ssl: Add option signature_algs

In TLS-1.2 The signature algorithm and the hash function algorithm
used to produce the digest that is used when creating the digital signature
may be negotiated through the signature algorithm extension RFC 5246.

We want to make these algorithm pairs configurable.
In connections using lower versions of TLS these algorithms are
implicit defined and can not be negotiated or configured.

DTLS is updated to not cause dialyzer errors, but needs to get a real
implementation later.

11 files changed, 297 insertions, 135 deletions

diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 153d3fef48..e490de7eeb 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -196,8 +196,7 @@ hello(start, #state{host = Host, port = Port, role = client,
     {Record, State} = next_record(State1),
     next_state(hello, hello, Record, State);
 
-hello(Hello = #client_hello{client_version = ClientVersion,
-			    extensions = #hello_extensions{hash_signs = HashSigns}},
+hello(Hello = #client_hello{client_version = ClientVersion},
       State = #state{connection_states = ConnectionStates0,
 		     port = Port, session = #session{own_certificate = Cert} = Session0,
 		     renegotiation = {Renegotiation, _},
@@ -209,9 +208,7 @@ hello(Hello = #client_hello{client_version = ClientVersion,
         {Version, {Type, Session},
 	 ConnectionStates,
 	 #hello_extensions{ec_point_formats = EcPointFormats,
-			   elliptic_curves = EllipticCurves} = ServerHelloExt} ->
-            HashSign = ssl_handshake:select_hashsign(HashSigns, Cert, 
-						     dtls_v1:corresponding_tls_version(Version)),
+			   elliptic_curves = EllipticCurves} = ServerHelloExt, HashSign} ->
             ssl_connection:hello({common_client_hello, Type, ServerHelloExt, HashSign},
 				 State#state{connection_states  = ConnectionStates,
 					     negotiated_version = Version,
diff --git a/lib/ssl/src/dtls_handshake.erl b/lib/ssl/src/dtls_handshake.erl
index 22c0ce7a13..50c84b712f 100644
--- a/lib/ssl/src/dtls_handshake.erl
+++ b/lib/ssl/src/dtls_handshake.erl
@@ -94,7 +94,10 @@ hello(#server_hello{server_version = Version, random = Random,
 
 hello(#client_hello{client_version = ClientVersion}, _Options, {_,_,_,_,ConnectionStates,_}, _Renegotiation) ->      
     %% Return correct typ to make dialyzer happy until we have time to make the real imp.
-    {ClientVersion, {new, #session{}}, ConnectionStates, #hello_extensions{}}.
+    HashSigns = tls_v1:default_signature_algs(dtls_v1:corresponding_tls_version(ClientVersion)),
+    {ClientVersion, {new, #session{}}, ConnectionStates, #hello_extensions{}, 
+     %% Placeholder for real hasign handling
+     hd(HashSigns)}.
 
 %% hello(Address, Port,
 %%       #ssl_tls{epoch = _Epoch, sequence_number = _Seq,
diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl
index 780bef5877..9045f8fef9 100644
--- a/lib/ssl/src/ssl.erl
+++ b/lib/ssl/src/ssl.erl
@@ -700,6 +700,10 @@ handle_options(Opts0, Role) ->
 		    srp_identity = handle_option(srp_identity, Opts, undefined),
 		    ciphers    = handle_cipher_option(proplists:get_value(ciphers, Opts, []), 
 						      RecordCb:highest_protocol_version(Versions)),
+		    signature_algs = handle_hashsigns_option(proplists:get_value(signature_algs, Opts, 
+									     default_option_role(server, 
+												 tls_v1:default_signature_algs(Versions), Role)),
+							 RecordCb:highest_protocol_version(Versions)), 
 		    %% Server side option
 		    reuse_session = handle_option(reuse_session, Opts, ReuseSessionFun),
 		    reuse_sessions = handle_option(reuse_sessions, Opts, true),
@@ -749,7 +753,7 @@ handle_options(Opts0, Role) ->
 		  alpn_preferred_protocols, next_protocols_advertised,
 		  client_preferred_next_protocols, log_alert,
 		  server_name_indication, honor_cipher_order, padding_check, crl_check, crl_cache,
-		  fallback],
+		  fallback, signature_algs],
 
     SockOpts = lists:foldl(fun(Key, PropList) ->
 				   proplists:delete(Key, PropList)
@@ -989,6 +993,18 @@ validate_option(crl_cache, {Cb, {_Handle, Options}} = Value) when is_atom(Cb) an
 validate_option(Opt, Value) ->
     throw({error, {options, {Opt, Value}}}).
 
+handle_hashsigns_option(Value, {Major, Minor} = Version) when is_list(Value) 
+							      andalso Major >= 3 andalso Minor >= 3->
+    case tls_v1:signature_algs(Version, Value) of
+	[] ->
+	    throw({error, {options, no_supported_algorithms, {signature_algs, Value}}});
+	_ ->	
+	    Value
+    end;
+handle_hashsigns_option(_, {Major, Minor} = Version) when Major >= 3 andalso Minor >= 3->
+    handle_hashsigns_option(tls_v1:default_signature_algs(Version), Version);
+handle_hashsigns_option(_, _Version) ->
+    undefined.
 
 validate_options([]) ->
 	[];
@@ -1285,6 +1301,13 @@ new_ssl_options([{server_name_indication, Value} | Rest], #ssl_options{} = Opts,
     new_ssl_options(Rest, Opts#ssl_options{server_name_indication = validate_option(server_name_indication, Value)}, RecordCB);
 new_ssl_options([{honor_cipher_order, Value} | Rest], #ssl_options{} = Opts, RecordCB) -> 
     new_ssl_options(Rest, Opts#ssl_options{honor_cipher_order = validate_option(honor_cipher_order, Value)}, RecordCB);
+new_ssl_options([{signature_algs, Value} | Rest], #ssl_options{} = Opts, RecordCB) -> 
+    new_ssl_options(Rest, 
+		    Opts#ssl_options{signature_algs = 
+					 handle_hashsigns_option(Value, 
+								 RecordCB:highest_protocol_version())}, 
+		    RecordCB);
+
 new_ssl_options([{Key, Value} | _Rest], #ssl_options{}, _) -> 
     throw({error, {options, {Key, Value}}}).
 
diff --git a/lib/ssl/src/ssl_cipher.erl b/lib/ssl/src/ssl_cipher.erl
index 974a6ec6b5..bef04c574f 100644
--- a/lib/ssl/src/ssl_cipher.erl
+++ b/lib/ssl/src/ssl_cipher.erl
@@ -43,11 +43,12 @@
 
 -export_type([cipher_suite/0,
 	      erl_cipher_suite/0, openssl_cipher_suite/0,
-	      key_algo/0]).
+	      hash/0, key_algo/0, sign_algo/0]).
 
 -type cipher()            :: null |rc4_128 | idea_cbc | des40_cbc | des_cbc | '3des_ede_cbc' 
 			   | aes_128_cbc |  aes_256_cbc | aes_128_gcm | aes_256_gcm | chacha20_poly1305.
 -type hash()              :: null | sha | md5 | sha224 | sha256 | sha384 | sha512.
+-type sign_algo()         :: rsa | dsa | ecdsa.
 -type key_algo()          :: null | rsa | dhe_rsa | dhe_dss | ecdhe_ecdsa| ecdh_ecdsa | ecdh_rsa| srp_rsa| srp_dss | psk | dhe_psk | rsa_psk | dh_anon | ecdh_anon | srp_anon.
 -type erl_cipher_suite()  :: {key_algo(), cipher(), hash()} % Pre TLS 1.2 
 			     %% TLS 1.2, internally PRE TLS 1.2 will use default_prf
diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl
index ec7d086934..f774873269 100644
--- a/lib/ssl/src/ssl_connection.erl
+++ b/lib/ssl/src/ssl_connection.erl
@@ -304,13 +304,9 @@ hello(#hello_request{}, #state{role = client} = State0, Connection) ->
     {Record, State} = Connection:next_record(State0),
     Connection:next_state(hello, hello, Record, State);
 
-hello({common_client_hello, Type, ServerHelloExt, NegotiatedHashSign},
+hello({common_client_hello, Type, ServerHelloExt},
       State, Connection) ->
-    do_server_hello(Type, ServerHelloExt,
-		    %% Note NegotiatedHashSign is only negotiated for real if
-		    %% if TLS version is at least TLS-1.2 
-		    State#state{hashsign_algorithm = NegotiatedHashSign}, Connection);
-
+    do_server_hello(Type, ServerHelloExt, State, Connection);
 hello(timeout, State, _) ->
     {next_state, hello, State, hibernate};
 
@@ -442,7 +438,8 @@ certify(#server_key_exchange{exchange_keys = Keys},
        Alg == srp_dss; Alg == srp_rsa; Alg == srp_anon ->
 
     Params = ssl_handshake:decode_server_key(Keys, Alg, Version),
-    HashSign = negotiated_hashsign(Params#server_key_params.hashsign, Alg, Version),
+    %% Use negotiated value if TLS-1.2 otherwhise return default
+    HashSign = negotiated_hashsign(Params#server_key_params.hashsign, Alg, PubKeyInfo, Version),
     case is_anonymous(Alg) of
 	true ->
 	    calculate_secret(Params#server_key_params.params,
@@ -464,11 +461,18 @@ certify(#server_key_exchange{} = Msg,
 
 certify(#certificate_request{hashsign_algorithms = HashSigns},
 	#state{session = #session{own_certificate = Cert},
-        negotiated_version = Version} = State0, Connection) ->
-    HashSign = ssl_handshake:select_hashsign(HashSigns, Cert, Version),
-    {Record, State} = Connection:next_record(State0#state{client_certificate_requested = true}),
-    Connection:next_state(certify, certify, Record,
-			  State#state{cert_hashsign_algorithm = HashSign});
+	       key_algorithm = KeyExAlg,
+	       ssl_options = #ssl_options{signature_algs = SupportedHashSigns},
+	       negotiated_version = Version} = State0, Connection) ->
+
+    case ssl_handshake:select_hashsign(HashSigns, Cert, KeyExAlg, SupportedHashSigns, Version) of
+	#alert {} = Alert ->
+	    Connection:handle_own_alert(Alert, Version, certify, State0);
+	NegotiatedHashSign -> 
+	    {Record, State} = Connection:next_record(State0#state{client_certificate_requested = true}),
+	    Connection:next_state(certify, certify, Record,
+				  State#state{cert_hashsign_algorithm = NegotiatedHashSign})
+    end;
 
 %% PSK and RSA_PSK might bypass the Server-Key-Exchange
 certify(#server_hello_done{},
@@ -576,13 +580,15 @@ cipher(#hello_request{}, State0, Connection) ->
 
 cipher(#certificate_verify{signature = Signature, hashsign_algorithm = CertHashSign},
        #state{role = server,
-	      public_key_info = {Algo, _, _} =PublicKeyInfo,
+	      key_algorithm = KexAlg,
+	      public_key_info = PublicKeyInfo,
 	      negotiated_version = Version,
 	      session = #session{master_secret = MasterSecret},
 	      tls_handshake_history = Handshake
 	     } = State0, Connection) ->
-
-    HashSign = ssl_handshake:select_hashsign_algs(CertHashSign, Algo, Version),
+    
+    %% Use negotiated value if TLS-1.2 otherwhise return default
+    HashSign = negotiated_hashsign(CertHashSign, KexAlg, PublicKeyInfo, Version),
     case ssl_handshake:certificate_verify(Signature, PublicKeyInfo,
 					  Version, HashSign, MasterSecret, Handshake) of
 	valid ->
@@ -1448,7 +1454,8 @@ rsa_psk_key_exchange(Version, PskIdentity, PremasterSecret, PublicKeyInfo = {Alg
 rsa_psk_key_exchange(_, _, _, _) ->
     throw (?ALERT_REC(?FATAL,?HANDSHAKE_FAILURE)).
 
-request_client_cert(#state{ssl_options = #ssl_options{verify = verify_peer},
+request_client_cert(#state{ssl_options = #ssl_options{verify = verify_peer, 
+						      signature_algs = SupportedHashSigns},
 			   connection_states = ConnectionStates0,
 			   cert_db = CertDbHandle,
 			   cert_db_ref = CertDbRef,
@@ -1456,7 +1463,9 @@ request_client_cert(#state{ssl_options = #ssl_options{verify = verify_peer},
     #connection_state{security_parameters =
 			  #security_parameters{cipher_suite = CipherSuite}} =
 	ssl_record:pending_connection_state(ConnectionStates0, read),
-    Msg = ssl_handshake:certificate_request(CipherSuite, CertDbHandle, CertDbRef, Version),
+    HashSigns = ssl_handshake:available_signature_algs(SupportedHashSigns, Version, [Version]),
+    Msg = ssl_handshake:certificate_request(CipherSuite, CertDbHandle, CertDbRef, 
+					    HashSigns, Version),
     State = Connection:send_handshake(Msg, State0),
     State#state{client_certificate_requested = true};
 
@@ -1881,15 +1890,16 @@ make_premaster_secret({MajVer, MinVer}, rsa) ->
 make_premaster_secret(_, _) ->
     undefined.
 
-negotiated_hashsign(undefined, Alg, Version) ->
+negotiated_hashsign(undefined, KexAlg, PubKeyInfo, Version) ->
     %% Not negotiated choose default 
-    case is_anonymous(Alg) of
+    case is_anonymous(KexAlg) of
 	true ->
 	    {null, anon};
 	false ->
-	    ssl_handshake:select_hashsign_algs(Alg, Version)
+	    {PubAlg, _, _} = PubKeyInfo,
+	    ssl_handshake:select_hashsign_algs(undefined, PubAlg, Version)
     end;
-negotiated_hashsign(HashSign = {_, _}, _, _) ->
+negotiated_hashsign(HashSign = {_, _}, _, _, _) ->
     HashSign.
 
 ssl_options_list(SslOptions) ->
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index e98073080a..644903cf4b 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -46,7 +46,7 @@
 
 %% Handshake messages
 -export([hello_request/0, server_hello/4, server_hello_done/0,
-	 certificate/4, certificate_request/4, key_exchange/3,
+	 certificate/4, certificate_request/5, key_exchange/3,
 	 finished/5,  next_protocol/1]).
 
 %% Handle handshake messages
@@ -64,8 +64,8 @@
 	]).
 
 %% Cipher suites handling
--export([available_suites/2, cipher_suites/2,
-	 select_session/10, supported_ecc/1]).
+-export([available_suites/2, available_signature_algs/3, cipher_suites/2,
+	 select_session/11, supported_ecc/1]).
 
 %% Extensions handling
 -export([client_hello_extensions/6,
@@ -74,8 +74,8 @@
 	]).
 
 %% MISC
--export([select_version/3, prf/5, select_hashsign/3, 
-	 select_hashsign_algs/2, select_hashsign_algs/3,
+-export([select_version/3, prf/5, select_hashsign/5, 
+	 select_hashsign_algs/3,
 	 premaster_secret/2, premaster_secret/3, premaster_secret/4]).
 
 %%====================================================================
@@ -120,7 +120,8 @@ server_hello(SessionId, Version, ConnectionStates, Extensions) ->
 server_hello_done() ->
     #server_hello_done{}.
 
-client_hello_extensions(Host, Version, CipherSuites, SslOpts, ConnectionStates, Renegotiation) ->
+client_hello_extensions(Host, Version, CipherSuites, 
+			#ssl_options{signature_algs = SupportedHashSigns, versions = AllVersions} = SslOpts, ConnectionStates, Renegotiation) ->
     {EcPointFormats, EllipticCurves} =
 	case advertises_ec_ciphers(lists:map(fun ssl_cipher:suite_definition/1, CipherSuites)) of
 	    true ->
@@ -134,7 +135,7 @@ client_hello_extensions(Host, Version, CipherSuites, SslOpts, ConnectionStates,
        renegotiation_info = renegotiation_info(tls_record, client,
 					       ConnectionStates, Renegotiation),
        srp = SRP,
-       hash_signs = advertised_hash_signs(Version),
+       signature_algs = available_signature_algs(SupportedHashSigns, Version, AllVersions),
        ec_point_formats = EcPointFormats,
        elliptic_curves = EllipticCurves,
        alpn = encode_alpn(SslOpts#ssl_options.alpn_advertised_protocols, Renegotiation),
@@ -203,14 +204,14 @@ client_certificate_verify(OwnCert, MasterSecret, Version,
     end.
 
 %%--------------------------------------------------------------------
--spec certificate_request(ssl_cipher:cipher_suite(), db_handle(), certdb_ref(), ssl_record:ssl_version()) ->
-    #certificate_request{}.
+-spec certificate_request(ssl_cipher:cipher_suite(), db_handle(), 
+			  certdb_ref(),  #hash_sign_algos{}, ssl_record:ssl_version()) ->
+				 #certificate_request{}.
 %%
 %% Description: Creates a certificate_request message, called by the server.
 %%--------------------------------------------------------------------
-certificate_request(CipherSuite, CertDbHandle, CertDbRef, Version) ->
+certificate_request(CipherSuite, CertDbHandle, CertDbRef, HashSigns, Version) ->
     Types = certificate_types(ssl_cipher:suite_definition(CipherSuite), Version),
-    HashSigns = advertised_hash_signs(Version),
     Authorities = certificate_authorities(CertDbHandle, CertDbRef),
     #certificate_request{
 		    certificate_types = Types,
@@ -351,6 +352,9 @@ verify_server_key(#server_key_params{params_bin = EncParams,
 %%
 %% Description: Checks that the certificate_verify message is valid.
 %%--------------------------------------------------------------------
+certificate_verify(_, _, _, undefined, _, _) ->
+    ?ALERT_REC(?FATAL, ?HANDSHAKE_FAILURE);
+
 certificate_verify(Signature, PublicKeyInfo, Version,
 		   HashSign = {HashAlgo, _}, MasterSecret, {_, Handshake}) ->
     Hash = calc_certificate_verify(Version, HashAlgo, MasterSecret, Handshake),
@@ -379,10 +383,11 @@ verify_signature(_Version, Hash, _HashAlgo, Signature, {?rsaEncryption, PubKey,
     end;
 verify_signature(_Version, Hash, {HashAlgo, dsa}, Signature, {?'id-dsa', PublicKey, PublicKeyParams}) ->
     public_key:verify({digest, Hash}, HashAlgo, Signature, {PublicKey, PublicKeyParams});
-verify_signature(_Version, Hash, {HashAlgo, ecdsa}, Signature,
+verify_signature(_, Hash, {HashAlgo, _SignAlg}, Signature,
 		 {?'id-ecPublicKey', PublicKey, PublicKeyParams}) ->
     public_key:verify({digest, Hash}, HashAlgo, Signature, {PublicKey, PublicKeyParams}).
 
+
 %%--------------------------------------------------------------------
 -spec certify(#certificate{}, db_handle(), certdb_ref(), integer() | nolimit,
 	      verify_peer | verify_none, {fun(), term}, fun(), term(), term(),
@@ -573,43 +578,46 @@ prf({3,_N}, Secret, Label, Seed, WantedLength) ->
 
 
 %%--------------------------------------------------------------------
--spec select_hashsign(#hash_sign_algos{}| undefined,  undefined | binary(), ssl_record:ssl_version()) ->
-			      {atom(), atom()} | undefined.
+-spec select_hashsign(#hash_sign_algos{} | undefined,  undefined | binary(), 
+		      atom(), [atom()], ssl_record:ssl_version()) ->
+			     {atom(), atom()} | undefined  | #alert{}.
 
 %%
-%% Description:
+%% Description: Handles signature_algorithms extension
 %%--------------------------------------------------------------------
-select_hashsign(_, undefined, _Version) ->
+select_hashsign(_, undefined, _,  _, _Version) ->
     {null, anon};
 %% The signature_algorithms extension was introduced with TLS 1.2. Ignore it if we have
 %% negotiated a lower version.
-select_hashsign(#hash_sign_algos{hash_sign_algos = HashSigns}, Cert, {Major, Minor} = Version)
-  when Major >= 3 andalso Minor >= 3 ->
-    #'OTPCertificate'{tbsCertificate = TBSCert} =public_key:pkix_decode_cert(Cert, otp),
+select_hashsign(HashSigns, Cert, KeyExAlgo, 
+		undefined, {Major, Minor} = Version)  when Major >= 3 andalso Minor >= 3->
+    select_hashsign(HashSigns, Cert, KeyExAlgo, tls_v1:default_signature_algs(Version), Version);
+select_hashsign(#hash_sign_algos{hash_sign_algos = HashSigns}, Cert, KeyExAlgo, SupportedHashSigns,
+		{Major, Minor}) when Major >= 3 andalso Minor >= 3 ->
+    #'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
     #'OTPSubjectPublicKeyInfo'{algorithm = {_,Algo, _}} = TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
-    DefaultHashSign = {_, Sign} = select_hashsign_algs(undefined, Algo, Version),
-    case lists:filter(fun({sha, dsa}) ->
+    Sign = cert_sign(Algo),
+    case lists:filter(fun({sha, dsa = S}) when S == Sign ->
 			      true;
 			 ({_, dsa}) ->
 			      false;
-			 ({Hash, S}) when  S == Sign ->
-			      ssl_cipher:is_acceptable_hash(Hash,
-							    proplists:get_value(hashs, crypto:supports()));
+			 ({_, _} = Algos) ->
+			      is_acceptable_hash_sign(Algos, Sign, KeyExAlgo, SupportedHashSigns);
 			 (_)  ->
 			      false
 		      end, HashSigns) of
 	[] ->
-	    DefaultHashSign;
-	[HashSign| _] ->
+	    ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY);
+	[HashSign | _] ->
 	    HashSign
     end;
-select_hashsign(_, Cert, Version) ->
+select_hashsign(_, Cert, _, _, Version) ->
     #'OTPCertificate'{tbsCertificate = TBSCert} = public_key:pkix_decode_cert(Cert, otp),
     #'OTPSubjectPublicKeyInfo'{algorithm = {_,Algo, _}} = TBSCert#'OTPTBSCertificate'.subjectPublicKeyInfo,
     select_hashsign_algs(undefined, Algo, Version).
 
 %%--------------------------------------------------------------------
--spec select_hashsign_algs(#hash_sign_algos{}| undefined, oid(), ssl_record:ssl_version()) ->
+-spec select_hashsign_algs({atom(), atom()}| undefined, oid(), ssl_record:ssl_version()) ->
 				  {atom(), atom()}.
 
 %% Description: For TLS 1.2 hash function and signature algorithm pairs can be
@@ -642,24 +650,6 @@ select_hashsign_algs(undefined, ?rsaEncryption, _) ->
 select_hashsign_algs(undefined, ?'id-dsa', _) ->
     {sha, dsa}.
 
--spec select_hashsign_algs(atom(),  ssl_record:ssl_version()) -> {atom(), atom()}.
-%% Wrap function to keep the knowledge of the default values in
-%% one place only 
-select_hashsign_algs(Alg, Version) when (Alg == rsa orelse
-				    Alg == dhe_rsa orelse
-				    Alg == dh_rsa orelse
-				    Alg == ecdhe_rsa orelse
-				    Alg == ecdh_rsa orelse
-				    Alg == srp_rsa) ->    
-    select_hashsign_algs(undefined, ?rsaEncryption, Version);
-select_hashsign_algs(Alg, Version) when (Alg == dhe_dss orelse
-				    Alg == dh_dss orelse
-				    Alg == srp_dss) ->
-    select_hashsign_algs(undefined, ?'id-dsa', Version);
-select_hashsign_algs(Alg, Version) when (Alg == ecdhe_ecdsa orelse
-					 Alg == ecdh_ecdsa) ->
-    select_hashsign_algs(undefined, ?'id-ecPublicKey', Version).
-
 %%--------------------------------------------------------------------
 -spec master_secret(atom(), ssl_record:ssl_version(), #session{} | binary(), #connection_states{},
 		   client | server) -> {binary(), #connection_states{}} | #alert{}.
@@ -1063,9 +1053,56 @@ available_suites(UserSuites, Version) ->
 			    lists:member(Suite, ssl_cipher:all_suites(Version))
 		    end, UserSuites).
 
-available_suites(ServerCert, UserSuites, Version, Curve) ->
+available_suites(ServerCert, UserSuites, Version, undefined, Curve) ->
     ssl_cipher:filter(ServerCert, available_suites(UserSuites, Version))
-	-- unavailable_ecc_suites(Curve).
+	-- unavailable_ecc_suites(Curve);
+available_suites(ServerCert, UserSuites, Version, HashSigns, Curve) ->
+    Suites = available_suites(ServerCert, UserSuites, Version, undefined, Curve),
+    filter_hashsigns(Suites, [ssl_cipher:suite_definition(Suite) || Suite <- Suites], HashSigns, []).
+filter_hashsigns([], [], _, Acc) ->
+    lists:reverse(Acc);
+filter_hashsigns([Suite | Suites], [{KeyExchange,_,_,_} | Algos], HashSigns,
+		 Acc) when KeyExchange == dhe_ecdsa;
+			   KeyExchange == ecdhe_ecdsa ->
+    do_filter_hashsigns(ecdsa, Suite, Suites, Algos, HashSigns, Acc);
+
+filter_hashsigns([Suite | Suites], [{KeyExchange,_,_,_} | Algos], HashSigns,
+		 Acc) when KeyExchange == rsa;
+			   KeyExchange == dhe_rsa;
+			   KeyExchange == ecdhe_rsa;
+			   KeyExchange == srp_rsa;
+			   KeyExchange == rsa_psk ->
+    do_filter_hashsigns(rsa, Suite, Suites, Algos, HashSigns, Acc);
+filter_hashsigns([Suite | Suites], [{KeyExchange,_,_,_} | Algos], HashSigns, Acc) when 
+      KeyExchange == dhe_dss;
+      KeyExchange == srp_dss ->							       
+    do_filter_hashsigns(dsa, Suite, Suites, Algos, HashSigns, Acc);
+filter_hashsigns([Suite | Suites], [{KeyExchange,_,_,_} | Algos], HashSigns, Acc) when 
+      KeyExchange == dh_dss; 
+      KeyExchange == dh_rsa; 
+      KeyExchange == dh_ecdsa;
+      KeyExchange == ecdh_rsa;    
+      KeyExchange == ecdh_ecdsa ->
+      %%  Fixed DH certificates MAY be signed with any hash/signature
+      %%  algorithm pair appearing in the hash_sign extension.  The names
+    %%  DH_DSS, DH_RSA, ECDH_ECDSA, and ECDH_RSA are historical.
+    filter_hashsigns(Suites, Algos, HashSigns, [Suite| Acc]);
+filter_hashsigns([Suite | Suites], [{KeyExchange,_,_,_} | Algos], HashSigns, Acc) when 
+      KeyExchange == dh_anon;
+      KeyExchange == ecdh_anon;
+      KeyExchange == srp_anon;
+      KeyExchange == psk;
+      KeyExchange == dhe_psk ->
+    %% In this case hashsigns is not used as the kexchange is anonaymous
+    filter_hashsigns(Suites, Algos, HashSigns, [Suite| Acc]).
+
+do_filter_hashsigns(SignAlgo, Suite, Suites, Algos, HashSigns, Acc) ->
+    case lists:keymember(SignAlgo, 2, HashSigns) of
+	true ->
+	    filter_hashsigns(Suites, Algos, HashSigns, [Suite| Acc]);
+	false ->
+	    filter_hashsigns(Suites, Algos, HashSigns, Acc)
+    end.
 
 unavailable_ecc_suites(no_curve) ->
     ssl_cipher:ec_keyed_suites();
@@ -1077,17 +1114,17 @@ cipher_suites(Suites, false) ->
 cipher_suites(Suites, true) ->
     Suites.
 
-select_session(SuggestedSessionId, CipherSuites, Compressions, Port, #session{ecc = ECCCurve} = 
+select_session(SuggestedSessionId, CipherSuites, HashSigns, Compressions, Port, #session{ecc = ECCCurve} = 
 		   Session, Version,
-	       #ssl_options{ciphers = UserSuites, honor_cipher_order = HCO} = SslOpts,
+	       #ssl_options{ciphers = UserSuites, honor_cipher_order = HonorCipherOrder} = SslOpts,
 	       Cache, CacheCb, Cert) ->
     {SessionId, Resumed} = ssl_session:server_id(Port, SuggestedSessionId,
 						 SslOpts, Cert,
 						 Cache, CacheCb),
     case Resumed of
         undefined ->
-	    Suites = available_suites(Cert, UserSuites, Version, ECCCurve),
-	    CipherSuite = select_cipher_suite(CipherSuites, Suites, HCO),
+	    Suites = available_suites(Cert, UserSuites, Version, HashSigns, ECCCurve),
+	    CipherSuite = select_cipher_suite(CipherSuites, Suites, HonorCipherOrder),
 	    Compression = select_compression(Compressions),
 	    {new, Session#session{session_id = SessionId,
 				  cipher_suite = CipherSuite,
@@ -1155,7 +1192,7 @@ handle_client_hello_extensions(RecordCB, Random, ClientCipherSuites,
 			       #hello_extensions{renegotiation_info = Info,
 						 srp = SRP,
 						 ec_point_formats = ECCFormat,
-                         alpn = ALPN,
+						 alpn = ALPN,
 						 next_protocol_negotiation = NextProtocolNegotiation}, Version,
 			       #ssl_options{secure_renegotiate = SecureRenegotation,
                                             alpn_preferred_protocols = ALPNPreferredProtocols} = Opts,
@@ -1324,7 +1361,7 @@ handle_renegotiation_info(_RecordCB, ConnectionStates, SecureRenegotation) ->
 
 hello_extensions_list(#hello_extensions{renegotiation_info = RenegotiationInfo,
 					srp = SRP,
-					hash_signs = HashSigns,
+					signature_algs = HashSigns,
 					ec_point_formats = EcPointFormats,
 					elliptic_curves = EllipticCurves,
                                         alpn = ALPN,
@@ -1799,7 +1836,7 @@ dec_hello_extensions(<<?UINT16(?SIGNATURE_ALGORITHMS_EXT), ?UINT16(Len),
     <<?UINT16(SignAlgoListLen), SignAlgoList/binary>> = ExtData,
     HashSignAlgos = [{ssl_cipher:hash_algorithm(Hash), ssl_cipher:sign_algorithm(Sign)} ||
 			<<?BYTE(Hash), ?BYTE(Sign)>> <= SignAlgoList],
-    dec_hello_extensions(Rest, Acc#hello_extensions{hash_signs =
+    dec_hello_extensions(Rest, Acc#hello_extensions{signature_algs =
 						    #hash_sign_algos{hash_sign_algos = HashSignAlgos}});
 
 dec_hello_extensions(<<?UINT16(?ELLIPTIC_CURVES_EXT), ?UINT16(Len),
@@ -1899,7 +1936,7 @@ from_2bytes(<<?UINT16(N), Rest/binary>>, Acc) ->
 key_exchange_alg(rsa) ->
     ?KEY_EXCHANGE_RSA;
 key_exchange_alg(Alg) when Alg == dhe_rsa; Alg == dhe_dss;
-			    Alg == dh_dss; Alg == dh_rsa; Alg == dh_anon ->
+			   Alg == dh_dss; Alg == dh_rsa; Alg == dh_anon ->
     ?KEY_EXCHANGE_DIFFIE_HELLMAN;
 key_exchange_alg(Alg) when Alg == ecdhe_rsa; Alg == ecdh_rsa;
 			   Alg == ecdhe_ecdsa; Alg == ecdh_ecdsa;
@@ -2008,27 +2045,16 @@ is_member(Suite, SupportedSuites) ->
 select_compression(_CompressionMetodes) ->
     ?NULL.
 
--define(TLSEXT_SIGALG_RSA(MD), {MD, rsa}).
--define(TLSEXT_SIGALG_DSA(MD), {MD, dsa}).
--define(TLSEXT_SIGALG_ECDSA(MD), {MD, ecdsa}).
-
--define(TLSEXT_SIGALG(MD), ?TLSEXT_SIGALG_ECDSA(MD), ?TLSEXT_SIGALG_RSA(MD)).
-
-advertised_hash_signs({Major, Minor}) when Major >= 3 andalso Minor >= 3 ->
-    HashSigns = [?TLSEXT_SIGALG(sha512),
-		 ?TLSEXT_SIGALG(sha384),
-		 ?TLSEXT_SIGALG(sha256),
-		 ?TLSEXT_SIGALG(sha224),
-		 ?TLSEXT_SIGALG(sha),
-		 ?TLSEXT_SIGALG_DSA(sha),
-		 ?TLSEXT_SIGALG_RSA(md5)],
-    CryptoSupport = crypto:supports(),
-    HasECC = proplists:get_bool(ecdsa,  proplists:get_value(public_keys, CryptoSupport)),
-    Hashs = proplists:get_value(hashs, CryptoSupport),
-    #hash_sign_algos{hash_sign_algos =
-			 lists:filter(fun({Hash, ecdsa}) -> HasECC andalso proplists:get_bool(Hash, Hashs);
-					 ({Hash, _}) -> proplists:get_bool(Hash, Hashs) end, HashSigns)};
-advertised_hash_signs(_) ->
+available_signature_algs(undefined, _, _)  ->
+    undefined;
+available_signature_algs(SupportedHashSigns, {Major, Minor}, AllVersions) when Major >= 3 andalso Minor >= 3 ->
+    case tls_record:lowest_protocol_version(AllVersions) of
+	{3, 3} ->
+	    #hash_sign_algos{hash_sign_algos = SupportedHashSigns};
+	_ ->
+	    undefined
+    end;	
+available_signature_algs(_, _, _) ->
     undefined.
 
 psk_secret(PSKIdentity, PSKLookup) ->
@@ -2123,3 +2149,25 @@ distpoints_lookup([DistPoint | Rest], Callback, CRLDbHandle) ->
 	CRLs ->
 	    [{DistPoint, {CRL, public_key:der_decode('CertificateList', CRL)}} ||  CRL <- CRLs]
     end.	
+
+cert_sign(?rsaEncryption) ->
+    rsa;
+cert_sign(?'id-ecPublicKey') ->
+    ecdsa;
+cert_sign(?'id-dsa') ->
+    dsa;
+cert_sign(Alg) ->
+    {_, Sign} =public_key:pkix_sign_types(Alg),
+    Sign.
+
+is_acceptable_hash_sign({_, Sign} = Algos, Sign, _, SupportedHashSigns) ->
+    is_acceptable_hash_sign(Algos, SupportedHashSigns);
+is_acceptable_hash_sign(Algos,_, KeyExAlgo, SupportedHashSigns) when KeyExAlgo == dh_ecdsa;
+								     KeyExAlgo == ecdh_rsa;    
+								     KeyExAlgo == ecdh_ecdsa ->
+    is_acceptable_hash_sign(Algos, SupportedHashSigns); 
+is_acceptable_hash_sign(_,_,_,_) ->
+    false.
+is_acceptable_hash_sign(Algos, SupportedHashSigns) ->
+    lists:member(Algos, SupportedHashSigns).
+
diff --git a/lib/ssl/src/ssl_handshake.hrl b/lib/ssl/src/ssl_handshake.hrl
index 58b4d5a23d..b74a65939b 100644
--- a/lib/ssl/src/ssl_handshake.hrl
+++ b/lib/ssl/src/ssl_handshake.hrl
@@ -95,7 +95,7 @@
 
 -record(hello_extensions, {
 	  renegotiation_info,
-	  hash_signs,          % supported combinations of hashes/signature algos
+	  signature_algs,          % supported combinations of hashes/signature algos
           alpn,
 	  next_protocol_negotiation = undefined, % [binary()]
 	  srp,
diff --git a/lib/ssl/src/ssl_internal.hrl b/lib/ssl/src/ssl_internal.hrl
index 8c7ed9c0d1..20f0b7d0da 100644
--- a/lib/ssl/src/ssl_internal.hrl
+++ b/lib/ssl/src/ssl_internal.hrl
@@ -135,7 +135,8 @@
 	  padding_check = true       :: boolean(),
 	  fallback = false           :: boolean(),
 	  crl_check                  :: boolean() | peer | best_effort, 
-	  crl_cache
+	  crl_cache,
+	  signature_algs
 	  }).
 
 -record(socket_options,
diff --git a/lib/ssl/src/tls_connection.erl b/lib/ssl/src/tls_connection.erl
index c3f0206d25..93716d31b8 100644
--- a/lib/ssl/src/tls_connection.erl
+++ b/lib/ssl/src/tls_connection.erl
@@ -182,8 +182,7 @@ hello(start, #state{host = Host, port = Port, role = client,
     next_state(hello, hello, Record, State);
 
 hello(Hello = #client_hello{client_version = ClientVersion,
-			    extensions = #hello_extensions{hash_signs = HashSigns,
-							   ec_point_formats = EcPointFormats,
+			    extensions = #hello_extensions{ec_point_formats = EcPointFormats,
 							   elliptic_curves = EllipticCurves}},
       State = #state{connection_states = ConnectionStates0,
 		     port = Port, session = #session{own_certificate = Cert} = Session0,
@@ -191,27 +190,28 @@ hello(Hello = #client_hello{client_version = ClientVersion,
 		     session_cache = Cache,
 		     session_cache_cb = CacheCb,
 		     negotiated_protocol = CurrentProtocol,
+		     key_algorithm = KeyExAlg,
 		     ssl_options = SslOpts}) ->
+
     case tls_handshake:hello(Hello, SslOpts, {Port, Session0, Cache, CacheCb,
-					      ConnectionStates0, Cert}, Renegotiation) of
+					      ConnectionStates0, Cert, KeyExAlg}, Renegotiation) of
         #alert{} = Alert ->
             handle_own_alert(Alert, ClientVersion, hello, State);
         {Version, {Type, Session},
-	 ConnectionStates, Protocol0, ServerHelloExt} ->
-
+	 ConnectionStates, Protocol0, ServerHelloExt, HashSign} ->
 	    Protocol = case Protocol0 of
-		undefined -> CurrentProtocol;
-		_ -> Protocol0
-	    end,
-
-            HashSign = ssl_handshake:select_hashsign(HashSigns, Cert, Version),
-            ssl_connection:hello({common_client_hello, Type, ServerHelloExt, HashSign},
+			   undefined -> CurrentProtocol;
+			   _ -> Protocol0
+		       end,
+	    ssl_connection:hello({common_client_hello, Type, ServerHelloExt},
 				 State#state{connection_states  = ConnectionStates,
 					     negotiated_version = Version,
+					     hashsign_algorithm = HashSign,
 					     session = Session,
 					     client_ecc = {EllipticCurves, EcPointFormats},
 					     negotiated_protocol = Protocol}, ?MODULE)
     end;
+
 hello(Hello = #server_hello{},
       #state{connection_states = ConnectionStates0,
 	     negotiated_version = ReqVersion,
@@ -1069,3 +1069,4 @@ handle_sni_extension(#client_hello{extensions = HelloExtensions}, State0) ->
     end;
 handle_sni_extension(_, State0) ->
     State0.
+
diff --git a/lib/ssl/src/tls_handshake.erl b/lib/ssl/src/tls_handshake.erl
index 0a6cb9f92d..ef718c13df 100644
--- a/lib/ssl/src/tls_handshake.erl
+++ b/lib/ssl/src/tls_handshake.erl
@@ -56,7 +56,7 @@ client_hello(Host, Port, ConnectionStates,
     Version = tls_record:highest_protocol_version(Versions),
     Pending = ssl_record:pending_connection_state(ConnectionStates, read),
     SecParams = Pending#connection_state.security_parameters,
-    AvailableCipherSuites = ssl_handshake:available_suites(UserSuites, Version), 
+    AvailableCipherSuites = ssl_handshake:available_suites(UserSuites, Version),     
     Extensions = ssl_handshake:client_hello_extensions(Host, Version, 
 						       AvailableCipherSuites,
 						       SslOpts, ConnectionStates, Renegotiation),
@@ -80,13 +80,13 @@ client_hello(Host, Port, ConnectionStates,
 -spec hello(#server_hello{} | #client_hello{}, #ssl_options{},
 	    #connection_states{} | {inet:port_number(), #session{}, db_handle(),
 				    atom(), #connection_states{}, 
-				    binary() | undefined},
+				    binary() | undefined, ssl_cipher:key_algo()},
 	    boolean()) ->
 		   {tls_record:tls_version(), session_id(), 
 		    #connection_states{}, alpn | npn, binary() | undefined}|
 		   {tls_record:tls_version(), {resumed | new, #session{}}, 
 		    #connection_states{}, binary() | undefined, 
-		    #hello_extensions{}} |
+		    #hello_extensions{}, {ssl_cipher:hash(), ssl_cipher:sign_algo()} | undefined} |
 		   #alert{}.
 %%
 %% Description: Handles a recieved hello message
@@ -149,26 +149,35 @@ get_tls_handshake(Version, Data, Buffer) ->
 %%% Internal functions
 %%--------------------------------------------------------------------
 handle_client_hello(Version, #client_hello{session_id = SugesstedId,
-				       cipher_suites = CipherSuites,
-				       compression_methods = Compressions,
-				       random = Random,
-				       extensions = #hello_extensions{elliptic_curves = Curves} = HelloExt},
-		#ssl_options{versions = Versions} = SslOpts,
-	 {Port, Session0, Cache, CacheCb, ConnectionStates0, Cert}, Renegotiation) ->
+					   cipher_suites = CipherSuites,
+					   compression_methods = Compressions,
+					   random = Random,
+					   extensions = #hello_extensions{elliptic_curves = Curves,
+									  signature_algs = ClientHashSigns} = HelloExt},
+		    #ssl_options{versions = Versions,
+				 signature_algs = SupportedHashSigns} = SslOpts,
+		    {Port, Session0, Cache, CacheCb, ConnectionStates0, Cert, _}, Renegotiation) ->
     case tls_record:is_acceptable_version(Version, Versions) of
 	true ->
+	    AvailableHashSigns = available_signature_algs(ClientHashSigns, SupportedHashSigns, Cert, Version),
 	    ECCCurve = ssl_handshake:select_curve(Curves, ssl_handshake:supported_ecc(Version)),
 	    {Type, #session{cipher_suite = CipherSuite} = Session1}
-		= ssl_handshake:select_session(SugesstedId, CipherSuites, Compressions,
+		= ssl_handshake:select_session(SugesstedId, CipherSuites, AvailableHashSigns, Compressions,
 					       Port, Session0#session{ecc = ECCCurve}, Version,
 					       SslOpts, Cache, CacheCb, Cert),
 	    case CipherSuite of 
 		no_suite ->
 		    ?ALERT_REC(?FATAL, ?INSUFFICIENT_SECURITY);
 		_ ->
-		    handle_client_hello_extensions(Version, Type, Random, CipherSuites, HelloExt,
-						   SslOpts, Session1, ConnectionStates0,
-						   Renegotiation)
+		    {KeyExAlg,_,_,_} = ssl_cipher:suite_definition(CipherSuite),
+		    case ssl_handshake:select_hashsign(ClientHashSigns, Cert, KeyExAlg, SupportedHashSigns, Version) of
+			#alert{} = Alert ->
+			    Alert;
+			HashSign ->
+			    handle_client_hello_extensions(Version, Type, Random, CipherSuites, HelloExt,
+							   SslOpts, Session1, ConnectionStates0,
+							   Renegotiation, HashSign)
+		    end
 	    end;
 	false ->
 	    ?ALERT_REC(?FATAL, ?PROTOCOL_VERSION)
@@ -245,14 +254,14 @@ enc_handshake(HandshakeMsg, Version) ->
 
 
 handle_client_hello_extensions(Version, Type, Random, CipherSuites,
-			HelloExt, SslOpts, Session0, ConnectionStates0, Renegotiation) ->
+			HelloExt, SslOpts, Session0, ConnectionStates0, Renegotiation, HashSign) ->
     try ssl_handshake:handle_client_hello_extensions(tls_record, Random, CipherSuites,
 						     HelloExt, Version, SslOpts,
 						     Session0, ConnectionStates0, Renegotiation) of
 	#alert{} = Alert ->
 	    Alert;
 	{Session, ConnectionStates, Protocol, ServerHelloExt} ->
-	    {Version, {Type, Session}, ConnectionStates, Protocol, ServerHelloExt}
+	    {Version, {Type, Session}, ConnectionStates, Protocol, ServerHelloExt, HashSign}
     catch throw:Alert ->
 	    Alert
     end.
@@ -269,3 +278,12 @@ handle_server_hello_extensions(Version, SessionId, Random, CipherSuite,
 	    {Version, SessionId, ConnectionStates, ProtoExt, Protocol}
     end.
 
+available_signature_algs(undefined, SupportedHashSigns, _, {Major, Minor}) when (Major < 3) andalso (Minor < 3) ->
+    SupportedHashSigns;
+available_signature_algs(#hash_sign_algos{hash_sign_algos = ClientHashSigns}, SupportedHashSigns, 
+		     _, {Major, Minor}) when (Major < 3) andalso (Minor < 3) ->
+    ordsets:intersection(ClientHashSigns, SupportedHashSigns);
+available_signature_algs(_, _, _, _) -> 
+    undefined.
+
+
diff --git a/lib/ssl/src/tls_v1.erl b/lib/ssl/src/tls_v1.erl
index 71e5f349dd..543bd33833 100644
--- a/lib/ssl/src/tls_v1.erl
+++ b/lib/ssl/src/tls_v1.erl
@@ -31,7 +31,8 @@
 
 -export([master_secret/4, finished/5, certificate_verify/3, mac_hash/7,
 	 setup_keys/8, suites/1, prf/5,
-	 ecc_curves/1, oid_to_enum/1, enum_to_oid/1]).
+	 ecc_curves/1, oid_to_enum/1, enum_to_oid/1, 
+	 default_signature_algs/1, signature_algs/2]).
 
 %%====================================================================
 %% Internal application API
@@ -258,6 +259,54 @@ suites(3) ->
     ] ++ suites(2).
 
 
+
+signature_algs({3, 3}, HashSigns) ->
+    CryptoSupports =  crypto:supports(),
+    Hashes = proplists:get_value(hashs, CryptoSupports),
+    PubKeys = proplists:get_value(public_keys, CryptoSupports),
+    Supported = lists:foldl(fun({Hash, dsa = Sign} = Alg, Acc) ->
+				    case proplists:get_bool(dss, PubKeys) 
+					andalso proplists:get_bool(Hash, Hashes)
+					andalso is_pair(Hash, Sign, Hashes)
+				    of
+					true ->
+					    [Alg | Acc];
+					false ->
+					    Acc
+				    end;
+			       ({Hash, Sign} = Alg, Acc) -> 
+				    case proplists:get_bool(Sign, PubKeys) 
+					andalso proplists:get_bool(Hash, Hashes) 
+					andalso is_pair(Hash, Sign, Hashes)
+				    of
+					true ->
+					    [Alg | Acc];
+					false ->
+					    Acc
+				    end
+			    end, [], HashSigns),
+    lists:reverse(Supported).
+
+default_signature_algs({3, 3} = Version) ->
+    Default = [%% SHA2
+	       {sha512, ecdsa},
+	       {sha512, rsa},
+	       {sha384, ecdsa},
+	       {sha384, rsa},
+	       {sha256, ecdsa},
+	       {sha256, rsa},
+	       {sha224, ecdsa},
+	       {sha224, rsa},
+	       %% SHA
+	       {sha, ecdsa},
+	       {sha, rsa},
+	       {sha, dsa},
+	       %% MD5
+	       {md5, rsa}],
+    signature_algs(Version, Default);
+default_signature_algs(_) ->
+    undefined.
+
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
@@ -342,6 +391,17 @@ finished_label(client) ->
 finished_label(server) ->
     <<"server finished">>.
 
+is_pair(sha, dsa, _) ->
+    true;
+is_pair(_, dsa, _) ->
+    false;
+is_pair(Hash, ecdsa, Hashs) ->
+    AtLeastSha = Hashs -- [md2,md4,md5],
+    lists:member(Hash, AtLeastSha);
+is_pair(Hash, rsa, Hashs) ->
+    AtLeastMd5 = Hashs -- [md2,md4],
+    lists:member(Hash, AtLeastMd5).
+
 %% list ECC curves in prefered order
 ecc_curves(_Minor) ->
     TLSCurves = [sect571r1,sect571k1,secp521r1,brainpoolP512r1,