ssl: Gracefulness behaviour when receiving partially malformed messages

1 files changed, 25 insertions, 14 deletions

diff --git a/lib/ssl/src/tls_handshake.erl b/lib/ssl/src/tls_handshake.erl
index 566b7db332..6e593950d9 100644
--- a/lib/ssl/src/tls_handshake.erl
+++ b/lib/ssl/src/tls_handshake.erl
@@ -109,19 +109,25 @@ hello(#client_hello{client_version = ClientVersion,
 		    cipher_suites = CipherSuites} = Hello,
       #ssl_options{versions = Versions} = SslOpts,
       Info, Renegotiation) ->
-    Version = ssl_handshake:select_version(tls_record, ClientVersion, Versions),
-    case ssl_cipher:is_fallback(CipherSuites) of
+    try
+	Version = ssl_handshake:select_version(tls_record, ClientVersion, Versions),
+	case ssl_cipher:is_fallback(CipherSuites) of
 	true -> 
-	    Highest = tls_record:highest_protocol_version(Versions),
-	    case tls_record:is_higher(Highest, Version) of
-		true ->
-		    ?ALERT_REC(?FATAL, ?INAPPROPRIATE_FALLBACK);
-		false ->				     
-		    handle_client_hello(Version, Hello, SslOpts, Info, Renegotiation)
-	    end;
-	false ->
-	    handle_client_hello(Version, Hello, SslOpts, Info, Renegotiation)
-    end.
+		Highest = tls_record:highest_protocol_version(Versions),
+		case tls_record:is_higher(Highest, Version) of
+		    true ->
+			?ALERT_REC(?FATAL, ?INAPPROPRIATE_FALLBACK);
+		    false ->				     
+			handle_client_hello(Version, Hello, SslOpts, Info, Renegotiation)
+		end;
+	    false ->
+		handle_client_hello(Version, Hello, SslOpts, Info, Renegotiation)
+	end
+    catch
+	_:_ ->
+	    ?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, malformed_handshake_data)
+    end.  
+
 %%--------------------------------------------------------------------
 -spec encode_handshake(tls_handshake(), tls_record:tls_version()) -> iolist().
 %%     
@@ -187,8 +193,13 @@ handle_client_hello(Version, #client_hello{session_id = SugesstedId,
 get_tls_handshake_aux(Version, <<?BYTE(Type), ?UINT24(Length),
 				 Body:Length/binary,Rest/binary>>, #ssl_options{v2_hello_compatible = V2Hello} = Opts,  Acc) ->
     Raw = <<?BYTE(Type), ?UINT24(Length), Body/binary>>,
-    Handshake = decode_handshake(Version, Type, Body, V2Hello),
-    get_tls_handshake_aux(Version, Rest, Opts, [{Handshake,Raw} | Acc]);
+    try decode_handshake(Version, Type, Body, V2Hello) of
+	Handshake ->
+	    get_tls_handshake_aux(Version, Rest, Opts, [{Handshake,Raw} | Acc])
+    catch
+	_:_ ->
+	    throw(?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE, handshake_decode_error))
+    end;
 get_tls_handshake_aux(_Version, Data, _, Acc) ->
     {lists:reverse(Acc), Data}.