diff options
Diffstat (limited to 'lib/kernel/src/auth.erl')
| -rw-r--r-- | lib/kernel/src/auth.erl | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/lib/kernel/src/auth.erl b/lib/kernel/src/auth.erl new file mode 100644 index 0000000000..62c0bef0cc --- /dev/null +++ b/lib/kernel/src/auth.erl @@ -0,0 +1,391 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 1996-2009. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% +-module(auth). +-behaviour(gen_server). + +-export([start_link/0]). + +%% Old documented interface - deprecated +-export([is_auth/1, cookie/0, cookie/1, node_cookie/1, node_cookie/2]). +-deprecated([{is_auth,1}, {cookie,'_'}, {node_cookie, '_'}]). + +%% New interface - meant for internal use within kernel only +-export([get_cookie/0, get_cookie/1, + set_cookie/1, set_cookie/2, + sync_cookie/0, + print/3]). + +%% gen_server callbacks +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + terminate/2, code_change/3]). + +-define(COOKIE_ETS_PROTECTION, protected). + +-record(state, { + our_cookie, %% Our own cookie + other_cookies %% The send-cookies of other nodes + }). + +-include("../include/file.hrl"). + +%%---------------------------------------------------------------------- +%% Exported functions +%%---------------------------------------------------------------------- + +start_link() -> + gen_server:start_link({local, auth}, auth, [], []). + +%%--Deprecated interface------------------------------------------------ + +-spec is_auth(Node :: node()) -> 'yes' | 'no'. + +is_auth(Node) -> + case net_adm:ping(Node) of + pong -> yes; + pang -> no + end. + +-spec cookie() -> atom(). + +cookie() -> + get_cookie(). + +-spec cookie(Cookies :: [atom(),...] | atom()) -> 'true'. + +cookie([Cookie]) -> + set_cookie(Cookie); +cookie(Cookie) -> + set_cookie(Cookie). + +-spec node_cookie(Cookies :: [atom(),...]) -> 'yes' | 'no'. + +node_cookie([Node, Cookie]) -> + node_cookie(Node, Cookie). + +-spec node_cookie(Node :: node(), Cookie :: atom()) -> 'yes' | 'no'. + +node_cookie(Node, Cookie) -> + set_cookie(Node, Cookie), + is_auth(Node). + +%%--"New" interface----------------------------------------------------- + +-spec get_cookie() -> atom(). + +get_cookie() -> + get_cookie(node()). + +-spec get_cookie(Node :: node()) -> atom(). + +get_cookie(_Node) when node() =:= nonode@nohost -> + nocookie; +get_cookie(Node) -> + gen_server:call(auth, {get_cookie, Node}). + +-spec set_cookie(Cookie :: atom()) -> 'true'. + +set_cookie(Cookie) -> + set_cookie(node(), Cookie). + +-spec set_cookie(Node :: node(), Cookie :: atom()) -> 'true'. + +set_cookie(_Node, _Cookie) when node() =:= nonode@nohost -> + erlang:error(distribution_not_started); +set_cookie(Node, Cookie) -> + gen_server:call(auth, {set_cookie, Node, Cookie}). + +-spec sync_cookie() -> any(). + +sync_cookie() -> + gen_server:call(auth, sync_cookie). + +-spec print(Node :: node(), Format :: string(), Args :: [_]) -> 'ok'. + +print(Node,Format,Args) -> + (catch gen_server:cast({auth,Node},{print,Format,Args})). + +%%--gen_server callbacks------------------------------------------------ + +init([]) -> + process_flag(trap_exit, true), + {ok, init_cookie()}. + +%% Opened is a list of servers we have opened up +%% The net kernel will let all message to the auth server +%% through as is + +handle_call({get_cookie, Node}, {_From,_Tag}, State) when Node =:= node() -> + {reply, State#state.our_cookie, State}; +handle_call({get_cookie, Node}, {_From,_Tag}, State) -> + case ets:lookup(State#state.other_cookies, Node) of + [{Node, Cookie}] -> + {reply, Cookie, State}; + [] -> + {reply, State#state.our_cookie, State} + end; +handle_call({set_cookie, Node, Cookie}, {_From,_Tag}, State) + when Node =:= node() -> + {reply, true, State#state{our_cookie = Cookie}}; + +%% +%% Happens when the distribution is brought up and +%% Someone wight have set up the cookie for our new nodename. +%% + +handle_call({set_cookie, Node, Cookie}, {_From,_Tag}, State) -> + ets:insert(State#state.other_cookies, {Node, Cookie}), + {reply, true, State}; + +handle_call(sync_cookie, _From, State) -> + case ets:lookup(State#state.other_cookies,node()) of + [{_N,C}] -> + ets:delete(State#state.other_cookies,node()), + {reply, true, State#state{our_cookie = C}}; + [] -> + {reply, true, State} + end; + +handle_call(echo, _From, O) -> + {reply, hello, O}. + +handle_cast({print,What,Args}, O) -> + %% always allow print outs + error_logger:error_msg(What,Args), + {noreply, O}. + +%% A series of bad messages that may come (from older distribution versions). + +handle_info({From,badcookie,net_kernel,{From,spawn,_M,_F,_A,_Gleader}}, O) -> + auth:print(node(From) ,"~n** Unauthorized spawn attempt to ~w **~n", + [node()]), + erlang:disconnect_node(node(From)), + {noreply, O}; +handle_info({From,badcookie,net_kernel,{From,spawn_link,_M,_F,_A,_Gleader}}, O) -> + auth:print(node(From), + "~n** Unauthorized spawn_link attempt to ~w **~n", + [node()]), + erlang:disconnect_node(node(From)), + {noreply, O}; +handle_info({_From,badcookie,ddd_server,_Mess}, O) -> + %% Ignore bad messages to the ddd server, they will be resent + %% If the authentication is succesful + {noreply, O}; +handle_info({From,badcookie,rex,_Msg}, O) -> + auth:print(getnode(From), + "~n** Unauthorized rpc attempt to ~w **~n",[node()]), + disconnect_node(node(From)), + {noreply, O}; +%% These two messages has to do with the old auth:is_auth() call (net_adm:ping) +handle_info({From,badcookie,net_kernel,{'$gen_call',{From,Tag},{is_auth,_Node}}}, O) -> %% ho ho + From ! {Tag, no}, + {noreply, O}; +handle_info({_From,badcookie,To,{{auth_reply,N},R}}, O) ->%% Let auth replys through + catch To ! {{auth_reply,N},R}, + {noreply, O}; +handle_info({From,badcookie,Name,Mess}, Opened) -> + %% This may be registered send as well as pid send. + case lists:member(Name, Opened) of + true -> + catch Name ! Mess; + false -> + case catch lists:member(element(1, Mess), Opened) of + true -> + catch Name ! Mess; %% Might be a pid as well + _ -> + auth:print(getnode(From), + "~n** Unauthorized send attempt ~w to ~w **~n", + [Mess,node()]), + erlang:disconnect_node(getnode(From)) + end + end, + {noreply, Opened}; +handle_info(_, O)-> % Ignore anything else especially EXIT signals + {noreply, O}. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +terminate(_Reason, _State) -> + ok. + +getnode(P) when is_pid(P) -> node(P); +getnode(P) -> P. + + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%%% +%%% Cookie functions +%%% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%% Read cookie from $HOME/.erlang.cookie and set it. +init_cookie() -> + case init:get_argument(nocookie) of + error -> + case init:get_argument(setcookie) of + {ok, [[C0]]} -> + C = list_to_atom(C0), + #state{our_cookie = C, + other_cookies = ets:new(cookies, + [?COOKIE_ETS_PROTECTION])}; + _ -> + %% Here is the default + case read_cookie() of + {error, Error} -> + error_logger:error_msg(Error, []), + %% Is this really this serious? + erlang:error(Error); + {ok, Co} -> + #state{our_cookie = list_to_atom(Co), + other_cookies = ets:new( + cookies, + [?COOKIE_ETS_PROTECTION])} + end + end; + _Other -> + #state{our_cookie = nocookie, + other_cookies = ets:new(cookies,[?COOKIE_ETS_PROTECTION])} + end. + +read_cookie() -> + case init:get_argument(home) of + {ok, [[Home]]} -> + read_cookie(filename:join(Home, ".erlang.cookie")); + _ -> + {error, "No home for cookie file"} + end. + +read_cookie(Name) -> + case file:raw_read_file_info(Name) of + {ok, #file_info {type=Type, mode=Mode, size=Size}} -> + case check_attributes(Name, Type, Mode, os:type()) of + ok -> read_cookie(Name, Size); + Error -> Error + end; + {error, enoent} -> + case create_cookie(Name) of + ok -> read_cookie(Name); + Error -> Error + end; + {error, Reason} -> + {error, make_error(Name, Reason)} + end. + +read_cookie(Name, Size) -> + case file:open(Name, [raw, read]) of + {ok, File} -> + case file:read(File, Size) of + {ok, List} -> + file:close(File), + check_cookie(List, []); + {error, Reason} -> + make_error(Name, Reason) + end; + {error, Reason} -> + make_error(Name, Reason) + end. + +make_error(Name, Reason) -> + {error, "Error when reading " ++ Name ++ ": " ++ atom_to_list(Reason)}. + +%% Verifies that only the owner can access the cookie file. + +check_attributes(Name, Type, _Mode, _Os) when Type =/= regular -> + {error, "Cookie file " ++ Name ++ " is of type " ++ Type}; +check_attributes(Name, _Type, Mode, {unix, _}) when (Mode band 8#077) =/= 0 -> + {error, "Cookie file " ++ Name ++ " must be accessible by owner only"}; +check_attributes(_Name, _Type, _Mode, _Os) -> + ok. + +%% Checks that the cookie has the correct format. + +check_cookie([Letter|Rest], Result) when $\s =< Letter, Letter =< $~ -> + check_cookie(Rest, [Letter|Result]); +check_cookie([X|Rest], Result) -> + check_cookie1([X|Rest], Result); +check_cookie([], Result) -> + check_cookie1([], Result). + +check_cookie1([$\n|Rest], Result) -> + check_cookie1(Rest, Result); +check_cookie1([$\r|Rest], Result) -> + check_cookie1(Rest, Result); +check_cookie1([$\s|Rest], Result) -> + check_cookie1(Rest, Result); +check_cookie1([_|_], _Result) -> + {error, "Bad characters in cookie"}; +check_cookie1([], []) -> + {error, "Too short cookie string"}; +check_cookie1([], Result) -> + {ok, lists:reverse(Result)}. + +%% Creates a new, random cookie. + +create_cookie(Name) -> + {_, S1, S2} = now(), + Seed = S2*10000+S1, + Cookie = random_cookie(20, Seed, []), + case file:open(Name, [write, raw]) of + {ok, File} -> + R1 = file:write(File, Cookie), + file:close(File), + R2 = file:raw_write_file_info(Name, make_info(Name)), + case {R1, R2} of + {ok, ok} -> + ok; + {{error,_Reason}, _} -> + {error, "Failed to create cookie file"}; + {ok, {error, Reason}} -> + {error, "Failed to change mode: " ++ atom_to_list(Reason)} + end; + {error,_Reason} -> + {error, "Failed to create cookie file"} + end. + +random_cookie(0, _, Result) -> + Result; +random_cookie(Count, X0, Result) -> + X = next_random(X0), + Letter = X*($Z-$A+1) div 16#1000000000 + $A, + random_cookie(Count-1, X, [Letter|Result]). + +%% Returns suitable information for a new cookie. +%% +%% Note: Since the generated cookie depends on the time the file was +%% created, and the time can be seen plainly in the file, we will +%% round down the file creation times to the nearest midnight to +%% give crackers some more work. + +make_info(Name) -> + Midnight = + case file:raw_read_file_info(Name) of + {ok, #file_info{atime={Date, _}}} -> + {Date, {0, 0, 0}}; + _ -> + {{1990, 1, 1}, {0, 0, 0}} + end, + #file_info{mode=8#400, atime=Midnight, mtime=Midnight, ctime=Midnight}. + +%% This RNG is from line 21 on page 102 in Knuth: The Art of Computer Programming, +%% Volume II, Seminumerical Algorithms. +%% +%% Returns an integer in the range 0..(2^35-1). + +next_random(X) -> + (X*17059465+1) band 16#fffffffff. |