Proof of concept discourse authentication

RIGS/discourse/sso.py

@@ -0,0 +1,46 @@
+import urllib
+from hashlib import sha256
+import hmac
+from base64 import b64decode, b64encode
+
+
+class DiscourseSSO:
+    def __init__(self, secret_key):
+        self.__secret_key = secret_key
+
+    def validate(self, payload, sig):
+        payload = urllib.unquote(payload)
+        computed_sig = hmac.new(
+            self.__secret_key.encode(),
+            payload.encode(),
+            sha256
+        ).hexdigest()
+        print(type(computed_sig), type(sig))
+        return hmac.compare_digest(unicode(computed_sig), sig)
+
+    def get_nonce(self, payload):
+        payload = b64decode(urllib.unquote(payload)).decode()
+        d = dict(nonce.split("=") for nonce in payload.split('&'))
+
+        if 'nonce' in d and d['nonce'] != '':
+            return d['nonce']
+        else:
+            raise Exception("Nonce could not be found in payload")
+
+    def get_data(self, payload):
+        payload = urllib.unquote(b64decode(urllib.unquote(payload)).decode())
+        d = dict(data.split("=") for data in payload.split('&'))
+
+        return d
+
+    def build_login_URL(self, nonce, redirect_uri):
+        data = {
+            'nonce': nonce,
+            'return_sso_url': redirect_uri
+        }
+
+        payload = urllib.urlencode(data)
+        payload = b64encode(payload.encode())
+        sig = hmac.new(self.__secret_key.encode(), payload, sha256).hexdigest()
+
+        return '/session/sso_provider?' + urllib.urlencode({'sso': payload, 'sig': sig})