ssh: option dh_gex_groups with tag ssh_moduli_file

Makes this existing option also accept a file in openssh format
OTP-13052

4 files changed, 100 insertions, 23 deletions

diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml
index 66f872490c..1e4dd91eb6 100644
--- a/lib/ssh/doc/src/ssh.xml
+++ b/lib/ssh/doc/src/ssh.xml
@@ -462,7 +462,7 @@ kex is implicit but public_key is set explicitly.</p>
 	</warning>
 	  </item>
 
-	  <tag><c><![CDATA[{dh_gex_groups, [{Size=integer(),G=integer(),P=integer()}] | {file,filename()} }]]></c></tag>
+	  <tag><c><![CDATA[{dh_gex_groups, [{Size=integer(),G=integer(),P=integer()}] | {file,filename()} {ssh_moduli_file,filename()} }]]></c></tag>
 	  <item>
 	    <p>Sets the groups that the server may choose among when diffie-hellman-group-exchange is negotiated.
 	    See RFC 4419 for details.
@@ -471,6 +471,8 @@ kex is implicit but public_key is set explicitly.</p>
 	    </p>
 	    <p>If the parameter is <c>{file,filename()}</c>, the file must exist and have one or more three-tuples terminated by a dot. The interpretation is as if the tuples had been given directly in the option.  The file is read when the daemon starts.
 	    </p>
+	    <p>If the parameter is <c>{ssh_moduli_file,filename()}</c>, the file must exist and be in ssh-keygen moduli file format.  The file is read when the daemon starts.
+	    </p>
 	  </item>
 
 	  <tag><c><![CDATA[{pwdfun, fun(User::string(), password::string()) -> boolean()}]]></c></tag>
diff --git a/lib/ssh/src/ssh.erl b/lib/ssh/src/ssh.erl
index 8d36c847de..9befceb51b 100644
--- a/lib/ssh/src/ssh.erl
+++ b/lib/ssh/src/ssh.erl
@@ -421,28 +421,59 @@ handle_ssh_option({user_interaction, Value} = Opt) when is_boolean(Value) ->
     Opt;
 handle_ssh_option({preferred_algorithms,[_|_]} = Opt) -> 
     handle_pref_algs(Opt);
-handle_ssh_option({dh_gex_groups,L=[{I1,I2,I3}|_]}) when is_integer(I1), I1>0, 
-							 is_integer(I2), I2>0,
-							 is_integer(I3), I3>0 ->
-    {dh_gex_groups, public_key:moduli_collect_per_size(
-		      lists:map(fun({N,G,P}) when is_integer(N),N>0,
-						  is_integer(G),G>0,
-						  is_integer(P),P>0 -> {N,{G,P}} end, L)
-		     )};
-handle_ssh_option({dh_gex_groups,{file,File=[C|_]}}=Opt) when is_integer(C), C>0 ->
-    %% A string, (file name)
-    case file:consult(File) of
-	{ok, List} ->
-	    try handle_ssh_option({dh_gex_groups,List}) of
-		{dh_gex_groups,_} = NewOpt ->
-		    NewOpt
-	    catch
-		_:_ ->
-		    throw({error, {{eoptions, Opt}, "Bad format in file"}})
-	    end;
-	Error ->
-	    throw({error, {{eoptions, Opt},{"Error reading file",Error}}})
-    end;
+
+handle_ssh_option({dh_gex_groups,L0}) when is_list(L0) ->
+    {dh_gex_groups,
+     collect_per_size(
+       lists:foldl(
+	 fun({N,G,P}, Acc) when is_integer(N),N>0,
+				is_integer(G),G>0,
+				is_integer(P),P>0 -> 
+		 [{N,{G,P}} | Acc];
+	    ({N,{G,P}}, Acc) when is_integer(N),N>0,
+				  is_integer(G),G>0,
+				  is_integer(P),P>0 ->
+		 [{N,{G,P}} | Acc];
+	    ({N,GPs}, Acc) when is_list(GPs) ->
+		 lists:foldr(fun({Gi,Pi}, Acci) when is_integer(Gi),Gi>0,
+						     is_integer(Pi),Pi>0 -> 
+				     [{N,{Gi,Pi}} | Acci]
+			     end, Acc, GPs)
+	 end, [], L0))};
+
+handle_ssh_option({dh_gex_groups,{Tag,File=[C|_]}}=Opt) when is_integer(C), C>0,
+							      Tag == file ;
+							      Tag == ssh_moduli_file ->
+    {ok,GroupDefs} =
+	case Tag of
+	    file -> 
+		file:consult(File);
+	    ssh_moduli_file ->
+		case file:open(File,[read]) of
+		    {ok,D} ->
+			try
+			    {ok,Moduli} = read_moduli_file(D, 1, []),
+			    file:close(D),
+			    {ok, Moduli}
+			catch
+			    _:_ ->
+				throw({error, {{eoptions, Opt}, "Bad format in file "++File}})
+			end;
+		    {error,enoent} ->
+			throw({error, {{eoptions, Opt}, "File not found:"++File}});
+		    {error,Error} ->
+			throw({error, {{eoptions, Opt}, io_lib:format("Error reading file ~s: ~p",[File,Error])}})
+		end
+	end,
+
+    try
+	handle_ssh_option({dh_gex_groups,GroupDefs})
+    catch
+	_:_ ->
+	    throw({error, {{eoptions, Opt}, "Bad format in file: "++File}})
+    end;	    
+    
+
 handle_ssh_option({dh_gex_limits,{Min,I,Max}} = Opt) when is_integer(Min), Min>0, 
 							  is_integer(I),   I>=Min,
 							  is_integer(Max), Max>=I ->
@@ -665,3 +696,33 @@ directory_exist_readable(Dir) ->
 		
 		    
 
+collect_per_size(L) ->
+    lists:foldr(
+      fun({Sz,GP}, [{Sz,GPs}|Acc]) -> [{Sz,[GP|GPs]}|Acc];
+	 ({Sz,GP}, Acc) -> [{Sz,[GP]}|Acc]
+      end, [], lists:sort(L)).
+
+read_moduli_file(D, I, Acc) ->
+    case io:get_line(D,"") of
+	{error,Error} ->
+	    {error,Error};
+	eof ->
+	    {ok, Acc};
+	"#" ++ _ -> read_moduli_file(D, I+1, Acc);
+	<<"#",_/binary>> ->  read_moduli_file(D, I+1, Acc);
+	Data ->
+	    Line = if is_binary(Data) -> binary_to_list(Data);
+		      is_list(Data) -> Data
+		   end,
+	    try
+		[_Time,_Type,_Tests,_Tries,Size,G,P] = string:tokens(Line," \r\n"),
+		M = {list_to_integer(Size),
+		     {list_to_integer(G), list_to_integer(P,16)}
+		    },
+		read_moduli_file(D, I+1, [M|Acc])
+	    catch
+		_:_ ->
+		    read_moduli_file(D, I+1, Acc)
+	    end
+    end.
+			   
diff --git a/lib/ssh/test/ssh_protocol_SUITE.erl b/lib/ssh/test/ssh_protocol_SUITE.erl
index 9d54f14ff6..0292c8d149 100644
--- a/lib/ssh/test/ssh_protocol_SUITE.erl
+++ b/lib/ssh/test/ssh_protocol_SUITE.erl
@@ -67,6 +67,7 @@ groups() ->
      {kex, [], [no_common_alg_server_disconnects,
 		no_common_alg_client_disconnects,
 		gex_client_init_option_groups,
+		gex_client_init_option_groups_moduli_file,
 		gex_client_init_option_groups_file
 		]},
      {service_requests, [], [bad_service_name,
@@ -90,6 +91,7 @@ init_per_testcase(no_common_alg_server_disconnects, Config) ->
     start_std_daemon(Config, [{preferred_algorithms,[{public_key,['ssh-rsa']}]}]);
 
 init_per_testcase(TC, Config) when TC == gex_client_init_option_groups ;
+				   TC == gex_client_init_option_groups_moduli_file ;
 				   TC == gex_client_init_option_groups_file ->
     Opts = case TC of
 	       gex_client_init_option_groups ->
@@ -98,6 +100,10 @@ init_per_testcase(TC, Config) when TC == gex_client_init_option_groups ;
 		   DataDir = ?config(data_dir, Config),
 		   F = filename:join(DataDir, "dh_group_test"),
 		   [{dh_gex_groups, {file,F}}];
+	       gex_client_init_option_groups_moduli_file ->
+		   DataDir = ?config(data_dir, Config),
+		   F = filename:join(DataDir, "dh_group_test.moduli"),
+		   [{dh_gex_groups, {ssh_moduli_file,F}}];
 	       _ ->
 		   []
 	   end,
@@ -110,6 +116,7 @@ init_per_testcase(_TestCase, Config) ->
 end_per_testcase(no_common_alg_server_disconnects, Config) ->
     stop_std_daemon(Config);
 end_per_testcase(TC, Config) when TC == gex_client_init_option_groups ;
+				  TC == gex_client_init_option_groups_moduli_file ;
 				  TC == gex_client_init_option_groups_file ->
     stop_std_daemon(Config);
 end_per_testcase(_TestCase, Config) ->
@@ -335,6 +342,10 @@ gex_client_init_option_groups_file(Config) ->
     do_gex_client_init(Config, {2000, 2048, 4000},
 		       {5,61}).
 
+gex_client_init_option_groups_moduli_file(Config) ->
+    do_gex_client_init(Config, {2000, 2048, 4000},
+		       {5,16#B7}).
+
 do_gex_client_init(Config, {Min,N,Max}, {G,P}) ->
     {ok,_} =
 	ssh_trpt_test_lib:exec(
diff --git a/lib/ssh/test/ssh_protocol_SUITE_data/dh_group_test.moduli b/lib/ssh/test/ssh_protocol_SUITE_data/dh_group_test.moduli
new file mode 100644
index 0000000000..f6995ba4c9
--- /dev/null
+++ b/lib/ssh/test/ssh_protocol_SUITE_data/dh_group_test.moduli
@@ -0,0 +1,3 @@
+20151021104105 2 6 100 2222 5 B7
+20151021104106 2 6 100 1111 5 4F
+