%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2007-2011. 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%
%%
%%----------------------------------------------------------------------
%% Purpose: Storage for trused certificats
%%----------------------------------------------------------------------
-module(ssl_certificate_db).
-include("ssl_internal.hrl").
-include_lib("public_key/include/public_key.hrl").
-export([create/0, remove/1, add_trusted_certs/3,
remove_trusted_certs/2, lookup_trusted_cert/4, issuer_candidate/2,
lookup_cached_certs/2, cache_pem_file/4, uncache_pem_file/2, lookup/2]).
-type time() :: {non_neg_integer(), non_neg_integer(), non_neg_integer()}.
%%====================================================================
%% Internal application API
%%====================================================================
%%--------------------------------------------------------------------
-spec create() -> [db_handle()].
%%
%% Description: Creates a new certificate db.
%% Note: lookup_trusted_cert/4 may be called from any process but only
%% the process that called create may call the other functions.
%%--------------------------------------------------------------------
create() ->
[ets:new(ssl_otp_certificate_db, [set, protected]),
ets:new(ssl_file_to_ref, [set, protected]),
ets:new(ssl_pid_to_file, [bag, private])].
%%--------------------------------------------------------------------
-spec remove([db_handle()]) -> term().
%%
%% Description: Removes database db
%%--------------------------------------------------------------------
remove(Dbs) ->
lists:foreach(fun(Db) -> true = ets:delete(Db) end, Dbs).
%%--------------------------------------------------------------------
-spec lookup_trusted_cert(db_handle(), certdb_ref(), serialnumber(), issuer()) ->
undefined | {ok, {der_cert(), #'OTPCertificate'{}}}.
%%
%% Description: Retrives the trusted certificate identified by
%% <SerialNumber, Issuer>. Ref is used as it is specified
%% for each connection which certificates are trusted.
%%--------------------------------------------------------------------
lookup_trusted_cert(DbHandle, Ref, SerialNumber, Issuer) ->
case lookup({Ref, SerialNumber, Issuer}, DbHandle) of
undefined ->
undefined;
[Certs] ->
{ok, Certs}
end.
lookup_cached_certs(DbHandle, File) ->
ets:lookup(DbHandle, {file, File}).
%%--------------------------------------------------------------------
-spec add_trusted_certs(pid(), string() | {der, list()}, [db_handle()]) -> {ok, [db_handle()]}.
%%
%% Description: Adds the trusted certificates from file <File> to the
%% runtime database. Returns Ref that should be handed to lookup_trusted_cert
%% together with the cert serialnumber and issuer.
%%--------------------------------------------------------------------
add_trusted_certs(_Pid, {der, DerList}, [CerDb, _,_]) ->
NewRef = make_ref(),
add_certs_from_der(DerList, NewRef, CerDb),
{ok, NewRef};
add_trusted_certs(Pid, File, [CertsDb, FileToRefDb, PidToFileDb]) ->
Ref = case lookup(File, FileToRefDb) of
undefined ->
NewRef = make_ref(),
add_certs_from_file(File, NewRef, CertsDb),
insert(File, NewRef, 1, FileToRefDb),
NewRef;
[OldRef] ->
ref_count(File,FileToRefDb,1),
OldRef
end,
insert(Pid, File, PidToFileDb),
{ok, Ref}.
%%--------------------------------------------------------------------
-spec cache_pem_file(pid(), string(), time(), [db_handle()]) -> term().
%%
%% Description: Cache file as binary in DB
%%--------------------------------------------------------------------
cache_pem_file(Pid, File, Time, [CertsDb, _FileToRefDb, PidToFileDb]) ->
{ok, PemBin} = file:read_file(File),
Content = public_key:pem_decode(PemBin),
insert({file, File}, {Time, Content}, CertsDb),
insert(Pid, File, PidToFileDb),
{ok, Content}.
%--------------------------------------------------------------------
-spec uncache_pem_file(string(), [db_handle()]) -> no_return().
%%
%% Description: If a cached file is no longer valid (changed on disk)
%% we must terminate the connections using the old file content, and
%% when those processes are finish the cache will be cleaned. It is
%% a rare but possible case a new ssl client/server is started with
%% a filename with the same name as previously started client/server
%% but with different content.
%% --------------------------------------------------------------------
uncache_pem_file(File, [_CertsDb, _FileToRefDb, PidToFileDb]) ->
Pids = select(PidToFileDb, [{{'$1', File},[],['$$']}]),
lists:foreach(fun([Pid]) ->
exit(Pid, shutdown)
end, Pids).
%%--------------------------------------------------------------------
-spec remove_trusted_certs(pid(), [db_handle()]) -> term().
%%
%% Description: Removes trusted certs originating from
%% the file associated to Pid from the runtime database.
%%--------------------------------------------------------------------
remove_trusted_certs(Pid, [CertsDb, FileToRefDb, PidToFileDb]) ->
Files = lookup(Pid, PidToFileDb),
delete(Pid, PidToFileDb),
Clear = fun(File) ->
delete({file,File}, CertsDb),
try
0 = ref_count(File, FileToRefDb, -1),
case lookup(File, FileToRefDb) of
[Ref] when is_reference(Ref) ->
remove_certs(Ref, CertsDb);
_ -> ok
end,
delete(File, FileToRefDb)
catch _:_ ->
ok
end
end,
case Files of
undefined -> ok;
_ ->
[Clear(File) || File <- Files],
ok
end.
%%--------------------------------------------------------------------
-spec issuer_candidate(no_candidate | cert_key() | {file, term()}, term()) ->
{cert_key(),{der_cert(), #'OTPCertificate'{}}} | no_more_candidates.
%%
%% Description: If a certificat does not define its issuer through
%% the extension 'ce-authorityKeyIdentifier' we can
%% try to find the issuer in the database over known
%% certificates.
%%--------------------------------------------------------------------
issuer_candidate(no_candidate, Db) ->
case ets:first(Db) of
'$end_of_table' ->
no_more_candidates;
{file, _} = Key ->
issuer_candidate(Key, Db);
Key ->
[Cert] = lookup(Key, Db),
{Key, Cert}
end;
issuer_candidate(PrevCandidateKey, Db) ->
case ets:next(Db, PrevCandidateKey) of
'$end_of_table' ->
no_more_candidates;
{file, _} = Key ->
issuer_candidate(Key, Db);
Key ->
[Cert] = lookup(Key, Db),
{Key, Cert}
end.
%%--------------------------------------------------------------------
-spec lookup(term(), db_handle()) -> term() | undefined.
%%
%% Description: Looks up an element in a certificat <Db>.
%%--------------------------------------------------------------------
lookup(Key, Db) ->
case ets:lookup(Db, Key) of
[] ->
undefined;
Contents ->
Pick = fun({_, Data}) -> Data;
({_,_,Data}) -> Data
end,
[Pick(Data) || Data <- Contents]
end.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
insert(Key, Data, Db) ->
true = ets:insert(Db, {Key, Data}).
insert(Key, Data, Count, Db) ->
true = ets:insert(Db, {Key, Count, Data}).
ref_count(Key, Db,N) ->
ets:update_counter(Db,Key,N).
delete(Key, Db) ->
_ = ets:delete(Db, Key).
select(Db, MatchSpec)->
ets:select(Db, MatchSpec).
remove_certs(Ref, CertsDb) ->
ets:match_delete(CertsDb, {{Ref, '_', '_'}, '_'}).
add_certs_from_der(DerList, Ref, CertsDb) ->
Add = fun(Cert) -> add_certs(Cert, Ref, CertsDb) end,
[Add(Cert) || Cert <- DerList].
add_certs_from_file(File, Ref, CertsDb) ->
Add = fun(Cert) -> add_certs(Cert, Ref, CertsDb) end,
{ok, PemBin} = file:read_file(File),
PemEntries = public_key:pem_decode(PemBin),
[Add(Cert) || {'Certificate', Cert, not_encrypted} <- PemEntries].
add_certs(Cert, Ref, CertsDb) ->
try ErlCert = public_key:pkix_decode_cert(Cert, otp),
TBSCertificate = ErlCert#'OTPCertificate'.tbsCertificate,
SerialNumber = TBSCertificate#'OTPTBSCertificate'.serialNumber,
Issuer = public_key:pkix_normalize_name(
TBSCertificate#'OTPTBSCertificate'.issuer),
insert({Ref, SerialNumber, Issuer}, {Cert,ErlCert}, CertsDb)
catch
error:_ ->
Report = io_lib:format("SSL WARNING: Ignoring a CA cert as "
"it could not be correctly decoded.~n", []),
error_logger:info_report(Report)
end.
