Changes to TLS::Callbacks for GH PR #457

Make TLS::Channel::m_callbacks a reference, so deriving from TLS::Callbacks works

Split out the compat (std::function) based interface to Compat_Callbacks.
This avoids the overhead of empty std::functions when using the virtual
interface, and ensures the virtual interface works since there is no
callback path that does not involve a vtable lookup.

Rename the TLS::Callback functions. Since the idea is that often an owning
class will pass *this as the callbacks argument, it is good to namespace
the virtual functions so as not to conflict with other names chosen by
the class. Specifically, prefixes all cb functions with tls_

Revert changes to use the old style alert callback (with no longer used data/len
params) so no API changes are required for old code. The new Callbacks interface
continues to just receive the alert code itself.

Switch to virtual function interface in CLI tls_client for testing.

Inline tls_server_handshake_state.h - only used in tls_server.cpp

Fix tests - test looked like it was creating a new client object but it
was not actually being used. And when enabled, it failed because the queues
were not being emptied in between. So, fix that.

1 files changed, 45 insertions, 12 deletions

diff --git a/src/lib/tls/tls_client.h b/src/lib/tls/tls_client.h
index 6452294cd..09af053af 100644
--- a/src/lib/tls/tls_client.h
+++ b/src/lib/tls/tls_client.h
@@ -23,6 +23,7 @@ namespace TLS {
 class BOTAN_DLL Client final : public Channel
    {
    public:
+
       /**
       * Set up a new TLS client session
       *
@@ -48,7 +49,51 @@ class BOTAN_DLL Client final : public Channel
       *        be preallocated for the read and write buffers. Smaller
       *        values just mean reallocations and copies are more likely.
       */
+     Client(Callbacks& callbacks,
+            Session_Manager& session_manager,
+            Credentials_Manager& creds,
+            const Policy& policy,
+            RandomNumberGenerator& rng,
+            const Server_Information& server_info = Server_Information(),
+            const Protocol_Version& offer_version = Protocol_Version::latest_tls_version(),
+            const std::vector<std::string>& next_protocols = {},
+            size_t reserved_io_buffer_size = TLS::Client::IO_BUF_DEFAULT_SIZE
+         );
 
+      /**
+      * DEPRECATED. This constructor is only provided for backward
+      * compatibility and should not be used in new code.
+      * 
+      * Set up a new TLS client session
+      *
+      * @param output_fn is called with data for the outbound socket
+      *
+      * @param app_data_cb is called when new application data is received
+      *
+      * @param alert_cb is called when a TLS alert is received
+      *
+      * @param handshake_cb is called when a handshake is completed
+      *
+      * @param session_manager manages session state
+      *
+      * @param creds manages application/user credentials
+      *
+      * @param policy specifies other connection policy information
+      *
+      * @param rng a random number generator
+      *
+      * @param server_info is identifying information about the TLS server
+      *
+      * @param offer_version specifies which version we will offer
+      *        to the TLS server.
+      *
+      * @param next_protocols specifies protocols to advertise with ALPN
+      *
+      * @param reserved_io_buffer_size This many bytes of memory will
+      *        be preallocated for the read and write buffers. Smaller
+      *        values just mean reallocations and copies are more likely.
+      */
+      BOTAN_DEPRECATED("Use TLS::Client(TLS::Callbacks ...)")
       Client(output_fn out,
              data_cb app_data_cb,
              alert_cb alert_cb,
@@ -82,18 +127,6 @@ class BOTAN_DLL Client final : public Channel
              const std::vector<std::string>& next_protocols = {}
          );
 
-
-     Client(const Callbacks& callbacks,
-            Session_Manager& session_manager,
-            Credentials_Manager& creds,
-            const Policy& policy,
-            RandomNumberGenerator& rng,
-            const Server_Information& server_info = Server_Information(),
-            const Protocol_Version& offer_version = Protocol_Version::latest_tls_version(),
-            const std::vector<std::string>& next_protocols = {},
-            size_t reserved_io_buffer_size = TLS::Client::IO_BUF_DEFAULT_SIZE
-         );
-
       const std::string& application_protocol() const { return m_application_protocol; }
    private:
       void init(const Protocol_Version& protocol_version,