ssh: Repair/add experimental diffie-hellman-group-exchange-sha1 support

DO NOT USE IN PRODUCTION!!!

This is a bug fixing of the previously partly impelmented kex algorithm.
There are more things to do, for example genrate/select better g,p pair obeying the min||n||max request.
It is not enabled by default, but may be enabled with the option
  {preferred_algorithms, [{kex, ['diffie-hellman-group-exchange-sha1']}]}

2 files changed, 93 insertions, 19 deletions

diff --git a/lib/ssh/test/ssh_basic_SUITE.erl b/lib/ssh/test/ssh_basic_SUITE.erl
index bf9fe54c57..c71463db30 100644
--- a/lib/ssh/test/ssh_basic_SUITE.erl
+++ b/lib/ssh/test/ssh_basic_SUITE.erl
@@ -42,6 +42,7 @@ suite() ->
 all() -> 
     [app_test,
      appup_test,
+     {group, 'diffie-hellman-group-exchange-sha1'},
      {group, dsa_key},
      {group, rsa_key},
      {group, dsa_pass_key},
@@ -92,6 +93,8 @@ groups() ->
 			    max_sessions_sftp_start_channel_parallel,
 			    max_sessions_sftp_start_channel_sequential
 			   ]},
+     {'diffie-hellman-group-exchange-sha1', [], ['diffie-hellman-group-exchange-sha1'
+						]},
      {dir_options, [], [user_dir_option,
 			system_dir_option]}
     ].
@@ -146,6 +149,17 @@ init_per_group(internal_error, Config) ->
     ssh_test_lib:setup_dsa(DataDir, PrivDir),
     file:delete(filename:join(PrivDir, "system/ssh_host_dsa_key")),
     Config;
+init_per_group('diffie-hellman-group-exchange-sha1', Config) ->
+    case lists:member('diffie-hellman-group-exchange-sha1',
+		      ssh_transport:supported_algorithms(kex)) of
+	true ->
+	    DataDir = ?config(data_dir, Config),
+	    PrivDir = ?config(priv_dir, Config),
+	    ssh_test_lib:setup_rsa(DataDir, PrivDir),
+	    Config;
+	false ->
+	    {skip,"diffie-hellman-group-exchange-sha1 is not supported"}
+    end;
 init_per_group(dir_options, Config) ->
     PrivDir = ?config(priv_dir, Config),
     %% Make unreadable dir:
@@ -818,6 +832,43 @@ ssh_msg_debug_fun_option_client(Config) ->
     end.
 
 %%--------------------------------------------------------------------
+'diffie-hellman-group-exchange-sha1'(Config) ->
+    process_flag(trap_exit, true),
+    SystemDir = filename:join(?config(priv_dir, Config), system),
+    UserDir = ?config(priv_dir, Config), 
+
+    {Pid, Host, Port} = ssh_test_lib:daemon([{system_dir, SystemDir},
+					     {user_dir, UserDir},
+					     {user_passwords, [{"foo", "bar"}]},
+					     {preferred_algorithms,
+					      [{kex, ['diffie-hellman-group-exchange-sha1']}]},
+					     {failfun, fun ssh_test_lib:failfun/2}]),
+    
+    ConnectionRef =
+	ssh_test_lib:connect(Host, Port, [{silently_accept_hosts, true},
+					  {user, "foo"},
+					  {password, "bar"},
+					  {user_dir, UserDir},
+					  {preferred_algorithms,
+					   [{kex, ['diffie-hellman-group-exchange-sha1']}]},
+					  {user_interaction, false}]),
+    check(ConnectionRef, Pid).
+
+check(ConnectionRef, Pid) ->
+    {ok, ChannelId} = ssh_connection:session_channel(ConnectionRef, infinity),
+    success = ssh_connection:exec(ConnectionRef, ChannelId,
+				  "1+1.", infinity),
+    Data = {ssh_cm, ConnectionRef, {data, ChannelId, 0, <<"2\n">>}},
+    case ssh_test_lib:receive_exec_result(Data) of
+	expected ->
+	    ok;
+	Other ->
+	    ct:fail(Other)
+    end,
+    ssh_test_lib:receive_exec_end(ConnectionRef, ChannelId),
+    ssh:stop_daemon(Pid).
+
+%%--------------------------------------------------------------------
 connectfun_disconnectfun_server(Config) ->
     PrivDir = ?config(priv_dir, Config),
     UserDir = filename:join(PrivDir, nopubkey), % to make sure we don't use public-key-auth
diff --git a/lib/ssh/test/ssh_sftp_SUITE.erl b/lib/ssh/test/ssh_sftp_SUITE.erl
index 6c631e6f6e..86ab503c20 100644
--- a/lib/ssh/test/ssh_sftp_SUITE.erl
+++ b/lib/ssh/test/ssh_sftp_SUITE.erl
@@ -64,12 +64,16 @@ end_per_suite(Config) ->
 groups() -> 
     [{not_unicode, [], [{group,erlang_server},
 			{group,openssh_server},
+			{group,'diffie-hellman-group-exchange-sha1'},
 			sftp_nonexistent_subsystem]},
 
      {unicode, [], [{group,erlang_server},
 		    {group,openssh_server},
 		    sftp_nonexistent_subsystem]},
      
+     {'diffie-hellman-group-exchange-sha1', [], [{group,erlang_server},
+						 {group,openssh_server}]},
+
      {erlang_server, [], [{group,write_read_tests},
 			  version_option,
 			  {group,remote_tar}]},
@@ -142,22 +146,26 @@ init_per_group(erlang_server, Config) ->
     User = ?config(user, Config),
     Passwd = ?config(passwd, Config),
     Sftpd = {_, HostX, PortX} =
-	ssh_test_lib:daemon([{system_dir, SysDir},
-			     {user_dir, PrivDir},
-			     {user_passwords,
-			      [{User, Passwd}]}]),
+	ssh_test_lib:daemon(extra_opts(Config) ++
+				[{system_dir, SysDir},
+				 {user_dir, PrivDir},
+				 {user_passwords,
+				  [{User, Passwd}]}]),
     [{peer, {fmt_host(HostX),PortX}}, {group, erlang_server}, {sftpd, Sftpd} | Config];
 
 init_per_group(openssh_server, Config) ->
     ct:comment("Begin ~p",[grps(Config)]),
     Host = ssh_test_lib:hostname(),
-    case (catch ssh_sftp:start_channel(Host,					      
-				       [{user_interaction, false},
-					{silently_accept_hosts, true}])) of
+    case (catch ssh_sftp:start_channel(Host,
+				       extra_opts(Config) ++
+					   [{user_interaction, false},
+					    {silently_accept_hosts, true}])) of
 	{ok, _ChannelPid, Connection} ->
 	    [{peer, {_HostName,{IPx,Portx}}}] = ssh:connection_info(Connection,[peer]),
 	    ssh:close(Connection),
 	    [{peer, {fmt_host(IPx),Portx}}, {group, openssh_server} | Config];
+	{error,"Key exchange failed"} ->
+	    {skip, "openssh server lacks 'diffie-hellman-group-exchange-sha1'"};
 	_ ->
 	    {skip, "No openssh server"} 
     end;
@@ -172,10 +180,11 @@ init_per_group(remote_tar, Config) ->
 	case ?config(group, Config) of
 	    erlang_server ->
 		ssh:connect(Host, Port,
-			    [{user, User},
-			     {password, Passwd},
-			     {user_interaction, false},
-			     {silently_accept_hosts, true}]);
+			    extra_opts(Config) ++
+				[{user, User},
+				 {password, Passwd},
+				 {user_interaction, false},
+				 {silently_accept_hosts, true}]);
 	    openssh_server ->
 		ssh:connect(Host, Port,
 			    [{user_interaction, false},
@@ -184,6 +193,17 @@ init_per_group(remote_tar, Config) ->
     [{remote_tar, true}, 
      {connection, Connection} | Config];
 
+init_per_group('diffie-hellman-group-exchange-sha1', Config) ->
+    case lists:member('diffie-hellman-group-exchange-sha1',
+		      ssh_transport:supported_algorithms(kex)) of
+	true ->
+	    [{extra_opts, [{preferred_algorithms, [{kex,['diffie-hellman-group-exchange-sha1']}]}]}
+	     | Config]; 
+
+	false ->
+	     {skip,"'diffie-hellman-group-exchange-sha1' not supported by this version of erlang ssh"}
+    end;
+
 init_per_group(write_read_tests, Config) ->
     ct:comment("Begin ~p",[grps(Config)]),
     Config.
@@ -194,7 +214,6 @@ grps(Config) ->
       lists:flatten([proplists:get_value(tc_group_properties,Config,[]),
 		     proplists:get_value(tc_group_path,Config,[])])).
 
-
 end_per_group(erlang_server, Config) ->
     ct:comment("End ~p",[grps(Config)]),
     Config;
@@ -249,10 +268,12 @@ init_per_testcase(Case, Config0) ->
 		{_,Host, Port} =  ?config(sftpd, Config2),
 		{ok, ChannelPid, Connection}  = 
 		    ssh_sftp:start_channel(Host, Port,
-					   [{user, User},
-					    {password, Passwd},
-					    {user_interaction, false},
-					    {silently_accept_hosts, true}]),
+					   extra_opts(Config2) ++
+					       [{user, User},
+						{password, Passwd},
+						{user_interaction, false},
+						{silently_accept_hosts, true}]
+					  ),
 		Sftp = {ChannelPid, Connection},
 		[{sftp, Sftp}, {watchdog, Dog} | Config2];
 	    openssh_server when Case == links ->
@@ -261,8 +282,9 @@ init_per_testcase(Case, Config0) ->
 		Host = ssh_test_lib:hostname(),
 		{ok, ChannelPid, Connection} = 
 		    ssh_sftp:start_channel(Host, 
-					   [{user_interaction, false},
-					    {silently_accept_hosts, true}]), 
+					    extra_opts(Config2) ++
+					       [{user_interaction, false},
+						{silently_accept_hosts, true}]), 
 		Sftp = {ChannelPid, Connection},
 		[{sftp, Sftp}, {watchdog, Dog} | Config2]
 	end,
@@ -910,7 +932,8 @@ prep(Config) ->
     ok = file:write_file_info(TestFile,
 			      FileInfo#file_info{mode = Mode}).
 
-
+extra_opts(Config) ->
+    proplists:get_value(extra_opts, Config, []).
 
 chk_tar(Items, Config) ->
     chk_tar(Items, Config, []).