%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2007-2017. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%----------------------------------------------------------------------
%% Purpose: Manages ssl sessions and trusted certifacates
%%----------------------------------------------------------------------
-module(ssl_manager).
-behaviour(gen_server).
%% Internal application API
-export([start_link/1, start_link_dist/1,
connection_init/3, cache_pem_file/2,
lookup_trusted_cert/4,
new_session_id/1, clean_cert_db/2,
register_session/2, register_session/3, invalidate_session/2,
insert_crls/2, insert_crls/3, delete_crls/1, delete_crls/2,
invalidate_session/3, name/1]).
-export([init_session_validator/1]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
terminate/2, code_change/3]).
-include("ssl_handshake.hrl").
-include("ssl_internal.hrl").
-include_lib("kernel/include/file.hrl").
-record(state, {
session_cache_client :: db_handle(),
session_cache_server :: db_handle(),
session_cache_cb :: atom(),
session_lifetime :: integer(),
certificate_db :: db_handle(),
session_validation_timer :: reference(),
last_delay_timer = {undefined, undefined},%% Keep for testing purposes
session_cache_client_max :: integer(),
session_cache_server_max :: integer(),
session_server_invalidator :: undefined | pid(),
session_client_invalidator :: undefined | pid()
}).
-define(GEN_UNIQUE_ID_MAX_TRIES, 10).
-define(SESSION_VALIDATION_INTERVAL, 60000).
-define(CLEAN_SESSION_DB, 60000).
-define(CLEAN_CERT_DB, 500).
-define(DEFAULT_MAX_SESSION_CACHE, 1000).
-define(LOAD_MITIGATION, 10).
%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
-spec name(normal | dist) -> atom().
%%
%% Description: Returns the registered name of the ssl manager process
%% in the operation modes 'normal' and 'dist'.
%%--------------------------------------------------------------------
name(normal) ->
?MODULE;
name(dist) ->
list_to_atom(atom_to_list(?MODULE) ++ "_dist").
%%--------------------------------------------------------------------
-spec start_link(list()) -> {ok, pid()} | ignore | {error, term()}.
%%
%% Description: Starts the ssl manager that takes care of sessions
%% and certificate caching.
%%--------------------------------------------------------------------
start_link(Opts) ->
MangerName = name(normal),
CacheName = ssl_pem_cache:name(normal),
gen_server:start_link({local, MangerName},
?MODULE, [MangerName, CacheName, Opts], []).
%%--------------------------------------------------------------------
-spec start_link_dist(list()) -> {ok, pid()} | ignore | {error, term()}.
%%
%% Description: Starts a special instance of the ssl manager to
%% be used by the erlang distribution. Note disables soft upgrade!
%%--------------------------------------------------------------------
start_link_dist(Opts) ->
DistMangerName = name(dist),
DistCacheName = ssl_pem_cache:name(dist),
gen_server:start_link({local, DistMangerName},
?MODULE, [DistMangerName, DistCacheName, Opts], []).
%%--------------------------------------------------------------------
-spec connection_init(binary()| {der, list()}, client | server,
{Cb :: atom(), Handle:: term()}) ->
{ok, map()}.
%%
%% Description: Do necessary initializations for a new connection.
%%--------------------------------------------------------------------
connection_init({der, _} = Trustedcerts, Role, CRLCache) ->
{ok, Extracted} = ssl_pkix_db:extract_trusted_certs(Trustedcerts),
call({connection_init, Extracted, Role, CRLCache});
connection_init(Trustedcerts, Role, CRLCache) ->
call({connection_init, Trustedcerts, Role, CRLCache}).
%%--------------------------------------------------------------------
-spec cache_pem_file(binary(), term()) -> {ok, term()} | {error, reason()}.
%%
%% Description: Cache a pem file and return its content.
%%--------------------------------------------------------------------
cache_pem_file(File, DbHandle) ->
case ssl_pkix_db:lookup(File, DbHandle) of
[Content] ->
{ok, Content};
undefined ->
case ssl_pkix_db:decode_pem_file(File) of
{ok, Content} ->
ssl_pem_cache:insert(File, Content),
{ok, Content};
Error ->
Error
end
end.
%%--------------------------------------------------------------------
-spec lookup_trusted_cert(term(), reference(), serialnumber(), issuer()) ->
undefined |
{ok, {der_cert(), #'OTPCertificate'{}}}.
%%
%% Description: Lookup the trusted cert with Key = {reference(),
%% serialnumber(), issuer()}.
%% --------------------------------------------------------------------
lookup_trusted_cert(DbHandle, Ref, SerialNumber, Issuer) ->
ssl_pkix_db:lookup_trusted_cert(DbHandle, Ref, SerialNumber, Issuer).
%%--------------------------------------------------------------------
-spec new_session_id(integer()) -> session_id().
%%
%% Description: Creates a session id for the server.
%%--------------------------------------------------------------------
new_session_id(Port) ->
call({new_session_id, Port}).
%%--------------------------------------------------------------------
-spec clean_cert_db(reference(), binary()) -> ok.
%%
%% Description: Send clean request of cert db to ssl_manager process should
%% be called by ssl-connection processes.
%%--------------------------------------------------------------------
clean_cert_db(Ref, File) ->
erlang:send_after(?CLEAN_CERT_DB, get(ssl_manager),
{clean_cert_db, Ref, File}),
ok.
%%--------------------------------------------------------------------
%%
%% Description: Make the session available for reuse.
%%--------------------------------------------------------------------
-spec register_session(host(), inet:port_number(), #session{}) -> ok.
register_session(Host, Port, Session) ->
cast({register_session, Host, Port, Session}).
-spec register_session(inet:port_number(), #session{}) -> ok.
register_session(Port, Session) ->
cast({register_session, Port, Session}).
%%--------------------------------------------------------------------
%%
%% Description: Make the session unavailable for reuse. After
%% a the session has been marked "is_resumable = false" for some while
%% it will be safe to remove the data from the session database.
%%--------------------------------------------------------------------
-spec invalidate_session(host(), inet:port_number(), #session{}) -> ok.
invalidate_session(Host, Port, Session) ->
load_mitigation(),
cast({invalidate_session, Host, Port, Session}).
-spec invalidate_session(inet:port_number(), #session{}) -> ok.
invalidate_session(Port, Session) ->
load_mitigation(),
cast({invalidate_session, Port, Session}).
insert_crls(Path, CRLs)->
insert_crls(Path, CRLs, normal).
insert_crls(?NO_DIST_POINT_PATH = Path, CRLs, ManagerType)->
put(ssl_manager, name(ManagerType)),
cast({insert_crls, Path, CRLs});
insert_crls(Path, CRLs, ManagerType)->
put(ssl_manager, name(ManagerType)),
call({insert_crls, Path, CRLs}).
delete_crls(Path)->
delete_crls(Path, normal).
delete_crls(?NO_DIST_POINT_PATH = Path, ManagerType)->
put(ssl_manager, name(ManagerType)),
cast({delete_crls, Path});
delete_crls(Path, ManagerType)->
put(ssl_manager, name(ManagerType)),
call({delete_crls, Path}).
%%====================================================================
%% gen_server callbacks
%%====================================================================
%%--------------------------------------------------------------------
-spec init(list()) -> {ok, #state{}}.
%% Possible return values not used now.
%% | {ok, #state{}, timeout()} | ignore | {stop, term()}.
%%
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([ManagerName, PemCacheName, Opts]) ->
put(ssl_manager, ManagerName),
put(ssl_pem_cache, PemCacheName),
process_flag(trap_exit, true),
CacheCb = proplists:get_value(session_cb, Opts, ssl_session_cache),
SessionLifeTime =
proplists:get_value(session_lifetime, Opts, ?'24H_in_sec'),
CertDb = ssl_pkix_db:create(PemCacheName),
ClientSessionCache =
CacheCb:init([{role, client} |
proplists:get_value(session_cb_init_args, Opts, [])]),
ServerSessionCache =
CacheCb:init([{role, server} |
proplists:get_value(session_cb_init_args, Opts, [])]),
Timer = erlang:send_after(SessionLifeTime * 1000 + 5000,
self(), validate_sessions),
{ok, #state{certificate_db = CertDb,
session_cache_client = ClientSessionCache,
session_cache_server = ServerSessionCache,
session_cache_cb = CacheCb,
session_lifetime = SessionLifeTime,
session_validation_timer = Timer,
session_cache_client_max =
max_session_cache_size(session_cache_client_max),
session_cache_server_max =
max_session_cache_size(session_cache_server_max),
session_client_invalidator = undefined,
session_server_invalidator = undefined
}}.
%%--------------------------------------------------------------------
-spec handle_call(msg(), from(), #state{}) -> {reply, reply(), #state{}}.
%% Possible return values not used now.
%% {reply, reply(), #state{}, timeout()} |
%% {noreply, #state{}} |
%% {noreply, #state{}, timeout()} |
%% {stop, reason(), reply(), #state{}} |
%% {stop, reason(), #state{}}.
%%
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call({{connection_init, <<>>, Role, {CRLCb, UserCRLDb}}, _Pid}, _From,
#state{certificate_db = [CertDb, FileRefDb, PemChace | _] = Db} = State) ->
Ref = make_ref(),
{reply, {ok, #{cert_db_ref => Ref,
cert_db_handle => CertDb,
fileref_db_handle => FileRefDb,
pem_cache => PemChace,
session_cache => session_cache(Role, State),
crl_db_info => {CRLCb, crl_db_info(Db, UserCRLDb)}}}, State};
handle_call({{connection_init, Trustedcerts, Role, {CRLCb, UserCRLDb}}, Pid}, _From,
#state{certificate_db = [CertDb, FileRefDb, PemChace | _] = Db} = State) ->
case add_trusted_certs(Pid, Trustedcerts, Db) of
{ok, Ref} ->
{reply, {ok, #{cert_db_ref => Ref,
cert_db_handle => CertDb,
fileref_db_handle => FileRefDb,
pem_cache => PemChace,
session_cache => session_cache(Role, State),
crl_db_info => {CRLCb, crl_db_info(Db, UserCRLDb)}}}, State};
{error, _} = Error ->
{reply, Error, State}
end;
handle_call({{insert_crls, Path, CRLs}, _}, _From,
#state{certificate_db = Db} = State) ->
ssl_pkix_db:add_crls(Db, Path, CRLs),
{reply, ok, State};
handle_call({{delete_crls, CRLsOrPath}, _}, _From,
#state{certificate_db = Db} = State) ->
ssl_pkix_db:remove_crls(Db, CRLsOrPath),
{reply, ok, State};
handle_call({{new_session_id, Port}, _},
_, #state{session_cache_cb = CacheCb,
session_cache_server = Cache} = State) ->
Id = new_id(Port, ?GEN_UNIQUE_ID_MAX_TRIES, Cache, CacheCb),
{reply, Id, State}.
%%--------------------------------------------------------------------
-spec handle_cast(msg(), #state{}) -> {noreply, #state{}}.
%% Possible return values not used now.
%% | {noreply, #state{}, timeout()} |
%% {stop, reason(), #state{}}.
%%
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast({register_session, Host, Port, Session}, State0) ->
State = ssl_client_register_session(Host, Port, Session, State0),
{noreply, State};
handle_cast({register_session, Port, Session}, State0) ->
State = server_register_session(Port, Session, State0),
{noreply, State};
handle_cast({invalidate_session, Host, Port,
#session{session_id = ID} = Session},
#state{session_cache_client = Cache,
session_cache_cb = CacheCb} = State) ->
invalidate_session(Cache, CacheCb, {{Host, Port}, ID}, Session, State);
handle_cast({invalidate_session, Port, #session{session_id = ID} = Session},
#state{session_cache_server = Cache,
session_cache_cb = CacheCb} = State) ->
invalidate_session(Cache, CacheCb, {Port, ID}, Session, State);
handle_cast({insert_crls, Path, CRLs},
#state{certificate_db = Db} = State) ->
ssl_pkix_db:add_crls(Db, Path, CRLs),
{noreply, State};
handle_cast({delete_crls, CRLsOrPath},
#state{certificate_db = Db} = State) ->
ssl_pkix_db:remove_crls(Db, CRLsOrPath),
{noreply, State}.
%%--------------------------------------------------------------------
-spec handle_info(msg(), #state{}) -> {noreply, #state{}}.
%% Possible return values not used now.
%% |{noreply, #state{}, timeout()} |
%% {stop, reason(), #state{}}.
%%
%% Description: Handling all non call/cast messages
%%-------------------------------------------------------------------
handle_info(validate_sessions, #state{session_cache_cb = CacheCb,
session_cache_client = ClientCache,
session_cache_server = ServerCache,
session_lifetime = LifeTime,
session_client_invalidator = Client,
session_server_invalidator = Server
} = State) ->
Timer = erlang:send_after(?SESSION_VALIDATION_INTERVAL,
self(), validate_sessions),
CPid = start_session_validator(ClientCache, CacheCb, LifeTime, Client),
SPid = start_session_validator(ServerCache, CacheCb, LifeTime, Server),
{noreply, State#state{session_validation_timer = Timer,
session_client_invalidator = CPid,
session_server_invalidator = SPid}};
handle_info({delayed_clean_session, Key, Cache}, #state{session_cache_cb = CacheCb
} = State) ->
CacheCb:delete(Cache, Key),
{noreply, State};
handle_info({clean_cert_db, Ref, File},
#state{certificate_db = [CertDb, {RefDb, FileMapDb} | _]} = State) ->
case ssl_pkix_db:lookup(Ref, RefDb) of
undefined -> %% Alredy cleaned
ok;
_ ->
clean_cert_db(Ref, CertDb, RefDb, FileMapDb, File)
end,
{noreply, State};
handle_info({'EXIT', Pid, _}, #state{session_client_invalidator = Pid} = State) ->
{noreply, State#state{session_client_invalidator = undefined}};
handle_info({'EXIT', Pid, _}, #state{session_server_invalidator = Pid} = State) ->
{noreply, State#state{session_server_invalidator = undefined}};
handle_info(_Info, State) ->
{noreply, State}.
%%--------------------------------------------------------------------
-spec terminate(reason(), #state{}) -> ok.
%%
%% Description: This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any necessary
%% cleaning up. When it returns, the gen_server terminates with Reason.
%% The return value is ignored.
%%--------------------------------------------------------------------
terminate(_Reason, #state{certificate_db = Db,
session_cache_client = ClientSessionCache,
session_cache_server = ServerSessionCache,
session_cache_cb = CacheCb,
session_validation_timer = Timer}) ->
erlang:cancel_timer(Timer),
ssl_pkix_db:remove(Db),
catch CacheCb:terminate(ClientSessionCache),
catch CacheCb:terminate(ServerSessionCache),
ok.
%%--------------------------------------------------------------------
-spec code_change(term(), #state{}, list()) -> {ok, #state{}}.
%%
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
call(Msg) ->
gen_server:call(get(ssl_manager), {Msg, self()}, infinity).
cast(Msg) ->
gen_server:cast(get(ssl_manager), Msg).
validate_session(Host, Port, Session, LifeTime) ->
case ssl_session:valid_session(Session, LifeTime) of
true ->
ok;
false ->
invalidate_session(Host, Port, Session)
end.
validate_session(Port, Session, LifeTime) ->
case ssl_session:valid_session(Session, LifeTime) of
true ->
ok;
false ->
invalidate_session(Port, Session)
end.
start_session_validator(Cache, CacheCb, LifeTime, undefined) ->
spawn_link(?MODULE, init_session_validator,
[[get(ssl_manager), Cache, CacheCb, LifeTime]]);
start_session_validator(_,_,_, Pid) ->
Pid.
init_session_validator([SslManagerName, Cache, CacheCb, LifeTime]) ->
put(ssl_manager, SslManagerName),
CacheCb:foldl(fun session_validation/2,
LifeTime, Cache).
session_validation({{{Host, Port}, _}, Session}, LifeTime) ->
validate_session(Host, Port, Session, LifeTime),
LifeTime;
session_validation({{Port, _}, Session}, LifeTime) ->
validate_session(Port, Session, LifeTime),
LifeTime.
delay_time() ->
case application:get_env(ssl, session_delay_cleanup_time) of
{ok, Time} when is_integer(Time) ->
Time;
_ ->
?CLEAN_SESSION_DB
end.
max_session_cache_size(CacheType) ->
case application:get_env(ssl, CacheType) of
{ok, Size} when is_integer(Size) ->
Size;
_ ->
?DEFAULT_MAX_SESSION_CACHE
end.
invalidate_session(Cache, CacheCb, Key, Session, State) ->
case CacheCb:lookup(Cache, Key) of
undefined -> %% Session is already invalidated
{noreply, State};
#session{is_resumable = new} ->
CacheCb:delete(Cache, Key),
{noreply, State};
_ ->
delayed_invalidate_session(CacheCb, Cache, Key, Session, State)
end.
delayed_invalidate_session(CacheCb, Cache, Key, Session,
#state{last_delay_timer = LastTimer} = State) ->
%% When a registered session is invalidated we need to
%% wait a while before deleting it as there might be
%% pending connections that rightfully needs to look up
%% the session data but new connections should not get to
%% use this session.
CacheCb:update(Cache, Key, Session#session{is_resumable = false}),
TRef =
erlang:send_after(delay_time(), self(),
{delayed_clean_session, Key, Cache}),
{noreply, State#state{last_delay_timer =
last_delay_timer(Key, TRef, LastTimer)}}.
last_delay_timer({{_,_},_}, TRef, {LastServer, _}) ->
{LastServer, TRef};
last_delay_timer({_,_}, TRef, {_, LastClient}) ->
{TRef, LastClient}.
%% If we can not generate a not allready in use session ID in
%% ?GEN_UNIQUE_ID_MAX_TRIES we make the new session uncacheable The
%% value of ?GEN_UNIQUE_ID_MAX_TRIES is stolen from open SSL which
%% states : "If we can not find a session id in
%% ?GEN_UNIQUE_ID_MAX_TRIES either the RAND code is broken or someone
%% is trying to open roughly very close to 2^128 (or 2^256) SSL
%% sessions to our server"
new_id(_, 0, _, _) ->
<<>>;
new_id(Port, Tries, Cache, CacheCb) ->
Id = ssl_cipher:random_bytes(?NUM_OF_SESSION_ID_BYTES),
case CacheCb:lookup(Cache, {Port, Id}) of
undefined ->
Now = erlang:monotonic_time(),
%% New sessions can not be set to resumable
%% until handshake is compleate and the
%% other session values are set.
CacheCb:update(Cache, {Port, Id}, #session{session_id = Id,
is_resumable = new,
time_stamp = Now}),
Id;
_ ->
new_id(Port, Tries - 1, Cache, CacheCb)
end.
clean_cert_db(Ref, CertDb, RefDb, FileMapDb, File) ->
case ssl_pkix_db:ref_count(Ref, RefDb, 0) of
0 ->
ssl_pkix_db:remove(Ref, RefDb),
ssl_pkix_db:remove(File, FileMapDb),
ssl_pkix_db:remove_trusted_certs(Ref, CertDb);
_ ->
ok
end.
ssl_client_register_session(Host, Port, Session, #state{session_cache_client = Cache,
session_cache_cb = CacheCb,
session_cache_client_max = Max,
session_client_invalidator = Pid0} = State) ->
TimeStamp = erlang:monotonic_time(),
NewSession = Session#session{time_stamp = TimeStamp},
case CacheCb:select_session(Cache, {Host, Port}) of
no_session ->
Pid = do_register_session({{Host, Port},
NewSession#session.session_id},
NewSession, Max, Pid0, Cache, CacheCb),
State#state{session_client_invalidator = Pid};
Sessions ->
register_unique_session(Sessions, NewSession, {Host, Port}, State)
end.
server_register_session(Port, Session, #state{session_cache_server_max = Max,
session_cache_server = Cache,
session_cache_cb = CacheCb,
session_server_invalidator = Pid0} = State) ->
TimeStamp = erlang:monotonic_time(),
NewSession = Session#session{time_stamp = TimeStamp},
Pid = do_register_session({Port, NewSession#session.session_id},
NewSession, Max, Pid0, Cache, CacheCb),
State#state{session_server_invalidator = Pid}.
do_register_session(Key, Session, Max, Pid, Cache, CacheCb) ->
try CacheCb:size(Cache) of
Size when Size >= Max ->
invalidate_session_cache(Pid, CacheCb, Cache);
_ ->
CacheCb:update(Cache, Key, Session),
Pid
catch
error:undef ->
CacheCb:update(Cache, Key, Session),
Pid
end.
%% Do not let dumb clients create a gigantic session table
%% for itself creating big delays at connection time.
register_unique_session(Sessions, Session, PartialKey,
#state{session_cache_client_max = Max,
session_cache_client = Cache,
session_cache_cb = CacheCb,
session_client_invalidator = Pid0} = State) ->
case exists_equivalent(Session , Sessions) of
true ->
State;
false ->
Pid = do_register_session({PartialKey,
Session#session.session_id},
Session, Max, Pid0, Cache, CacheCb),
State#state{session_client_invalidator = Pid}
end.
exists_equivalent(_, []) ->
false;
exists_equivalent(#session{
peer_certificate = PeerCert,
own_certificate = OwnCert,
compression_method = Compress,
cipher_suite = CipherSuite,
srp_username = SRP,
ecc = ECC} ,
[#session{
peer_certificate = PeerCert,
own_certificate = OwnCert,
compression_method = Compress,
cipher_suite = CipherSuite,
srp_username = SRP,
ecc = ECC} | _]) ->
true;
exists_equivalent(Session, [ _ | Rest]) ->
exists_equivalent(Session, Rest).
add_trusted_certs(Pid, Trustedcerts, Db) ->
try
ssl_pkix_db:add_trusted_certs(Pid, Trustedcerts, Db)
catch
_:Reason ->
{error, Reason}
end.
session_cache(client, #state{session_cache_client = Cache}) ->
Cache;
session_cache(server, #state{session_cache_server = Cache}) ->
Cache.
crl_db_info([_,_,_,Local], {internal, Info}) ->
{Local, Info};
crl_db_info(_, UserCRLDb) ->
UserCRLDb.
%% Only start a session invalidator if there is not
%% one already active
invalidate_session_cache(undefined, CacheCb, Cache) ->
start_session_validator(Cache, CacheCb, {invalidate_before, erlang:monotonic_time()}, undefined);
invalidate_session_cache(Pid, _CacheCb, _Cache) ->
Pid.
load_mitigation() ->
MSec = rand:uniform(?LOAD_MITIGATION),
receive
after
MSec ->
continue
end.
