Introduce the authentication handler.

The user handler will also receive the ability to answer with
JSON bodies soon.

dudeswave/ebin/dudeswave.app

@@ -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,[]}},

dudeswave/src/Makefile

@@ -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}
 

dudeswave/src/dudeswave_app.erl

@@ -40,7 +40,7 @@ start(_Type, StartArgs) ->
 
 	Dispatch = cowboy_router:compile([
 	    {'_', [
-	        {"/user/:username", dudeswave_user_handler, #{bucket => ?USERSBUCK,
+	        {"/api/v1/user", dudeswave_user_handler, #{bucket => ?USERSBUCK,
 	            cookies => ?COOKIESBUCK}},
 	        {"/", dudeswave_handler, #{bucket => ?APPBUCK}}
 	    ]}

dudeswave/src/dudeswave_auth.erl

@@ -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.
@@ -55,11 +55,13 @@ authenticate(User, Cookie, Bucket) ->
 	case storage:read(Bucket, Cookie) of
 		{ok, [R]} ->
 			CurTime = calendar:now_to_universal_time(erlang:timestamp()),
-			CookieTime = lists:keyfind(until, 1, R#object.metadata),
+			CookieTime = R#object.value,
+			CookieUser = lists:keyfind(user, 1, R#object.metadata),
+
 			if
 				CookieTime >= CurTime ->
 					if
-						User =:= R#object.value -> true;
+						User =:= CookieUser -> true;
 						true -> false
 					end;
 				true -> false
@@ -118,7 +120,7 @@ authenticate(User, Password, Cookies, Bucket) ->
 			if
 				Auth =:= Hash ->
 					Cookie = base64:encode(rand:bytes(64)),
-					case storage:write(Cookies, <<Cookie/binary>>, User, [{until, Validity}]) of
+					case storage:write(Cookies, <<Cookie/binary>>, Validity, [{user, User}]) of
 						ok -> {true, Cookie, Validity};
 						{error, Reason} -> {error, Reason}
 					end;
@@ -128,6 +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.
 

dudeswave/src/dudeswave_auth_handler.erl

@@ -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.

dudeswave/src/dudeswave_user_handler.erl

@@ -17,33 +17,28 @@
 -moduledoc """
 JSON API to manage users.
 
-The username should be passed as one of the tokens of the request path, like
+The username is passed in a cookie. The handler recover it from the
+session. Cookies are:
 
 ```
-/user/foo
-/user/foo/details
+dudename # the actual username
+dudeauth # the authentication cookie
 ```
 
-However, the first form is preferred.
-
-The user parameter must be called `username` as this module expects it
-in order to work properly. All the requests must be done with a valid
-session cookie in order to work.
-
 If the session is not valid, all the requests will return `403 Forbidden` to
 the client. In case a technical problem occurs, `500 Internal Server Error`
 is returned.
 
 This module accepts four methods:
 
-- GET /user/:username
+- GET /api/v1/user
 	Retrieve user's details. However, this call requires the user to have
 	a valid cookie set. Not suitable for a public page.
 
-- POST /user/:username
+- POST /api/v1/user
 	Update user's details, like their name, description and whatnot.
 
-- DELETE /user/:username
+- DELETE /api/v1/user
 	Remove a user forever. The data is delete immediately. However,
 	it's content is left up there. Probably a specific option will be added
 	later. This request does not have a body. The call deletes the user
@@ -51,7 +46,7 @@ This module accepts four methods:
 	for the simple reason that we may make the call asynchronous
 	to remove additional content in background.
 
-- PUT /user/:username
+- PUT /api/v1/user
 	Register a user. The registration takes only three parameter: username,
 	password and e-mail. The e-mail is required if a confirmation message
 	is to be sent. The plan is to have a separate process handle this, so the
@@ -59,10 +54,11 @@ This module accepts four methods:
 
 JSON APIs
 
-GET /user/:username
+GET /api/v1/user
 
 ```
 {
+	"user" : "foo",
 	"email": "foo@example.com",
 	"description": "A wonderful user",
 	"name": "Fantastic Foo"
@@ -74,7 +70,7 @@ Response codes:
 - 200 OK (Success)
 - 404 Not Found
 
-PUT /user/:username
+PUT /api/v1/user
 
 ```
 {
@@ -89,7 +85,7 @@ Response codes:
 - 400 Bad Request
 - 409 Conflict (User already exists)
 
-POST /user/:username
+POST /api/v1/user
 
 ```
 {
@@ -105,12 +101,11 @@ Response codes:
 - 400 Bad Request
 - 404 Not Found
 
-DELETE /user/:username
+DELETE /api/v1/user
 
 - 202 Accepted
 - 404 Not Found
 
-
 """.
 
 -behaviour(cowboy_handler).
@@ -146,9 +141,9 @@ forbidden(Req, State) ->
 		<<"PUT">> ->
 			{false, Req, State};
 		_ ->
-			#{dudeauth := Auth} = cowboy_req:match_cookies([dudeauth], Req),
+			#{dudeauth := Auth, dudename := User} = cowboy_req:match_cookies([dudeauth,
+			    dudename], Req),
 			{ok, Bucket} = maps:find(cookies, State),
-			User = cowboy_req:binding(username, Req),
 
 			case dudeswave_auth:authenticate({cookie, User, Auth}, Bucket) of
 				{error, service_unavailable} -> exit(service_unavailable);
@@ -178,7 +173,7 @@ content_types_accepted(Req, State) ->
 	end.
 
 resource_exists(Req, State) ->
-	User = cowboy_req:binding(username, Req),
+	#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
 	{ok, Bucket} = maps:find(bucket, State),
 
 	case dudeswave_auth:user_details(User, Bucket) of
@@ -205,7 +200,7 @@ allow_missing_post(Req, State) -> {false, Req, State}.
 
 delete_resource(Req, State) ->
 	{ok, Bucket} = maps:find(bucket, State),
-	User = cowboy_req:binding(username, Req),
+	#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
 
 	case dudeswave_auth:delete(User, Bucket) of
 		ok -> {true, Req, State};
@@ -220,7 +215,7 @@ delete_completed(Req, State) -> {false, Req, State}.
 
 create_user(Req, State) ->
 	{ok, Bucket} = maps:find(bucket, State),
-	User = cowboy_req:binding(username, Req),
+	#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
 
 	#{<<"password">> := Pass, <<"email">> := Email}  = json:decode(cowboy_req:body(req)),
 
@@ -231,7 +226,7 @@ create_user(Req, State) ->
 
 modify_user(Req, State) ->
 	{ok, Bucket} = maps:find(bucket, State),
-	User = cowboy_req:binding(username, Req),
+	#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
 
 	#{<<"email">> := Email, <<"description">> := Desc,
 	    <<"name">> := Name} = json:decode(cowboy_req:body(req)),
@@ -243,8 +238,10 @@ modify_user(Req, State) ->
 
 user_details(Req, State) ->
 	#{details := Details} = State,
+	#{dudename := User} = cowboy_req:match_cookies([dudename], Req),
+	Data = Details#{user => User},
 
-	{iolist_to_binary(json:encode(Details)), Req, State}.
+	{iolist_to_binary(json:encode(Data)), Req, State}.
 
 %
 % gen_server callbacks