EAUTH

Authorization library for Synrc Erlang Stack

Overview

• Simple e-mail authorization library for your web-application on n2o / kvs.

Dependency

• WebSocket Application Server for Enterprises n2o
• Abstract Term Database kvs
• SMTP server and client gen_smtp
• Unicode eXtention ux

Installation

Open you project and modify dependency section in file rebar.config:

{deps, [
    
    ***
    
    {eauth,       ".*", {git, "git://github.com/erlang-one/eauth",      {tag, "master"} }}
]}.

Open you project and setup basic settings in file sys.config:

[
    ***
    
    {eauth, [
        {hash_algorithm,sha512},
        {salt_local,<<63,0,56,7>>},
        {wrong_delay,400},
        {password_symbols,<<"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789">>},
        {password_length,16},
        {salt_length,4},
        {smtp_login,<<"mailbox@domain.com">>},
        {smtp_password,<<"application_password">>},
        {smtp_relay,<<"smtp.mailservice.com">>},
        {smtp_tls,always}
    ]}
]

All config fields you can find in eauth/include/eauth.hrl file, just translate names to lowercase.

Api

Sign In

• eauth:signin(Mail :: binary(), Passwd :: binary()) -> {error, Error} | {ok, User}.
• Error :: login_required | password_required | wrong_password | user_not_found
• User :: #user{}, see eauth/include/eauth_user.hrl
• Snippet:

    case eauth:signin(wf:q(login),wf:q(passwd)) of
        {ok,#user{id=Uid}=User} -> wf:user(Uid);
        {error,Error} -> wf:warning(?MODULE,"Error signin: ~p",[Error])
    end

Activate

• eauth:activate(Key :: binary) -> {error,activation_not_found} | {ok,{Mail,PasswordHash,Salt}}.
• Mail2 :: binary()
• PasswordHash :: binary()
• Salt :: binary()
• Snippet:

    case eauth:activate(Key) of
        {error,activation_not_found} -> skip;
        {ok,{Mail,PasswordHash,Salt}} ->
            Uid=kvs:next_id(user,1),
            {ok,_}=kvs:add(#user{id=Uid,email=Mail,password=PasswordHash,salt=Salt}),
            wf:user(Uid),
            wf:info(?MODULE,"New user created ~p",[Uid])
    end

Join

• eauth:join(Mail,JoinMessageFun) -> {error, {Error, Mail2}} | {ok, Mail2)}.
• Error :: network_error | already_registered | wait_activation | wrong_email
• Mail2 :: binary()
• Snippet:

    Mail=wf:q(email),
    Status=eauth:join(Mail,fun(Password,Key) ->
        ActivateUrl=["http://domain.com/join/",Key],
        Subject="Welcome!",
        Body=["<h1>Thanks you for registering</h1><p>You password: ",wf:html_encode(Password),"</p>",
            "<p>Finishing registration link: <a href=\"",ActivateUrl,"\">",wf:html_encode(ActivateUrl),"</a></p>"],
        {Subject,Body}.)

Reset password

• eauth:reset(Mail,resetMessage) -> {error, Error} | {ok,{PasswordHash, Salt}}
• Error :: user_deleted | user_not_found
• PasswordHash :: binary()
• Salt :: binary()
• Snippet:

    Mail=wf:q(login),
    ResetMessageFun=fun(Password) ->
        Subject="Reset password",
        Body=["<h1>You password has been resetting</h1><p>You password: ",wf:html_encode(Password),"</p>"],
        {Subject,Body}
    end,
    case eauth:reset(Mail,ResetMessageFun) of
        {error,_} -> ok;
        {ok,{PasswordHash,Salt}} ->
            case kvs:index(user,email,Mail) of
                [#user{}=User] -> kvs:put(User#user{password=PasswordHash,salt=Salt});
                _ -> skip
            end
    end

User / State access

Use -include_lib("eauth/include/eauth_user.hrl"). in you project for define #user{}.

• eauth_user:get() -> #user{} | undefined – Get session user from database
• eauth_user:user() -> #user{} | undefined – Get user from state
• eauth_user:user(User) -> User – Write user to state
• eauth_user:is_alive(#user{} | any()) -> true | false – Check for non-deleted user

By default, user (in state) stored in process state. You can override this if want store user in custom state. Just setup function_state and function_state_user in sys.config as {Mod,Fun}.

function_state() -> State % get custom state
function_state(State) -> State % write custom state
function_state_user(State) -> User % get from custom state
function_state_user(State,User) -> State % write to custom state

Credits

• @m-2k
• @rusjava8