Merge pull request #3 from guyrt/master

[twitter-api-cdsw-solutions] / oauthlib / oauth1 / rfc5849 / endpoints / signature_only.py

diff --git a/oauthlib/oauth1/rfc5849/endpoints/signature_only.py b/oauthlib/oauth1/rfc5849/endpoints/signature_only.py
new file mode 100644 (file)
index 0000000..2f8e7c9
--- /dev/null
+++ b/oauthlib/oauth1/rfc5849/endpoints/signature_only.py
@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+"""
+oauthlib.oauth1.rfc5849.endpoints.signature_only
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This module is an implementation of the signing logic of OAuth 1.0 RFC 5849.
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+import logging
+
+from .base import BaseEndpoint
+from .. import errors
+
+log = logging.getLogger(__name__)
+
+
+class SignatureOnlyEndpoint(BaseEndpoint):
+
+    """An endpoint only responsible for verifying an oauth signature."""
+
+    def validate_request(self, uri, http_method='GET',
+                         body=None, headers=None):
+        """Validate a signed OAuth request.
+
+        :param uri: The full URI of the token request.
+        :param http_method: A valid HTTP verb, i.e. GET, POST, PUT, HEAD, etc.
+        :param body: The request body as a string.
+        :param headers: The request headers as a dict.
+        :returns: A tuple of 2 elements.
+                  1. True if valid, False otherwise.
+                  2. An oauthlib.common.Request object.
+        """
+        try:
+            request = self._create_request(uri, http_method, body, headers)
+        except errors.OAuth1Error:
+            return False, None
+
+        try:
+            self._check_transport_security(request)
+            self._check_mandatory_parameters(request)
+        except errors.OAuth1Error:
+            return False, request
+
+        if not self.request_validator.validate_timestamp_and_nonce(
+                request.client_key, request.timestamp, request.nonce, request):
+            return False, request
+
+        # The server SHOULD return a 401 (Unauthorized) status code when
+        # receiving a request with invalid client credentials.
+        # Note: This is postponed in order to avoid timing attacks, instead
+        # a dummy client is assigned and used to maintain near constant
+        # time request verification.
+        #
+        # Note that early exit would enable client enumeration
+        valid_client = self.request_validator.validate_client_key(
+            request.client_key, request)
+        if not valid_client:
+            request.client_key = self.request_validator.dummy_client
+
+        valid_signature = self._check_signature(request)
+
+        # We delay checking validity until the very end, using dummy values for
+        # calculations and fetching secrets/keys to ensure the flow of every
+        # request remains almost identical regardless of whether valid values
+        # have been supplied. This ensures near constant time execution and
+        # prevents malicious users from guessing sensitive information
+        v = all((valid_client, valid_signature))
+        if not v:
+            log.info("[Failure] request verification failed.")
+            log.info("Valid client: %s", valid_client)
+            log.info("Valid signature: %s", valid_signature)
+        return v, request