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# -*- coding: utf-8 -*-
from __future__ import absolute_import
"""
oauthlib.oauth1.rfc5849
~~~~~~~~~~~~~~
This module is an implementation of various logic needed
for signing and checking OAuth 1.0 RFC 5849 requests.
"""
import logging
import urlparse
from oauthlib.common import Request, urlencode
from . import parameters, signature, utils
SIGNATURE_HMAC = u"HMAC-SHA1"
SIGNATURE_RSA = u"RSA-SHA1"
SIGNATURE_PLAINTEXT = u"PLAINTEXT"
SIGNATURE_METHODS = (SIGNATURE_HMAC, SIGNATURE_RSA, SIGNATURE_PLAINTEXT)
SIGNATURE_TYPE_AUTH_HEADER = u'AUTH_HEADER'
SIGNATURE_TYPE_QUERY = u'QUERY'
SIGNATURE_TYPE_BODY = u'BODY'
CONTENT_TYPE_FORM_URLENCODED = u'application/x-www-form-urlencoded'
class Client(object):
"""A client used to sign OAuth 1.0 RFC 5849 requests"""
def __init__(self, client_key,
client_secret=None,
resource_owner_key=None,
resource_owner_secret=None,
callback_uri=None,
signature_method=SIGNATURE_HMAC,
signature_type=SIGNATURE_TYPE_AUTH_HEADER,
rsa_key=None, verifier=None):
self.client_key = client_key
self.client_secret = client_secret
self.resource_owner_key = resource_owner_key
self.resource_owner_secret = resource_owner_secret
self.signature_method = signature_method
self.signature_type = signature_type
self.callback_uri = callback_uri
self.rsa_key = rsa_key
self.verifier = verifier
if self.signature_method == SIGNATURE_RSA and self.rsa_key is None:
raise ValueError('rsa_key is required when using RSA signature method.')
def get_oauth_signature(self, request):
"""Get an OAuth signature to be used in signing a request
"""
if self.signature_method == SIGNATURE_PLAINTEXT:
# fast-path
return signature.sign_plaintext(self.client_secret,
self.resource_owner_secret)
uri, headers, body = self._render(request)
collected_params = signature.collect_parameters(
uri_query=urlparse.urlparse(uri).query,
body=body,
headers=headers)
logging.debug("Collected params: {0}".format(collected_params))
normalized_params = signature.normalize_parameters(collected_params)
normalized_uri = signature.normalize_base_string_uri(request.uri)
logging.debug("Normalized params: {0}".format(normalized_params))
logging.debug("Normalized URI: {0}".format(normalized_uri))
base_string = signature.construct_base_string(request.http_method,
normalized_uri, normalized_params)
logging.debug("Base signing string: {0}".format(base_string))
if self.signature_method == SIGNATURE_HMAC:
sig = signature.sign_hmac_sha1(base_string, self.client_secret,
self.resource_owner_secret)
elif self.signature_method == SIGNATURE_RSA:
sig = signature.sign_rsa_sha1(base_string, self.rsa_key)
else:
sig = signature.sign_plaintext(self.client_secret,
self.resource_owner_secret)
logging.debug("Signature: {0}".format(sig))
return sig
def get_oauth_params(self):
"""Get the basic OAuth parameters to be used in generating a signature.
"""
params = [
(u'oauth_nonce', utils.generate_nonce()),
(u'oauth_timestamp', utils.generate_timestamp()),
(u'oauth_version', u'1.0'),
(u'oauth_signature_method', self.signature_method),
(u'oauth_consumer_key', self.client_key),
]
if self.resource_owner_key:
params.append((u'oauth_token', self.resource_owner_key))
if self.callback_uri:
params.append((u'oauth_callback', self.callback_uri))
if self.verifier:
params.append((u'oauth_verifier', self.verifier))
return params
def _render(self, request, formencode=False):
"""Render a signed request according to signature type
Returns a 3-tuple containing the request URI, headers, and body.
If the formencode argument is True and the body contains parameters, it
is escaped and returned as a valid formencoded string.
"""
# TODO what if there are body params on a header-type auth?
# TODO what if there are query params on a body-type auth?
uri, headers, body = request.uri, request.headers, request.body
# TODO: right now these prepare_* methods are very narrow in scope--they
# only affect their little thing. In some cases (for example, with
# header auth) it might be advantageous to allow these methods to touch
# other parts of the request, like the headers—so the prepare_headers
# method could also set the Content-Type header to x-www-form-urlencoded
# like the spec requires. This would be a fundamental change though, and
# I'm not sure how I feel about it.
if self.signature_type == SIGNATURE_TYPE_AUTH_HEADER:
headers = parameters.prepare_headers(request.oauth_params, request.headers)
elif self.signature_type == SIGNATURE_TYPE_BODY and request.decoded_body is not None:
body = parameters.prepare_form_encoded_body(request.oauth_params, request.decoded_body)
if formencode:
body = urlencode(body)
headers['Content-Type'] = u'application/x-www-form-urlencoded'
elif self.signature_type == SIGNATURE_TYPE_QUERY:
uri = parameters.prepare_request_uri_query(request.oauth_params, request.uri)
else:
raise ValueError('Unknown signature type specified.')
return uri, headers, body
def sign(self, uri, http_method=u'GET', body=None, headers=None):
"""Sign a request
Signs an HTTP request with the specified parts.
Returns a 3-tuple of the signed request's URI, headers, and body.
Note that http_method is not returned as it is unaffected by the OAuth
signing process.
The body argument may be a dict, a list of 2-tuples, or a formencoded
string. The Content-Type header must be 'application/x-www-form-urlencoded'
if it is present.
If the body argument is not one of the above, it will be returned
verbatim as it is unaffected by the OAuth signing process. Attempting to
sign a request with non-formencoded data using the OAuth body signature
type is invalid and will raise an exception.
If the body does contain parameters, it will be returned as a properly-
formatted formencoded string.
All string data MUST be unicode. This includes strings inside body
dicts, for example.
"""
# normalize request data
request = Request(uri, http_method, body, headers)
# sanity check
content_type = request.headers.get('Content-Type', None)
multipart = content_type and content_type.startswith('multipart/')
should_have_params = content_type == CONTENT_TYPE_FORM_URLENCODED
has_params = request.decoded_body is not None
# 3.4.1.3.1. Parameter Sources
# [Parameters are collected from the HTTP request entity-body, but only
# if [...]:
# * The entity-body is single-part.
if multipart and has_params:
raise ValueError("Headers indicate a multipart body but body contains parameters.")
# * The entity-body follows the encoding requirements of the
# "application/x-www-form-urlencoded" content-type as defined by
# [W3C.REC-html40-19980424].
elif should_have_params and not has_params:
raise ValueError("Headers indicate a formencoded body but body was not decodable.")
# * The HTTP request entity-header includes the "Content-Type"
# header field set to "application/x-www-form-urlencoded".
elif not should_have_params and has_params:
raise ValueError("Body contains parameters but Content-Type header was not set.")
# 3.5.2. Form-Encoded Body
# Protocol parameters can be transmitted in the HTTP request entity-
# body, but only if the following REQUIRED conditions are met:
# o The entity-body is single-part.
# o The entity-body follows the encoding requirements of the
# "application/x-www-form-urlencoded" content-type as defined by
# [W3C.REC-html40-19980424].
# o The HTTP request entity-header includes the "Content-Type" header
# field set to "application/x-www-form-urlencoded".
elif self.signature_type == SIGNATURE_TYPE_BODY and not (
should_have_params and has_params and not multipart):
raise ValueError('Body signatures may only be used with form-urlencoded content')
# generate the basic OAuth parameters
request.oauth_params = self.get_oauth_params()
# generate the signature
request.oauth_params.append((u'oauth_signature', self.get_oauth_signature(request)))
# render the signed request and return it
return self._render(request, formencode=True)
class Server(object):
"""A server used to verify OAuth 1.0 RFC 5849 requests"""
def __init__(self, signature_method=SIGNATURE_HMAC, rsa_key=None):
self.signature_method = signature_method
self.rsa_key = rsa_key
def get_client_secret(self, client_key):
raise NotImplementedError("Subclasses must implement this function.")
def get_resource_owner_secret(self, resource_owner_key):
raise NotImplementedError("Subclasses must implement this function.")
def get_signature_type_and_params(self, uri_query, headers, body):
signature_types_with_oauth_params = filter(lambda s: s[1], (
(SIGNATURE_TYPE_AUTH_HEADER, utils.filter_oauth_params(
signature.collect_parameters(headers=headers,
exclude_oauth_signature=False))),
(SIGNATURE_TYPE_BODY, utils.filter_oauth_params(
signature.collect_parameters(body=body,
exclude_oauth_signature=False))),
(SIGNATURE_TYPE_QUERY, utils.filter_oauth_params(
signature.collect_parameters(uri_query=uri_query,
exclude_oauth_signature=False))),
))
if len(signature_types_with_oauth_params) > 1:
raise ValueError('oauth_ params must come from only 1 signature type but were found in %s' % ', '.join(
[s[0] for s in signature_types_with_oauth_params]))
try:
signature_type, params = signature_types_with_oauth_params[0]
except IndexError:
raise ValueError('oauth_ params are missing. Could not determine signature type.')
return signature_type, dict(params)
def check_client_key(self, client_key):
raise NotImplementedError("Subclasses must implement this function.")
def check_resource_owner_key(self, client_key, resource_owner_key):
raise NotImplementedError("Subclasses must implement this function.")
def check_timestamp_and_nonce(self, timestamp, nonce):
raise NotImplementedError("Subclasses must implement this function.")
def check_request_signature(self, uri, http_method=u'GET', body='',
headers=None):
"""Check a request's supplied signature to make sure the request is
valid.
Servers should return HTTP status 400 if a ValueError exception
is raised and HTTP status 401 on return value False.
Per `section 3.2`_ of the spec.
.. _`section 3.2`: http://tools.ietf.org/html/rfc5849#section-3.2
"""
headers = headers or {}
signature_type = None
# FIXME: urlparse does not return unicode!
uri_query = urlparse.urlparse(uri).query
signature_type, params = self.get_signature_type_and_params(uri_query,
headers, body)
# the parameters may not include duplicate oauth entries
filtered_params = utils.filter_oauth_params(params)
if len(filtered_params) != len(params):
raise ValueError("Duplicate OAuth entries.")
params = dict(params)
request_signature = params.get(u'oauth_signature')
client_key = params.get(u'oauth_consumer_key')
resource_owner_key = params.get(u'oauth_token')
nonce = params.get(u'oauth_nonce')
timestamp = params.get(u'oauth_timestamp')
callback_uri = params.get(u'oauth_callback')
verifier = params.get(u'oauth_verifier')
signature_method = params.get(u'oauth_signature_method')
# ensure all mandatory parameters are present
if not all((request_signature, client_key, nonce,
timestamp, signature_method)):
raise ValueError("Missing OAuth parameters.")
# if version is supplied, it must be "1.0"
if u'oauth_version' in params and params[u'oauth_version'] != u'1.0':
raise ValueError("Invalid OAuth version.")
# signature method must be valid
if not signature_method in SIGNATURE_METHODS:
raise ValueError("Invalid signature method.")
# ensure client key is valid
if not self.check_client_key(client_key):
return False
# ensure resource owner key is valid and not expired
if not self.check_resource_owner_key(client_key, resource_owner_key):
return False
# ensure the nonce and timestamp haven't been used before
if not self.check_timestamp_and_nonce(timestamp, nonce):
return False
# FIXME: extract realm, then self.check_realm
# oauth_client parameters depend on client chosen signature method
# which may vary for each request, section 3.4
# HMAC-SHA1 and PLAINTEXT share parameters
if signature_method == SIGNATURE_RSA:
oauth_client = Client(client_key,
resource_owner_key=resource_owner_key,
callback_uri=callback_uri,
signature_method=signature_method,
signature_type=signature_type,
rsa_key=self.rsa_key, verifier=verifier)
else:
client_secret = self.get_client_secret(client_key)
resource_owner_secret = self.get_resource_owner_secret(
resource_owner_key)
oauth_client = Client(client_key,
client_secret=client_secret,
resource_owner_key=resource_owner_key,
resource_owner_secret=resource_owner_secret,
callback_uri=callback_uri,
signature_method=signature_method,
signature_type=signature_type,
verifier=verifier)
request = Request(uri, http_method, body, headers)
request.oauth_params = params
client_signature = oauth_client.get_oauth_signature(request)
# FIXME: use near constant time string compare to avoid timing attacks
return client_signature == request_signature