Support setting the number of pad bytes in a heartbeat message. Use

random instead of all-zero padding. Check on sanity of received pads
to the extent possible. Bugzilla 269.

1 files changed, 49 insertions, 47 deletions

diff --git a/src/lib/tls/tls_channel.h b/src/lib/tls/tls_channel.h
index 8aea2dab0..c5da583a1 100644
--- a/src/lib/tls/tls_channel.h
+++ b/src/lib/tls/tls_channel.h
@@ -1,6 +1,6 @@
 /*
 * TLS Channel
-* (C) 2011,2012,2014 Jack Lloyd
+* (C) 2011,2012,2014,2015 Jack Lloyd
 *
 * Released under the terms of the Botan license
 */
@@ -31,6 +31,21 @@ class Handshake_State;
 class BOTAN_DLL Channel
    {
    public:
+      Channel(std::function<void (const byte[], size_t)> socket_output_fn,
+              std::function<void (const byte[], size_t)> data_cb,
+              std::function<void (Alert, const byte[], size_t)> alert_cb,
+              std::function<bool (const Session&)> handshake_cb,
+              Session_Manager& session_manager,
+              RandomNumberGenerator& rng,
+              bool is_datagram,
+              size_t reserved_io_buffer_size);
+
+      Channel(const Channel&) = delete;
+
+      Channel& operator=(const Channel&) = delete;
+
+      virtual ~Channel();
+
       /**
       * Inject TLS traffic received from counterparty
       * @return a hint as the how many more bytes we need to process the
@@ -46,14 +61,6 @@ class BOTAN_DLL Channel
       size_t received_data(const std::vector<byte>& buf);
 
       /**
-      * Perform a handshake timeout check. This does nothing unless
-      * this is a DTLS channel with a pending handshake state, in
-      * which case we check for timeout and potentially retransmit
-      * handshake packets.
-      */
-      bool timeout_check();
-
-      /**
       * Inject plaintext intended for counterparty
       * Throws an exception if is_active() is false
       */
@@ -107,22 +114,29 @@ class BOTAN_DLL Channel
       */
       bool is_closed() const;
 
+
       /**
-      * Attempt to renegotiate the session
-      * @param force_full_renegotiation if true, require a full renegotiation,
-      *                                 otherwise allow session resumption
+      * @return certificate chain of the peer (may be empty)
       */
-      void renegotiate(bool force_full_renegotiation = false);
+      std::vector<X509_Certificate> peer_cert_chain() const;
 
       /**
-      * @return true iff the peer supports heartbeat messages
+      * Key material export (RFC 5705)
+      * @param label a disambiguating label string
+      * @param context a per-association context value
+      * @param length the length of the desired key in bytes
+      * @return key of length bytes
       */
-      bool peer_supports_heartbeats() const;
+      SymmetricKey key_material_export(const std::string& label,
+                                       const std::string& context,
+                                       size_t length) const;
 
       /**
-      * @return true iff we are allowed to send heartbeat messages
+      * Attempt to renegotiate the session
+      * @param force_full_renegotiation if true, require a full renegotiation,
+      * otherwise allow session resumption
       */
-      bool heartbeat_sending_allowed() const;
+      void renegotiate(bool force_full_renegotiation = false);
 
       /**
       * @return true iff the counterparty supports the secure
@@ -131,47 +145,35 @@ class BOTAN_DLL Channel
       bool secure_renegotiation_supported() const;
 
       /**
-      * Attempt to send a heartbeat message (if negotiated with counterparty)
-      * @param payload will be echoed back
-      * @param payload_size size of payload in bytes
+      * Perform a handshake timeout check. This does nothing unless
+      * this is a DTLS channel with a pending handshake state, in
+      * which case we check for timeout and potentially retransmit
+      * handshake packets.
       */
-      void heartbeat(const byte payload[], size_t payload_size);
+      bool timeout_check();
 
       /**
-      * Attempt to send a heartbeat message (if negotiated with counterparty)
+      * @return true iff the peer supports heartbeat messages
       */
-      void heartbeat() { heartbeat(nullptr, 0); }
+      bool peer_supports_heartbeats() const;
 
       /**
-      * @return certificate chain of the peer (may be empty)
+      * @return true iff we are allowed to send heartbeat messages
       */
-      std::vector<X509_Certificate> peer_cert_chain() const;
+      bool heartbeat_sending_allowed() const;
 
       /**
-      * Key material export (RFC 5705)
-      * @param label a disambiguating label string
-      * @param context a per-association context value
-      * @param length the length of the desired key in bytes
-      * @return key of length bytes
+      * Attempt to send a heartbeat message (if negotiated with counterparty)
+      * @param payload will be echoed back
+      * @param payload_size size of payload in bytes
+      * @param pad_bytes include 16 + pad_bytes extra bytes in the message (not echoed)
       */
-      SymmetricKey key_material_export(const std::string& label,
-                                       const std::string& context,
-                                       size_t length) const;
-
-      Channel(std::function<void (const byte[], size_t)> socket_output_fn,
-              std::function<void (const byte[], size_t)> data_cb,
-              std::function<void (Alert, const byte[], size_t)> alert_cb,
-              std::function<bool (const Session&)> handshake_cb,
-              Session_Manager& session_manager,
-              RandomNumberGenerator& rng,
-              bool is_datagram,
-              size_t reserved_io_buffer_size);
-
-      Channel(const Channel&) = delete;
-
-      Channel& operator=(const Channel&) = delete;
+      void heartbeat(const byte payload[], size_t payload_size, size_t pad_bytes = 0);
 
-      virtual ~Channel();
+      /**
+      * Attempt to send a heartbeat message (if negotiated with counterparty)
+      */
+      void heartbeat() { heartbeat(nullptr, 0); }
    protected:
 
       virtual void process_handshake_msg(const Handshake_State* active_state,