ssl: Add hostname check of server certificate

When the server_name_indication is sent automatize the
clients check of that the hostname is present in the
servers certificate. Currently server_name_indication shall
be on the dns_id format. If server_name_indication is disabled
it is up to the user to do its own check in the verify_fun.

6 files changed, 65 insertions, 51 deletions

diff --git a/lib/ssl/src/dtls_handshake.erl b/lib/ssl/src/dtls_handshake.erl
index 1ed63f8a83..37a46b862e 100644
--- a/lib/ssl/src/dtls_handshake.erl
+++ b/lib/ssl/src/dtls_handshake.erl
@@ -65,9 +65,8 @@ client_hello(Host, Port, Cookie, ConnectionStates,
     TLSVersion = dtls_v1:corresponding_tls_version(Version),
     CipherSuites = ssl_handshake:available_suites(UserSuites, TLSVersion),
 
-    Extensions = ssl_handshake:client_hello_extensions(Host, TLSVersion, CipherSuites,
+    Extensions = ssl_handshake:client_hello_extensions(TLSVersion, CipherSuites,
                                                        SslOpts, ConnectionStates, Renegotiation),
-
     Id = ssl_session:client_id({Host, Port, SslOpts}, Cache, CacheCb, OwnCert),
 
     #client_hello{session_id = Id,
diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl
index dfee4b2243..d9e47c43ad 100644
--- a/lib/ssl/src/ssl.erl
+++ b/lib/ssl/src/ssl.erl
@@ -112,7 +112,7 @@ connect(Host, Port, Options) ->
 
 connect(Host, Port, Options, Timeout) when (is_integer(Timeout) andalso Timeout >= 0) or (Timeout == infinity) ->
     try
-	{ok, Config} = handle_options(Options, client),
+	{ok, Config} = handle_options(Options, client, Host),
 	case Config#config.connection_cb of
 	    tls_connection ->
 		tls_socket:connect(Host,Port,Config,Timeout);
@@ -632,8 +632,12 @@ do_listen(Port,  #config{transport_info = {Transport, _, _, _}} = Config, dtls_c
 %% Handle extra ssl options given to ssl_accept
 -spec handle_options([any()], #ssl_options{}) -> #ssl_options{}
       ;             ([any()], client | server) -> {ok, #config{}}.
+handle_options(Opts, Role) ->
+    handle_options(Opts, Role, undefined).   
+
+
 handle_options(Opts0, #ssl_options{protocol = Protocol, cacerts = CaCerts0,
-				   cacertfile = CaCertFile0} = InheritedSslOpts) ->
+				   cacertfile = CaCertFile0} = InheritedSslOpts, _) ->
     RecordCB = record_cb(Protocol),
     CaCerts = handle_option(cacerts, Opts0, CaCerts0),
     {Verify, FailIfNoPeerCert, CaCertDefault, VerifyFun, PartialChainHanlder,
@@ -666,7 +670,7 @@ handle_options(Opts0, #ssl_options{protocol = Protocol, cacerts = CaCerts0,
     end;
 
 %% Handle all options in listen and connect
-handle_options(Opts0, Role) ->
+handle_options(Opts0, Role, Host) ->
     Opts = proplists:expand([{binary, [{mode, binary}]},
 			     {list, [{mode, list}]}], Opts0),
     assert_proplist(Opts),
@@ -738,7 +742,9 @@ handle_options(Opts0, Role) ->
 			make_next_protocol_selector(
 			  handle_option(client_preferred_next_protocols, Opts, undefined)),
 		    log_alert = handle_option(log_alert, Opts, true),
-		    server_name_indication = handle_option(server_name_indication, Opts, undefined),
+		    server_name_indication = handle_option(server_name_indication, Opts, 
+                                                           default_option_role(client,
+                                                                               server_name_indication_default(Host), Role)),
 		    sni_hosts = handle_option(sni_hosts, Opts, []),
 		    sni_fun = handle_option(sni_fun, Opts, undefined),
 		    honor_cipher_order = handle_option(honor_cipher_order, Opts, 
@@ -982,12 +988,20 @@ validate_option(next_protocols_advertised = Opt, Value) when is_list(Value) ->
 
 validate_option(next_protocols_advertised, undefined) ->
     undefined;
-validate_option(server_name_indication, Value) when is_list(Value) ->
+validate_option(server_name_indication = Opt, Value) when is_list(Value) ->
+    %% RFC 6066, Section 3: Currently, the only server names supported are
+    %% DNS hostnames
+     case inet_parse:domain(Value) of
+        false -> 
+           throw({error, {options, {{Opt, Value}}}});
+        true -> 
+            Value
+     end;
+validate_option(server_name_indication, undefined = Value) ->
     Value;
 validate_option(server_name_indication, disable) ->
-    disable;
-validate_option(server_name_indication, undefined) ->
     undefined;
+
 validate_option(sni_hosts, []) ->
     [];
 validate_option(sni_hosts, [{Hostname, SSLOptions} | Tail]) when is_list(Hostname) ->
@@ -1445,3 +1459,8 @@ include_security_info([Item | Items]) ->
         false  ->
             include_security_info(Items)
     end.
+
+server_name_indication_default(Host) when is_list(Host) ->
+    Host;
+server_name_indication_default(_) ->
+    undefined.
diff --git a/lib/ssl/src/ssl_certificate.erl b/lib/ssl/src/ssl_certificate.erl
index 2046ec75b3..0dd5e5c5cf 100644
--- a/lib/ssl/src/ssl_certificate.erl
+++ b/lib/ssl/src/ssl_certificate.erl
@@ -125,7 +125,7 @@ file_to_crls(File, DbHandle) ->
 %% Description:  Validates ssl/tls specific extensions
 %%--------------------------------------------------------------------
 validate(_,{extension, #'Extension'{extnID = ?'id-ce-extKeyUsage',
-				    extnValue = KeyUse}}, UserState = {Role, _,_, _, _}) ->
+				    extnValue = KeyUse}}, UserState = {Role, _,_, _, _, _}) ->
     case is_valid_extkey_usage(KeyUse, Role) of
 	true ->
 	    {valid, UserState};
@@ -138,8 +138,15 @@ validate(_, {bad_cert, _} = Reason, _) ->
     {fail, Reason};
 validate(_, valid, UserState) ->
     {valid, UserState};
-validate(_, valid_peer, UserState) ->
-    {valid, UserState}.
+validate(Cert, valid_peer, UserState = {client, _,_, Hostname, _, _}) when Hostname =/= undefined ->
+    case public_key:pkix_verify_hostname(Cert, [{dns_id, Hostname}]) of
+        true ->
+            {valid, UserState};
+        false ->
+            {fail, {bad_cert, hostname_check_failed}}
+    end;
+validate(_, valid_peer, UserState) ->    
+   {valid, UserState}.
 
 %%--------------------------------------------------------------------
 -spec is_valid_key_usage(list(), term()) -> boolean().
diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl
index d9707115d5..be64081599 100644
--- a/lib/ssl/src/ssl_connection.erl
+++ b/lib/ssl/src/ssl_connection.erl
@@ -501,13 +501,7 @@ certify(internal, #certificate{} = Cert,
 	       crl_db = CRLDbInfo,
 	       ssl_options = Opts} = State, Connection) ->
     case ssl_handshake:certify(Cert, CertDbHandle, CertDbRef, 
-			       Opts#ssl_options.depth,
-			       Opts#ssl_options.verify,
-			       Opts#ssl_options.verify_fun,
-			       Opts#ssl_options.partial_chain,
-			       Opts#ssl_options.crl_check,
-			       CRLDbInfo,		       
-			       Role) of
+			       Opts, CRLDbInfo, Role) of
         {PeerCert, PublicKeyInfo} ->
 	    handle_peer_cert(Role, PeerCert, PublicKeyInfo,
 			     State#state{client_certificate_requested = false}, Connection);
diff --git a/lib/ssl/src/ssl_handshake.erl b/lib/ssl/src/ssl_handshake.erl
index 2520fee238..58db8449d6 100644
--- a/lib/ssl/src/ssl_handshake.erl
+++ b/lib/ssl/src/ssl_handshake.erl
@@ -50,7 +50,7 @@
 	 finished/5,  next_protocol/1]).
 
 %% Handle handshake messages
--export([certify/10, client_certificate_verify/6, certificate_verify/6, verify_signature/5,
+-export([certify/6, client_certificate_verify/6, certificate_verify/6, verify_signature/5,
 	 master_secret/4, server_key_exchange_hash/2, verify_connection/6,
 	 init_handshake_history/0, update_handshake_history/3, verify_server_key/5
 	]).
@@ -68,7 +68,7 @@
 	 select_session/11, supported_ecc/1, available_signature_algs/4]).
 
 %% Extensions handling
--export([client_hello_extensions/6,
+-export([client_hello_extensions/5,
 	 handle_client_hello_extensions/9, %% Returns server hello extensions
 	 handle_server_hello_extensions/9, select_curve/2, select_curve/3
 	]).
@@ -119,7 +119,7 @@ server_hello(SessionId, Version, ConnectionStates, Extensions) ->
 server_hello_done() ->
     #server_hello_done{}.
 
-client_hello_extensions(Host, Version, CipherSuites, 
+client_hello_extensions(Version, CipherSuites, 
 			#ssl_options{signature_algs = SupportedHashSigns,
 				     eccs = SupportedECCs} = SslOpts, ConnectionStates, Renegotiation) ->
     {EcPointFormats, EllipticCurves} =
@@ -142,7 +142,7 @@ client_hello_extensions(Host, Version, CipherSuites,
        next_protocol_negotiation =
 	   encode_client_protocol_negotiation(SslOpts#ssl_options.next_protocol_selector,
 					      Renegotiation),
-       sni = sni(Host, SslOpts#ssl_options.server_name_indication)}.
+       sni = sni(SslOpts#ssl_options.server_name_indication)}.
 
 %%--------------------------------------------------------------------
 -spec certificate(der_cert(), db_handle(), certdb_ref(), client | server) -> #certificate{} | #alert{}.
@@ -388,24 +388,26 @@ verify_signature(_, Hash, {HashAlgo, _SignAlg}, Signature,
 
 
 %%--------------------------------------------------------------------
--spec certify(#certificate{}, db_handle(), certdb_ref(), integer() | nolimit,
-	      verify_peer | verify_none, {fun(), term}, fun(), term(), term(),
+-spec certify(#certificate{}, db_handle(), certdb_ref(), #ssl_options{}, term(),
 	      client | server) ->  {der_cert(), public_key_info()} | #alert{}.
 %%
 %% Description: Handles a certificate handshake message
 %%--------------------------------------------------------------------
 certify(#certificate{asn1_certificates = ASN1Certs}, CertDbHandle, CertDbRef,
-	MaxPathLen, _Verify, ValidationFunAndState0, PartialChain, CRLCheck, CRLDbHandle, Role) ->
+        Opts, CRLDbHandle, Role) ->    
+
     [PeerCert | _] = ASN1Certs,       
     try
 	{TrustedCert, CertPath}  =
-	    ssl_certificate:trusted_cert_and_path(ASN1Certs, CertDbHandle, CertDbRef, PartialChain),
-        ValidationFunAndState = validation_fun_and_state(ValidationFunAndState0, Role, 
+	    ssl_certificate:trusted_cert_and_path(ASN1Certs, CertDbHandle, CertDbRef,  
+                                                  Opts#ssl_options.partial_chain),
+        ValidationFunAndState = validation_fun_and_state(Opts#ssl_options.verify_fun, Role, 
                                                          CertDbHandle, CertDbRef,  
-                                                         CRLCheck, CRLDbHandle, CertPath),
+                                                         Opts#ssl_options.server_name_indication,
+                                                         Opts#ssl_options.crl_check, CRLDbHandle, CertPath),
 	case public_key:pkix_path_validation(TrustedCert,
 					     CertPath,
-					     [{max_path_length, MaxPathLen},
+					     [{max_path_length,  Opts#ssl_options.depth},
 					      {verify_fun, ValidationFunAndState}]) of
 	    {ok, {PublicKeyInfo,_}} ->
 		{PeerCert, PublicKeyInfo};
@@ -1522,25 +1524,16 @@ select_shared_curve([Curve | Rest], Curves) ->
 	    select_shared_curve(Rest, Curves)
     end.
 
-%% RFC 6066, Section 3: Currently, the only server names supported are
-%% DNS hostnames
-sni(_, disable) ->
+sni(undefined) ->
     undefined;
-sni(Host, undefined) ->
-    sni1(Host);
-sni(_Host, SNIOption) ->
-    sni1(SNIOption).
-
-sni1(Hostname) ->
-    case inet_parse:domain(Hostname) of
-        false -> undefined;
-        true -> #sni{hostname = Hostname}
-    end.
+sni(Hostname) ->
+    #sni{hostname = Hostname}.
+
 %%--------------------------------------------------------------------
 %%% Internal functions
 %%--------------------------------------------------------------------
 validation_fun_and_state({Fun, UserState0}, Role,  CertDbHandle, CertDbRef, 
-                         CRLCheck, CRLDbHandle, CertPath) ->
+                         ServerNameIndication, CRLCheck, CRLDbHandle, CertPath) ->
     {fun(OtpCert, {extension, _} = Extension, {SslState, UserState}) ->
 	     case ssl_certificate:validate(OtpCert,
 					   Extension,
@@ -1557,9 +1550,9 @@ validation_fun_and_state({Fun, UserState0}, Role,  CertDbHandle, CertDbRef,
 	(OtpCert, VerifyResult, {SslState, UserState}) ->
 	     apply_user_fun(Fun, OtpCert, VerifyResult, UserState,
 			    SslState, CertPath)
-     end, {{Role, CertDbHandle, CertDbRef, CRLCheck, CRLDbHandle}, UserState0}};
+     end, {{Role, CertDbHandle, CertDbRef, ServerNameIndication, CRLCheck, CRLDbHandle}, UserState0}};
 validation_fun_and_state(undefined, Role, CertDbHandle, CertDbRef, 
-                         CRLCheck, CRLDbHandle, CertPath) ->
+                         ServerNameIndication, CRLCheck, CRLDbHandle, CertPath) ->
     {fun(OtpCert, {extension, _} = Extension, SslState) ->
 	     ssl_certificate:validate(OtpCert,
 				      Extension,
@@ -1568,8 +1561,10 @@ validation_fun_and_state(undefined, Role, CertDbHandle, CertDbRef,
                                                (VerifyResult == valid_peer) -> 
 	     case crl_check(OtpCert, CRLCheck, CertDbHandle, CertDbRef, 
                             CRLDbHandle, VerifyResult, CertPath) of
-		 valid ->
-		     {VerifyResult, SslState};
+		 valid ->                     
+                     ssl_certificate:validate(OtpCert,
+                                              VerifyResult,
+                                              SslState);
 		 Reason ->
 		     {fail, Reason}
 	     end;
@@ -1577,10 +1572,10 @@ validation_fun_and_state(undefined, Role, CertDbHandle, CertDbRef,
 	     ssl_certificate:validate(OtpCert,
 				      VerifyResult,
 				      SslState)
-     end, {Role, CertDbHandle, CertDbRef, CRLCheck, CRLDbHandle}}.
+     end, {Role, CertDbHandle, CertDbRef, ServerNameIndication, CRLCheck, CRLDbHandle}}.
 
 apply_user_fun(Fun, OtpCert, VerifyResult, UserState0, 
-	       {_, CertDbHandle, CertDbRef, CRLCheck, CRLDbHandle} = SslState, CertPath) when
+	       {_, CertDbHandle, CertDbRef, _, CRLCheck, CRLDbHandle} = SslState, CertPath) when
       (VerifyResult == valid) or (VerifyResult == valid_peer) ->
     case Fun(OtpCert, VerifyResult, UserState0) of
 	{Valid, UserState} when (Valid == valid) or (Valid == valid_peer) ->
diff --git a/lib/ssl/src/tls_handshake.erl b/lib/ssl/src/tls_handshake.erl
index 9da7b43be3..b54540393a 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),
     #{security_parameters := SecParams} = ssl_record:pending_connection_state(ConnectionStates, read),
     AvailableCipherSuites = ssl_handshake:available_suites(UserSuites, Version),     
-    Extensions = ssl_handshake:client_hello_extensions(Host, Version, 
+    Extensions = ssl_handshake:client_hello_extensions(Version, 
 						       AvailableCipherSuites,
 						       SslOpts, ConnectionStates, Renegotiation),
     CipherSuites =