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python/gdata/tlslite/SharedKeyDB.py

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+"""Class for storing shared keys."""
+
+from utils.cryptomath import *
+from utils.compat import *
+from mathtls import *
+from Session import Session
+from BaseDB import BaseDB
+
+class SharedKeyDB(BaseDB):
+    """This class represent an in-memory or on-disk database of shared
+    keys.
+
+    A SharedKeyDB can be passed to a server handshake function to
+    authenticate a client based on one of the shared keys.
+
+    This class is thread-safe.
+    """
+
+    def __init__(self, filename=None):
+        """Create a new SharedKeyDB.
+
+        @type filename: str
+        @param filename: Filename for an on-disk database, or None for
+        an in-memory database.  If the filename already exists, follow
+        this with a call to open().  To create a new on-disk database,
+        follow this with a call to create().
+        """
+        BaseDB.__init__(self, filename, "shared key")
+
+    def _getItem(self, username, valueStr):
+        session = Session()
+        session._createSharedKey(username, valueStr)
+        return session
+
+    def __setitem__(self, username, sharedKey):
+        """Add a shared key to the database.
+
+        @type username: str
+        @param username: The username to associate the shared key with.
+        Must be less than or equal to 16 characters in length, and must
+        not already be in the database.
+
+        @type sharedKey: str
+        @param sharedKey: The shared key to add.  Must be less than 48
+        characters in length.
+        """
+        BaseDB.__setitem__(self, username, sharedKey)
+
+    def _setItem(self, username, value):
+        if len(username)>16:
+            raise ValueError("username too long")
+        if len(value)>=48:
+            raise ValueError("shared key too long")
+        return value
+
+    def _checkItem(self, value, username, param):
+        newSession = self._getItem(username, param)
+        return value.masterSecret == newSession.masterSecret