Introduce the authentication handler.

The user handler will also receive the ability to answer with
JSON bodies soon.
main
absc 2024-08-09 22:19:17 +00:00
parent 51675065a9
commit dcc7bc3ca3
4 changed files with 263 additions and 2 deletions

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@ -3,7 +3,7 @@
{vsn,"1.0.0"},
{modules,[dudeswave,dudeswave_app,dudeswave_handler,
dudeswave_user_handler,dudeswave_supervisor,
dudeswave_auth]},
dudeswave_auth,dudeswave_auth_handler]},
{registered,[]},
{applications,[kernel,stdlib,erts,cowboy,ranch]},
{mod,{dudeswave_app,[]}},

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@ -6,6 +6,7 @@ ERLC?= erlc -server
OBJS= dudeswave.beam dudeswave_app.beam
OBJS+= dudeswave_supervisor.beam dudeswave_handler.beam
OBJS+= dudeswave_user_handler.beam dudeswave_auth.beam
OBJS+= dudeswave_auth_handler.beam
all: ${OBJS}

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@ -27,7 +27,7 @@ from the dudeswave database.
-include_lib("storage/include/storage.hrl").
-export([authenticate/3, authenticate/4, details/2, new/4,
update/5, delete/2]).
update/5, delete/2, logout/3]).
-doc """
Verify a session with an existing cookie.
@ -130,6 +130,38 @@ authenticate(User, Password, Cookies, Bucket) ->
{error, Reason} -> {error, Reason}
end.
-doc """
Close an existing session
Spec:
```
-spec logout(User, Cookie, Bucket) -> ok | {error, Reason} when
User :: binary(),
Cookie :: binary(),
Bucket :: atom(),
Reason :: term().
```
Invalidate and delete `Cookie` associated with `User` from the system.
""".
-spec logout(User, Cookie, Bucket) -> ok | {error, Reason} when
User :: binary(),
Cookie :: binary(),
Bucket :: atom(),
Reason :: term().
logout(User, Cookie, Bucket) ->
case storage:read(Bucket, Cookie) of
{ok, [R]} ->
{user, User} = lists:keyfind(user, 1, R#object.metadata),
storage:delete(Bucket, Cookie);
{ok, []} ->
{error, not_found};
{error, Reason} ->
{error, Reason}
end.
-doc """
Return user details.

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@ -0,0 +1,228 @@
%
% Copyright (c) 2024 Andrea Biscuola <a@abiscuola.com>
%
% Permission to use, copy, modify, and distribute this software for any
% purpose with or without fee is hereby granted, provided that the above
% copyright notice and this permission notice appear in all copies.
%
% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%
-module(dudeswave_auth_handler).
-moduledoc """
JSON API to authenticate users.
```
/api/v1/auth
```
Cookies used in this module are:
```
dudename: The username.
dudeauth: Authentication cookie.
This module accepts four methods:
- POST /api/v1/auth
Authenticate a user with it's password. If successful, set the new
cookies with the authentication details in the browser.
- DELETE /api/v1/auth
Logout the user from the current session and invalidate all the
authentication cookies, if present.
If an operation fails, the response JSON is in the form:
```
{
"error": "error string"
}
```
JSON APIs
POST /api/v1/auth
```
{
"user": "foo",
"password": "SecurePassword123",
}
```
Response codes:
- 200 OK
- 400 Bad Request
- 404 Not Found
Response body:
If authentication successful:
```
{
"result": "ok"
}
```
DELETE /api/v1/auth
- 202 Accepted
- 404 Not Found
If operation successful;
```
{
"result": "deleted"
}
```
""".
-behaviour(cowboy_handler).
-export([init/2, terminate/3]).
%
% Callbacks exports
%
-export([allowed_methods/2, content_types_accepted/2,
known_methods/2, is_authorized/2, forbidden/2,
resource_exists/2, is_conflict/2, previously_existed/2,
allow_missing_post/2, delete_resource/2, delete_completed/2,
login/2, logout/2]).
%
% Cowboy standard callbacks
%
init(Req, State) ->
{cowboy_rest, Req, State}.
known_methods(Req, State) ->
{[<<"POST">>, <<"DELETE">>], Req, State}.
allowed_methods(Req, State) ->
{[<<"POST">>, <<"DELETE">>], Req, State}.
is_authorized(Req, State) -> {true, Req, State}.
forbidden(Req, State) ->
case cowboy_req:method(Req) of
<<"POST">> ->
{false, Req, State};
_ ->
#{dudeauth := Auth, dudename := User} = cowboy_req:match_cookies([dudeauth,
dudename], Req),
{ok, Bucket} = maps:find(cookies, State),
case dudeswave_auth:authenticate(User, Auth, Bucket) of
{error, service_unavailable} -> exit(service_unavailable);
true -> {false, Req, State};
false ->
Resp = json:encode(#{<<"error">> => <<"authentication required">>}),
Req0 = cowboy_req:reply(403, #{}, Resp, Req),
{true, Req0, State}
end
end.
content_types_accepted(Req, State) ->
case cowboy_req:method(Req) of
<<"POST">> ->
{[{<<"application/json">>, login}], Req, State};
<<"DELETE">> ->
{[{<<"application/json">>, logout}], Req, State}
end.
resource_exists(Req, State) ->
#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
{ok, Bucket} = maps:find(bucket, State),
case dudeswave_auth:user_details(User, Bucket) of
[] ->
Resp = json:encode(#{<<"error">> => <<"user does not exists">>}),
Req0 = cowboy_req:reply(404, #{}, Resp, Req),
{false, Req0, State};
{error, Reason} -> exit(Reason);
_ ->
NewState = State#{
bucket => Bucket,
user_exists => true
},
{true, Req, NewState}
end.
previously_existed(Req, State) -> {false, Req, State}.
is_conflict(Req, #{user_exists := true}) ->
{false, Req, []};
is_conflict(Req, State) -> {true, Req, State}.
allow_missing_post(Req, State) -> {false, Req, State}.
delete_resource(Req, State) ->
{ok, Bucket} = maps:find(bucket, State),
#{dudename := User, dudeauth := Auth} = cowboy_req:match_cookies([dudename,
dudeauth], Req),
case dudeswave_auth:logout(User, Auth, Bucket) of
ok ->
Req0 = cowboy_req:set_resp_cookie(<<"dudeauth">>, Auth, Req,
#{max_age => 0}),
Req1 = cowboy_req:set_resp_cookie(<<"dudename">>, User, Req0,
#{max_age => 0}),
Resp = json:encode(#{<<"result">> => <<"deleted">>}),
Req2 = cowboy_req:reply(200, #{}, Resp, Req1),
{true, Req2, State};
{error, _} -> {false, Req, State}
end.
delete_completed(Req, State) -> {false, Req, State}.
%
% Custom callbacks
%
login(Req, State) ->
{ok, Cookies} = maps:find(State, cookies),
{ok, Bucket} = maps:find(State, bucket),
{ok, Data, Req0} = cowboy_req:read_body(Req),
#{<<"user">> := User, <<"password">> := Pass} = json:decode(Data),
case dudeswave_auth:authenticate(User, Pass, Cookies, Bucket) of
{true, Cookie, Validity} ->
Resp = json:encode(#{<<"result">> => <<"ok">>}),
Req1 = cowboy_req:set_resp_cookie(<<"dudeauth">>, Cookie, Req0,
#{max_age => Validity}),
Req2 = cowboy_req:set_resp_cookie(<<"dudename">>, User, Req1,
#{max_age => Validity}),
Req3 = cowboy_req:reply(200, #{}, Resp, Req2),
{true, Req3, State};
false ->
Resp = json:encode(#{<<"error">> => <<"authentication failed">>}),
Req1 = cowboy_req:reply(401, #{}, Resp, Req0),
{false, Req1, State};
{error, _} ->
Resp = json:encode(#{<<"error">> => <<"internal error">>}),
Req1 = cowboy_req:reply(500, #{}, Resp, Req0),
{false, Req1, State}
end.
% Provided but not used
logout(Req, State) -> {ok, Req, State}.
%
% gen_server callbacks
%
terminate(_Reason, _Req, _State) -> ok.