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-rw-r--r--lib/ssh/doc/src/ssh.xml5
-rw-r--r--lib/ssh/src/ssh.erl22
-rw-r--r--lib/ssh/src/ssh_auth.erl49
-rw-r--r--lib/ssh/src/ssh_connection_handler.erl28
4 files changed, 91 insertions, 13 deletions
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml
index b84b3a3dcb..4ab25a8f9b 100644
--- a/lib/ssh/doc/src/ssh.xml
+++ b/lib/ssh/doc/src/ssh.xml
@@ -142,6 +142,11 @@
some reason, the other algorithm is tried. The default is
to try <c><![CDATA[ssh_rsa]]></c> first.</p>
</item>
+ <tag><c><![CDATA[{pref_public_key_algs, list()}]]></c></tag>
+ <item>
+ <p>List of public key algorithms to try to use, ssh_rsa and ssh_dsa available.
+ Will override <c><![CDATA[{public_key_alg, ssh_rsa | ssh_dsa}]]></c></p>
+ </item>
<tag><c><![CDATA[{connect_timeout, timeout()}]]></c></tag>
<item>
<p>Sets a timeout on the transport layer connection. Defaults to infinity.</p>
diff --git a/lib/ssh/src/ssh.erl b/lib/ssh/src/ssh.erl
index 3395f73884..66d1d024ed 100644
--- a/lib/ssh/src/ssh.erl
+++ b/lib/ssh/src/ssh.erl
@@ -342,6 +342,8 @@ handle_option([{exec, _} = Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
handle_option([{auth_methods, _} = Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
+handle_option([{pref_public_key_algs, _} = Opt | Rest], SocketOptions, SshOptions) ->
+ handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
handle_option([Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, [handle_inet_option(Opt) | SocketOptions], SshOptions).
@@ -357,6 +359,13 @@ handle_ssh_option({user_interaction, Value} = Opt) when Value == true; Value ==
Opt;
handle_ssh_option({public_key_alg, Value} = Opt) when Value == ssh_rsa; Value == ssh_dsa ->
Opt;
+handle_ssh_option({pref_public_key_algs, Value} = Opt) when is_list(Value), length(Value) >= 1 ->
+ case check_pref_algs(Value) of
+ true ->
+ Opt;
+ _ ->
+ throw({error, {eoptions, Opt}})
+ end;
handle_ssh_option({connect_timeout, Value} = Opt) when is_integer(Value); Value == infinity ->
Opt;
handle_ssh_option({user, Value} = Opt) when is_list(Value) ->
@@ -424,7 +433,18 @@ handle_inet_option({reuseaddr, _} = Opt) ->
%% Option verified by inet
handle_inet_option(Opt) ->
Opt.
-
+%% Check preferred algs
+check_pref_algs([]) ->
+ true;
+check_pref_algs([H|T]) ->
+ case H of
+ ssh_dsa ->
+ check_pref_algs(T);
+ ssh_rsa ->
+ check_pref_algs(T);
+ _ ->
+ false
+ end.
%% Has IPv6 been disabled?
inetopt(true) ->
inet;
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl
index aa452a8e09..27e44df554 100644
--- a/lib/ssh/src/ssh_auth.erl
+++ b/lib/ssh/src/ssh_auth.erl
@@ -118,15 +118,37 @@ init_userauth_request_msg(#ssh{opts = Opts} = Ssh) ->
service = "ssh-connection",
method = "none",
data = <<>>},
- FirstAlg = algorithm(proplists:get_value(public_key_alg, Opts,
- ?PREFERRED_PK_ALG)),
- SecondAlg = other_alg(FirstAlg),
- AllowUserInt = proplists:get_value(user_interaction, Opts, true),
- Prefs = method_preference(FirstAlg, SecondAlg, AllowUserInt),
- ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
- userauth_preference = Prefs,
- userauth_methods = none,
- service = "ssh-connection"});
+ case proplists:get_value(pref_public_key_algs, Opts, false) of
+ false ->
+ FirstAlg = algorithm(proplists:get_value(public_key_alg, Opts,
+ ?PREFERRED_PK_ALG)),
+ SecondAlg = other_alg(FirstAlg),
+ AllowUserInt = proplists:get_value(user_interaction, Opts, true),
+ Prefs = method_preference(FirstAlg, SecondAlg, AllowUserInt),
+ ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
+ userauth_preference = Prefs,
+ userauth_methods = none,
+ service = "ssh-connection"});
+ Algs ->
+ FirstAlg = algorithm(lists:nth(1, Algs)),
+ case length(Algs) =:= 2 of
+ true ->
+ SecondAlg = other_alg(FirstAlg),
+ AllowUserInt = proplists:get_value(user_interaction, Opts, true),
+ Prefs = method_preference(FirstAlg, SecondAlg, AllowUserInt),
+ ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
+ userauth_preference = Prefs,
+ userauth_methods = none,
+ service = "ssh-connection"});
+ _ ->
+ AllowUserInt = proplists:get_value(user_interaction, Opts, true),
+ Prefs = method_preference(FirstAlg, AllowUserInt),
+ ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User,
+ userauth_preference = Prefs,
+ userauth_methods = none,
+ service = "ssh-connection"})
+ end
+ end;
{error, no_user} ->
ErrStr = "Could not determine the users name",
throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_ILLEGAL_USER_NAME,
@@ -287,6 +309,15 @@ method_preference(Alg1, Alg2, false) ->
{"publickey", ?MODULE, publickey_msg,[Alg2]},
{"password", ?MODULE, password_msg, []}
].
+method_preference(Alg1, true) ->
+ [{"publickey", ?MODULE, publickey_msg, [Alg1]},
+ {"password", ?MODULE, password_msg, []},
+ {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []}
+ ];
+method_preference(Alg1, false) ->
+ [{"publickey", ?MODULE, publickey_msg, [Alg1]},
+ {"password", ?MODULE, password_msg, []}
+ ].
user_name(Opts) ->
Env = case os:type() of
diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 5b3d1b8a1b..d8950a7b67 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -718,8 +718,18 @@ init_ssh(server = Role, Vsn, Version, Options, Socket) ->
available_host_keys = supported_host_keys(Role, KeyCb, Options)
}.
-supported_host_keys(client, _, _) ->
- ["ssh-rsa", "ssh-dss"];
+supported_host_keys(client, _, Options) ->
+ try
+ case extract_algs(proplists:get_value(pref_public_key_algs, Options, false), []) of
+ false ->
+ ["ssh-rsa", "ssh-dss"];
+ Algs ->
+ Algs
+ end
+ catch
+ exit:Reason ->
+ {stop, {shutdown, Reason}}
+ end;
supported_host_keys(server, KeyCb, Options) ->
lists:foldl(fun(Type, Acc) ->
case available_host_key(KeyCb, Type, Options) of
@@ -731,7 +741,19 @@ supported_host_keys(server, KeyCb, Options) ->
end, [],
%% Prefered alg last so no need to reverse
["ssh-dss", "ssh-rsa"]).
-
+extract_algs(false, _) ->
+ false;
+extract_algs([],[]) ->
+ false;
+extract_algs([], NewList) ->
+ lists:reverse(NewList);
+extract_algs([H|T], NewList) ->
+ case H of
+ ssh_dsa ->
+ extract_algs(T, ["ssh-dss"|NewList]);
+ ssh_rsa ->
+ extract_algs(T, ["ssh-rsa"|NewList])
+ end.
available_host_key(KeyCb, "ssh-dss"= Alg, Opts) ->
case KeyCb:host_key('ssh-dss', Opts) of
{ok, _} ->