Implement QUIC key extraction.

net/quic/quic_crypto_stream.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_QUIC_CRYPTO_STREAM_H_
 #define NET_QUIC_QUIC_CRYPTO_STREAM_H_
 
 #include "base/basictypes.h"
 #include "net/quic/crypto/crypto_framer.h"
 #include "net/quic/crypto/crypto_utils.h"
@@ skipping 28 matching lines @@
       const CryptoHandshakeMessage& message) OVERRIDE;
 
   // ReliableQuicStream implementation
   virtual uint32 ProcessRawData(const char* data, uint32 data_len) OVERRIDE;
   virtual QuicPriority EffectivePriority() const OVERRIDE;
 
   // Sends |message| to the peer.
   // TODO(wtc): return a success/failure status.
   void SendHandshakeMessage(const CryptoHandshakeMessage& message);
 
+  // Performs key extraction to derive a new secret of |result_len| bytes
+  // dependent on |label|, |context|, and the stream's negotiated subkey secret.
+  // Returns false if the handshake has not been confirmed or the parameters are
+  // invalid (e.g. |label| contains null bytes); returns true on success.
+  bool ExportKeyingMaterial(base::StringPiece label,
+                            base::StringPiece context,
+                            size_t result_len,
+                            std::string* result) const;
+
   bool encryption_established() const { return encryption_established_; }
   bool handshake_confirmed() const { return handshake_confirmed_; }
 
   const QuicCryptoNegotiatedParameters& crypto_negotiated_params() const;
 
  protected:
   bool encryption_established_;
   bool handshake_confirmed_;
 
   QuicCryptoNegotiatedParameters crypto_negotiated_params_;
 
  private:
   CryptoFramer crypto_framer_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicCryptoStream);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CRYPTO_STREAM_H_