ssl: Add new API functions

10 files changed, 508 insertions, 81 deletions

diff --git a/lib/ssl/doc/src/ssl.xml b/lib/ssl/doc/src/ssl.xml
index 8c1b1541c7..029f29cdb3 100644
--- a/lib/ssl/doc/src/ssl.xml
+++ b/lib/ssl/doc/src/ssl.xml
@@ -197,6 +197,18 @@
        | sect193r1 | sect193r2 | secp192k1 | secp192r1 | sect163k1
        | sect163r1 | sect163r2 | secp160k1 | secp160r1 | secp160r2</c></p></item>
 
+       <tag><c>hello_extensions() =</c></tag>
+       <item><p><c>#{renegotiation_info => 
+                   signature_algs => [{hash(), ecsda| rsa| dsa}] | undefined
+		   alpn => binary() | undefined,
+		   next_protocol_negotiation,
+		   srp => string() | undefined,
+		   ec_point_formats ,
+		   elliptic_curves = [oid] | undefined
+		   sni = string()} 
+       }</c></p></item>
+      
+
     </taglist>
   </section>
 
@@ -211,8 +223,16 @@
       <tag><c>{protocol, tls | dtls}</c></tag>
       <item><p>Choose TLS or DTLS protocol for the transport layer security.
       Defaults to <c>tls</c> Introduced in OTP 20, DTLS support is considered
-      experimental in this release. DTLS over other transports than UDP are not yet supported.</p></item>
-
+      experimental in this release. Other transports than UDP are not yet supported.</p></item>
+
+      <tag><c>{handshake, hello | full}</c></tag>
+      <item><p> Defaults to <c>full</c>. If hello is specified the handshake will
+      pause after the hello message and give the user a possibility make decisions
+      based on hello extensions before continuing or aborting the handshake by calling
+      <seealso marker="#handshake_continue-3"> handshake_continue/3</seealso> or
+      <seealso marker="#handshake_cancel-1"> handshake_cancel/1</seealso>
+      </p></item>
+      
       <tag><c>{cert, public_key:der_encoded()}</c></tag>
       <item><p>The DER-encoded users certificate. If this option
       is supplied, it overrides option <c>certfile</c>.</p></item>
@@ -919,15 +939,16 @@ fun(srp, Username :: string(), UserState :: term()) ->
    
     <func>
       <name>connect(Socket, SslOptions) -> </name>
-      <name>connect(Socket, SslOptions, Timeout) -> {ok, TLSSocket}
+      <name>connect(Socket, SslOptions, Timeout) -> {ok, TLSSocket} | {ok, TLSSocket, Ext}
 	| {error, Reason}</name>
       <fsummary>Upgrades a <c>gen_tcp</c>, or
 	equivalent, connected socket to an TLS socket.</fsummary>
       <type>
 	<v>Socket = socket()</v>
-	<v>SslOptions = [ssl_option()]</v>
+	<v>SslOptions = [{handshake, hello| full} | ssl_option()]</v>
 	<v>Timeout = integer() | infinity</v>
 	<v>TLSSocket = sslsocket()</v>
+	<v>Ext = hello_extensions()</v>
 	<v>Reason = term()</v>
       </type>
       <desc><p>Upgrades a <c>gen_tcp</c>, or equivalent,
@@ -938,14 +959,25 @@ fun(srp, Username :: string(), UserState :: term()) ->
 	  the option <c>server_name_indication</c> shall also be specified,
 	  if it is not no Server Name Indication extension will be sent,
 	  and <seealso marker="public_key:public_key#pkix_verify_hostname-2">public_key:pkix_verify_hostname/2</seealso>
-	  will be called with the IP-address of the connection as <c>ReferenceID</c>, which is proably not what you want.</p></note>
+	  will be called with the IP-address of the connection as <c>ReferenceID</c>, which is proably not what you want.</p>
+	  </note>
+
+	  <p> If the option <c>{handshake, hello}</c> is used the
+	  handshake is paused after receiving the server hello message
+	  and the success response is <c>{ok, TLSSocket, Ext}</c>
+	  instead of <c>{ok, TLSSocket}</c>. Thereafter the handshake is continued or
+	  canceled by calling <seealso marker="#handshake_continue-3">
+	  <c>handshake_continue/3</c></seealso> or <seealso
+	  marker="#handshake_cancel-1"><c>handshake_cancel/1</c></seealso>.	 
+	  </p>
+	  
     </desc>
     </func>
 
     <func>
       <name>connect(Host, Port, Options) -></name>
       <name>connect(Host, Port, Options, Timeout) ->
-	  {ok, SslSocket} | {error, Reason}</name>
+	  {ok, SslSocket}| {ok, TLSSocket, Ext} | {error, Reason}</name>
       <fsummary>Opens an TLS/DTLS connection to <c>Host</c>, <c>Port</c>.</fsummary>
       <type>
 	  <v>Host = host()</v>
@@ -972,6 +1004,16 @@ fun(srp, Username :: string(), UserState :: term()) ->
       <c>dns_id</c> will be assumed with a fallback to <c>ip</c> if that fails. </p>
       <note><p>According to good practices certificates should not use IP-addresses as "server names". It would
       be very surprising if this happen outside a closed network. </p></note> 
+
+
+      <p> If the option <c>{handshake, hello}</c> is used the
+	  handshake is paused after receiving the server hello message
+	  and the success response is <c>{ok, TLSSocket, Ext}</c>
+	  instead of <c>{ok, TLSSocket}</c>. Thereafter the handshake is continued or
+	  canceled by calling <seealso marker="#handshake_continue-3">
+	  <c>handshake_continue/3</c></seealso> or <seealso
+	  marker="#handshake_cancel-1"><c>handshake_cancel/1</c></seealso>.
+	  </p>
       </desc>
     </func>
 
@@ -1113,6 +1155,85 @@ fun(srp, Username :: string(), UserState :: term()) ->
     </func>
 
     <func>
+      <name>handshake(Socket) -> </name>
+      <name>handshake(Socket, Timeout) -> {ok, Socket}  | {error, Reason}</name>
+      <fsummary>Performs server-side SSL/TLS handshake.</fsummary>
+      <type>
+        <v>Socket = sslsocket()</v>
+        <v>Timeout = integer()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Performs the SSL/TLS/DTLS server-side handshake.</p>
+	<p><c>Socket</c> is a socket as returned by
+	<seealso marker="#transport_accept-2">ssl:transport_accept/[1,2]</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>handshake(Socket, SslOptions) -> </name>
+      <name>handshake(Socket, SslOptions, Timeout) -> {ok, Socket} | {ok, Socket, Ext} | {error, Reason}</name>
+      <fsummary>Performs server-side SSL/TLS/DTLS handshake.</fsummary>
+      <type>
+        <v>Socket = socket() | sslsocket() </v>
+	<v>Ext = hello_extensions()</v>
+	<v>SslOptions = [{handshake, hello| full} | ssl_option()]</v>
+        <v>Timeout = integer()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>If <c>Socket</c> is a ordinary <c>socket()</c>: upgrades a <c>gen_tcp</c>,
+	or equivalent, socket to an SSL socket, that is, performs
+        the SSL/TLS server-side handshake and returns the SSL socket.</p>
+
+	<warning><p>The Socket shall be in passive mode ({active,
+	false}) before calling this function or the handshake can fail
+	due to a race condition.</p></warning>
+	
+	<p>If <c>Socket</c> is an <c>sslsocket()</c>: provides extra SSL/TLS/DTLS
+	options to those specified in
+	<seealso marker="#listen-2">ssl:listen/2 </seealso> and then performs
+	the SSL/TLS/DTLS handshake.</p>
+
+	<p>
+	  If option <c>{handshake, hello}</c> is specified the handshake is
+	  paused after receiving the client hello message and the
+	  sucess response is <c>{ok, TLSSocket, Ext}</c>  instead of <c>{ok,
+	  TLSSocket}</c>. Thereafter the handshake is continued or
+	  canceled by calling <seealso marker="#handshake_continue-3">
+	  <c>handshake_continue/3</c></seealso> or <seealso
+	  marker="#handshake_cancel-1"><c>handshake_cancel/1</c></seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>handshake_cancel(Socket) -> ok </name>
+      <fsummary>Cancel handshake with a fatal alert</fsummary>
+      <type>
+        <v>Socket = sslsocket()</v>
+      </type>
+      <desc>
+        <p>Cancel the handshake with a fatal <c>USER_CANCELED</c> alert.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>handshake_continue(Socket, SSLOptions, Timeout) -> 	{ok, Socket} | {error, Reason}</name>
+      <fsummary>Continue the SSL/TLS handshake.</fsummary>
+      <type>
+        <v>Socket = sslsocket()</v>
+	<v>SslOptions = [ssl_option()]</v>
+	<v>Timeout = integer()</v>
+	<v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Continue the SSL/TLS handshake possiby with new, additional or changed options.</p>
+      </desc>
+    </func>
+    
+    <func>
       <name>listen(Port, Options) ->
 	{ok, ListenSocket} | {error, Reason}</name>
       <fsummary>Creates an SSL listen socket.</fsummary>
diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 59548fa61e..220da71123 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -55,7 +55,7 @@
 
 %% gen_statem state functions
 -export([init/3, error/3, downgrade/3, %% Initiation and take down states
-	 hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states 
+	 hello/3, user_hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states 
 	 connection/3]). 
 %% gen_statem callbacks
 -export([callback_mode/0, terminate/3, code_change/4, format_status/2]).
@@ -491,10 +491,11 @@ hello(enter, _, #state{role = client} = State0) ->
     {State, Actions} = handle_flight_timer(State0),
     {keep_state, State, Actions}; 
 hello(internal, #client_hello{cookie = <<>>,
-			      client_version = Version} = Hello, #state{role = server,
-									transport_cb = Transport,
-									socket = Socket,
-                                                                        protocol_specific = #{current_cookie_secret := Secret}} = State0) ->
+			      client_version = Version} = Hello, 
+      #state{role = server,
+             transport_cb = Transport,
+             socket = Socket,
+             protocol_specific = #{current_cookie_secret := Secret}} = State0) ->
     {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket),
     Cookie = dtls_handshake:cookie(Secret, IP, Port, Hello),
     %% FROM RFC 6347 regarding HelloVerifyRequest message:
@@ -508,24 +509,6 @@ hello(internal, #client_hello{cookie = <<>>,
     {State2, Actions} = send_handshake(VerifyRequest, State1),
     {Record, State} = next_record(State2),
     next_event(?FUNCTION_NAME, Record, State#state{tls_handshake_history = ssl_handshake:init_handshake_history()}, Actions);
-hello(internal, #client_hello{cookie = Cookie} = Hello, #state{role = server,
-							       transport_cb = Transport,
-							       socket = Socket,
-                                                               protocol_specific = #{current_cookie_secret := Secret,
-                                                                                     previous_cookie_secret := PSecret}} = State0) ->
-    {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket),
-    case dtls_handshake:cookie(Secret, IP, Port, Hello) of
-	Cookie ->
-	    handle_client_hello(Hello, State0);
-	_ ->
-            case dtls_handshake:cookie(PSecret, IP, Port, Hello) of
-               	Cookie -> 
-                    handle_client_hello(Hello, State0);
-                _ ->
-                    %% Handle bad cookie as new cookie request RFC 6347 4.1.2
-                    hello(internal, Hello#client_hello{cookie = <<>>}, State0) 
-            end
-    end;
 hello(internal, #hello_verify_request{cookie = Cookie}, #state{role = client,
 							       host = Host, port = Port, 
 							       ssl_options = SslOpts,
@@ -550,6 +533,34 @@ hello(internal, #hello_verify_request{cookie = Cookie}, #state{role = client,
 						   Hello#client_hello.session_id}},
     {Record, State} = next_record(State3),
     next_event(?FUNCTION_NAME, Record, State, Actions);
+hello(internal, #client_hello{extensions = Extensions} = Hello, #state{ssl_options = #ssl_options{handshake = hello},
+                                                                       start_or_recv_from = From} = State) ->
+    {next_state, user_hello, State#state{start_or_recv_from = undefined,
+                                             hello = Hello},
+     [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]};
+hello(internal, #server_hello{extensions = Extensions} = Hello, #state{ssl_options = #ssl_options{handshake = hello},
+                                                                       start_or_recv_from = From} = State) ->
+    {next_state, user_hello, State#state{start_or_recv_from = undefined,
+                                             hello = Hello},
+     [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]};     
+hello(internal, #client_hello{cookie = Cookie} = Hello, #state{role = server,
+							       transport_cb = Transport,
+							       socket = Socket,
+                                                               protocol_specific = #{current_cookie_secret := Secret,
+                                                                                     previous_cookie_secret := PSecret}} = State0) ->
+    {ok, {IP, Port}} = dtls_socket:peername(Transport, Socket),
+    case dtls_handshake:cookie(Secret, IP, Port, Hello) of
+	Cookie ->
+	    handle_client_hello(Hello, State0);
+	_ ->
+            case dtls_handshake:cookie(PSecret, IP, Port, Hello) of
+               	Cookie -> 
+                    handle_client_hello(Hello, State0);
+                _ ->
+                    %% Handle bad cookie as new cookie request RFC 6347 4.1.2
+                    hello(internal, Hello#client_hello{cookie = <<>>}, State0) 
+            end
+    end;
 hello(internal, #server_hello{} = Hello,
       #state{connection_states = ConnectionStates0,
 	     negotiated_version = ReqVersion,
@@ -576,6 +587,11 @@ hello(state_timeout, Event, State) ->
 hello(Type, Event, State) ->
     gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
+user_hello(enter, _, State) ->
+    {keep_state, State};     
+user_hello(Type, Event, State) ->
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
+
 %%--------------------------------------------------------------------
 -spec abbreviated(gen_statem:event_type(), term(), #state{}) ->
 			 gen_statem:state_function_result().
diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl
index 9796324605..5b6d92ebf4 100644
--- a/lib/ssl/src/ssl.erl
+++ b/lib/ssl/src/ssl.erl
@@ -33,6 +33,7 @@
 -export([connect/3, connect/2, connect/4,
 	 listen/2, transport_accept/1, transport_accept/2,
 	 handshake/1, handshake/2, handshake/3, 
+         handshake_continue/3, handshake_cancel/1,
          ssl_accept/1, ssl_accept/2, ssl_accept/3,
 	 controlling_process/2, peername/1, peercert/1, sockname/1,
 	 close/1, close/2, shutdown/2, recv/2, recv/3, send/2,
@@ -46,7 +47,7 @@
          format_error/1, renegotiate/1, prf/5, negotiated_protocol/1, 
 	 connection_information/1, connection_information/2]).
 %% Misc
--export([handle_options/2, tls_version/1]).
+-export([handle_options/2, tls_version/1, new_ssl_options/3]).
 
 -include("ssl_api.hrl").
 -include("ssl_internal.hrl").
@@ -194,7 +195,7 @@ ssl_accept(Socket, SslOptions, Timeout) ->
             Error
      end.
 %%--------------------------------------------------------------------
--spec handshake(#sslsocket{}) -> ok | {error, reason()}.
+-spec handshake(#sslsocket{}) -> {ok, #sslsocket{}} | {error, reason()}.
 -spec handshake(#sslsocket{} | port(), timeout()| [ssl_option()
 						    | transport_option()]) ->
                        {ok, #sslsocket{}} | {error, reason()}.
@@ -254,6 +255,24 @@ handshake(Socket, SslOptions, Timeout) when is_port(Socket),
     catch
 	Error = {error, _Reason} -> Error
     end.
+
+%%--------------------------------------------------------------------
+-spec handshake_continue(#sslsocket{}, [ssl_option()], timeout()) -> 
+                                {ok, #sslsocket{}} | {error, reason()}.
+%%
+%%
+%% Description: Continues the handshke possible with newly supplied options.
+%%--------------------------------------------------------------------
+handshake_continue(Socket, SSLOptions, Timeout) ->
+    ssl_connection:handshake_continue(Socket, SSLOptions, Timeout).
+%%--------------------------------------------------------------------
+-spec  handshake_cancel(#sslsocket{}) -> term().
+%%
+%% Description: Cancels the handshakes sending a close alert.
+%%--------------------------------------------------------------------
+handshake_cancel(Socket) ->
+    ssl_connection:handshake_cancel(Socket).
+
 %%--------------------------------------------------------------------
 -spec  close(#sslsocket{}) -> term().
 %%
@@ -917,7 +936,8 @@ handle_options(Opts0, Role, Host) ->
 					     client, Role),
 		    crl_check = handle_option(crl_check, Opts, false),
 		    crl_cache = handle_option(crl_cache, Opts, {ssl_crl_cache, {internal, []}}),
-                    max_handshake_size = handle_option(max_handshake_size, Opts, ?DEFAULT_MAX_HANDSHAKE_SIZE)
+                    max_handshake_size = handle_option(max_handshake_size, Opts, ?DEFAULT_MAX_HANDSHAKE_SIZE),
+                    handshake = handle_option(handshake, Opts, full)
 		   },
 
     CbInfo  = proplists:get_value(cb_info, Opts, default_cb_info(Protocol)),
@@ -933,8 +953,7 @@ handle_options(Opts0, Role, Host) ->
 		  client_preferred_next_protocols, log_alert,
 		  server_name_indication, honor_cipher_order, padding_check, crl_check, crl_cache,
 		  fallback, signature_algs, eccs, honor_ecc_order, beast_mitigation,
-                  max_handshake_size],
-
+                  max_handshake_size, handshake],
     SockOpts = lists:foldl(fun(Key, PropList) ->
 				   proplists:delete(Key, PropList)
 			   end, Opts, SslOptions),
@@ -946,8 +965,6 @@ handle_options(Opts0, Role, Host) ->
 		 inet_user = Sock, transport_info = CbInfo, connection_cb = ConnetionCb
 		}}.
 
-
-
 handle_option(OptionName, Opts, Default, Role, Role) ->
     handle_option(OptionName, Opts, Default);
 handle_option(_, _, undefined = Value, _, _) ->
@@ -1175,6 +1192,10 @@ validate_option(protocol, Value = tls) ->
     Value;
 validate_option(protocol, Value = dtls) ->
     Value;
+validate_option(handshake, hello = Value) ->
+    Value;
+validate_option(handshake, full = Value) ->
+    Value;
 validate_option(Opt, Value) ->
     throw({error, {options, {Opt, Value}}}).
 
diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl
index 6b3a403f0e..f816979b9f 100644
--- a/lib/ssl/src/ssl_connection.erl
+++ b/lib/ssl/src/ssl_connection.erl
@@ -38,7 +38,7 @@
 
 %% Setup
 
--export([connect/8, handshake/7, handshake/2, handshake/3, hello/3,
+-export([connect/8, handshake/7, handshake/2, handshake/3,
          handshake_continue/3, handshake_cancel/1,
 	 socket_control/4, socket_control/5, start_or_recv_cancel_timer/2]).
 
@@ -59,11 +59,11 @@
 
 %% Help functions for tls|dtls_connection.erl
 -export([handle_session/7, ssl_config/3,
-	 prepare_connection/2, hibernate_after/3]).
+	 prepare_connection/2, hibernate_after/3, map_extensions/1]).
 
 %% General gen_statem state functions with extra callback argument 
 %% to determine if it is an SSL/TLS or DTLS gen_statem machine
--export([init/4, error/4, hello/4, abbreviated/4, certify/4, cipher/4,
+-export([init/4, error/4, hello/4, user_hello/4, abbreviated/4, certify/4, cipher/4,
          connection/4, death_row/4, downgrade/4]).
 
 %% gen_statem callbacks
@@ -113,7 +113,8 @@ handshake(Connection, Port, Socket, Opts, User, CbInfo, Timeout) ->
     end.	
 
 %%--------------------------------------------------------------------
--spec handshake(#sslsocket{}, timeout()) ->  {ok, #sslsocket{}} | {error, reason()}.
+-spec handshake(#sslsocket{}, timeout()) ->  {ok, #sslsocket{}} |
+                                                 {ok,  #sslsocket{}, map()}| {error, reason()}.
 %%
 %% Description: Starts ssl handshake. 
 %%--------------------------------------------------------------------
@@ -121,6 +122,8 @@ handshake(#sslsocket{pid = Pid} = Socket, Timeout) ->
     case call(Pid, {start, Timeout}) of
 	connected ->
 	    {ok, Socket};
+        {ok, Ext} ->
+            {ok, Socket, Ext};
  	Error ->
 	    Error
     end.
@@ -139,6 +142,31 @@ handshake(#sslsocket{pid = Pid} = Socket, SslOptions, Timeout) ->
 	    Error
     end.
 
+%%--------------------------------------------------------------------
+-spec handshake_continue(#sslsocket{}, [ssl_option()],
+                         timeout()) ->  {ok,  #sslsocket{}}| {error, reason()}.
+%%
+%% Description: Continues handshake with new options
+%%--------------------------------------------------------------------
+handshake_continue(#sslsocket{pid = Pid} = Socket, SslOptions, Timeout) ->  
+    case call(Pid, {handshake_continue, SslOptions, Timeout}) of
+	connected ->
+	    {ok, Socket};
+ 	Error ->
+	    Error
+    end.
+%%--------------------------------------------------------------------
+-spec handshake_cancel(#sslsocket{}) ->  ok | {error, reason()}.
+%%
+%% Description: Cancels connection
+%%--------------------------------------------------------------------
+handshake_cancel(#sslsocket{pid = Pid}) ->  
+    case call(Pid, cancel) of
+	closed ->
+            ok;
+        Error ->
+	    Error
+    end.
 %--------------------------------------------------------------------
 -spec socket_control(tls_connection | dtls_connection, port(), pid(), atom()) -> 
     {ok, #sslsocket{}} | {error, reason()}.  
@@ -529,6 +557,9 @@ handle_session(#server_hello{cipher_suite = CipherSuite,
 -spec ssl_config(#ssl_options{}, client | server, #state{}) -> #state{}.
 %%--------------------------------------------------------------------
 ssl_config(Opts, Role, State) ->
+    ssl_config(Opts, Role, State, new).
+
+ssl_config(Opts, Role, State0, Type) ->
     {ok, #{cert_db_ref := Ref, 
            cert_db_handle := CertDbHandle, 
            fileref_db_handle := FileRefHandle, 
@@ -538,20 +569,26 @@ ssl_config(Opts, Role, State) ->
            dh_params := DHParams,
            own_certificate := OwnCert}} =
 	ssl_config:init(Opts, Role), 
-    Handshake = ssl_handshake:init_handshake_history(),
     TimeStamp = erlang:monotonic_time(),
-    Session = State#state.session,
-    State#state{tls_handshake_history = Handshake,
-		session = Session#session{own_certificate = OwnCert,
-					  time_stamp = TimeStamp},
-		file_ref_db = FileRefHandle,
-		cert_db_ref = Ref,
-		cert_db = CertDbHandle,
-		crl_db = CRLDbHandle,
-		session_cache = CacheHandle,
-		private_key = Key,
-		diffie_hellman_params = DHParams,
-		ssl_options = Opts}.
+    Session = State0#state.session,
+    State = State0#state{session = Session#session{own_certificate = OwnCert,
+                                                   time_stamp = TimeStamp},
+                         file_ref_db = FileRefHandle,
+                         cert_db_ref = Ref,
+                         cert_db = CertDbHandle,
+                         crl_db = CRLDbHandle,
+                         session_cache = CacheHandle,
+                         private_key = Key,
+                         diffie_hellman_params = DHParams,
+                         ssl_options = Opts},
+    case Type of
+        new ->
+            Handshake = ssl_handshake:init_handshake_history(),
+            State#state{tls_handshake_history = Handshake};
+        continue ->
+            State
+    end.
+
 
 %%====================================================================
 %% gen_statem general state functions with connection cb argument
@@ -581,7 +618,8 @@ init({call, From}, {start, {Opts, EmOpts}, Timeout},
         end,
 	State = ssl_config(SslOpts, Role, State0),
 	init({call, From}, {start, Timeout}, 
-	     State#state{ssl_options = SslOpts, socket_options = new_emulated(EmOpts, SockOpts)}, Connection)
+	     State#state{ssl_options = SslOpts, 
+                         socket_options = new_emulated(EmOpts, SockOpts)}, Connection)
     catch throw:Error ->
 	    stop_and_reply(normal, {reply, From, {error, Error}}, State0)
     end;
@@ -614,6 +652,23 @@ hello(info, Msg, State, _) ->
 hello(Type, Msg, State, Connection) ->
     handle_common_event(Type, Msg, ?FUNCTION_NAME, State, Connection).
 
+user_hello({call, From}, cancel, #state{negotiated_version = Version} = State, _) ->
+    gen_statem:reply(From, ok),
+    handle_own_alert(?ALERT_REC(?FATAL, ?USER_CANCELED, user_canceled),
+                     Version, ?FUNCTION_NAME, State);
+user_hello({call, From}, {handshake_continue, NewOptions, Timeout}, #state{hello = Hello,
+                                                                           role = Role,
+                                                                           start_or_recv_from = RecvFrom,
+                                                                           ssl_options = Options0} = State0, _Connection) ->
+    Timer = start_or_recv_cancel_timer(Timeout, RecvFrom),
+    Options = ssl:handle_options(NewOptions, Options0#ssl_options{handshake = full}),
+    State = ssl_config(Options, Role, State0, continue),
+    {next_state, hello, State#state{start_or_recv_from = From,
+                                    timer = Timer}, 
+     [{next_event, internal, Hello}]};
+user_hello(_, _, _, _) ->
+    {keep_state_and_data, [postpone]}.
+
 %%--------------------------------------------------------------------
 -spec abbreviated(gen_statem:event_type(),
 		  #hello_request{} | #finished{} | term(),
@@ -2287,7 +2342,24 @@ hibernate_after(connection = StateName,
     {next_state, StateName, State, [{timeout, HibernateAfter, hibernate} | Actions]};
 hibernate_after(StateName, State, Actions) ->
     {next_state, StateName, State, Actions}.
- 
+
+map_extensions(#hello_extensions{renegotiation_info = RenegotiationInfo,
+                                 signature_algs = SigAlg,          
+                                 alpn = Alpn,
+                                 next_protocol_negotiation = Next, 
+                                 srp = SRP,
+                                 ec_point_formats = ECPointFmt,
+                                 elliptic_curves = ECCCurves,
+                                 sni = SNI}) ->
+    #{renegotiation_info => ssl_handshake:extension_value(RenegotiationInfo),
+      signature_algs =>  ssl_handshake:extension_value(SigAlg),
+      alpn =>  ssl_handshake:extension_value(Alpn),
+      srp  => ssl_handshake:extension_value(SRP),
+      next_protocol => ssl_handshake:extension_value(Next),
+      ec_point_formats  => ssl_handshake:extension_value(ECPointFmt),
+      elliptic_curves => ssl_handshake:extension_value(ECCCurves),
+      sni => ssl_handshake:extension_value(SNI)}.
+
 terminate_alert(normal, Version, ConnectionStates, Connection)  ->
     Connection:encode_alert(?ALERT_REC(?WARNING, ?CLOSE_NOTIFY),
 		     Version, ConnectionStates);
diff --git a/lib/ssl/src/ssl_connection.hrl b/lib/ssl/src/ssl_connection.hrl
index f9d2149170..d315c393b4 100644
--- a/lib/ssl/src/ssl_connection.hrl
+++ b/lib/ssl/src/ssl_connection.hrl
@@ -77,7 +77,8 @@
 	  renegotiation        :: undefined | {boolean(), From::term() | internal | peer},
 	  start_or_recv_from   :: term(),
 	  timer                :: undefined | reference(), % start_or_recive_timer
-	  %%send_queue           :: queue:queue(),
+          %%send_queue           :: queue:queue(),
+          hello,                %%:: #client_hello{} | #server_hello{}, 
 	  terminated = false                          ::boolean(),
 	  allow_renegotiate = true                    ::boolean(),
           expecting_next_protocol_negotiation = false ::boolean(),
@@ -88,11 +89,11 @@
 	  sni_hostname = undefined,
 	  downgrade,
 	  flight_buffer = []   :: list() | map(),  %% Buffer of TLS/DTLS records, used during the TLS handshake
-				   %% to when possible pack more than on TLS record into the 
-				   %% underlaying packet format. Introduced by DTLS - RFC 4347.
-				   %% The mecahnism is also usefull in TLS although we do not
-				   %% need to worry about packet loss in TLS. In DTLS we need to track DTLS handshake seqnr
-	 flight_state = reliable,  %% reliable | {retransmit, integer()}| {waiting, ref(), integer()} - last two is used in DTLS over udp.   
+          %% to when possible pack more than one TLS record into the 
+          %% underlaying packet format. Introduced by DTLS - RFC 4347.
+          %% The mecahnism is also usefull in TLS although we do not
+          %% need to worry about packet loss in TLS. In DTLS we need to track DTLS handshake seqnr
+          flight_state = reliable,  %% reliable | {retransmit, integer()}| {waiting, ref(), integer()} - last two is used in DTLS over udp.   
           protocol_specific = #{}      :: map()                    
 	 }).
 -define(DEFAULT_DIFFIE_HELLMAN_PARAMS,
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index e1f813ea95..54eb920bda 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -53,7 +53,7 @@
 -export([certify/7, certificate_verify/6, verify_signature/5,
 	 master_secret/4, server_key_exchange_hash/2, verify_connection/6,
 	 init_handshake_history/0, update_handshake_history/2, verify_server_key/5,
-         select_version/3
+         select_version/3, extension_value/1
 	]).
 
 %% Encode
@@ -139,8 +139,8 @@ certificate(OwnCert, CertDbHandle, CertDbRef, server) ->
     case ssl_certificate:certificate_chain(OwnCert, CertDbHandle, CertDbRef) of
 	{ok, _, Chain} ->
 	    #certificate{asn1_certificates = Chain};
-	{error, _} ->
-            ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, server_has_no_suitable_certificates)
+	{error, Error} ->
+            ?ALERT_REC(?FATAL, ?INTERNAL_ERROR, {server_has_no_suitable_certificates, Error})
     end.
 
 %%--------------------------------------------------------------------
@@ -1166,6 +1166,25 @@ srp_user(#ssl_options{srp_identity = {UserName, _}}) ->
 srp_user(_) ->
     undefined.
 
+extension_value(undefined) ->
+    undefined;
+extension_value(#sni{hostname = HostName}) ->
+    HostName;
+extension_value(#ec_point_formats{ec_point_format_list = List}) ->
+    List;
+extension_value(#elliptic_curves{elliptic_curve_list = List}) ->
+    List;
+extension_value(#hash_sign_algos{hash_sign_algos = Algos}) ->
+    Algos;
+extension_value(#alpn{extension_data = Data}) ->
+    Data;
+extension_value(#next_protocol_negotiation{extension_data = Data}) ->
+    Data;
+extension_value(#srp{username = Name}) ->
+    Name;
+extension_value(#renegotiation_info{renegotiated_connection = Data}) ->
+    Data.
+
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
diff --git a/lib/ssl/src/ssl_internal.hrl b/lib/ssl/src/ssl_internal.hrl
index d354910f33..5df00de0e5 100644
--- a/lib/ssl/src/ssl_internal.hrl
+++ b/lib/ssl/src/ssl_internal.hrl
@@ -144,7 +144,8 @@
 	  signature_algs,
 	  eccs,
 	  honor_ecc_order            :: boolean(),
-          max_handshake_size         :: integer()
+          max_handshake_size         :: integer(),
+          handshake
          }).
 
 -record(socket_options,
diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index 754eab63e0..ef84c5320e 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -62,7 +62,7 @@
 
 %% gen_statem state functions
 -export([init/3, error/3, downgrade/3, %% Initiation and take down states
-	 hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states 
+	 hello/3, user_hello/3, certify/3, cipher/3, abbreviated/3, %% Handshake states 
 	 connection/3, death_row/3]).
 %% gen_statem callbacks
 -export([callback_mode/0, terminate/3, code_change/4, format_status/2]).
@@ -80,7 +80,7 @@ start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = false},_, Tracker}
 	{ok, Pid} = tls_connection_sup:start_child([Role, Host, Port, Socket, 
 						    Opts, User, CbInfo]), 
 	{ok, SslSocket} = ssl_connection:socket_control(?MODULE, Socket, Pid, CbModule, Tracker),
-	ssl_connection:handshake(SslSocket, Timeout)
+        ssl_connection:handshake(SslSocket, Timeout)
     catch
 	error:{badmatch, {error, _} = Error} ->
 	    Error
@@ -93,7 +93,7 @@ start_fsm(Role, Host, Port, Socket, {#ssl_options{erl_dist = true},_, Tracker} =
 	{ok, Pid} = tls_connection_sup:start_child_dist([Role, Host, Port, Socket, 
 							 Opts, User, CbInfo]), 
 	{ok, SslSocket} = ssl_connection:socket_control(?MODULE, Socket, Pid, CbModule, Tracker),
-	ssl_connection:handshake(SslSocket, Timeout)
+        ssl_connection:handshake(SslSocket, Timeout)
     catch
 	error:{badmatch, {error, _} = Error} ->
 	    Error
@@ -452,6 +452,16 @@ error(_, _, _) ->
 	    #state{}) ->
 		   gen_statem:state_function_result().
 %%--------------------------------------------------------------------
+hello(internal, #client_hello{extensions = Extensions} = Hello, #state{ssl_options = #ssl_options{handshake = hello},
+                                                                        start_or_recv_from = From} = State) ->
+     {next_state, user_hello, State#state{start_or_recv_from = undefined,
+                                              hello = Hello},
+     [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]};
+hello(internal, #server_hello{extensions = Extensions} = Hello, #state{ssl_options = #ssl_options{handshake = hello},
+                                                                       start_or_recv_from = From} = State) ->
+    {next_state, user_hello, State#state{start_or_recv_from = undefined,
+                                             hello = Hello},
+     [{reply, From, {ok, ssl_connection:map_extensions(Extensions)}}]};     
 hello(internal, #client_hello{client_version = ClientVersion} = Hello,
       #state{connection_states = ConnectionStates0,
 	     port = Port, session = #session{own_certificate = Cert} = Session0,
@@ -461,7 +471,6 @@ hello(internal, #client_hello{client_version = ClientVersion} = Hello,
 	     negotiated_protocol = CurrentProtocol,
 	     key_algorithm = KeyExAlg,
 	     ssl_options = SslOpts} = State) ->
-
     case tls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb,
 					      ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of
         #alert{} = Alert ->
@@ -480,7 +489,7 @@ hello(internal, #client_hello{client_version = ClientVersion} = Hello,
                                       session = Session,
                                       negotiated_protocol = Protocol})
     end;
-hello(internal, #server_hello{} = Hello,
+hello(internal, #server_hello{} = Hello,      
       #state{connection_states = ConnectionStates0,
 	     negotiated_version = ReqVersion,
 	     role = client,
@@ -498,6 +507,9 @@ hello(info, Event, State) ->
 hello(Type, Event, State) ->
     gen_handshake(?FUNCTION_NAME, Type, Event, State).
 
+user_hello(Type, Event, State) ->
+    gen_handshake(?FUNCTION_NAME, Type, Event, State).
+
 %%--------------------------------------------------------------------
 -spec abbreviated(gen_statem:event_type(), term(), #state{}) ->
 			 gen_statem:state_function_result().
@@ -744,7 +756,7 @@ gen_handshake(StateName, Type, Event,
 						       malformed_handshake_data),
 					    Version, StateName, State)  
     end.
-	    
+
 gen_info(Event, connection = StateName,  #state{negotiated_version = Version} = State) ->
     try handle_info(Event, StateName, State) of
 	Result ->
diff --git a/lib/ssl/test/ssl_basic_SUITE.erl b/lib/ssl/test/ssl_basic_SUITE.erl
index 0e910d0393..fe4f02f100 100644
--- a/lib/ssl/test/ssl_basic_SUITE.erl
+++ b/lib/ssl/test/ssl_basic_SUITE.erl
@@ -164,7 +164,10 @@ api_tests() ->
      accept_pool,
      prf,
      socket_options,
-     cipher_suites
+     cipher_suites,
+     handshake_continue,
+     hello_client_cancel,
+     hello_server_cancel
     ].
 
 api_tests_tls() ->
@@ -630,6 +633,84 @@ new_options_in_accept(Config) when is_list(Config) ->
     
     ssl_test_lib:close(Server),
     ssl_test_lib:close(Client).
+
+%%--------------------------------------------------------------------
+handshake_continue() ->
+    [{doc, "Test API function ssl:handshake_continue/3"}].
+handshake_continue(Config) when is_list(Config) -> 
+    ClientOpts = ssl_test_lib:ssl_options(client_verification_opts, Config),
+    ServerOpts = ssl_test_lib:ssl_options(server_verification_opts, Config),
+    {ClientNode, ServerNode, Hostname} = ssl_test_lib:run_where(Config),
+
+    Server = ssl_test_lib:start_server([{node, ServerNode}, {port, 0}, 
+					{from, self()}, 
+					{mfa, {ssl_test_lib, send_recv_result_active, []}},
+                                        {options, ssl_test_lib:ssl_options([{reuseaddr, true}, {handshake, hello}], 
+                                                                           Config)},
+                                        {continue_options, proplists:delete(reuseaddr, ServerOpts)}
+                                       ]),
+    
+    Port = ssl_test_lib:inet_port(Server),
+
+    Client = ssl_test_lib:start_client([{node, ClientNode}, {port, Port},
+					{host, Hostname},
+                                        {from, self()}, 
+                                        {mfa, {ssl_test_lib, send_recv_result_active, []}},
+                                        {options, ssl_test_lib:ssl_options([{handshake, hello}], 
+                                                                           Config)},
+                                        {continue_options,  proplists:delete(reuseaddr, ClientOpts)}]),
+     
+    ssl_test_lib:check_result(Server, ok, Client, ok),
+    
+    ssl_test_lib:close(Server),
+    ssl_test_lib:close(Client).
+
+%%--------------------------------------------------------------------
+hello_client_cancel() ->
+    [{doc, "Test API function ssl:handshake_cancel/1 on the client side"}].
+hello_client_cancel(Config) when is_list(Config) -> 
+    ServerOpts = ssl_test_lib:ssl_options(server_verification_opts, Config),
+    ServerOpts = ssl_test_lib:ssl_options(server_verification_opts, Config),
+    {ClientNode, ServerNode, Hostname} = ssl_test_lib:run_where(Config),
+
+    Server = ssl_test_lib:start_server([{node, ServerNode}, {port, 0}, 
+					{from, self()}, 
+					{options, ssl_test_lib:ssl_options([{handshake, hello}], Config)},
+                                        {continue_options, proplists:delete(reuseaddr, ServerOpts)}]),
+    
+    Port = ssl_test_lib:inet_port(Server),
+
+    %% That is ssl:handshake_cancel returns ok
+    {connect_failed, ok} = ssl_test_lib:start_client([{node, ClientNode}, {port, Port},
+                                                      {host, Hostname},
+                                                      {from, self()}, 
+                                                      {options, ssl_test_lib:ssl_options([{handshake, hello}], Config)},
+                                                      {continue_options, cancel}]),
+    
+    ssl_test_lib:check_result(Server, {error, {tls_alert, "user canceled"}}).
+%%--------------------------------------------------------------------
+
+hello_server_cancel() ->
+    [{doc, "Test API function ssl:handshake_cancel/1 on the server side"}].
+hello_server_cancel(Config) when is_list(Config) -> 
+    ClientOpts = ssl_test_lib:ssl_options(client_verification_opts, Config),
+    {ClientNode, ServerNode, Hostname} = ssl_test_lib:run_where(Config),
+
+    Server = ssl_test_lib:start_server([{node, ServerNode}, {port, 0}, 
+					{from, self()}, 
+					{options, ssl_test_lib:ssl_options([{handshake, hello}], Config)},
+                                        {continue_options, cancel}]),
+    
+    Port = ssl_test_lib:inet_port(Server),
+
+    {connect_failed, _} = ssl_test_lib:start_client([{node, ClientNode}, {port, Port},
+                                                     {host, Hostname},
+                                                     {from, self()}, 
+                                                     {options, ssl_test_lib:ssl_options([{handshake, hello}], Config)},
+                                                     {continue_options, proplists:delete(reuseaddr, ClientOpts)}]),
+    
+    ssl_test_lib:check_result(Server, ok).
+
 %%--------------------------------------------------------------------
 prf() ->
     [{doc,"Test that ssl:prf/5 uses the negotiated PRF."}].
diff --git a/lib/ssl/test/ssl_test_lib.erl b/lib/ssl/test/ssl_test_lib.erl
index 23b2f3cab5..a9f7dd9675 100644
--- a/lib/ssl/test/ssl_test_lib.erl
+++ b/lib/ssl/test/ssl_test_lib.erl
@@ -79,17 +79,21 @@ run_server(ListenSocket, Opts, N) ->
     Pid ! {accepter, N, Server},
     run_server(ListenSocket, Opts, N-1).
 
-do_run_server(_, {error, timeout} = Result, Opts)  ->
+do_run_server(_, {error, _} = Result, Opts)  ->
+    ct:log("Server error result ~p~n", [Result]),
+    Pid = proplists:get_value(from, Opts),
+    Pid ! {self(), Result};
+do_run_server(_, ok = Result, Opts) ->
+    ct:log("Server cancel result ~p~n", [Result]),
     Pid = proplists:get_value(from, Opts),
     Pid ! {self(), Result};
-
 do_run_server(ListenSocket, AcceptSocket, Opts) ->
     Node = proplists:get_value(node, Opts),
     Pid = proplists:get_value(from, Opts),
     Transport = proplists:get_value(transport, Opts, ssl),
     {Module, Function, Args} = proplists:get_value(mfa, Opts),
     ct:log("~p:~p~nServer: apply(~p,~p,~p)~n",
-		       [?MODULE,?LINE, Module, Function, [AcceptSocket | Args]]),
+           [?MODULE,?LINE, Module, Function, [AcceptSocket | Args]]),
     case rpc:call(Node, Module, Function, [AcceptSocket | Args]) of
 	no_result_msg ->
 	    ok;
@@ -117,7 +121,8 @@ connect(#sslsocket{} = ListenSocket, Opts) ->
     ReconnectTimes =  proplists:get_value(reconnect_times, Opts, 0),
     Timeout = proplists:get_value(timeout, Opts, infinity),
     SslOpts = proplists:get_value(ssl_extra_opts, Opts, []),
-    AcceptSocket = connect(ListenSocket, Node, 1 + ReconnectTimes, dummy, Timeout, SslOpts),
+    ContOpts = proplists:get_value(continue_options, Opts, []),
+    AcceptSocket = connect(ListenSocket, Node, 1 + ReconnectTimes, dummy, Timeout, SslOpts, ContOpts),
     case ReconnectTimes of
 	0 ->
 	    AcceptSocket;
@@ -132,10 +137,45 @@ connect(ListenSocket, Opts) ->
 				  [ListenSocket]),
     AcceptSocket.
 
-connect(_, _, 0, AcceptSocket, _, _) ->
+connect(_, _, 0, AcceptSocket, _, _, _) ->
     AcceptSocket;
-
-connect(ListenSocket, Node, N, _, Timeout, []) ->
+connect(ListenSocket, Node, _N, _, Timeout, SslOpts, cancel) ->
+    ct:log("ssl:transport_accept(~p)~n", [ListenSocket]),
+    {ok, AcceptSocket} = rpc:call(Node, ssl, transport_accept, 
+				  [ListenSocket]),    
+    ct:log("~p:~p~nssl:handshake(~p,~p,~p)~n", [?MODULE,?LINE, AcceptSocket, SslOpts,Timeout]),
+
+    case rpc:call(Node, ssl, handshake, [AcceptSocket, SslOpts, Timeout]) of
+	{ok, Socket0, Ext} ->
+            ct:log("Ext ~p:~n", [Ext]),            
+            ct:log("~p:~p~nssl:handshake_cancel(~p)~n", [?MODULE,?LINE, Socket0]),            
+            rpc:call(Node, ssl, handshake_cancel, [Socket0]);
+        Result ->
+	    ct:log("~p:~p~nssl:handshake@~p ret ~p",[?MODULE,?LINE, Node,Result]),
+	    Result
+    end;
+connect(ListenSocket, Node, N, _, Timeout, SslOpts, [_|_] =ContOpts) ->
+    ct:log("ssl:transport_accept(~p)~n", [ListenSocket]),
+    {ok, AcceptSocket} = rpc:call(Node, ssl, transport_accept, 
+				  [ListenSocket]),    
+    ct:log("~p:~p~nssl:handshake(~p,~p,~p)~n", [?MODULE,?LINE, AcceptSocket, SslOpts,Timeout]),
+
+    case rpc:call(Node, ssl, handshake, [AcceptSocket, SslOpts, Timeout]) of
+	{ok, Socket0, Ext} ->
+            ct:log("Ext ~p:~n", [Ext]),            
+            ct:log("~p:~p~nssl:handshake_continue(~p,~p,~p)~n", [?MODULE,?LINE, Socket0, ContOpts,Timeout]),            
+            case rpc:call(Node, ssl, handshake_continue, [Socket0, ContOpts, Timeout]) of
+                {ok, Socket} ->
+                    connect(ListenSocket, Node, N-1, Socket, Timeout, SslOpts, ContOpts);
+                Error ->
+                    ct:log("~p:~p~nssl:handshake_continue@~p ret ~p",[?MODULE,?LINE, Node,Error]),
+                    Error
+            end;
+	Result ->
+	    ct:log("~p:~p~nssl:handshake@~p ret ~p",[?MODULE,?LINE, Node,Result]),
+	    Result
+    end;
+connect(ListenSocket, Node, N, _, Timeout, [], ContOpts) ->
     ct:log("ssl:transport_accept(~p)~n", [ListenSocket]),
     {ok, AcceptSocket} = rpc:call(Node, ssl, transport_accept, 
 				  [ListenSocket]),    
@@ -143,12 +183,12 @@ connect(ListenSocket, Node, N, _, Timeout, []) ->
 
     case rpc:call(Node, ssl, ssl_accept, [AcceptSocket, Timeout]) of
 	ok ->
-	    connect(ListenSocket, Node, N-1, AcceptSocket, Timeout, []);
+	    connect(ListenSocket, Node, N-1, AcceptSocket, Timeout, [], ContOpts);
 	Result ->
 	    ct:log("~p:~p~nssl:ssl_accept@~p ret ~p",[?MODULE,?LINE, Node,Result]),
 	    Result
     end;
-connect(ListenSocket, Node, _, _, Timeout, Opts) ->
+connect(ListenSocket, Node, _, _, Timeout, Opts, _) ->
     ct:log("ssl:transport_accept(~p)~n", [ListenSocket]),
     {ok, AcceptSocket} = rpc:call(Node, ssl, transport_accept, 
 				  [ListenSocket]),    
@@ -187,8 +227,17 @@ run_client(Opts) ->
     Pid = proplists:get_value(from, Opts),
     Transport =  proplists:get_value(transport, Opts, ssl),
     Options = proplists:get_value(options, Opts),
+    ContOpts = proplists:get_value(continue_options, Opts, []),
     ct:log("~p:~p~n~p:connect(~p, ~p)@~p~n", [?MODULE,?LINE, Transport, Host, Port, Node]),
     ct:log("SSLOpts: ~p", [Options]),
+    case ContOpts of
+        [] ->
+            client_loop(Node, Host, Port, Pid, Transport, Options, Opts);
+        _ ->
+            client_cont_loop(Node, Host, Port, Pid, Transport, Options, ContOpts, Opts)
+    end.
+
+client_loop(Node, Host, Port, Pid, Transport, Options, Opts) ->
     case rpc:call(Node, Transport, connect, [Host, Port, Options]) of
 	{ok, Socket} ->
 	    Pid ! {connected, Socket},
@@ -245,6 +294,40 @@ run_client(Opts) ->
             Pid ! {connect_failed, {badrpc,BadRPC}}
     end.
 
+client_cont_loop(Node, Host, Port, Pid, Transport, Options, cancel, _Opts) ->
+    case rpc:call(Node, Transport, connect, [Host, Port, Options]) of
+        {ok, Socket, _} ->
+           Result = rpc:call(Node, Transport, handshake_cancel, [Socket]),
+            ct:log("~p:~p~nClient: Cancel: ~p ~n", [?MODULE,?LINE, Result]),
+            Pid ! {connect_failed, Result};
+        {error, Reason} ->
+	    ct:log("~p:~p~nClient: connection failed: ~p ~n", [?MODULE,?LINE, Reason]),
+	    Pid ! {connect_failed, Reason}
+    end;
+
+client_cont_loop(Node, Host, Port, Pid, Transport, Options, ContOpts, Opts) ->
+    case rpc:call(Node, Transport, connect, [Host, Port, Options]) of
+        {ok, Socket0, _} ->
+            ct:log("~p:~p~nClient: handshake_continue(~p, ~p, infinity) ~n", [?MODULE, ?LINE, Socket0, ContOpts]),
+            case rpc:call(Node, Transport, handshake_continue, [Socket0, ContOpts, infinity]) of
+                {ok, Socket} ->
+                    Pid ! {connected, Socket},
+                    {Module, Function, Args} = proplists:get_value(mfa, Opts),
+                    ct:log("~p:~p~nClient: apply(~p,~p,~p)~n",
+                           [?MODULE,?LINE, Module, Function, [Socket | Args]]),
+                    case rpc:call(Node, Module, Function, [Socket | Args]) of
+                        no_result_msg ->
+                            ok;
+                        Msg ->
+                            ct:log("~p:~p~nClient Msg: ~p ~n", [?MODULE,?LINE, Msg]),
+                            Pid ! {self(), Msg}
+                    end
+	    end;
+        {error, Reason} ->
+            ct:log("~p:~p~nClient: connection failed: ~p ~n", [?MODULE,?LINE, Reason]),
+            Pid ! {connect_failed, Reason}
+    end.
+            
 close(Pid) ->
     ct:log("~p:~p~nClose ~p ~n", [?MODULE,?LINE, Pid]),
     Monitor = erlang:monitor(process, Pid),