%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2007-2010. 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_lib("public_key/include/public_key.hrl").
-export([create/0, remove/1, add_trusted_certs/3,
remove_trusted_certs/2, lookup_trusted_cert/3, issuer_candidate/1,
lookup_cached_certs/1, cache_pem_file/3]).
%%====================================================================
%% Internal application API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: create() -> Db
%% Db = term() - Reference to the crated database
%%
%% Description: Creates a new certificate db.
%% Note: lookup_trusted_cert/3 may be called from any process but only
%% the process that called create may call the other functions.
%%--------------------------------------------------------------------
create() ->
[ets:new(certificate_db_name(), [named_table, set, protected]),
ets:new(ssl_file_to_ref, [named_table, set, protected]),
ets:new(ssl_pid_to_file, [bag, private])].
%%--------------------------------------------------------------------
%% Function: delete(Db) -> _
%% Db = Database refererence as returned by create/0
%%
%% Description: Removes database db
%%--------------------------------------------------------------------
remove(Dbs) ->
lists:foreach(fun(Db) -> true = ets:delete(Db) end, Dbs).
%%--------------------------------------------------------------------
%% Function: lookup_trusted_cert(Ref, SerialNumber, Issuer) -> {BinCert,DecodedCert}
%% Ref = ref()
%% SerialNumber = integer()
%% Issuer = {rdnSequence, IssuerAttrs}
%% BinCert = binary()
%%
%% 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(Ref, SerialNumber, Issuer) ->
case lookup({Ref, SerialNumber, Issuer}, certificate_db_name()) of
undefined ->
undefined;
[Certs] ->
{ok, Certs}
end.
lookup_cached_certs(File) ->
ets:lookup(certificate_db_name(), {file, File}).
%%--------------------------------------------------------------------
%% Function: add_trusted_certs(Pid, File, Db) -> {ok, Ref}
%% Pid = pid()
%% File = string()
%% Db = Database refererence as returned by create/0
%% Ref = ref()
%%
%% 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, 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}.
%%--------------------------------------------------------------------
%% Function: cache_pem_file(Pid, File, Db) -> FileContent
%%
%% Description: Cache file as binary in DB
%%--------------------------------------------------------------------
cache_pem_file(Pid, File, [CertsDb, _FileToRefDb, PidToFileDb]) ->
Res = {ok, Content} = public_key:pem_to_der(File),
insert({file, File}, Content, CertsDb),
insert(Pid, File, PidToFileDb),
Res.
%%--------------------------------------------------------------------
%% Function: remove_trusted_certs(Pid, Db) -> _
%%
%% 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.
%%--------------------------------------------------------------------
%% Function: issuer_candidate() -> {Key, Candidate} | no_more_candidates
%%
%% Candidate
%%
%%
%% 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 = certificate_db_name(),
case ets:first(Db) of
'$end_of_table' ->
no_more_candidates;
{file, _} = Key ->
issuer_candidate(Key);
Key ->
[Cert] = lookup(Key, Db),
{Key, Cert}
end;
issuer_candidate(PrevCandidateKey) ->
Db = certificate_db_name(),
case ets:next(Db, PrevCandidateKey) of
'$end_of_table' ->
no_more_candidates;
{file, _} = Key ->
issuer_candidate(Key);
Key ->
[Cert] = lookup(Key, Db),
{Key, Cert}
end.
%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
certificate_db_name() ->
ssl_otp_certificate_db.
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).
lookup(Key, Db) ->
case ets:lookup(Db, Key) of
[] ->
undefined;
Contents ->
Pick = fun({_, Data}) -> Data;
({_,_,Data}) -> Data
end,
[Pick(Data) || Data <- Contents]
end.
remove_certs(Ref, CertsDb) ->
ets:match_delete(CertsDb, {{Ref, '_', '_'}, '_'}).
add_certs_from_file(File, Ref, CertsDb) ->
Decode = fun(Cert) ->
{ok, ErlCert} = public_key:pkix_decode_cert(Cert, otp),
TBSCertificate = ErlCert#'OTPCertificate'.tbsCertificate,
SerialNumber = TBSCertificate#'OTPTBSCertificate'.serialNumber,
Issuer = public_key:pkix_normalize_general_name(
TBSCertificate#'OTPTBSCertificate'.issuer),
insert({Ref, SerialNumber, Issuer}, {Cert,ErlCert}, CertsDb)
end,
{ok,Der} = public_key:pem_to_der(File),
[Decode(Cert) || {cert, Cert, not_encrypted} <- Der].
