diff options
| -rw-r--r-- | lib/ssh/src/ssh_options.erl | 270 | ||||
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 19 |
2 files changed, 214 insertions, 75 deletions
diff --git a/lib/ssh/src/ssh_options.erl b/lib/ssh/src/ssh_options.erl index b41ad8b33b..d8931da774 100644 --- a/lib/ssh/src/ssh_options.erl +++ b/lib/ssh/src/ssh_options.erl @@ -170,9 +170,10 @@ handle_options(Role, PropList0, Opts0) when is_map(Opts0), OptionDefinitions), %% Enter the user's values into the map; unknown keys are %% treated as socket options - lists:foldl(fun(KV, Vals) -> - save(KV, OptionDefinitions, Vals) - end, InitialMap, PropList1) + final_preferred_algorithms( + lists:foldl(fun(KV, Vals) -> + save(KV, OptionDefinitions, Vals) + end, InitialMap, PropList1)) catch error:{eoptions, KV, undefined} -> {error, {eoptions,KV}}; @@ -509,6 +510,15 @@ default(common) -> class => user_options }, + %% NOTE: This option is supposed to be used only in this very module (?MODULE). There is + %% a final stage in handle_options that "merges" the preferred_algorithms option and this one. + %% The preferred_algorithms is the one to use in the rest of the ssh application! + {modify_algorithms, def} => + #{default => undefined, % signals error if unsupported algo in preferred_algorithms :( + chk => fun check_modify_algorithms/1, + class => user_options + }, + {id_string, def} => #{default => undefined, % FIXME: see ssh_transport:ssh_vsn/0 chk => fun(random) -> @@ -820,83 +830,193 @@ valid_hash(L, Ss) when is_list(L) -> lists:all(fun(S) -> valid_hash(S,Ss) end, L valid_hash(X, _) -> error_in_check(X, "Expect atom or list in fingerprint spec"). %%%---------------------------------------------------------------- -check_preferred_algorithms(Algs) -> - [error_in_check(K,"Bad preferred_algorithms key") - || {K,_} <- Algs, - not lists:keymember(K,1,ssh:default_algorithms())], +check_modify_algorithms(M) when is_list(M) -> + [error_in_check(Op_KVs, "Bad modify_algorithms") + || Op_KVs <- M, + not is_tuple(Op_KVs) + orelse (size(Op_KVs) =/= 2) + orelse (not lists:member(element(1,Op_KVs), [append,prepend,rm]))], + {true, [{Op,normalize_mod_algs(KVs,false)} || {Op,KVs} <- M]}; +check_modify_algorithms(_) -> + error_in_check(modify_algorithms, "Bad option value. List expected."). + + + + +normalize_mod_algs(KVs, UseDefaultAlgs) -> + normalize_mod_algs(ssh_transport:algo_classes(), KVs, [], UseDefaultAlgs). + +normalize_mod_algs([K|Ks], KVs0, Acc, UseDefaultAlgs) -> + %% Pick the expected keys in order and check if they are in the user's list + {Vs1, KVs} = + case lists:keytake(K, 1, KVs0) of + {value, {K,Vs0}, KVs1} -> + {Vs0, KVs1}; + false -> + {[], KVs0} + end, + Vs = normalize_mod_alg_list(K, Vs1, UseDefaultAlgs), + normalize_mod_algs(Ks, KVs, [{K,Vs} | Acc], UseDefaultAlgs); +normalize_mod_algs([], [], Acc, _) -> + %% No values left in the key-value list after removing the expected entries + %% (thats good) + lists:reverse(Acc); +normalize_mod_algs([], [{K,_}|_], _, _) -> + %% Some values left in the key-value list after removing the expected entries + %% (thats bad) + case ssh_transport:algo_class(K) of + true -> error_in_check(K, "Duplicate key"); + false -> error_in_check(K, "Unknown key") + end; +normalize_mod_algs([], [X|_], _, _) -> + error_in_check(X, "Bad list element"). + + + +%%% Handle the algorithms list +normalize_mod_alg_list(K, Vs, UseDefaultAlgs) -> + normalize_mod_alg_list(K, + ssh_transport:algo_two_spec_class(K), + Vs, + def_alg(K,UseDefaultAlgs)). + + +normalize_mod_alg_list(_K, _, [], Default) -> + Default; + +normalize_mod_alg_list(K, true, [{client2server,L1}], [_,{server2client,L2}]) -> + [nml1(K,{client2server,L1}), + {server2client,L2}]; + +normalize_mod_alg_list(K, true, [{server2client,L2}], [{client2server,L1},_]) -> + [{client2server,L1}, + nml1(K,{server2client,L2})]; + +normalize_mod_alg_list(K, true, [{server2client,L2},{client2server,L1}], _) -> + [nml1(K,{client2server,L1}), + nml1(K,{server2client,L2})]; + +normalize_mod_alg_list(K, true, [{client2server,L1},{server2client,L2}], _) -> + [nml1(K,{client2server,L1}), + nml1(K,{server2client,L2})]; + +normalize_mod_alg_list(K, true, L0, _) -> + L = nml(K,L0), % Throws errors + [{client2server,L}, + {server2client,L}]; + +normalize_mod_alg_list(K, false, L, _) -> + nml(K,L). + + +nml1(K, {T,V}) when T==client2server ; T==server2client -> + {T, nml({K,T}, V)}. + +nml(K, L) -> + [error_in_check(K, "Bad value for this key") % This is a throw + || V <- L, + not is_atom(V) + ], + case L -- lists:usort(L) of + [] -> ok; + Dups -> error_in_check({K,Dups}, "Duplicates") % This is a throw + end, + L. - try alg_duplicates(Algs, [], []) - of - [] -> - {true, - [case proplists:get_value(Key, Algs) of - undefined -> - {Key,DefAlgs}; - Vals -> - handle_pref_alg(Key,Vals,SupAlgs) - end - || {{Key,DefAlgs}, {Key,SupAlgs}} <- lists:zip(ssh:default_algorithms(), - ssh_transport:supported_algorithms()) - ] - }; - - Dups -> - error_in_check(Dups, "Duplicates") - catch - _:_ -> - false - end. -alg_duplicates([{K,V}|KVs], Ks, Dups0) -> - Dups = - case lists:member(K,Ks) of - true -> [K|Dups0]; - false -> Dups0 - end, - case V--lists:usort(V) of - [] -> alg_duplicates(KVs, [K|Ks], Dups); - Ds -> alg_duplicates(KVs, [K|Ks], Dups++Ds) +def_alg(K, false) -> + case ssh_transport:algo_two_spec_class(K) of + false -> []; + true -> [{client2server,[]}, {server2client,[]}] end; -alg_duplicates([], _Ks, Dups) -> - Dups. - -handle_pref_alg(Key, - Vs=[{client2server,C2Ss=[_|_]},{server2client,S2Cs=[_|_]}], - [{client2server,Sup_C2Ss},{server2client,Sup_S2Cs}] - ) -> - chk_alg_vs(Key, C2Ss, Sup_C2Ss), - chk_alg_vs(Key, S2Cs, Sup_S2Cs), - {Key, Vs}; - -handle_pref_alg(Key, - Vs=[{server2client,[_|_]},{client2server,[_|_]}], - Sup=[{client2server,_},{server2client,_}] - ) -> - handle_pref_alg(Key, lists:reverse(Vs), Sup); - -handle_pref_alg(Key, - Vs=[V|_], - Sup=[{client2server,_},{server2client,_}] - ) when is_atom(V) -> - handle_pref_alg(Key, [{client2server,Vs},{server2client,Vs}], Sup); - -handle_pref_alg(Key, - Vs=[V|_], - Sup=[S|_] - ) when is_atom(V), is_atom(S) -> - chk_alg_vs(Key, Vs, Sup), - {Key, Vs}; - -handle_pref_alg(Key, Vs, _) -> - error_in_check({Key,Vs}, "Badly formed list"). - -chk_alg_vs(OptKey, Values, SupportedValues) -> - case (Values -- SupportedValues) of - [] -> Values; - [none] -> [none]; % for testing only - Bad -> error_in_check({OptKey,Bad}, "Unsupported value(s) found") +def_alg(K, true) -> + ssh_transport:default_algorithms(K). + + + +check_preferred_algorithms(Algs) when is_list(Algs) -> + check_input_ok(Algs), + {true, normalize_mod_algs(Algs, true)}; + +check_preferred_algorithms(Algs) when is_list(Algs) -> + check_preferred_algorithms({false,Algs}); + +check_preferred_algorithms(_) -> + error_in_check(modify_algorithms, "Bad option value. List expected."). + + +check_input_ok(Algs) -> + [error_in_check(KVs, "Bad preferred_algorithms") + || KVs <- Algs, + not is_tuple(KVs) + orelse (size(KVs) =/= 2)]. + +%%%---------------------------------------------------------------- +final_preferred_algorithms(Options) -> + Result = + case ?GET_OPT(modify_algorithms, Options) of + undefined -> + rm_non_supported(true, + ?GET_OPT(preferred_algorithms, Options)); + ModAlgs -> + rm_non_supported(false, + eval_ops(?GET_OPT(preferred_algorithms, Options), + ModAlgs)) + end, + error_if_empty(Result), % Throws errors if any value list is empty + ?PUT_OPT({preferred_algorithms,Result}, Options). + +eval_ops(PrefAlgs, ModAlgs) -> + lists:foldl(fun eval_op/2, PrefAlgs, ModAlgs). + +eval_op({Op,AlgKVs}, PrefAlgs) -> + eval_op(Op, AlgKVs, PrefAlgs, []). + +eval_op(Op, [{C,L1}|T1], [{C,L2}|T2], Acc) -> + eval_op(Op, T1, T2, [{C,eval_op(Op,L1,L2,[])} | Acc]); + +eval_op(_, [], [], Acc) -> lists:reverse(Acc); +eval_op(rm, Opt, Pref, []) when is_list(Opt), is_list(Pref) -> Pref -- Opt; +eval_op(append, Opt, Pref, []) when is_list(Opt), is_list(Pref) -> (Pref--Opt) ++ Opt; +eval_op(prepend, Opt, Pref, []) when is_list(Opt), is_list(Pref) -> Opt ++ (Pref--Opt). + + +rm_non_supported(UnsupIsErrorFlg, KVs) -> + [{K,rmns(K,Vs, UnsupIsErrorFlg)} || {K,Vs} <- KVs]. + +rmns(K, Vs, UnsupIsErrorFlg) -> + case ssh_transport:algo_two_spec_class(K) of + false -> + rm_unsup(Vs, ssh_transport:supported_algorithms(K), UnsupIsErrorFlg, K); + true -> + [{C, rm_unsup(Vsx, Sup, UnsupIsErrorFlg, {K,C})} + || {{C,Vsx},{C,Sup}} <- lists:zip(Vs,ssh_transport:supported_algorithms(K)) + ] end. +rm_unsup(A, B, Flg, ErrInf) -> + case A--B of + Unsup=[_|_] when Flg==true -> error({eoptions, + {preferred_algorithms,{ErrInf,Unsup}}, + "Unsupported value(s) found" + }); + Unsup -> A -- Unsup + end. + + +error_if_empty([{K,[]}|_]) -> + error({eoptions, K, "Empty resulting algorithm list"}); +error_if_empty([{K,[{client2server,[]}, {server2client,[]}]}]) -> + error({eoptions, K, "Empty resulting algorithm list"}); +error_if_empty([{K,[{client2server,[]}|_]} | _]) -> + error({eoptions, {K,client2server}, "Empty resulting algorithm list"}); +error_if_empty([{K,[_,{server2client,[]}|_]} | _]) -> + error({eoptions, {K,server2client}, "Empty resulting algorithm list"}); +error_if_empty([_|T]) -> + error_if_empty(T); +error_if_empty([]) -> + ok. + %%%---------------------------------------------------------------- forbidden_option(K,V) -> Txt = io_lib:format("The option '~s' is used internally. The " diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 412f5de9de..c48c0800e4 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -34,6 +34,8 @@ -export([next_seqnum/1, supported_algorithms/0, supported_algorithms/1, default_algorithms/0, default_algorithms/1, + algo_classes/0, algo_class/1, + algo_two_spec_classes/0, algo_two_spec_class/1, handle_packet_part/4, handle_hello_version/1, key_exchange_init_msg/1, @@ -81,6 +83,23 @@ default_algorithms() -> [{K,default_algorithms(K)} || K <- algo_classes()]. algo_classes() -> [kex, public_key, cipher, mac, compression]. +algo_class(kex) -> true; +algo_class(public_key) -> true; +algo_class(cipher) -> true; +algo_class(mac) -> true; +algo_class(compression) -> true; +algo_class(_) -> false. + + +algo_two_spec_classes() -> [cipher, mac, compression]. + +algo_two_spec_class(cipher) -> true; +algo_two_spec_class(mac) -> true; +algo_two_spec_class(compression) -> true; +algo_two_spec_class(_) -> false. + + + default_algorithms(kex) -> supported_algorithms(kex, [ 'diffie-hellman-group1-sha1' % Gone in OpenSSH 7.3.p1 |