Merge branch 'hans/ssh/rsa-sha2-star_hostkey'

4 files changed, 26 insertions, 32 deletions

diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 6a6b9896cb..a77cfe51b5 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -1712,7 +1712,12 @@ ext_info({"server-sig-algs",SigAlgs}, D0 = #data{ssh_params=#ssh{role=client,
                     ],
     CommonAlgs = [Alg || Alg <- ServerSigAlgs,
                          lists:member(Alg, ClientSigAlgs)],
-    D0#data{ssh_params = Ssh0#ssh{userauth_pubkeys = CommonAlgs} };
+    SelectedAlgs =
+        case CommonAlgs of
+            [] -> ClientSigAlgs; % server-sig-algs value is just an advice
+            _ -> CommonAlgs
+        end,
+    D0#data{ssh_params = Ssh0#ssh{userauth_pubkeys = SelectedAlgs} };
 
 ext_info(_, D0) ->
     %% Not implemented
diff --git a/lib/ssh/src/ssh_message.erl b/lib/ssh/src/ssh_message.erl
index 609040826f..4f2eeca026 100644
--- a/lib/ssh/src/ssh_message.erl
+++ b/lib/ssh/src/ssh_message.erl
@@ -598,8 +598,8 @@ decode_kex_init(<<?DEC_BIN(Data,__0), Rest/binary>>, Acc, N) ->
 %%% Signature decode/encode
 %%%
 
-decode_signature(<<?DEC_BIN(_Alg,__0), ?UINT32(_), Signature/binary>>) ->
-    Signature.
+decode_signature(<<?DEC_BIN(Alg,__0), ?UINT32(_), Signature/binary>>) ->
+    {binary_to_list(Alg), Signature}.
 
 
 encode_signature({#'RSAPublicKey'{},Sign}, Signature) ->
diff --git a/lib/ssh/src/ssh_options.erl b/lib/ssh/src/ssh_options.erl
index 12c0190082..aebb5a7062 100644
--- a/lib/ssh/src/ssh_options.erl
+++ b/lib/ssh/src/ssh_options.erl
@@ -392,12 +392,6 @@ default(server) ->
             class => user_options
            },
 
-      {preferred_algorithms, def} =>
-          #{default => ssh:default_algorithms(),
-            chk => fun check_preferred_algorithms/1,
-            class => user_options
-           },
-
 %%%%% Undocumented
       {infofun, def} =>
           #{default => fun(_,_,_) -> void end,
@@ -436,26 +430,11 @@ default(client) ->
            },
 
       {pref_public_key_algs, def} =>
-          #{default => ssh_transport:default_algorithms(public_key) -- ['rsa-sha2-256',
-                                                                        'rsa-sha2-512'],
+          #{default => ssh_transport:default_algorithms(public_key),
             chk => fun check_pref_public_key_algs/1,
             class => user_options
            },
 
-      {preferred_algorithms, def} =>
-          #{default => [{K,Vs} || {K,Vs0} <- ssh:default_algorithms(),
-                                  Vs <- [case K of
-                                             public_key -> 
-                                                 Vs0 -- ['rsa-sha2-256',
-                                                         'rsa-sha2-512'];
-                                             _ ->
-                                                 Vs0
-                                         end]
-                       ],
-            chk => fun check_preferred_algorithms/1,
-            class => user_options
-           },
-
       {dh_gex_limits, def} =>
           #{default => {1024, 6144, 8192},      % FIXME: Is this true nowadays?
             chk => fun({Min,I,Max}) ->
@@ -521,6 +500,12 @@ default(common) ->
              class => user_options
             },
 
+       {preferred_algorithms, def} =>
+           #{default => ssh:default_algorithms(),
+             chk => fun check_preferred_algorithms/1,
+             class => user_options
+            },
+
        {id_string, def} => 
            #{default => undefined, % FIXME: see ssh_transport:ssh_vsn/0
              chk => fun(random) -> 
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 1a15798080..412f5de9de 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -776,16 +776,20 @@ extract_public_key(#'ECPrivateKey'{parameters = {namedCurve,OID},
     {#'ECPoint'{point=Q}, {namedCurve,OID}}.
 
 
-verify_host_key(#ssh{algorithms=Alg}=SSH, PublicKey, Digest, Signature) ->
-    case verify(Digest, sha(Alg#alg.hkey), Signature, PublicKey) of
-	false ->
-	    {error, bad_signature};
-	true ->
-	    known_host_key(SSH, PublicKey, public_algo(PublicKey))
+verify_host_key(#ssh{algorithms=Alg}=SSH, PublicKey, Digest, {AlgStr,Signature}) ->
+    case atom_to_list(Alg#alg.hkey) of
+        AlgStr ->
+            case verify(Digest, sha(Alg#alg.hkey), Signature, PublicKey) of
+                false ->
+                    {error, bad_signature};
+                true ->
+                    known_host_key(SSH, PublicKey, public_algo(PublicKey))
+            end;
+        _ ->
+            {error, bad_signature_name}
     end.
 
 
-
 accepted_host(Ssh, PeerName, Public, Opts) ->
     case ?GET_OPT(silently_accept_hosts, Opts) of