ssl: Fix failing property tests

- Updated message generators:
  ClientHello, ServerHello and EncryptedExtensions

- Fixed encoding of the extensions 'signature_algorithms' and
  'signature_algorithms_cert'

- Updated empty extension definitions

Change-Id: I9415e2d022744b9ed4667d20aee2553637ed49f8

4 files changed, 386 insertions, 176 deletions

diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index 1e812c92a8..da2e92a76b 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -75,7 +75,7 @@
 	 handle_client_hello_extensions/9, %% Returns server hello extensions
 	 handle_server_hello_extensions/9, select_curve/2, select_curve/3,
          select_hashsign/4, select_hashsign/5,
-	 select_hashsign_algs/3
+	 select_hashsign_algs/3, empty_extensions/2
 	]).
 
 %%====================================================================
@@ -646,7 +646,15 @@ encode_extensions([#hash_sign_algos{hash_sign_algos = HashSignAlgos} | Rest], Ac
     Len = ListLen + 2,
     encode_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_EXT),
 				 ?UINT16(Len), ?UINT16(ListLen), SignAlgoList/binary, Acc/binary>>);
-encode_extensions([#signature_scheme_list{
+encode_extensions([#signature_algorithms{
+                            signature_scheme_list = SignatureSchemes} | Rest], Acc) ->
+    SignSchemeList = << <<(ssl_cipher:signature_scheme(SignatureScheme)):16 >> ||
+		       SignatureScheme <- SignatureSchemes >>,
+    ListLen = byte_size(SignSchemeList),
+    Len = ListLen + 2,
+    encode_extensions(Rest, <<?UINT16(?SIGNATURE_ALGORITHMS_EXT),
+				 ?UINT16(Len), ?UINT16(ListLen), SignSchemeList/binary, Acc/binary>>);
+encode_extensions([#signature_algorithms_cert{
                             signature_scheme_list = SignatureSchemes} | Rest], Acc) ->
     SignSchemeList = << <<(ssl_cipher:signature_scheme(SignatureScheme)):16 >> ||
 		       SignatureScheme <- SignatureSchemes >>,
@@ -711,7 +719,7 @@ decode_handshake(Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32
        session_id = Session_ID,
        cipher_suite = Cipher_suite,
        compression_method = Comp_method,
-       extensions = empty_hello_extensions(Version, server)};
+       extensions = empty_extensions(Version, server_hello)};
 
 decode_handshake(Version, ?SERVER_HELLO, <<?BYTE(Major), ?BYTE(Minor), Random:32/binary,
 		       ?BYTE(SID_length), Session_ID:SID_length/binary,
@@ -780,7 +788,12 @@ decode_vector(<<?UINT16(Len), Vector:Len/binary>>) ->
 %% Description: Decodes TLS hello extensions
 %%--------------------------------------------------------------------
 decode_hello_extensions(Extensions, Version, Role) ->
-    decode_extensions(Extensions, Version, empty_hello_extensions(Version, Role)).
+    MessageType =
+        case Role of
+            client -> client_hello;
+            server -> server_hello
+        end,
+    decode_extensions(Extensions, Version, empty_extensions(Version, MessageType)).
 
 %%--------------------------------------------------------------------
 -spec decode_extensions(binary(),tuple()) -> map().
@@ -1049,14 +1062,14 @@ maybe_add_tls13_extensions({3,4},
     HelloExtensions#{client_hello_versions => 
                          #client_hello_versions{versions = SupportedVersions},
                      signature_algs_cert =>
-                         signature_scheme_list(SignatureSchemes)};
+                         signature_algs_cert(SignatureSchemes)};
 maybe_add_tls13_extensions(_, HelloExtensions, _) ->
     HelloExtensions.
 
-signature_scheme_list(undefined) ->
+signature_algs_cert(undefined) ->
     undefined;
-signature_scheme_list(SignatureSchemes) ->
-    #signature_scheme_list{signature_scheme_list = SignatureSchemes}.
+signature_algs_cert(SignatureSchemes) ->
+    #signature_algorithms_cert{signature_scheme_list = SignatureSchemes}.
 
 handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
                                Exts, Version,
@@ -1071,7 +1084,7 @@ handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
 						      ClientCipherSuites, Compression,
 						      ConnectionStates0, Renegotiation, SecureRenegotation),
 
-    Empty = empty_hello_extensions(Version, client),
+    Empty = empty_extensions(Version, server_hello),
     ServerHelloExtensions = Empty#{renegotiation_info => renegotiation_info(RecordCB, server,
                                                                             ConnectionStates, Renegotiation),
                                    ec_point_formats => server_ecc_extension(Version, maps:get(ec_point_formats, Exts, undefined))
@@ -1279,7 +1292,7 @@ get_cert_params(Cert) ->
 
 get_signature_scheme(undefined) ->
     undefined;
-get_signature_scheme(#signature_scheme_list{
+get_signature_scheme(#signature_algorithms_cert{
                         signature_scheme_list = ClientSignatureSchemes}) ->
     ClientSignatureSchemes.
 
@@ -2101,7 +2114,8 @@ decode_extensions(<<?UINT16(?SRP_EXT), ?UINT16(Len), ?BYTE(SRPLen),
     decode_extensions(Rest, Version, Acc#{srp => #srp{username = SRP}});
 
 decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
-		       ExtData:Len/binary, Rest/binary>>, Version, Acc) ->
+		       ExtData:Len/binary, Rest/binary>>, Version, Acc)
+  when Version < {3,4} ->
     SignAlgoListLen = Len - 2,
     <<?UINT16(SignAlgoListLen), SignAlgoList/binary>> = ExtData,
     HashSignAlgos = [{ssl_cipher:hash_algorithm(Hash), ssl_cipher:sign_algorithm(Sign)} ||
@@ -2110,6 +2124,17 @@ decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
                                               #hash_sign_algos{hash_sign_algos =
                                                                    HashSignAlgos}});
 
+decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
+		       ExtData:Len/binary, Rest/binary>>, Version, Acc)
+  when Version =:= {3,4} ->
+    SignSchemeListLen = Len - 2,
+    <<?UINT16(SignSchemeListLen), SignSchemeList/binary>> = ExtData,
+    SignSchemes = [ssl_cipher:signature_scheme(SignScheme) ||
+			<<?UINT16(SignScheme)>> <= SignSchemeList],
+    decode_extensions(Rest, Version, Acc#{signature_algs =>
+                                              #signature_algorithms{
+                                                 signature_scheme_list = SignSchemes}});
+
 decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT), ?UINT16(Len),
 		       ExtData:Len/binary, Rest/binary>>, Version, Acc) ->
     SignSchemeListLen = Len - 2,
@@ -2117,7 +2142,7 @@ decode_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_CERT_EXT), ?UINT16(Len),
     SignSchemes = [ssl_cipher:signature_scheme(SignScheme) ||
 			<<?UINT16(SignScheme)>> <= SignSchemeList],
     decode_extensions(Rest, Version, Acc#{signature_algs_cert =>
-                                              #signature_scheme_list{
+                                              #signature_algorithms_cert{
                                                  signature_scheme_list = SignSchemes}});
 
 decode_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
@@ -2756,27 +2781,37 @@ cert_curve(Cert, ECCCurve0, CipherSuite) ->
             {ECCCurve0, CipherSuite}
     end.
 
-empty_hello_extensions({3, 4}, server) ->
-    #{server_hello_selected_version => undefined,
-      key_share => undefined,
-      pre_shared_key => undefined,
-      sni => undefined
-     };
-empty_hello_extensions({3, 4}, client) -> 
-    #{client_hello_versions => undefined,
-      signature_algs => undefined,
-      signature_algs_cert => undefined,
+empty_extensions() ->
+     #{}.
+
+empty_extensions({3,4}, client_hello) ->
+    #{
       sni => undefined,
+      %% max_fragment_length => undefined,
+      %% status_request => undefined,
+      elliptic_curves => undefined,
+      signature_algs => undefined,
+      %% use_srtp => undefined,
+      %% heartbeat => undefined,
       alpn => undefined,
+      %% signed_cert_timestamp => undefined,
+      %% client_cert_type => undefined,
+      %% server_cert_type => undefined,
+      %% padding => undefined,
       key_share => undefined,
-      pre_shared_key => undefined
+      pre_shared_key => undefined,
+      %% psk_key_exhange_modes => undefined,
+      %% early_data => undefined,
+      %% cookie => undefined,
+      client_hello_versions => undefined,
+      %% cert_authorities => undefined,
+      %% post_handshake_auth => undefined,
+      signature_algs_cert => undefined
      };
-empty_hello_extensions({3, 3}, client) -> 
-    Ext = empty_hello_extensions({3,2}, client),
-    Ext#{client_hello_versions => undefined,
-         signature_algs => undefined,
-         signature_algs_cert => undefined};
-empty_hello_extensions(_, client) ->
+empty_extensions({3, 3}, client_hello) ->
+    Ext = empty_extensions({3,2}, client_hello),
+    Ext#{signature_algs => undefined};
+empty_extensions(_, client_hello) ->
     #{renegotiation_info => undefined,
       alpn => undefined,
       next_protocol_negotiation => undefined,
@@ -2784,11 +2819,13 @@ empty_hello_extensions(_, client) ->
       ec_point_formats => undefined,
       elliptic_curves => undefined,
       sni => undefined};
-empty_hello_extensions(_, server) ->
+empty_extensions({3,4}, server_hello) ->
+    #{server_hello_selected_version => undefined,
+      key_share => undefined,
+      pre_shared_key => undefined
+     };
+empty_extensions(_, server_hello) ->
     #{renegotiation_info => undefined,
       alpn => undefined,
       next_protocol_negotiation => undefined,
-      ec_point_formats => undefined,
-      sni => undefined}.
-empty_extensions() ->
-     #{}.
+      ec_point_formats => undefined}.
diff --git a/lib/ssl/src/ssl_handshake.hrl b/lib/ssl/src/ssl_handshake.hrl
index 4336742e76..1fd143a641 100644
--- a/lib/ssl/src/ssl_handshake.hrl
+++ b/lib/ssl/src/ssl_handshake.hrl
@@ -315,9 +315,9 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 -define(SIGNATURE_ALGORITHMS_EXT, 13).
 
--record(hash_sign_algos, {
-	  hash_sign_algos
-	 }).
+-record(hash_sign_algos, {hash_sign_algos}).
+%% RFC 8446 (TLS 1.3)
+-record(signature_algorithms, {signature_scheme_list}).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% RFC 7301 Application-Layer Protocol Negotiation  
@@ -436,6 +436,6 @@
 
 -define(SIGNATURE_ALGORITHMS_CERT_EXT, 50).
 
--record(signature_scheme_list, {signature_scheme_list}).
+-record(signature_algorithms_cert, {signature_scheme_list}).
 
 -endif. % -ifdef(ssl_handshake).
diff --git a/lib/ssl/test/property_test/ssl_eqc_handshake.erl b/lib/ssl/test/property_test/ssl_eqc_handshake.erl
index 99c6554f15..8b3b81aaf1 100644
--- a/lib/ssl/test/property_test/ssl_eqc_handshake.erl
+++ b/lib/ssl/test/property_test/ssl_eqc_handshake.erl
@@ -85,17 +85,14 @@ prop_tls_hs_encode_decode() ->
 	   ).
 
 %%--------------------------------------------------------------------
-%% Message Generators  --------------------------------------------------
+%% Message Generators  -----------------------------------------------
 %%--------------------------------------------------------------------
 
-tls_version() ->
-    oneof([?'TLS_v1.3', ?'TLS_v1.2', ?'TLS_v1.1', ?'TLS_v1', ?'SSL_v3']). 
-
 tls_msg(?'TLS_v1.3'= Version) ->
     oneof([client_hello(Version),
            server_hello(Version),
            %%new_session_ticket()
-           #end_of_early_data{},
+          #end_of_early_data{},
            encrypted_extensions(),
            certificate_1_3(),
            %%certificate_request_1_3,
@@ -104,7 +101,8 @@ tls_msg(?'TLS_v1.3'= Version) ->
            key_update()
           ]);
 tls_msg(Version) ->
-    oneof([#hello_request{},
+    oneof([
+           #hello_request{},
            client_hello(Version),
            server_hello(Version),
            certificate(),
@@ -116,6 +114,9 @@ tls_msg(Version) ->
            finished()
           ]).
 
+%%
+%% Shared messages
+%%
 client_hello(?'TLS_v1.3' = Version) ->
     #client_hello{session_id = session_id(),
 		  client_version = ?'TLS_v1.2',
@@ -150,10 +151,6 @@ server_hello(Version) ->
 		  extensions = server_hello_extensions(Version)    
                  }.
 
-encrypted_extensions() ->
-    ?LET(Exts, extensions(?'TLS_v1.3'),
-         #encrypted_extensions{extensions = Exts}).
-        
 certificate() ->
     #certificate{
        asn1_certificates = certificate_chain()
@@ -166,17 +163,35 @@ certificate_1_3() ->
              entries = certificate_entries(Certs, [])  
             }).
 
-key_update() ->
-    #key_update{request_update = request_update()}.
-
 finished() ->
     ?LET(Size, digest_size(),
          #finished{verify_data = crypto:strong_rand_bytes(Size)}).
 
+%%
+%% TLS 1.0-1.2 messages
+%%
+
+
+
+%%
+%% TLS 1.3 messages
+%%
+
+encrypted_extensions() ->
+    ?LET(Exts, extensions(?'TLS_v1.3', encrypted_extensions),
+         #encrypted_extensions{extensions = Exts}).
+
+
+key_update() ->
+    #key_update{request_update = request_update()}.
+
+
 %%--------------------------------------------------------------------
 %% Messge Data Generators  -------------------------------------------
 %%--------------------------------------------------------------------
 
+tls_version() ->
+    oneof([?'TLS_v1.3', ?'TLS_v1.2', ?'TLS_v1.1', ?'TLS_v1', ?'SSL_v3']).
 
 cipher_suite(Version) ->
     oneof(cipher_suites(Version)).
@@ -200,52 +215,14 @@ server_random(_) ->
     crypto:strong_rand_bytes(32).
 
 
-client_hello_extensions(?'TLS_v1.3' = Version) ->
-    ?LET({Versions, Ext}, {supported_versions(Version), c_hello_extensions(Version)},
-         maps:merge(Ext, #{client_hello_versions => client_hello_versions(Versions)})
-        );
-client_hello_extensions(?'TLS_v1.2' = Version) ->
-    ?LET({Versions, Exts}, {supported_versions(Version),  c_hello_extensions(Version)}, 
-         maps:merge(Exts, #{client_hello_versions => client_hello_versions(Versions)})
-        );
 client_hello_extensions(Version) ->
-    ?LET(Exts,
-         c_hello_extensions(Version),
-         maps:merge(empty_hello_extensions(Version, client), Exts)).
-
-server_hello_extensions(?'TLS_v1.3' = Version) ->
-    ?LET(Exts,       
-         s_hello_extensions(Version),
-         maps:merge(Exts, #{server_hello_selected_version => server_hello_selected_version(Version)}));
-server_hello_extensions(Version) ->
-    ?LET(Exts,    
-         s_hello_extensions(Version),
-         Exts).
-
-c_hello_extensions(?'TLS_v1.3'= Version) ->
-    ?LET({KeyShare, PreShare}, {key_share_client_hello(),
-                                pre_shared_keyextension()},
-         maps:merge(empty_hello_extensions(Version, client),
-                    #{key_share => KeyShare,
-                      pre_shared_key => PreShare
-                     })
-        );
-c_hello_extensions(Version) ->
-    ?LET(Exts, extensions(Version),
-         maps:merge(empty_hello_extensions(Version, client),
+    ?LET(Exts, extensions(Version, client_hello),
+         maps:merge(ssl_handshake:empty_extensions(Version, client_hello),
                     Exts)).
 
-s_hello_extensions(?'TLS_v1.3'= Version) ->
-    ?LET({KeyShare, PreShare}, {key_share_server_hello(),
-                                pre_shared_keyextension()},
-         maps:merge(empty_hello_extensions(Version, server),
-                    #{key_share => KeyShare,
-                      pre_shared_key => PreShare
-                     })
-        );
-s_hello_extensions(Version) ->
-    ?LET(Exts, extensions(Version),
-         maps:merge(empty_hello_extensions(Version, server),
+server_hello_extensions(Version) ->
+    ?LET(Exts, extensions(Version, server_hello),
+         maps:merge(ssl_handshake:empty_extensions(Version, server_hello),
                     Exts)).
 
 key_share_client_hello() ->
@@ -260,83 +237,260 @@ pre_shared_keyextension() ->
      oneof([undefined]).
      %%oneof([#pre_shared_keyextension{},undefined]).
 
-extensions(?'TLS_v1.3') ->
-    ?LET({Ext_1_3, Exts}, {extensions_1_3(), extensions(?'TLS_v1.2')}, maps:merge(Ext_1_3, Exts));
-extensions(?'SSL_v3') ->
+%% +--------------------------------------------------+-------------+
+%% | Extension                                        |     TLS 1.3 |
+%% +--------------------------------------------------+-------------+
+%% | server_name [RFC6066]                            |      CH, EE |
+%% |                                                  |             |
+%% | max_fragment_length [RFC6066]                    |      CH, EE |
+%% |                                                  |             |
+%% | status_request [RFC6066]                         |  CH, CR, CT |
+%% |                                                  |             |
+%% | supported_groups [RFC7919]                       |      CH, EE |
+%% |                                                  |             |
+%% | signature_algorithms (RFC 8446)                  |      CH, CR |
+%% |                                                  |             |
+%% | use_srtp [RFC5764]                               |      CH, EE |
+%% |                                                  |             |
+%% | heartbeat [RFC6520]                              |      CH, EE |
+%% |                                                  |             |
+%% | application_layer_protocol_negotiation [RFC7301] |      CH, EE |
+%% |                                                  |             |
+%% | signed_certificate_timestamp [RFC6962]           |  CH, CR, CT |
+%% |                                                  |             |
+%% | client_certificate_type [RFC7250]                |      CH, EE |
+%% |                                                  |             |
+%% | server_certificate_type [RFC7250]                |      CH, EE |
+%% |                                                  |             |
+%% | padding [RFC7685]                                |          CH |
+%% |                                                  |             |
+%% | key_share (RFC 8446)                             | CH, SH, HRR |
+%% |                                                  |             |
+%% | pre_shared_key (RFC 8446)                        |      CH, SH |
+%% |                                                  |             |
+%% | psk_key_exchange_modes (RFC 8446)                |          CH |
+%% |                                                  |             |
+%% | early_data (RFC 8446)                            | CH, EE, NST |
+%% |                                                  |             |
+%% | cookie (RFC 8446)                                |     CH, HRR |
+%% |                                                  |             |
+%% | supported_versions (RFC 8446)                    | CH, SH, HRR |
+%% |                                                  |             |
+%% | certificate_authorities (RFC 8446)               |      CH, CR |
+%% |                                                  |             |
+%% | oid_filters (RFC 8446)                           |          CR |
+%% |                                                  |             |
+%% | post_handshake_auth (RFC 8446)                   |          CH |
+%% |                                                  |             |
+%% | signature_algorithms_cert (RFC 8446)             |      CH, CR |
+%% +--------------------------------------------------+-------------+
+extensions(?'TLS_v1.3' = Version, client_hello) ->
+     ?LET({
+           ServerName,
+           %% MaxFragmentLength,
+           %% StatusRequest,
+           SupportedGroups,
+           SignatureAlgorithms,
+           %% UseSrtp,
+           %% Heartbeat,
+           ALPN,
+           %% SignedCertTimestamp,
+           %% ClientCertiticateType,
+           %% ServerCertificateType,
+           %% Padding,
+           %% KeyShare,
+           %% PreSharedKey,
+           %% PSKKeyExchangeModes,
+           %% EarlyData,
+           %% Cookie,
+           SupportedVersions,
+           %% CertAuthorities,
+           %% PostHandshakeAuth,
+           SignatureAlgorithmsCert
+          },
+          {
+           oneof([server_name(), undefined]),
+           %% oneof([max_fragment_length(), undefined]),
+           %% oneof([status_request(), undefined]),
+           oneof([supported_groups(Version), undefined]),
+           oneof([signature_algs(Version), undefined]),
+           %% oneof([use_srtp(), undefined]),
+           %% oneof([heartbeat(), undefined]),
+           oneof([alpn(), undefined]),
+           %% oneof([signed_cert_timestamp(), undefined]),
+           %% oneof([client_cert_type(), undefined]),
+           %% oneof([server_cert_type(), undefined]),
+           %% oneof([padding(), undefined]),
+           %% oneof([key_share(), undefined]),
+           %% oneof([pre_shared_key(), undefined]),
+           %% oneof([psk_key_exchange_modes(), undefined]),
+           %% oneof([early_data(), undefined]),
+           %% oneof([cookie(), undefined]),
+           oneof([client_hello_versions(Version), undefined]),
+           %% oneof([cert_authorities(), undefined]),
+           %% oneof([post_handshake_auth(), undefined]),
+           oneof([signature_algs_cert(), undefined])
+          },
+          maps:filter(fun(_, undefined) ->
+                              false;
+                         (_,_) ->
+                              true
+                      end,
+                      #{
+                        sni => ServerName,
+                        %% max_fragment_length => MaxFragmentLength,
+                        %% status_request => StatusRequest,
+                        elliptic_curves => SupportedGroups,
+                        signature_algs => SignatureAlgorithms,
+                        %% use_srtp => UseSrtp,
+                        %% heartbeat => Heartbeat,
+                        alpn => ALPN,
+                        %% signed_cert_timestamp => SignedCertTimestamp,
+                        %% client_cert_type => ClientCertificateType,
+                        %% server_cert_type => ServerCertificateType,
+                        %% padding => Padding,
+                        %% key_share => KeyShare,
+                        %% pre_shared_key => PreSharedKey,
+                        %% psk_key_exhange_modes => PSKKeyExchangeModes,
+                        %% early_data => EarlyData,
+                        %% cookie => Cookie,
+                        client_hello_versions => SupportedVersions,
+                        %% cert_authorities => CertAuthorities,
+                        %% post_handshake_auth => PostHandshakeAuth,
+                        signature_algs_cert => SignatureAlgorithmsCert
+                       }));
+extensions(?'SSL_v3', client_hello) ->
     #{};
-extensions(Version) ->
-    ?LET({SNI, ECPoitF, ECCurves, ALPN, NextP, SRP}, 
-         {oneof([sni(), undefined]),
-          oneof([ec_poit_formats(), undefined]),
+extensions(Version, client_hello) ->
+    ?LET({
+          SNI,
+          ECPoitF,
+          ECCurves,
+          ALPN,
+          NextP,
+          SRP
+          %% RenegotiationInfo
+         },
+         {
+          oneof([sni(), undefined]),
+          oneof([ec_point_formats(), undefined]),
           oneof([elliptic_curves(Version), undefined]), 
           oneof([alpn(),  undefined]), 
           oneof([next_protocol_negotiation(), undefined]),
-          oneof([srp(), undefined])},  
+          oneof([srp(), undefined])
+          %% oneof([renegotiation_info(), undefined])
+         },
          maps:filter(fun(_, undefined) -> 
                              false;
                         (_,_) -> 
                              true 
                      end, 
-                     #{sni => SNI,
+                     #{
+                       sni => SNI,
                        ec_point_formats => ECPoitF,
                        elliptic_curves => ECCurves,
                        alpn => ALPN,
                        next_protocol_negotiation => NextP,
-                       srp => SRP})).  
-
-extensions_1_3() ->
-    %% ?LET(Entry, key_share_entry(), 
-    %%          maps:filter(fun(_, undefined) -> 
-    %%                              false;
-    %%                         (_,_) -> 
-    %%                              true 
-    %%                      end, #{key_share_entry => Entry})).
-    ?LET({HashSign, SigAlgCert}, {oneof([hash_sign_algos(?'TLS_v1.2')]),  oneof([signature_scheme_list()])},  
-         #{signature_algs => HashSign,
-           signature_algs_cert => SigAlgCert}).      
-
-empty_hello_extensions({3, 4}, server) ->
-    #{server_hello_selected_version => undefined,
-      key_share => undefined,
-      pre_shared_key => undefined,
-      sni => undefined
-     };
-empty_hello_extensions({3, 4}, client) -> 
-    #{client_hello_versions => undefined,
-      signature_algs => undefined,
-      signature_algs_cert => undefined,
-      sni => undefined,
-      alpn => undefined,
-      key_share => undefined,
-      pre_shared_key => undefined      
-     };
-empty_hello_extensions({3, 3}, client) -> 
-    Ext = empty_hello_extensions({3,2}, client),
-    Ext#{client_hello_versions => undefined,
-         signature_algs => undefined,
-         signature_algs_cert => undefined};
-empty_hello_extensions(_, client) ->
-    #{renegotiation_info => undefined,
-      alpn => undefined,
-      next_protocol_negotiation => undefined,
-      srp => undefined,
-      ec_point_formats => undefined,
-      elliptic_curves => undefined,
-      sni => undefined};
-empty_hello_extensions(_, server) ->
-    #{renegotiation_info => undefined,
-      alpn => undefined,
-      next_protocol_negotiation => undefined,
-      ec_point_formats => undefined,
-      sni => undefined}.
+                       srp => SRP
+                       %% renegotiation_info => RenegotiationInfo
+                      }));
+extensions(?'TLS_v1.3' = Version, server_hello) ->
+    ?LET({
+          %% KeyShare,
+          %% PreSharedKeys,
+          SupportedVersions
+         },
+         {
+          %% oneof([key_share(), undefined]),
+          %% oneof([pre_shared_keys(),  undefined]),
+          oneof([server_hello_selected_version(), undefined])
+         },
+         maps:filter(fun(_, undefined) ->
+                             false;
+                        (_,_) ->
+                             true
+                     end,
+                     #{
+                       %% key_share => KeyShare,
+                       %% pre_shared_keys => PreSharedKeys,
+                       server_hello_selected_version => SupportedVersions
+                      }));
+extensions(Version, server_hello) ->
+    ?LET({
+          ECPoitF,
+          ALPN,
+          NextP
+          %% RenegotiationInfo,
+         },
+         {
+          oneof([ec_point_formats(), undefined]),
+          oneof([alpn(),  undefined]),
+          oneof([next_protocol_negotiation(), undefined])
+          %% oneof([renegotiation_info(), undefined]),
+         },
+         maps:filter(fun(_, undefined) ->
+                             false;
+                        (_,_) ->
+                             true
+                     end,
+                     #{
+                       ec_point_formats => ECPoitF,
+                       alpn => ALPN,
+                       next_protocol_negotiation => NextP
+                       %% renegotiation_info => RenegotiationInfo
+                      }));
+extensions(?'TLS_v1.3' = Version, encrypted_extensions) ->
+     ?LET({
+           ServerName,
+           %% MaxFragmentLength,
+           SupportedGroups,
+           %% UseSrtp,
+           %% Heartbeat,
+           ALPN
+           %% ClientCertiticateType,
+           %% ServerCertificateType,
+           %% EarlyData
+          },
+          {
+           oneof([server_name(), undefined]),
+           %% oneof([max_fragment_length(), undefined]),
+           oneof([supported_groups(Version), undefined]),
+           %% oneof([use_srtp(), undefined]),
+           %% oneof([heartbeat(), undefined]),
+           oneof([alpn(), undefined])
+           %% oneof([client_cert_type(), undefined]),
+           %% oneof([server_cert_type(), undefined]),
+           %% oneof([early_data(), undefined])
+          },
+          maps:filter(fun(_, undefined) ->
+                              false;
+                         (_,_) ->
+                              true
+                      end,
+                      #{
+                        sni => ServerName,
+                        %% max_fragment_length => MaxFragmentLength,
+                        elliptic_curves => SupportedGroups,
+                        %% use_srtp => UseSrtp,
+                        %% heartbeat => Heartbeat,
+                        alpn => ALPN
+                        %% client_cert_type => ClientCertificateType,
+                        %% server_cert_type => ServerCertificateType,
+                        %% early_data => EarlyData
+                       })).
+
+server_name() ->
+  ?LET(ServerName, sni(),
+       ServerName).
+    %% sni().
 
 signature_algs_cert() ->
-    ?LET(Algs, signature_scheme_list(),
-         Algs).
+    ?LET(List,  sig_scheme_list(),
+         #signature_algorithms_cert{signature_scheme_list = List}).
 
-signature_scheme_list() ->
+signature_algorithms() ->
     ?LET(List,  sig_scheme_list(), 
-         #signature_scheme_list{signature_scheme_list = List}).
+         #signature_algorithms{signature_scheme_list = List}).
 
 sig_scheme_list() ->
     oneof([[rsa_pkcs1_sha256],
@@ -357,16 +511,23 @@ sig_scheme_list() ->
             ecdsa_sha1]
           ]).
 
-supported_versions(?'TLS_v1.3') ->
-    oneof([[{3,4}],
-           [{3,3},{3,4}],
-           [{3,4},{3,3},{3,2},{3,1},{3,0}]
-          ]);
-supported_versions(_) ->
-    oneof([[{3,3}],
-           [{3,3},{3,2}],
-           [{3,3},{3,2},{3,1},{3,0}]
-          ]).
+client_hello_versions(?'TLS_v1.3') ->
+    ?LET(SupportedVersions,
+         oneof([[{3,4}],
+                [{3,3},{3,4}],
+                [{3,4},{3,3},{3,2},{3,1},{3,0}]
+               ]),
+        #client_hello_versions{versions = SupportedVersions});
+client_hello_versions(_) ->
+    ?LET(SupportedVersions,
+         oneof([[{3,3}],
+                [{3,3},{3,2}],
+                [{3,3},{3,2},{3,1},{3,0}]
+               ]),
+        #client_hello_versions{versions = SupportedVersions}).
+
+server_hello_selected_version() ->
+    #server_hello_selected_version{selected_version = {3,4}}.
 
 request_update() ->
      oneof([?UPDATE_NOT_REQUESTED, ?UPDATE_REQUESTED]).
@@ -431,13 +592,25 @@ certificate_types(?'TLS_v1.2') ->
 certificate_types(_) ->
     iolist_to_binary([<<?BYTE(?ECDSA_SIGN)>>, <<?BYTE(?RSA_SIGN)>>, <<?BYTE(?DSS_SIGN)>>]).
 
+
+
+signature_algs({3,4}) ->
+    ?LET(Algs, signature_algorithms(),
+         Algs);
+signature_algs({3,3} = Version) ->
+        #hash_sign_algos{hash_sign_algos = hash_alg_list(Version)};
+signature_algs(Version) when Version < {3,3} ->
+    undefined.
+
+
+
 hashsign_algorithms({_, N} = Version) when N >= 3 ->                                 
     #hash_sign_algos{hash_sign_algos = hash_alg_list(Version)};
 hashsign_algorithms(_) -> 
     undefined.
 
 hash_alg_list(Version) ->
-    ?LET(NumOf, choose(0,15),
+    ?LET(NumOf, choose(1,15),
 	 ?LET(List, [hash_alg(Version) || _ <- lists:seq(1,NumOf)],
 	      lists:usort(List)
              )).
@@ -481,27 +654,27 @@ key_share_entry() ->
     undefined.
     %%#key_share_entry{}.
 
-client_hello_versions(Versions) ->
-    #client_hello_versions{versions = Versions}. 
-
 server_hello_selected_version(Version) ->
     #server_hello_selected_version{selected_version = Version}.
 
 sni() ->
     #sni{hostname = net_adm:localhost()}.
 
-ec_poit_formats() ->
+ec_point_formats() ->
     #ec_point_formats{ec_point_format_list = ec_point_format_list()}.
  
 ec_point_format_list() ->
     [?ECPOINT_UNCOMPRESSED].
 
-elliptic_curves({_, Minor}) ->
+elliptic_curves({_, Minor}) when Minor < 4 ->
     Curves = tls_v1:ecc_curves(Minor),
     #elliptic_curves{elliptic_curve_list = Curves}.
 
-hash_sign_algos(Version) ->
-    #hash_sign_algos{hash_sign_algos = hash_alg_list(Version)}.
+%% RFC 8446 (TLS 1.3) renamed the "elliptic_curve" extension.
+supported_groups({_, Minor}) when Minor >= 4 ->
+    SupportedGroups = tls_v1:groups(Minor),
+    #supported_groups{supported_groups = SupportedGroups}.
+
 
 alpn() ->
     ?LET(ExtD,  alpn_protocols(), #alpn{extension_data = ExtD}).
@@ -520,7 +693,7 @@ renegotiation_info() ->
     #renegotiation_info{renegotiated_connection = 0}.
 
 gen_name() -> 
-    ?LET(Size, choose(0,10), gen_string(Size)).
+    ?LET(Size, choose(1,10), gen_string(Size)).
 
 gen_char() -> 
     choose($a,$z).
diff --git a/lib/ssl/test/ssl_handshake_SUITE.erl b/lib/ssl/test/ssl_handshake_SUITE.erl
index 861fecc554..c35ee6cb57 100644
--- a/lib/ssl/test/ssl_handshake_SUITE.erl
+++ b/lib/ssl/test/ssl_handshake_SUITE.erl
@@ -112,7 +112,7 @@ decode_hello_handshake(_Config) ->
 
 decode_single_hello_extension_correctly(_Config) -> 
     Renegotiation = <<?UINT16(?RENEGOTIATION_EXT), ?UINT16(1), 0>>,
-    Extensions = ssl_handshake:decode_extensions(Renegotiation),
+    Extensions = ssl_handshake:decode_extensions(Renegotiation, {3,3}),
     #{renegotiation_info := #renegotiation_info{renegotiated_connection = <<0>>}} = Extensions.
 
 decode_supported_elliptic_curves_hello_extension_correctly(_Config) ->
@@ -200,7 +200,7 @@ signature_algorithms(Config) ->
                    hash_sign_algos = [{sha512, rsa},
                                       {sha, dsa},
                                       {sha, rsa}]},
-    Schemes0 = #signature_scheme_list{
+    Schemes0 = #signature_algorithms_cert{
                  signature_scheme_list = [rsa_pkcs1_sha1,
                                           ecdsa_sha1]},
     {sha512, rsa} = ssl_handshake:select_hashsign(
@@ -216,7 +216,7 @@ signature_algorithms(Config) ->
                       Cert, ecdhe_rsa,
                       tls_v1:default_signature_algs({3,3}),
                    {3,3}),
-    Schemes1 = #signature_scheme_list{
+    Schemes1 = #signature_algorithms_cert{
                   signature_scheme_list = [rsa_pkcs1_sha256,
                                            ecdsa_sha1]},
     %% Signature not supported