Fix various issues in TLS found using BoGo

 - BoGo sends unparseable OCSP responses, so we have to accomodate for
   this by delaying decoding until verification and simply ignoring
   OCSP responses that we can't parse.
 - Check that there is no trailing garbage at the end of various messages.
 - Don't send empty SNI
 - Check the TLS record header versions (previously ignored)
 - For CBC 1/n-1 splitting split every record instead of just first.
   I think this is not a problem but it is what BoGo expects.
 - New Channel::application_protocol virtual (previously was
   implemented on both Client and Server but not shared).
 - Changes to resumption version handling.
 - Fix server version selection when newer versions are disabled.

New policy hooks added in service of BoGo:
 - maximum_certificate_chain_size gives the maximum cert chain in bytes
   that we'll accept.
 - allow_resumption_for_renegotiation specifies if a renegotiation
   attempt can be simply (re-)resumed instead.
 - abort_handshake_on_undesired_renegotiation - previously we just
   ignored it with a warning alert. Now behavior is configurable.
 - request_client_certificate_authentication
 - require_client_certificate_authentication

1 files changed, 6 insertions, 4 deletions

diff --git a/src/lib/tls/tls_alert.cpp b/src/lib/tls/tls_alert.cpp
index e1e8c6eb6..60c9c4b98 100644
--- a/src/lib/tls/tls_alert.cpp
+++ b/src/lib/tls/tls_alert.cpp
@@ -6,7 +6,7 @@
 */
 
 #include <botan/tls_alert.h>
-#include <botan/exceptn.h>
+#include <botan/tls_exceptn.h>
 
 namespace Botan {
 
@@ -15,13 +15,13 @@ namespace TLS {
 Alert::Alert(const secure_vector<uint8_t>& buf)
    {
    if(buf.size() != 2)
-      throw Decoding_Error("Alert: Bad size " + std::to_string(buf.size()) +
-                           " for alert message");
+      throw Decoding_Error("Bad size (" + std::to_string(buf.size()) +
+                           ") for TLS alert message");
 
    if(buf[0] == 1)      m_fatal = false;
    else if(buf[0] == 2) m_fatal = true;
    else
-      throw Decoding_Error("Alert: Bad code for alert level");
+      throw TLS_Exception(Alert::ILLEGAL_PARAMETER, "Bad code for TLS alert level");
 
    const uint8_t dc = buf[1];
 
@@ -103,6 +103,8 @@ std::string Alert::type_string() const
          return "bad_certificate_hash_value";
       case UNKNOWN_PSK_IDENTITY:
          return "unknown_psk_identity";
+      case CERTIFICATE_REQUIRED:
+         return "certificate_required";
       case NO_APPLICATION_PROTOCOL:
          return "no_application_protocol";