Merged in certs branch in preparation for 0.9.3pre2

git-svn-id: https://svn.mcs.anl.gov/repos/bcfg/trunk/bcfg2@2928 ce84e21b-d406-0410-9b95-82705330c041

1 files changed, 131 insertions, 0 deletions

diff --git a/src/lib/tlslite/Session.py b/src/lib/tlslite/Session.py
new file mode 100755
index 000000000..a951f4589
--- /dev/null
+++ b/src/lib/tlslite/Session.py
@@ -0,0 +1,131 @@
+"""Class representing a TLS session."""
+
+from utils.compat import *
+from mathtls import *
+from constants import *
+
+class Session:
+    """
+    This class represents a TLS session.
+
+    TLS distinguishes between connections and sessions.  A new
+    handshake creates both a connection and a session.  Data is
+    transmitted over the connection.
+
+    The session contains a more permanent record of the handshake.  The
+    session can be inspected to determine handshake results.  The
+    session can also be used to create a new connection through
+    "session resumption". If the client and server both support this,
+    they can create a new connection based on an old session without
+    the overhead of a full handshake.
+
+    The session for a L{tlslite.TLSConnection.TLSConnection} can be
+    retrieved from the connection's 'session' attribute.
+
+    @type srpUsername: str
+    @ivar srpUsername: The client's SRP username (or None).
+
+    @type sharedKeyUsername: str
+    @ivar sharedKeyUsername: The client's shared-key username (or
+    None).
+
+    @type clientCertChain: L{tlslite.X509CertChain.X509CertChain} or
+    L{cryptoIDlib.CertChain.CertChain}
+    @ivar clientCertChain: The client's certificate chain (or None).
+
+    @type serverCertChain: L{tlslite.X509CertChain.X509CertChain} or
+    L{cryptoIDlib.CertChain.CertChain}
+    @ivar serverCertChain: The server's certificate chain (or None).
+    """
+
+    def __init__(self):
+        self.masterSecret = createByteArraySequence([])
+        self.sessionID = createByteArraySequence([])
+        self.cipherSuite = 0
+        self.srpUsername = None
+        self.sharedKeyUsername = None
+        self.clientCertChain = None
+        self.serverCertChain = None
+        self.resumable = False
+        self.sharedKey = False
+
+    def _clone(self):
+        other = Session()
+        other.masterSecret = self.masterSecret
+        other.sessionID = self.sessionID
+        other.cipherSuite = self.cipherSuite
+        other.srpUsername = self.srpUsername
+        other.sharedKeyUsername = self.sharedKeyUsername
+        other.clientCertChain = self.clientCertChain
+        other.serverCertChain = self.serverCertChain
+        other.resumable = self.resumable
+        other.sharedKey = self.sharedKey
+        return other
+
+    def _calcMasterSecret(self, version, premasterSecret, clientRandom,
+                         serverRandom):
+        if version == (3,0):
+            self.masterSecret = PRF_SSL(premasterSecret,
+                                concatArrays(clientRandom, serverRandom), 48)
+        elif version in ((3,1), (3,2)):
+            self.masterSecret = PRF(premasterSecret, "master secret",
+                                concatArrays(clientRandom, serverRandom), 48)
+        else:
+            raise AssertionError()
+
+    def valid(self):
+        """If this session can be used for session resumption.
+
+        @rtype: bool
+        @return: If this session can be used for session resumption.
+        """
+        return self.resumable or self.sharedKey
+
+    def _setResumable(self, boolean):
+        #Only let it be set if this isn't a shared key
+        if not self.sharedKey:
+            #Only let it be set to True if the sessionID is non-null
+            if (not boolean) or (boolean and self.sessionID):
+                self.resumable = boolean
+
+    def getCipherName(self):
+        """Get the name of the cipher used with this connection.
+
+        @rtype: str
+        @return: The name of the cipher used with this connection.
+        Either 'aes128', 'aes256', 'rc4', or '3des'.
+        """
+        if self.cipherSuite in CipherSuite.aes128Suites:
+            return "aes128"
+        elif self.cipherSuite in CipherSuite.aes256Suites:
+            return "aes256"
+        elif self.cipherSuite in CipherSuite.rc4Suites:
+            return "rc4"
+        elif self.cipherSuite in CipherSuite.tripleDESSuites:
+            return "3des"
+        else:
+            return None
+
+    def _createSharedKey(self, sharedKeyUsername, sharedKey):
+        if len(sharedKeyUsername)>16:
+            raise ValueError()
+        if len(sharedKey)>47:
+            raise ValueError()
+
+        self.sharedKeyUsername = sharedKeyUsername
+
+        self.sessionID = createByteArrayZeros(16)
+        for x in range(len(sharedKeyUsername)):
+            self.sessionID[x] = ord(sharedKeyUsername[x])
+
+        premasterSecret = createByteArrayZeros(48)
+        sharedKey = chr(len(sharedKey)) + sharedKey
+        for x in range(48):
+            premasterSecret[x] = ord(sharedKey[x % len(sharedKey)])
+
+        self.masterSecret = PRF(premasterSecret, "shared secret",
+                                createByteArraySequence([]), 48)
+        self.sharedKey = True
+        return self
+
+