__(self, assoc_handle, sig, signed, invalidate_handle=None): """Construct me. These parameters are assigned directly as class attributes, see my L{class documentation} for their descriptions. @type assoc_handle: str @type sig: str @type signed: list of pairs @type invalidate_handle: str """ self.assoc_handle = assoc_handle self.sig = sig self.signed = signed self.invalidate_handle = invalidate_handle def fromQuery(klass, query): """Construct me from a web query. @param query: The query parameters as a dictionary with each key mapping to one value. @type query: dict @returntype: L{CheckAuthRequest} """ self = klass.__new__(klass) try: self.assoc_handle = query[OPENID_PREFIX + 'assoc_handle'] self.sig = query[OPENID_PREFIX + 'sig'] signed_list = query[OPENID_PREFIX + 'signed'] except KeyError, e: raise ProtocolError(query, text="%s request missing required parameter %s" " from query %s" % (self.mode, e.args[0], query)) self.invalidate_handle = query.get(OPENID_PREFIX + 'invalidate_handle') signed_list = signed_list.split(',') signed_pairs = [] for field in signed_list: try: if field == 'mode': # XXX KLUDGE HAX WEB PROTOCoL BR0KENNN # openid.mode is currently check_authentication because # that's the mode of this request. But the signature # was made on something with a different openid.mode. # http://article.gmane.org/gmane.comp.web.openid.general/537 value = "id_res" else: value = query[OPENID_PREFIX + field] except KeyError, e: raise ProtocolError( query, text="Couldn't find signed field %r in query %s" % (field, query)) else: signed_pairs.append((field, value)) self.signed = signed_pairs return self fromQuery = classmethod(fromQuery) def answer(self, signatory): """Respond to this request. Given a L{Signatory}, I can check the validity of the signature and the X{C{invalidate_handle}}. @param signatory: The L{Signatory} to use to check the signature. @type signatory: L{Signatory} @returns: A response with an X{C{is_valid}} (and, if appropriate X{C{invalidate_handle}}) field. @returntype: L{OpenIDResponse} """ is_valid = signatory.verify(self.assoc_handle, self.sig, self.signed) # Now invalidate that assoc_handle so it this checkAuth message cannot # be replayed. signatory.invalidate(self.assoc_handle, dumb=True) response = OpenIDResponse(self) response.fields['is_valid'] = (is_valid and "true") or "false" if self.invalidate_handle: assoc = signatory.getAssociation(self.invalidate_handle, dumb=False) if not assoc: response.fields['invalidate_handle'] = self.invalidate_handle return response def __str__(self): if self.invalidate_handle: ih = " invalidate? %r" % (self.invalidate_handle,) else: ih = "" s = "<%s handle: %r sig: %r: signed: %r%s>" % ( self.__class__.__name__, self.assoc_handle, self.sig, self.signed, ih) return s class PlainTextServerSession(object): """An object that knows how to handle association requests with no session type. @cvar session_type: The session_type for this association session. There is no type defined for plain-text in the OpenID specification, so we use 'plaintext'. @type session_type: str @see: U{OpenID Specs, Mode: associate } @see: AssociateRequest """ session_type = 'plaintext' def fromQuery(cls, unused_request): return cls() fromQuery = classmethod(fromQuery) def answer(self, secret): return {'mac_key': oidutil.toBase64(secret)} class DiffieHellmanServerSession(object): """An object that knows how to handle association requests with the Diffie-Hellman session type. @cvar session_type: The session_type for this association session. @type session_type: str @ivar dh: The Diffie-Hellman algorithm values for this request @type dh: DiffieHellman @ivar consumer_pubkey: The public key sent by the consumer in the associate request @type consumer_pubkey: long @see: U{OpenID Specs, Mode: associate } @see: AssociateRequest """ session_type = 'DH-SHA1' def __init__(self, dh, consumer_pubkey): self.dh = dh self.consumer_pubkey = consumer_pubkey def fromQuery(cls, query): """ @param query: The associate request's query parameters @type query: {str:str} @returntype: L{DiffieHellmanServerSession} @raises ProtocolError: When parameters required to establish the session are missing. """ dh_modulus = query.get('openid.dh_modulus') dh_gen = query.get('openid.dh_gen') if (dh_modulus is None and dh_gen is not None or dh_gen is None and dh_modulus is not None): if dh_modulus is None: missing = 'modulus' else: missing = 'generator' raise ProtocolError('If non-default modulus or generator is ' 'supplied, both must be supplied. Missing %s' % (missing,)) if dh_modulus or dh_gen: dh_modulus = cryptutil.base64ToLong(dh_modulus) dh_gen = cryptutil.base64ToLong(dh_gen) dh = DiffieHellman(dh_modulus, dh_gen) else: dh = DiffieHellman.fromDefaults() consumer_pubkey = query.get('openid.dh_consumer_public') if consumer_pubkey is None: raise ProtocolError("Public key for DH-SHA1 session " "not found in query %s" % (query,)) consumer_pubkey = cryptutil.base64ToLong(consumer_pubkey) return cls(dh, consumer_pubkey) fromQuery = classmethod(fromQuery) def answer(self, secret): mac_key = self.dh.xorSecret(self.consumer_pubkey, secret) return { 'dh_server_public': cryptutil.longToBase64(self.dh.public), 'enc_mac_key': oidutil.toBase64(mac_key), } class AssociateRequest(OpenIDRequest): """A request to establish an X{association}. @cvar mode: "X{C{check_authentication}}" @type mode: str @ivar assoc_type: The type of association. The protocol currently only defines one value for this, "X{C{HMAC-SHA1}}". @type assoc_type: str @ivar session: An object that knows how to handle association requests of a certain type. @see: U{OpenID Specs, Mode: associate } """ mode = "associate" assoc_type = 'HMAC-SHA1' session_classes = { None: PlainTextServerSession, 'DH-SHA1': DiffieHellmanServerSession, } def __init__(self, session): """Construct me. The session is assigned directly as a class attribute. See my L{class documentation} for its description. """ super(AssociateRequest, self).__init__() self.session = session def fromQuery(klass, query): """Construct me from a web query. @param query: The query parameters as a dictionary with each key mapping to one value. @type query: dict @returntype: L{AssociateRequest} """ session_type = query.get(OPENID_PREFIX + 'session_type') try: session_class = klass.session_classes[session_type] except KeyError: raise ProtocolError(query, "Unknown session type %r" % (session_type,)) try: session = session_class.fromQuery(query) except ValueError, why: raise ProtocolError(query, 'Error parsing %s session: %s' % (session_class.session_type, why[0])) return klass(session) fromQuery = classmethod(fromQuery) def answer(self, assoc): """Respond to this request with an X{association}. @param assoc: The association to send back. @type assoc: L{openid.association.Association} @returns: A response with the association information, encrypted to the consumer's X{public key} if appropriate. @returntype: L{OpenIDResponse} """ response = OpenIDResponse(self) response.fields.update({ 'expires_in': '%d' % (assoc.getExpiresIn(),), 'assoc_type': 'HMAC-SHA1', 'assoc_handle': assoc.handle, }) response.fields.update(self.session.answer(assoc.secret)) if self.session.session_type != 'plaintext': response.fields['session_type'] = self.session.session_type return response class CheckIDRequest(OpenIDRequest): """A request to confirm the identity of a user. This class handles requests for openid modes X{C{checkid_immediate}} and X{C{checkid_setup}}. @cvar mode: "X{C{checkid_immediate}}" or "X{C{checkid_setup}}" @type mode: str @ivar immediate: Is this an immediate-mode request? @type immediate: bool @ivar identity: The identity URL being checked. @type identity: str @ivar trust_root: "Are you Frank?" asks the checkid request. "Who wants to know?" C{trust_root}, that's who. This URL identifies the party making the request, and the user will use that to make her decision about what answer she trusts them to have. @type trust_root: str @ivar return_to: The URL to send the user agent back to to reply to this request. @type return_to: str @ivar assoc_handle: Provided in smart mode requests, a handle for a previously established association. C{None} for dumb mode requests. @type assoc_handle: str """ def __init__(self, identity, return_to, trust_root=None, immediate=False, assoc_handle=None): """Construct me. These parameters are assigned directly as class attributes, see my L{class documentation} for their descriptions. @raises MalformedReturnURL: When the C{return_to} URL is not a URL. """ self.assoc_handle = assoc_handle self.identity = identity self.return_to = return_to self.trust_root = trust_root or return_to if immediate: self.immediate = True self.mode = "checkid_immediate" else: self.immediate = False self.mode = "checkid_setup" if not TrustRoot.parse(self.return_to): raise MalformedReturnURL(None, self.return_to) if not self.trustRootValid(): raise UntrustedReturnURL(None, self.return_to, self.trust_root) def fromQuery(klass, query): """Construct me from a web query. @raises ProtocolError: When not all required parameters are present in the query. @raises MalformedReturnURL: When the C{return_to} URL is not a URL. @raises UntrustedReturnURL: When the C{return_to} URL is outside the C{trust_root}. @param query: The query parameters as a dictionary with each key mapping to one value. @type query: dict @returntype: L{CheckIDRequest} """ self = klass.__new__(klass) mode = query[OPENID_PREFIX + 'mode'] if mode == "checkid_immediate": self.immediate = True self.mode = "checkid_immediate" else: self.immediate = False self.mode = "checkid_setup" required = [ 'identity', 'return_to', ] for field in required: value = query.get(OPENID_PREFIX + field) if not value: raise ProtocolError( query, text="Missing required field %s from %r" % (field, query)) setattr(self, field, value) # There's a case for making self.trust_root be a TrustRoot # here. But if TrustRoot isn't currently part of the "public" API, # I'm not sure it's worth doing. self.trust_root = query.get(OPENID_PREFIX + 'trust_root', self.return_to) self.assoc_handle = query.get(OPENID_PREFIX + 'assoc_handle') # Using TrustRoot.parse here is a bit misleading, as we're not # parsing return_to as a trust root at all. However, valid URLs # are valid trust roots, so we can use this to get an idea if it # is a valid URL. Not all trust roots are valid return_to URLs, # however (particularly ones with wildcards), so this is still a # little sketchy. if not TrustRoot.parse(self.return_to): raise MalformedReturnURL(query, self.return_to) # I first thought that checking to see if the return_to is within # the trust_root is premature here, a logic-not-decoding thing. But # it was argued that this is really part of data validation. A # request with an invalid trust_root/return_to is broken regardless of # application, right? if not self.trustRootValid(): raise UntrustedReturnURL(query, self.return_to, self.trust_root) return self fromQuery = classmethod(fromQuery) def trustRootValid(self): """Is my return_to under my trust_root? @returntype: bool """ if not self.trust_root: return True tr = TrustRoot.parse(self.trust_root) if tr is None: raise MalformedTrustRoot(None, self.trust_root) return tr.validateURL(self.return_to) def answer(self, allow, server_url=None): """Respond to this request. @param allow: Allow this user to claim this identity, and allow the consumer to have this information? @type allow: bool @param server_url: When an immediate mode request does not succeed, it gets back a URL where the request may be carried out in a not-so-immediate fashion. Pass my URL in here (the fully qualified address of this server's endpoint, i.e. C{http://example.com/server}), and I will use it as a base for the URL for a new request. Optional for requests where C{CheckIDRequest.immediate} is C{False} or C{allow} is C{True}. @type server_url: str @returntype: L{OpenIDResponse} """ if allow or self.immediate: mode = 'id_res' else: mode = 'cancel' response = OpenIDResponse(self) if allow: response.addFields(None, { 'mode': mode, 'identity': self.identity, 'return_to': self.return_to, }) else: response.addField(None, 'mode', mode, False) if self.immediate: if not server_url: raise ValueError("setup_url is required for allow=False " "in immediate mode.") # Make a new request just like me, but with immediate=False. setup_request = self.__class__( self.identity, self.return_to, self.trust_root, immediate=False, assoc_handle=self.assoc_handle) setup_url = setup_request.encodeToURL(server_url) response.addField(None, 'user_setup_url', setup_url, False) return response def encodeToURL(self, server_url): """Encode this request as a URL to GET. @param server_url: The URL of the OpenID server to make this request of. @type server_url: str @returntype: str """ # Imported from the alternate reality where these classes are used # in both the client and server code, so Requests are Encodable too. # That's right, code imported from alternate realities all for the # love of you, id_res/user_setup_url. q = {'mode': self.mode, 'identity': self.identity, 'return_to': self.return_to} if self.trust_root: q['trust_root'] = self.trust_root if self.assoc_handle: q['assoc_handle'] = self.assoc_handle q = dict([(OPENID_PREFIX + k, v) for k, v in q.iteritems()]) return oidutil.appendArgs(server_url, q) def getCancelURL(self): """Get the URL to cancel this request. Useful for creating a "Cancel" button on a web form so that operation can be carried out directly without another trip through the server. (Except you probably want to make another trip through the server so that it knows that the user did make a decision. Or you could simulate this method by doing C{.answer(False).encodeToURL()}) @returntype: str @returns: The return_to URL with openid.mode = cancel. """ if self.immediate: raise ValueError("Cancel is not an appropriate response to " "immediate mode requests.") return oidutil.appendArgs(self.return_to, {OPENID_PREFIX + 'mode': 'cancel'}) def __str__(self): return '<%s id:%r im:%s tr:%r ah:%r>' % (self.__class__.__name__, self.identity, self.immediate, self.trust_root, self.assoc_handle) class OpenIDResponse(object): """I am a response to an OpenID request. @ivar request: The request I respond to. @type request: L{OpenIDRequest} @ivar fields: My parameters as a dictionary with each key mapping to one value. Keys are parameter names with no leading "C{openid.}". e.g. "C{identity}" and "C{mac_key}", never "C{openid.identity}". @type fields: dict @ivar signed: The names of the fields which should be signed. @type signed: list of str """ # Implementer's note: In a more symmetric client/server # implementation, there would be more types of OpenIDResponse # object and they would have validated attributes according to the # type of response. But as it is, Response objects in a server are # basically write-only, their only job is to go out over the wire, # so this is just a loose wrapper around OpenIDResponse.fields. def __init__(self, request): """Make a response to an L{OpenIDRequest}. @type request: L{OpenIDRequest} """ self.request = request self.fields = {} self.signed = [] def __str__(self): return "%s for %s: %s" % ( self.__class__.__name__, self.request.__class__.__name__, self.fields) def addField(self, namespace, key, value, signed=True): """Add a field to this response. @param namespace: The extension namespace the field is in, with no leading "C{openid.}" e.g. "C{sreg}". @type namespace: str @param key: The field's name, e.g. "C{fullname}". @type key: str @param value: The field's value. @type value: str @param signed: Whether this field should be signed. @type signed: bool """ if namespace: key = '%s.%s' % (namespace, key) self.fields[key] = value if signed and key not in self.signed: self.signed.append(key) def addFields(self, namespace, fields, signed=True): """Add a number of fields to this response. @param namespace: The extension namespace the field is in, with no leading "C{openid.}" e.g. "C{sreg}". @type namespace: str @param fields: A dictionary with the fields to add. e.g. C{{"fullname": "Frank the Goat"}} @param signed: Whether these fields should be signed. @type signed: bool """ for key, value in fields.iteritems(): self.addField(namespace, key, value, signed) def update(self, namespace, other): """Update my fields with those from another L{OpenIDResponse}. The idea here is that if you write an OpenID extension, it could produce a Response object with C{fields} and C{signed} attributes, and you could merge it with me using this method before I am signed and sent. All entries in C{other.fields} will have their keys prefixed with C{namespace} and added to my fields. All elements of C{other.signed} will be prefixed with C{namespace} and added to my C{signed} list. @param namespace: The extension namespace the field is in, with no leading "C{openid.}" e.g. "C{sreg}". @type namespace: str @param other: A response object to update from. @type other: L{OpenIDResponse} """ if namespace: namespaced_fields = dict([('%s.%s' % (namespace, k), v) for k, v in other.fields.iteritems()]) namespaced_signed = ['%s.%s' % (namespace, k) for k in other.signed] else: namespaced_fields = other.fields namespaced_signed = other.signed self.fields.update(namespaced_fields) self.signed.extend(namespaced_signed) def needsSigning(self): """Does this response require signing? @returntype: bool """ return ( (self.request.mode in ['checkid_setup', 'checkid_immediate']) and self.signed ) # implements IEncodable def whichEncoding(self): """How should I be encoded? @returns: one of ENCODE_URL or ENCODE_KVFORM. """ if self.request.mode in BROWSER_REQUEST_MODES: return ENCODE_URL else: return ENCODE_KVFORM def encodeToURL(self): """Encode a response as a URL for the user agent to GET. You will generally use this URL with a HTTP redirect. @returns: A URL to direct the user agent back to. @returntype: str """ fields = dict( [(OPENID_PREFIX + k, v.encode('UTF8')) for k, v in self.fields.iteritems()]) return oidutil.appendArgs(self.request.return_to, fields) def encodeToKVForm(self): """Encode a response in key-value colon/newline format. This is a machine-readable format used to respond to messages which came directly from the consumer and not through the user agent. @see: OpenID Specs, U{Key-Value Colon/Newline format} @returntype: str """ return kvform.dictToKV(self.fields) def __str__(self): return "%s for %s: signed%s %s" % ( self.__class__.__name__, self.request.__class__.__name__, self.signed, self.fields) class WebResponse(object): """I am a response to an OpenID request in terms a web server understands. I generally come from an L{Encoder}, either directly or from L{Server.encodeResponse}. @ivar code: The HTTP code of this response. @type code: int @ivar headers: Headers to include in this response. @type headers: dict @ivar body: The body of this response. @type body: str """ def __init__(self, code=HTTP_OK, headers=None, body=""): """Construct me. These parameters are assigned directly as class attributes, see my L{class documentation} for their descriptions. """ self.code = code if headers is not None: self.headers = headers else: self.headers = {} self.body = body class Signatory(object): """I sign things. I also check signatures. All my state is encapsulated in an L{OpenIDStore}, which means I'm not generally pickleable but I am easy to reconstruct. @cvar SECRET_LIFETIME: The number of seconds a secret remains valid. @type SECRET_LIFETIME: int """ SECRET_LIFETIME = 14 * 24 * 60 * 60 # 14 days, in seconds # keys have a bogus server URL in them because the filestore # really does expect that key to be a URL. This seems a little # silly for the server store, since I expect there to be only one # server URL. _normal_key = 'http://localhost/|normal' _dumb_key = 'http://localhost/|dumb' def __init__(self, store): """Create a new Signatory. @param store: The back-end where my associations are stored. @type store: L{openid.store.interface.OpenIDStore} """ assert store is not None self.store = store def verify(self, assoc_handle, sig, signed_pairs): """Verify that the signature for some data is valid. @param assoc_handle: The handle of the association used to sign the data. @type assoc_handle: str @param sig: The base-64 encoded signature to check. @type sig: str @param signed_pairs: The data to check, an ordered list of key-value pairs. The keys should be as they are in the request's C{signed} list, without any C{"openid."} prefix. @type signed_pairs: list of pairs @returns: C{True} if the signature is valid, C{False} if not. @returntype: bool """ assoc = self.getAssociation(assoc_handle, dumb=True) if not assoc: oidutil.log("failed to get assoc with handle %r to verify sig %r" % (assoc_handle, sig)) return False # Not using Association.checkSignature here is intentional; # Association should not know things like "the list of signed pairs is # in the request's 'signed' parameter and it is comma-separated." expected_sig = oidutil.toBase64(assoc.sign(signed_pairs)) return sig == expected_sig def sign(self, response): """Sign a response. I take a L{OpenIDResponse}, create a signature for everything in its L{signed} list, and return a new copy of the response object with that signature included. @param response: A response to sign. @type response: L{OpenIDResponse} @returns: A signed copy of the response. @returntype: L{OpenIDResponse} """ signed_response = deepcopy(response) assoc_handle = response.request.assoc_handle if assoc_handle: # normal mode assoc = self.getAssociation(assoc_handle, dumb=False) if not assoc: # fall back to dumb mode signed_response.fields['invalidate_handle'] = assoc_handle assoc = self.createAssociation(dumb=True) else: # dumb mode. assoc = self.createAssociation(dumb=True) signed_response.fields['assoc_handle'] = assoc.handle assoc.addSignature(signed_response.signed, signed_response.fields, prefix='') return signed_response def createAssociation(self, dumb=True, assoc_type='HMAC-SHA1'): """Make a new association. @param dumb: Is this association for a dumb-mode transaction? @type dumb: bool @param assoc_type: The type of association to create. Currently there is only one type defined, C{HMAC-SHA1}. @type assoc_type: str @returns: the new association. @returntype: L{openid.association.Association} """ secret = cryptutil.getBytes(20) uniq = oidutil.toBase64(cryptutil.getBytes(4)) handle = '{%s}{%x}{%s}' % (assoc_type, int(time.time()), uniq) assoc = Association.fromExpiresIn( self.SECRET_LIFETIME, handle, secret, assoc_type) if dumb: key = self._dumb_key else: key = self._normal_key self.store.storeAssociation(key, assoc) return assoc def getAssociation(self, assoc_handle, dumb): """Get the association with the specified handle. @type assoc_handle: str @param dumb: Is this association used with dumb mode? @type dumb: bool @returns: the association, or None if no valid association with that handle was found. @returntype: L{openid.association.Association} """ # Hmm. We've created an interface that deals almost entirely with # assoc_handles. The only place outside the Signatory that uses this # (and thus the only place that ever sees Association objects) is # when creating a response to an association request, as it must have # the association's secret. if assoc_handle is None: raise ValueError("assoc_handle must not be None") if dumb: key = self._dumb_key else: key = self._normal_key assoc = self.store.getAssociation(key, assoc_handle) if assoc is not None and assoc.expiresIn <= 0: oidutil.log("requested %sdumb key %r is expired (by %s seconds)" % ((not dumb) and 'not-' or '', assoc_handle, assoc.expiresIn)) self.store.removeAssociation(key, assoc_handle) assoc = None return assoc def invalidate(self, assoc_handle, dumb): """Invalidates the association with the given handle. @type assoc_handle: str @param dumb: Is this association used with dumb mode? @type dumb: bool """ if dumb: key = self._dumb_key else: key = self._normal_key self.store.removeAssociation(key, assoc_handle) class Encoder(object): """I encode responses in to L{WebResponses}. If you don't like L{WebResponses}, you can do your own handling of L{OpenIDResponses} with L{OpenIDResponse.whichEncoding}, L{OpenIDResponse.encodeToURL}, and L{OpenIDResponse.encodeToKVForm}. """ responseFactory = WebResponse def encode(self, response): """Encode a response to a L{WebResponse}. @raises EncodingError: When I can't figure out how to encode this message. """ encode_as = response.whichEncoding() if encode_as == ENCODE_KVFORM: wr = self.responseFactory(body=response.encodeToKVForm()) if isinstance(response, Exception): wr.code = HTTP_ERROR elif encode_as == ENCODE_URL: location = response.encodeToURL() wr = self.responseFactory(code=HTTP_REDIRECT, headers={'location': location}) else: # Can't encode this to a protocol message. You should probably # render it to HTML and show it to the user. raise EncodingError(response) return wr class SigningEncoder(Encoder): """I encode responses in to L{WebResponses}, signing them when required. """ def __init__(self, signatory): """Create a L{SigningEncoder}. @param signatory: The L{Signatory} I will make signatures with. @type signatory: L{Signatory} """ self.signatory = signatory def encode(self, response): """Encode a response to a L{WebResponse}, signing it first if appropriate. @raises EncodingError: When I can't figure out how to encode this message. @raises AlreadySigned: When this response is already signed. @returntype: L{WebResponse} """ # the isinstance is a bit of a kludge... it means there isn't really # an adapter to make the interfaces quite match. if (not isinstance(response, Exception)) and response.needsSigning(): if not self.signatory: raise ValueError( "Must have a store to sign this request: %s" % (response,), response) if 'sig' in response.fields: raise AlreadySigned(response) response = self.signatory.sign(response) return super(SigningEncoder, self).encode(response) class Decoder(object): """I decode an incoming web request in to a L{OpenIDRequest}. """ _handlers = { 'checkid_setup': CheckIDRequest.fromQuery, 'checkid_immediate': CheckIDRequest.fromQuery, 'check_authentication': CheckAuthRequest.fromQuery, 'associate': AssociateRequest.fromQuery, } def decode(self, query): """I transform query parameters into an L{OpenIDRequest}. If the query does not seem to be an OpenID request at all, I return C{None}. @param query: The query parameters as a dictionary with each key mapping to one value. @type query: dict @raises ProtocolError: When the query does not seem to be a valid OpenID request. @returntype: L{OpenIDRequest} """ if not query: return None myquery = dict(filter(lambda (k, v): k.startswith(OPENID_PREFIX), query.iteritems())) if not myquery: return None mode = myquery.get(OPENID_PREFIX + 'mode') if isinstance(mode, list): raise TypeError("query dict must have one value for each key, " "not lists of values. Query is %r" % (query,)) if not mode: raise ProtocolError( query, text="No %smode value in query %r" % ( OPENID_PREFIX, query)) handler = self._handlers.get(mode, self.defaultDecoder) return handler(query) def defaultDecoder(self, query): """Called to decode queries when no handler for that mode is found. @raises ProtocolError: This implementation always raises L{ProtocolError}. """ mode = query[OPENID_PREFIX + 'mode'] raise ProtocolError( query, text="No decoder for mode %r" % (mode,)) class Server(object): """I handle requests for an OpenID server. Some types of requests (those which are not C{checkid} requests) may be handed to my L{handleRequest} method, and I will take care of it and return a response. For your convenience, I also provide an interface to L{Decoder.decode} and L{SigningEncoder.encode} through my methods L{decodeRequest} and L{encodeResponse}. All my state is encapsulated in an L{OpenIDStore}, which means I'm not generally pickleable but I am easy to reconstruct. Example:: oserver = Server(FileOpenIDStore(data_path)) request = oserver.decodeRequest(query) if request.mode in ["checkid_immediate", "checkid_setup"]: if self.isAuthorized(request.identity, request.trust_root): response = request.answer(True) elif request.immediate: response = request.answer(False, self.base_url) else: self.showDecidePage(request) return else: response = oserver.handleRequest(request) webresponse = oserver.encode(response) @ivar signatory: I'm using this for associate requests and to sign things. @type signatory: L{Signatory} @ivar decoder: I'm using this to decode things. @type decoder: L{Decoder} @ivar encoder: I'm using this to encode things. @type encoder: L{Encoder} """ signatoryClass = Signatory encoderClass = SigningEncoder decoderClass = Decoder def __init__(self, store): """A new L{Server}. @param store: The back-end where my associations are stored. @type store: L{openid.store.interface.OpenIDStore} """ self.store = store self.signatory = self.signatoryClass(self.store) self.encoder = self.encoderClass(self.signatory) self.decoder = self.decoderClass() def handleRequest(self, request): """Handle a request. Give me a request, I will give you a response. Unless it's a type of request I cannot handle myself, in which case I will raise C{NotImplementedError}. In that case, you can handle it yourself, or add a method to me for handling that request type. @raises NotImplementedError: When I do not have a handler defined for that type of request. """ handler = getattr(self, 'openid_' + request.mode, None) if handler is not None: return handler(request) else: raise NotImplementedError( "%s has no handler for a request of mode %r." % (self, request.mode)) def openid_check_authentication(self, request): """Handle and respond to {check_authentication} requests. @returntype: L{OpenIDResponse} """ return request.answer(self.signatory) def openid_associate(self, request): """Handle and respond to {associate} requests. @returntype: L{OpenIDResponse} """ assoc = self.signatory.createAssociation(dumb=False) return request.answer(assoc) def decodeRequest(self, query): """Transform query parameters into an L{OpenIDRequest}. If the query does not seem to be an OpenID request at all, I return C{None}. @param query: The query parameters as a dictionary with each key mapping to one value. @type query: dict @raises ProtocolError: When the query does not seem to be a valid OpenID request. @returntype: L{OpenIDRequest} @see: L{Decoder.decode} """ return self.decoder.decode(query) def encodeResponse(self, response): """Encode a response to a L{WebResponse}, signing it first if appropriate. @raises EncodingError: When I can't figure out how to encode this message. @raises AlreadySigned: When this response is already signed. @returntype: L{WebResponse} @see: L{Encoder.encode} """ return self.encoder.encode(response) class ProtocolError(Exception): """A message did not conform to the OpenID protocol. @ivar query: The query that is failing to be a valid OpenID request. @type query: dict """ def __init__(self, query, text=None): """When an error occurs. @param query: The query that is failing to be a valid OpenID request. @type query: dict @param text: A message about the encountered error. Set as C{args[0]}. @type text: str """ self.query = query Exception.__init__(self, text) def hasReturnTo(self): """Did this request have a return_to parameter? @returntype: bool """ if self.query is None: return False else: return (OPENID_PREFIX + 'return_to') in self.query # implements IEncodable def encodeToURL(self): """Encode a response as a URL for the user agent to GET. You will generally use this URL with a HTTP redirect. @returns: A URL to direct the user agent back to. @returntype: str """ return_to = self.query.get(OPENID_PREFIX + 'return_to') if not return_to: raise ValueError("I have no return_to URL.") return oidutil.appendArgs(return_to, { 'openid.mode': 'error', 'openid.error': str(self), }) def encodeToKVForm(self): """Encode a response in key-value colon/newline format. This is a machine-readable format used to respond to messages which came directly from the consumer and not through the user agent. @see: OpenID Specs, U{Key-Value Colon/Newline format} @returntype: str """ return kvform.dictToKV({ 'mode': 'error', 'error': str(self), }) def whichEncoding(self): """How should I be encoded? @returns: one of ENCODE_URL, ENCODE_KVFORM, or None. If None, I cannot be encoded as a protocol message and should be displayed to the user. """ if self.hasReturnTo(): return ENCODE_URL if self.query is None: return None mode = self.query.get('openid.mode') if mode: if mode not in BROWSER_REQUEST_MODES: return ENCODE_KVFORM # According to the OpenID spec as of this writing, we are probably # supposed to switch on request type here (GET versus POST) to figure # out if we're supposed to print machine-readable or human-readable # content at this point. GET/POST seems like a pretty lousy way of # making the distinction though, as it's just as possible that the # user agent could have mistakenly been directed to post to the # server URL. # Basically, if your request was so broken that you didn't manage to # include an openid.mode, I'm not going to worry too much about # returning you something you can't parse. return None class EncodingError(Exception): """Could not encode this as a protocol message. You should probably render it and show it to the user. @ivar response: The response that failed to encode. @type response: L{OpenIDResponse} """ def __init__(self, response): Exception.__init__(self, response) self.response = response class AlreadySigned(EncodingError): """This response is already signed.""" class UntrustedReturnURL(ProtocolError): """A return_to is outside the trust_root.""" def __init__(self, query, return_to, trust_root): ProtocolError.__init__(self, query) self.return_to = return_to self.trust_root = trust_root def __str__(self): return "return_to %r not under trust_root %r" % (self.return_to, self.trust_root) class MalformedReturnURL(ProtocolError): """The return_to URL doesn't look like a valid URL.""" def __init__(self, query, return_to): self.return_to = return_to ProtocolError.__init__(self, query) class MalformedTrustRoot(ProtocolError): """The trust root is not well-formed. @see: OpenID Specs, U{openid.trust_root} """ pass #class IEncodable: # Interface # def encodeToURL(return_to): # """Encode a response as a URL for redirection. # # @returns: A URL to direct the user agent back to. # @returntype: str # """ # pass # # def encodeToKvform(): # """Encode a response in key-value colon/newline format. # # This is a machine-readable format used to respond to messages which # came directly from the consumer and not through the user agent. # # @see: OpenID Specs, # U{Key-Value Colon/Newline format} # # @returntype: str # """ # pass # # def whichEncoding(): # """How should I be encoded? # # @returns: one of ENCODE_URL, ENCODE_KVFORM, or None. If None, # I cannot be encoded as a protocol message and should be # displayed to the user. # """ # pass