Some protocols (e.g. EAP-PEAP, EAP-TLS, EAP-TTLS) that use TLS as

transport layer need to generate additional application specific
key material. One way to generate such material is to use the TLS
PRF and key material from the TLS session itself.

This change makes it possible to use a TLS sessions PRF either with
the session internal or caller supplied key material to generate
additional key material.

1 files changed, 38 insertions, 1 deletions

diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl
index 28dd0c85d0..59133dccf0 100644
--- a/lib/ssl/src/ssl_connection.erl
+++ b/lib/ssl/src/ssl_connection.erl
@@ -40,7 +40,8 @@
 -export([send/2, recv/3, connect/7, ssl_accept/6, handshake/2,
 	 socket_control/3, close/1, shutdown/2,
 	 new_user/2, get_opts/2, set_opts/2, info/1, session_info/1, 
-	 peer_certificate/1, sockname/1, peername/1, renegotiation/1]).
+	 peer_certificate/1, sockname/1, peername/1, renegotiation/1,
+	 prf/5]).
 
 %% Called by ssl_connection_sup
 -export([start_link/7]). 
@@ -273,6 +274,16 @@ peer_certificate(ConnectionPid) ->
 renegotiation(ConnectionPid) ->
     sync_send_all_state_event(ConnectionPid, renegotiate). 
 
+%%--------------------------------------------------------------------
+-spec prf(pid(), binary() | 'master_secret', binary(),
+	  binary() | ssl:prf_secret(), non_neg_integer()) ->
+		 {ok, binary()} | {error, reason()} | {'EXIT', term()}.
+%%
+%% Description: use a ssl sessions TLS PRF to generate key material
+%%--------------------------------------------------------------------
+prf(ConnectionPid, Secret, Label, Seed, WantedLength) ->
+    sync_send_all_state_event(ConnectionPid, {prf, Secret, Label, Seed, WantedLength}).
+
 %%====================================================================
 %% ssl_connection_sup API
 %%====================================================================
@@ -868,6 +879,32 @@ handle_sync_event(renegotiate, From, connection, State) ->
 handle_sync_event(renegotiate, _, StateName, State) ->
     {reply, {error, already_renegotiating}, StateName, State, get_timeout(State)};
 
+handle_sync_event({prf, Secret, Label, Seed, WantedLength}, _, StateName,
+		  #state{connection_states = ConnectionStates,
+			 negotiated_version = Version} = State) ->
+    ConnectionState =
+	ssl_record:current_connection_state(ConnectionStates, read),
+    SecParams = ConnectionState#connection_state.security_parameters,
+    #security_parameters{master_secret = MasterSecret,
+			 client_random = ClientRandom,
+			 server_random = ServerRandom} = SecParams,
+    Reply = try
+		SecretToUse = case Secret of
+				  _ when is_binary(Secret) -> Secret;
+				  master_secret -> MasterSecret
+			      end,
+		SeedToUse = lists:reverse(
+			      lists:foldl(fun(X, Acc) when is_binary(X) -> [X|Acc];
+					     (client_random, Acc) -> [ClientRandom|Acc];
+					     (server_random, Acc) -> [ServerRandom|Acc]
+					  end, [], Seed)),
+		ssl_handshake:prf(Version, SecretToUse, Label, SeedToUse, WantedLength)
+	    catch
+		exit:_ -> {error, badarg};
+		error:Reason -> {error, Reason}
+	    end,
+    {reply, Reply, StateName, State, get_timeout(State)};
+
 handle_sync_event(info, _, StateName, 
 		  #state{negotiated_version = Version,
 			 session = #session{cipher_suite = Suite}} = State) ->