diff options
| -rw-r--r-- | lib/ssh/src/ssh.hrl | 10 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_auth.erl | 112 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_connection_handler.erl | 61 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_file.erl | 3 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 54 | ||||
| -rw-r--r-- | lib/ssh/test/ssh_options_SUITE.erl | 39 |
6 files changed, 153 insertions, 126 deletions
diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl index 27a8cfedbc..923e9309f4 100644 --- a/lib/ssh/src/ssh.hrl +++ b/lib/ssh/src/ssh.hrl @@ -242,7 +242,12 @@ | ?COMMON_OPTION . -type opaque_client_options() :: - {keyboard_interact_fun, fun((term(),term(),term()) -> term())} + {keyboard_interact_fun, fun((Name::iodata(), + Instruction::iodata(), + Prompts::[{Prompt::iodata(),Echo::boolean()}] + ) -> + [Response::iodata()] + )} | opaque_common_options(). -type host_accepting_client_options() :: @@ -382,9 +387,6 @@ algorithms, %% #alg{} - key_cb, %% Private/Public key callback module - io_cb, %% Interaction callback module - send_mac = none, %% send MAC algorithm send_mac_key, %% key used in send MAC algorithm send_mac_size = 0, diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 4e4aa440de..9632168e65 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -91,8 +91,10 @@ unique(L) -> %%%---- userauth_request_msg "callbacks" -password_msg([#ssh{opts = Opts, io_cb = IoCb, - user = User, service = Service} = Ssh0]) -> +password_msg([#ssh{opts = Opts, + user = User, + service = Service} = Ssh0]) -> + IoCb = ?GET_INTERNAL_OPT(io_cb, Opts), {Password,Ssh} = case ?GET_OPT(password, Opts) of undefined when IoCb == ssh_no_io -> @@ -137,9 +139,7 @@ keyboard_interactive_msg([#ssh{user = User, get_public_key(SigAlg, #ssh{opts = Opts}) -> KeyAlg = key_alg(SigAlg), - {KeyCb,KeyCbOpts} = ?GET_OPT(key_cb, Opts), - UserOpts = ?GET_OPT(user_options, Opts), - case KeyCb:user_key(KeyAlg, [{key_cb_private,KeyCbOpts}|UserOpts]) of + case ssh_transport:call_KeyCb(user_key, [KeyAlg], Opts) of {ok, PrivKey} -> try %% Check the key - the KeyCb may be a buggy plugin @@ -387,11 +387,9 @@ handle_userauth_info_request(#ssh_msg_userauth_info_request{name = Name, instruction = Instr, num_prompts = NumPrompts, data = Data}, - #ssh{opts = Opts, - io_cb = IoCb - } = Ssh) -> + #ssh{opts=Opts} = Ssh) -> PromptInfos = decode_keyboard_interactive_prompts(NumPrompts,Data), - case keyboard_interact_get_responses(IoCb, Opts, Name, Instr, PromptInfos) of + case keyboard_interact_get_responses(Opts, Name, Instr, PromptInfos) of not_ok -> not_ok; Responses -> @@ -498,9 +496,7 @@ get_password_option(Opts, User) -> pre_verify_sig(User, KeyBlob, Opts) -> try Key = public_key:ssh_decode(KeyBlob, ssh2_pubkey), % or exception - {KeyCb,KeyCbOpts} = ?GET_OPT(key_cb, Opts), - UserOpts = ?GET_OPT(user_options, Opts), - KeyCb:is_auth_key(Key, User, [{key_cb_private,KeyCbOpts}|UserOpts]) + ssh_transport:call_KeyCb(is_auth_key, [Key, User], Opts) catch _:_ -> false @@ -509,10 +505,8 @@ pre_verify_sig(User, KeyBlob, Opts) -> verify_sig(SessionId, User, Service, AlgBin, KeyBlob, SigWLen, #ssh{opts = Opts} = Ssh) -> try Alg = binary_to_list(AlgBin), - {KeyCb,KeyCbOpts} = ?GET_OPT(key_cb, Opts), - UserOpts = ?GET_OPT(user_options, Opts), Key = public_key:ssh_decode(KeyBlob, ssh2_pubkey), % or exception - true = KeyCb:is_auth_key(Key, User, [{key_cb_private,KeyCbOpts}|UserOpts]), + true = ssh_transport:call_KeyCb(is_auth_key, [Key, User], Opts), PlainText = build_sig_data(SessionId, User, Service, KeyBlob, Alg), <<?UINT32(AlgSigLen), AlgSig:AlgSigLen/binary>> = SigWLen, <<?UINT32(AlgLen), _Alg:AlgLen/binary, @@ -536,56 +530,78 @@ build_sig_data(SessionId, User, Service, KeyBlob, Alg) -> +key_alg('rsa-sha2-256') -> 'ssh-rsa'; +key_alg('rsa-sha2-512') -> 'ssh-rsa'; +key_alg(Alg) -> Alg. + +%%%================================================================ +%%% +%%% Keyboard-interactive +%%% + decode_keyboard_interactive_prompts(_NumPrompts, Data) -> ssh_message:decode_keyboard_interactive_prompts(Data, []). -keyboard_interact_get_responses(IoCb, Opts, Name, Instr, PromptInfos) -> - NumPrompts = length(PromptInfos), +keyboard_interact_get_responses(Opts, Name, Instr, PromptInfos) -> keyboard_interact_get_responses(?GET_OPT(user_interaction, Opts), ?GET_OPT(keyboard_interact_fun, Opts), - ?GET_OPT(password, Opts), IoCb, Name, - Instr, PromptInfos, Opts, NumPrompts). + ?GET_OPT(password, Opts), + Name, + Instr, + PromptInfos, + Opts). -keyboard_interact_get_responses(_, _, not_ok, _, _, _, _, _, _) -> +%% Don't re-try an already rejected password. This could happen if both keyboard-interactive +%% and password methods are tried: +keyboard_interact_get_responses(_, _, not_ok, _, _, _, _) -> not_ok; -keyboard_interact_get_responses(_, undefined, Password, _, _, _, _, _, - 1) when Password =/= undefined -> - [Password]; %% Password auth implemented with keyboard-interaction and passwd is known -keyboard_interact_get_responses(_, _, _, _, _, _, _, _, 0) -> + +%% Only one password requestedm and we have got one via the 'password' option for the daemon: +keyboard_interact_get_responses(_, undefined, Pwd, _, _, [_], _) when Pwd =/= undefined -> + [Pwd]; %% Password auth implemented with keyboard-interaction and passwd is known + +%% No password requested (keyboard-interactive): +keyboard_interact_get_responses(_, _, _, _, _, [], _) -> []; -keyboard_interact_get_responses(false, undefined, undefined, _, _, _, [Prompt|_], Opts, _) -> - ssh_no_io:read_line(Prompt, Opts); %% Throws error as keyboard interaction is not allowed -keyboard_interact_get_responses(true, undefined, _,IoCb, Name, Instr, PromptInfos, Opts, _) -> - keyboard_interact(IoCb, Name, Instr, PromptInfos, Opts); -keyboard_interact_get_responses(true, Fun, _Pwd, _IoCb, Name, Instr, PromptInfos, _Opts, NumPrompts) -> - keyboard_interact_fun(Fun, Name, Instr, PromptInfos, NumPrompts). - -keyboard_interact(IoCb, Name, Instr, Prompts, Opts) -> + +%% user_interaction is forbidden (by option user_interaction) and we have to ask +%% the user for one or more. +%% Throw an error: +keyboard_interact_get_responses(false, undefined, undefined, _, _, [Prompt|_], Opts) -> + ssh_no_io:read_line(Prompt, Opts); + +%% One or more passwords are requested, we may prompt the user and no fun is used +%% to get the responses: +keyboard_interact_get_responses(true, undefined, _, Name, Instr, PromptInfos, Opts) -> + prompt_user_for_passwords(Name, Instr, PromptInfos, Opts); + +%% The passwords are provided with a fun. Use that one! +keyboard_interact_get_responses(true, Fun, _Pwd, Name, Instr, PromptInfos, _Opts) -> + keyboard_interact_fun(Fun, Name, Instr, PromptInfos). + + + +prompt_user_for_passwords(Name, Instr, PromptInfos, Opts) -> + IoCb = ?GET_INTERNAL_OPT(io_cb, Opts), write_if_nonempty(IoCb, Name), write_if_nonempty(IoCb, Instr), lists:map(fun({Prompt, true}) -> IoCb:read_line(Prompt, Opts); ({Prompt, false}) -> IoCb:read_password(Prompt, Opts) end, - Prompts). + PromptInfos). -write_if_nonempty(_, "") -> ok; -write_if_nonempty(_, <<>>) -> ok; -write_if_nonempty(IoCb, Text) -> IoCb:format("~s~n",[Text]). - - -keyboard_interact_fun(KbdInteractFun, Name, Instr, PromptInfos, NumPrompts) -> - Prompts = lists:map(fun({Prompt, _Echo}) -> Prompt end, - PromptInfos), - case KbdInteractFun(Name, Instr, Prompts) of - Rs when length(Rs) == NumPrompts -> - Rs; - _Rs -> +keyboard_interact_fun(KbdInteractFun, Name, Instr, PromptInfos) -> + case KbdInteractFun(Name, Instr, PromptInfos) of + Responses when is_list(Responses), + length(Responses) == length(PromptInfos) -> + Responses; + _ -> nok end. -key_alg('rsa-sha2-256') -> 'ssh-rsa'; -key_alg('rsa-sha2-512') -> 'ssh-rsa'; -key_alg(Alg) -> Alg. +write_if_nonempty(_, "") -> ok; +write_if_nonempty(_, <<>>) -> ok; +write_if_nonempty(IoCb, Text) -> IoCb:format("~s~n",[Text]). diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl index 30eafc2f2a..7c87591cf2 100644 --- a/lib/ssh/src/ssh_connection_handler.erl +++ b/lib/ssh/src/ssh_connection_handler.erl @@ -447,7 +447,6 @@ init_ssh_record(Role, Socket, Opts) -> init_ssh_record(Role, Socket, PeerAddr, Opts) -> AuthMethods = ?GET_OPT(auth_methods, Opts), S0 = #ssh{role = Role, - key_cb = ?GET_OPT(key_cb, Opts), opts = Opts, userauth_supported_methods = AuthMethods, available_host_keys = available_hkey_algorithms(Role, Opts), @@ -472,10 +471,11 @@ init_ssh_record(Role, Socket, PeerAddr, Opts) -> S1 = S0#ssh{c_vsn = Vsn, c_version = Version, - io_cb = case ?GET_OPT(user_interaction, Opts) of - true -> ssh_io; - false -> ssh_no_io - end, + opts = ?PUT_INTERNAL_OPT({io_cb, case ?GET_OPT(user_interaction, Opts) of + true -> ssh_io; + false -> ssh_no_io + end}, + Opts), userauth_quiet_mode = ?GET_OPT(quiet_mode, Opts), peer = {PeerName, PeerAddr}, local = LocalName @@ -488,7 +488,6 @@ init_ssh_record(Role, Socket, PeerAddr, Opts) -> server -> S0#ssh{s_vsn = Vsn, s_version = Version, - io_cb = ?GET_INTERNAL_OPT(io_cb, Opts, ssh_io), userauth_methods = string:tokens(AuthMethods, ","), kb_tries_left = 3, peer = {undefined, PeerAddr}, @@ -1686,18 +1685,19 @@ peer_role(client) -> server; peer_role(server) -> client. %%-------------------------------------------------------------------- -available_hkey_algorithms(Role, Options) -> - KeyCb = ?GET_OPT(key_cb, Options), - case [A || A <- available_hkey_algos(Options), - (Role==client) orelse available_host_key(KeyCb, A, Options) - ] of - - [] when Role==client -> - error({shutdown, "No public key algs"}); - - [] when Role==server -> - error({shutdown, "No host key available"}); +available_hkey_algorithms(client, Options) -> + case available_hkey_algos(Options) of + [] -> + error({shutdown, "No public key algs"}); + Algs -> + [atom_to_list(A) || A<-Algs] + end; +available_hkey_algorithms(server, Options) -> + case [A || A <- available_hkey_algos(Options), + is_usable_host_key(A, Options)] of + [] -> + error({shutdown, "No host key available"}); Algs -> [atom_to_list(A) || A<-Algs] end. @@ -1713,18 +1713,6 @@ available_hkey_algos(Options) -> AvailableAndSupported. -%% Alg :: atom() -available_host_key({KeyCb,KeyCbOpts}, Alg, Opts) -> - UserOpts = ?GET_OPT(user_options, Opts), - case KeyCb:host_key(Alg, [{key_cb_private,KeyCbOpts}|UserOpts]) of - {ok,Key} -> - %% Check the key - the KeyCb may be a buggy plugin - ssh_transport:valid_key_sha_alg(Key, Alg); - _ -> - false - end. - - send_msg(Msg, State=#data{ssh_params=Ssh0}) when is_tuple(Msg) -> {Bytes, Ssh} = ssh_transport:ssh_packet(Msg, Ssh0), send_bytes(Bytes, State), @@ -1844,10 +1832,21 @@ ext_info(_, D0) -> D0. %%%---------------------------------------------------------------- -is_usable_user_pubkey(A, Ssh) -> - case ssh_auth:get_public_key(A, Ssh) of +is_usable_user_pubkey(Alg, Ssh) -> + try ssh_auth:get_public_key(Alg, Ssh) of {ok,_} -> true; _ -> false + catch + _:_ -> false + end. + +%%%---------------------------------------------------------------- +is_usable_host_key(Alg, Opts) -> + try ssh_transport:get_host_key(Alg, Opts) + of + _PrivHostKey -> true + catch + _:_ -> false end. %%%---------------------------------------------------------------- diff --git a/lib/ssh/src/ssh_file.erl b/lib/ssh/src/ssh_file.erl index 072a42d91e..510269bbb1 100644 --- a/lib/ssh/src/ssh_file.erl +++ b/lib/ssh/src/ssh_file.erl @@ -275,7 +275,8 @@ identity_pass_phrase("rsa-sha2-512" ) -> rsa_pass_phrase; %% Not yet implemented: identity_pass_phrase("ssh-ed448" ) -> ed448_pass_phrase; identity_pass_phrase("ecdsa-sha2-"++_) -> ecdsa_pass_phrase; identity_pass_phrase(P) when is_atom(P) -> - identity_pass_phrase(atom_to_list(P)). + identity_pass_phrase(atom_to_list(P)); +identity_pass_phrase(_) -> undefined. lookup_host_key_fd(Fd, KeyToMatch, Host, KeyType) -> case io:get_line(Fd, '') of diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index b99f79a47c..9ff20454cd 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -51,7 +51,9 @@ extract_public_key/1, ssh_packet/2, pack/2, valid_key_sha_alg/2, - sha/1, sign/3, verify/5]). + sha/1, sign/3, verify/5, + get_host_key/2, + call_KeyCb/3]). -export([dbg_trace/3]). @@ -433,7 +435,8 @@ key_exchange_first_msg(Kex, Ssh0) when Kex == 'ecdh-sha2-nistp256' ; %%% handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0 = #ssh{algorithms = #alg{kex=Kex, - hkey=SignAlg} = Algs}) -> + hkey=SignAlg} = Algs, + opts = Opts}) -> %% server {G, P} = dh_group(Kex), if @@ -441,7 +444,7 @@ handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Sz = dh_bits(Algs), {Public, Private} = generate_key(dh, [P,G,2*Sz]), K = compute_key(dh, E, Private, [P,G]), - MyPrivHostKey = get_host_key(Ssh0, SignAlg), + MyPrivHostKey = get_host_key(SignAlg, Opts), MyPubHostKey = extract_public_key(MyPrivHostKey), H = kex_hash(Ssh0, MyPubHostKey, sha(Kex), {E,Public,K}), H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), @@ -580,14 +583,15 @@ handle_kex_dh_gex_init(#ssh_msg_kex_dh_gex_init{e = E}, #ssh{keyex_key = {{Private, Public}, {G, P}}, keyex_info = {Min, Max, NBits}, algorithms = #alg{kex=Kex, - hkey=SignAlg}} = Ssh0) -> + hkey=SignAlg}, + opts = Opts} = Ssh0) -> %% server if 1=<E, E=<(P-1) -> K = compute_key(dh, E, Private, [P,G]), if 1<K, K<(P-1) -> - MyPrivHostKey = get_host_key(Ssh0, SignAlg), + MyPrivHostKey = get_host_key(SignAlg, Opts), MyPubHostKey = extract_public_key(MyPrivHostKey), H = kex_hash(Ssh0, MyPubHostKey, sha(Kex), {Min,NBits,Max,P,G,E,Public,K}), H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), @@ -655,7 +659,8 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK %%% handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, Ssh0 = #ssh{algorithms = #alg{kex=Kex, - hkey=SignAlg}}) -> + hkey=SignAlg}, + opts = Opts}) -> %% at server Curve = ecdh_curve(Kex), {MyPublic, MyPrivate} = generate_key(ecdh, Curve), @@ -663,7 +668,7 @@ handle_kex_ecdh_init(#ssh_msg_kex_ecdh_init{q_c = PeerPublic}, compute_key(ecdh, PeerPublic, MyPrivate, Curve) of K -> - MyPrivHostKey = get_host_key(Ssh0, SignAlg), + MyPrivHostKey = get_host_key(SignAlg, Opts), MyPubHostKey = extract_public_key(MyPrivHostKey), H = kex_hash(Ssh0, MyPubHostKey, sha(Curve), {PeerPublic, MyPublic, K}), H_SIG = sign(H, sha(SignAlg), MyPrivHostKey), @@ -779,10 +784,8 @@ sid(#ssh{session_id = Id}, _) -> Id. %% %% The host key should be read from storage %% -get_host_key(SSH, SignAlg) -> - #ssh{key_cb = {KeyCb,KeyCbOpts}, opts = Opts} = SSH, - UserOpts = ?GET_OPT(user_options, Opts), - case KeyCb:host_key(SignAlg, [{key_cb_private,KeyCbOpts}|UserOpts]) of +get_host_key(SignAlg, Opts) -> + case call_KeyCb(host_key, [SignAlg], Opts) of {ok, PrivHostKey} -> %% Check the key - the KeyCb may be a buggy plugin case valid_key_sha_alg(PrivHostKey, SignAlg) of @@ -793,6 +796,11 @@ get_host_key(SSH, SignAlg) -> exit({error, {Result, unsupported_key_type}}) end. +call_KeyCb(F, Args, Opts) -> + {KeyCb,KeyCbOpts} = ?GET_OPT(key_cb, Opts), + UserOpts = ?GET_OPT(user_options, Opts), + apply(KeyCb, F, Args ++ [[{key_cb_private,KeyCbOpts}|UserOpts]]). + extract_public_key(#'RSAPrivateKey'{modulus = N, publicExponent = E}) -> #'RSAPublicKey'{modulus = N, publicExponent = E}; extract_public_key(#'DSAPrivateKey'{y = Y, p = P, q = Q, g = G}) -> @@ -861,8 +869,9 @@ accepted_host(Ssh, PeerName, Public, Opts) -> end. -yes_no(Ssh, Prompt) -> - (Ssh#ssh.io_cb):yes_no(Prompt, Ssh#ssh.opts). +yes_no(#ssh{opts=Opts}, Prompt) -> + IoCb = ?GET_INTERNAL_OPT(io_cb, Opts, ssh_io), + IoCb:yes_no(Prompt, Opts). fmt_hostkey('ssh-rsa') -> "RSA"; @@ -874,18 +883,16 @@ fmt_hostkey("ecdsa"++_) -> "ECDSA"; fmt_hostkey(X) -> X. -known_host_key(#ssh{opts = Opts, key_cb = {KeyCb,KeyCbOpts}, peer = {PeerName,_}} = Ssh, +known_host_key(#ssh{opts = Opts, peer = {PeerName,_}} = Ssh, Public, Alg) -> - UserOpts = ?GET_OPT(user_options, Opts), - case is_host_key(KeyCb, Public, PeerName, Alg, [{key_cb_private,KeyCbOpts}|UserOpts]) of - {_,true} -> + case call_KeyCb(is_host_key, [Public, PeerName, Alg], Opts) of + true -> ok; - {_,false} -> + false -> DoAdd = ?GET_OPT(save_accepted_host, Opts), case accepted_host(Ssh, PeerName, Public, Opts) of true when DoAdd == true -> - {_,R} = add_host_key(KeyCb, PeerName, Public, [{key_cb_private,KeyCbOpts}|UserOpts]), - R; + call_KeyCb(add_host_key, [PeerName, Public], Opts); true when DoAdd == false -> ok; false -> @@ -895,13 +902,6 @@ known_host_key(#ssh{opts = Opts, key_cb = {KeyCb,KeyCbOpts}, peer = {PeerName,_} end end. -is_host_key(KeyCb, Public, PeerName, Alg, Data) -> - {KeyCb, KeyCb:is_host_key(Public, PeerName, Alg, Data)}. - -add_host_key(KeyCb, PeerName, Public, Data) -> - {KeyCb, KeyCb:add_host_key(PeerName, Public, Data)}. - - %% Each of the algorithm strings MUST be a comma-separated list of %% algorithm names (see ''Algorithm Naming'' in [SSH-ARCH]). Each %% supported (allowed) algorithm MUST be listed in order of preference. diff --git a/lib/ssh/test/ssh_options_SUITE.erl b/lib/ssh/test/ssh_options_SUITE.erl index daf62483cd..60d0da2a39 100644 --- a/lib/ssh/test/ssh_options_SUITE.erl +++ b/lib/ssh/test/ssh_options_SUITE.erl @@ -49,7 +49,7 @@ server_userpassword_option/1, server_pwdfun_option/1, server_pwdfun_4_option/1, - server_pwdfun_4_option_repeat/1, + server_keyboard_interactive/1, ssh_connect_arg4_timeout/1, ssh_connect_negtimeout_parallel/1, ssh_connect_negtimeout_sequential/1, @@ -99,7 +99,7 @@ all() -> server_userpassword_option, server_pwdfun_option, server_pwdfun_4_option, - server_pwdfun_4_option_repeat, + server_keyboard_interactive, {group, dir_options}, ssh_connect_timeout, ssh_connect_arg4_timeout, @@ -381,7 +381,7 @@ server_pwdfun_4_option(Config) -> %%-------------------------------------------------------------------- -server_pwdfun_4_option_repeat(Config) -> +server_keyboard_interactive(Config) -> UserDir = proplists:get_value(user_dir, Config), SysDir = proplists:get_value(data_dir, Config), %% Test that the state works @@ -396,19 +396,28 @@ server_pwdfun_4_option_repeat(Config) -> {pwdfun,PWDFUN}]), %% Try with passwords "incorrect", "Bad again" and finally "bar" - KIFFUN = fun(_,_,_) -> + KIFFUN = fun(_Name, _Instr, _PromptInfos) -> K={k,self()}, - case get(K) of - undefined -> - put(K,1), - ["incorrect"]; - 2 -> - put(K,3), - ["bar"]; - S-> - put(K,S+1), - ["Bad again"] - end + Answer = + case get(K) of + undefined -> + put(K,1), + ["incorrect"]; + 2 -> + put(K,3), + ["bar"]; + S-> + put(K,S+1), + ["Bad again"] + end, + ct:log("keyboard_interact_fun:~n" + " Name = ~p~n" + " Instruction = ~p~n" + " Prompts = ~p~n" + "~nAnswer:~n ~p~n", + [_Name, _Instr, _PromptInfos, Answer]), + + Answer end, ConnectionRef2 = |