def parse(cls, jwt): """Parse a JWT from a string.""" algorithm, payload, signature = jwt.split(".") signed_data = algorithm + "." + payload algorithm = json.loads(decode_bytes(algorithm))["alg"] payload = json.loads(decode_bytes(payload)) signature = decode_bytes(signature) return cls(algorithm, payload, signature, signed_data)
def parse(cls, jwt): """Parse a JWT from a string.""" algorithm, payload, signature = jwt.split(".") signed_data = algorithm + "." + payload try: algorithm = decode_json_bytes(algorithm)["alg"] except KeyError: raise ValueError("badly formed JWT") payload = decode_json_bytes(payload) signature = decode_bytes(signature) return cls(algorithm, payload, signature, signed_data)
def verify(self, assertion, audience=None): """Verify the given VEP assertion. This method posts the given VEP assertion to the remove verifier service. If it is successfully verified then a dict giving the email and audience is returned. If it is not valid then an error is raised. If the 'audience' argument is given, it first verifies that the audience of the assertion matches the one given. This can help avoid doing lots of crypto for assertions that can't be valid. If you don't specify an audience, you *MUST* validate the audience value returned by this method. """ # Read audience from assertion if not specified. if audience is None: token = json.loads(decode_bytes(assertion))["assertion"] audience = json.loads(decode_bytes(token.split(".")[1]))["aud"] # Encode the data into x-www-form-urlencoded. post_data = {"assertion": assertion, "audience": audience} post_data = "&".join("%s=%s" % item for item in post_data.items()) # Post it to the verifier. resp = self.urlopen(self.verifier_url, post_data) try: info = resp.info() except AttributeError: info = {} content_length = info.get("Content-Length") if content_length is None: data = resp.read() else: data = resp.read(int(content_length)) data = json.loads(data) # Did it come back clean? if data.get('status') != "okay": raise ValueError(str(data)) assert data.get('audience') == audience return data
def verify(self, assertion, audience=None, now=None): """Verify the given VEP assertion. This method parses a VEP identity assertion, verifies the bundled chain of certificates and signatures, and returns the extracted email address and audience. If the 'audience' argument is given, it first verifies that the audience of the assertion matches the one given. This can help avoid doing lots of crypto for assertions that can't be valid. If you don't specify an audience, you *MUST* validate the audience value returned by this method. If the 'now' argument is given, it is used as the current time in milliseconds. This lets you verify expired assertions. """ if now is None: now = int(time.time() * 1000) data = json.loads(decode_bytes(assertion)) # Check that the assertion is usable and valid. # No point doing all that crypto if we're going to fail out anyway. assertion = JWT.parse(data["assertion"]) if audience is not None: if assertion.payload["aud"] != audience: raise ValueError("mismatched audience") if assertion.payload["exp"] < now: raise ValueError("expired assertion") # Follow the certificate chain to get to the claiming principal. certificates = data["certificates"] certificates = [JWT.parse(c) for c in certificates] cert = self.verify_certificate_chain(certificates, now=now) email = cert.payload["principal"]["email"] # Check that the root issuer is trusted. root_issuer = certificates[0].payload["iss"] if root_issuer not in self.trusted_secondaries: if not email.endswith("@" + root_issuer): msg = "untrusted root issuer: %s" % (root_issuer,) raise ValueError(msg) # Check the signature on the assertion. if not assertion.check_signature(cert.payload["public-key"]): raise ValueError("invalid signature on assertion") # Looks good! return {"status": "okay", "audience": assertion.payload["aud"], "email": email}
def test_encode_decode_bytes(self): self.assertEquals("HELLO", decode_bytes(encode_bytes("HELLO"))) self.assertEquals("HELLO", decode_bytes(encode_bytes(u"HELLO"))) self.assertRaises(ValueError, decode_bytes, u"\N{SNOWMAN}") self.assertRaises(ValueError, decode_bytes, "A===")