nickva commented on code in PR #6069: URL: https://github.com/apache/couchdb/pull/6069#discussion_r3917061551
########## src/couch_replicator/src/couch_replicator_auth_ibm.erl: ########## @@ -0,0 +1,793 @@ +% 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. + +% This module allows a replication source or target to use an IAM api key for authentication. +% +% Features; +% +% Automatic refreshing of time-limited token before expiration +% Deduplication - only one token will be acquired for each distinct IAM api key +% +% Implementation details +% +% As api keys are sensitive, the only copy of api keys is held in a private ETS table +% owned by this module's gen_server. An opaque reference is returned to clients (this is +% a message authentication code where the key is a non-persisted value generated by the +% gen_server) + +-module(couch_replicator_auth_ibm). + +-behaviour(couch_replicator_auth). +-behaviour(gen_server). +-behaviour(config_listener). + +-export([ + sup_initialize/0, + sup_cleanup/1, + initialize/1, + update_headers/2, + handle_response/3, + cleanup/1 +]). + +%% gen_server callbacks +-export([ + init/1, + handle_call/3, + handle_cast/2, + handle_info/2, + terminate/2 +]). + +% config_listener callbacks +-export([ + handle_config_change/5, + handle_config_terminate/3 +]). + +-include_lib("couch_replicator/include/couch_replicator_api_wrap.hrl"). + +-define(MINUTE, 60). +-define(PUBLIC, couch_replicator_auth_ibm_public). +-define(PRIVATE, couch_replicator_auth_ibm_private). + +-record(worker_state, { + api_key_mac, + last_used +}). + +-record(state, { + gun_mref, + gun_pid, + mac_key, + token_uri_map +}). + +-record(public_entry, { + api_key_mac, + token +}). + +-record(private_entry, { + api_key_mac, + api_key_uuid, + api_key, + expires_ref, + gun_body = [], + gun_status_code, + gun_stream_ref, + last_used, + refresh_ref, + token_updated_at, + waiters = [] +}). + +%% callbacks + +sup_initialize() -> + application:ensure_all_started(gun), + {ok, _} = gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). + +sup_cleanup(_) -> + ok = gen_server:stop(?MODULE). + +initialize(#httpdb{} = HttpDb) -> + case extract_api_key(HttpDb) of + {ok, APIKey} -> + case gen_server:call(?MODULE, {register, APIKey}) of + {ok, APIKeyMAC} -> + WorkerState = #worker_state{api_key_mac = APIKeyMAC, last_used = now_secs()}, + {ok, HttpDb, WorkerState}; + {error, Reason} -> + {error, Reason} + end; + {error, _} -> + ignore + end. + +update_headers(WorkerState, Headers) when is_list(Headers) -> + case get_token(WorkerState) of + {ok, Token} -> + { + [{~"Authorization", <<"Bearer ", Token/binary>>} | Headers], + update_last_used(WorkerState) + }; + {error, Reason} -> + couch_log:warning("Error when retrieving token: ~p", [Reason]), + {Headers, WorkerState} + end. + +handle_response(WorkerState, _StatusCode, _Headers) -> + {continue, WorkerState}. + +cleanup(_WorkerState) -> + ok. + +get_token(#worker_state{} = WorkerState) -> + #worker_state{api_key_mac = APIKeyMAC} = WorkerState, + case ets:lookup(?PUBLIC, APIKeyMAC) of + [#public_entry{token = Token}] when is_binary(Token) -> + {ok, Token}; + [#public_entry{}] -> + gen_server:call(?MODULE, {get_token, APIKeyMAC}, token_timeout()); + [] -> + {error, no_token} + end. + +update_last_used(#worker_state{} = WorkerState) -> + #worker_state{api_key_mac = APIKeyMAC, last_used = LastUsed} = WorkerState, + Now = now_secs(), + %% only send a message once per minute at most. + case Now - LastUsed > ?MINUTE of + true -> + ?MODULE ! {update_last_used, APIKeyMAC}, + WorkerState#worker_state{last_used = Now}; + false -> + WorkerState + end. + +%% gen_server callbacks. + +init(_) -> + case token_uri_map() of + {ok, TokenURIMap} -> + ?PUBLIC = ets:new(?PUBLIC, [protected, {keypos, #public_entry.api_key_mac}, named_table]), + ?PRIVATE = ets:new(?PRIVATE, [ + private, {keypos, #private_entry.api_key_mac}, named_table + ]), + ok = config:listen_for_changes(?MODULE, nil), + start_gun(#state{ + mac_key = crypto:strong_rand_bytes(32), + token_uri_map = TokenURIMap + }); + {error, Reason} -> + {error, Reason} + end. + +handle_call({register, APIKey}, _From, State) -> + case ets:match_object(?PRIVATE, #private_entry{api_key = APIKey, _ = '_'}) of + [#private_entry{} = Entry] -> + self() ! {update_last_used, Entry#private_entry.api_key_mac}, + {reply, {ok, Entry#private_entry.api_key_mac}, State}; + [] -> + GunStreamRef = acquire_token(APIKey, State), + APIKeyMAC = mac(State#state.mac_key, APIKey), + true = ets:insert_new(?PUBLIC, #public_entry{ + api_key_mac = APIKeyMAC + }), + true = ets:insert_new(?PRIVATE, #private_entry{ + api_key = APIKey, + api_key_mac = APIKeyMAC, + gun_stream_ref = GunStreamRef, + last_used = now_secs() + }), + {reply, {ok, APIKeyMAC}, State} + end; +handle_call({get_token, APIKeyMAC}, From, State) -> + case ets:lookup(?PUBLIC, APIKeyMAC) of + [] -> + {reply, {error, no_such_api_key}, State}; + [#public_entry{token = Token}] when Token /= undefined -> + {reply, {ok, Token}, State}; + [#public_entry{}] -> + [#private_entry{} = Entry] = ets:lookup(?PRIVATE, APIKeyMAC), + ets:insert(?PRIVATE, Entry#private_entry{waiters = [From | Entry#private_entry.waiters]}), + case Entry of + #private_entry{gun_stream_ref = GunStreamRef} when + GunStreamRef /= undefined + -> + ok; + #private_entry{} -> + self() ! {refresh_token, APIKeyMAC} + end, + {noreply, State} + end; +handle_call(_Msg, _From, State) -> + {reply, {error, unexpected_msg}, State}. + +handle_cast(_Msg, State) -> + {noreply, State}. + +handle_info({update_last_used, APIKeyMAC}, State) -> + ets:update_element(?PRIVATE, APIKeyMAC, {#private_entry.last_used, now_secs()}), + {noreply, State}; +handle_info({refresh_token, APIKeyMAC}, State) -> + case ets:lookup(?PRIVATE, APIKeyMAC) of + [] -> + ok; + [#private_entry{gun_stream_ref = undefined} = Entry] -> + case Entry#private_entry.last_used > Entry#private_entry.token_updated_at of + true -> + couch_log:notice("~p: refreshing api key ~s", [ + ?MODULE, Entry#private_entry.api_key_uuid + ]), + GunStreamRef = acquire_token(Entry#private_entry.api_key, State), + ets:insert(?PRIVATE, Entry#private_entry{gun_stream_ref = GunStreamRef}); + false -> + %% let it expire + ok + end; + [#private_entry{}] -> + ok + end, + {noreply, State}; +handle_info({expire_api_key_entry, APIKeyMAC}, State) -> + case ets:lookup(?PRIVATE, APIKeyMAC) of + [] -> + ok; + [#private_entry{} = Entry] -> + couch_log:warning("~p: api key entry ~s passed expiration time", [ + ?MODULE, Entry#private_entry.api_key_uuid + ]), + ets:delete(?PUBLIC, APIKeyMAC), + ets:delete(?PRIVATE, APIKeyMAC), + cancel_timer(Entry#private_entry.refresh_ref), + cancel_timer(Entry#private_entry.expires_ref), + reply_all(Entry, {error, expired_api_key_entry}) + end, + {noreply, State}; +handle_info( + {gun_response, GunPid, GunStreamRef, fin, StatusCode, _Headers}, + #state{gun_pid = GunPid} = State +) -> + case match_on_gun_stream_ref(GunStreamRef) of + [#private_entry{} = Entry] -> + reply_and_reset(Entry, {error, {unexpected_status_code, StatusCode}}); + _ -> + ok + end, + {noreply, State}; +handle_info( + {gun_response, GunPid, GunStreamRef, nofin, StatusCode, _Headers}, + #state{gun_pid = GunPid} = State +) -> + case match_on_gun_stream_ref(GunStreamRef) of + [#private_entry{} = Entry] -> + ets:insert(?PRIVATE, Entry#private_entry{gun_status_code = StatusCode}); + _ -> + couch_log:warning("NO MATCH", []), Review Comment: Debug line? -- This is an automated message from the Apache Git Service. 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