%%%----------------------------------------------------------------------
%%% File    : ejabberd_auth_odbc.erl
%%% Author  : Alexey Shchepin <[email protected]>
%%% Purpose : Authentification via ODBC
%%% Created : 12 Dec 2004 by Alexey Shchepin <[email protected]>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2010   ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------

-module(ejabberd_auth_odbc).
-author('[email protected]').

%% External exports
-export([start/1,
     set_password/3,
     check_password/3,
     check_password/5,
     try_register/3,
     dirty_get_registered_users/0,
     get_vh_registered_users/1,
     get_vh_registered_users/2,
     get_vh_registered_users_number/1,
     get_vh_registered_users_number/2,
     get_password/2,
     get_password_s/2,
     is_user_exists/2,
     remove_user/2,
     remove_user/3,
     plain_password_required/0
    ]).

-include("ejabberd.hrl").

%%%----------------------------------------------------------------------
%%% Custom SHA added by Henrik P. Hessel 05/15/2011
%%%----------------------------------------------------------------------
sha_pass(Pass) ->
    sha2:hexdigest512(string:concat(Pass, "YOUR SALT")).

%%%----------------------------------------------------------------------
%%% API
%%%----------------------------------------------------------------------
start(_Host) ->
    ok.

plain_password_required() ->
    false.

%% @spec (User, Server, Password) -> true | false | {error, Error}
check_password(User, Server, Password) ->
    ShaPassword = sha_pass(Password),
    case jlib:nodeprep(User) of
    error ->
        false;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        try odbc_queries:get_password(LServer, Username) of
        {selected, ["password"], [{ShaPassword}]} ->
            Password /= ""; %% Password is correct, and not empty
        {selected, ["password"], [{_Password2}]} ->
            false; %% Password is not correct
        {selected, ["password"], []} ->
            false; %% Account does not exist
        {error, _Error} ->
            false %% Typical error is that table doesn't exist
        catch
        _:_ ->
            false %% Typical error is database not accessible
        end
    end.

%% @spec (User, Server, Password, Digest, DigestGen) -> true | false | {error, Error}
check_password(User, Server, Password, Digest, DigestGen) ->
    ShaPassword = sha_pass(Password),
    case jlib:nodeprep(User) of
    error ->
        false;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        try odbc_queries:get_password(LServer, Username) of
        %% Account exists, check if password is valid
        {selected, ["password"], [{Passwd}]} ->
            DigRes = if
                 Digest /= "" ->
                     Digest == DigestGen(Passwd);
                 true ->
                     false
                 end,
            if DigRes ->
                true;
               true ->
                (Passwd == ShaPassword) and (Password /= "")
            end;
        {selected, ["password"], []} ->
            false; %% Account does not exist
        {error, _Error} ->
            false %% Typical error is that table doesn't exist
        catch
        _:_ ->
            false %% Typical error is database not accessible
        end
    end.

%% @spec (User::string(), Server::string(), Password::string()) ->
%%       ok | {error, invalid_jid}
set_password(User, Server, Password) ->
    case jlib:nodeprep(User) of
    error ->
        {error, invalid_jid};
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        Pass = ejabberd_odbc:escape(Password),
        ShaPassword = sha_pass(Pass),
        LServer = jlib:nameprep(Server),
        case catch odbc_queries:set_password_t(LServer, Username, ShaPassword) of
            {atomic, ok} -> ok;
            Other -> {error, Other}
        end
    end.


%% @spec (User, Server, Password) -> {atomic, ok} | {atomic, exists} | {error, invalid_jid}
try_register(User, Server, Password) ->
    case jlib:nodeprep(User) of
    error ->
        {error, invalid_jid};
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        Pass = ejabberd_odbc:escape(Password),
        ShaPassword = sha_pass(Pass),
        LServer = jlib:nameprep(Server),
        case catch odbc_queries:add_user(LServer, Username, ShaPassword) of
        {updated, 1} ->
            {atomic, ok};
        _ ->
            {atomic, exists}
        end
    end.

dirty_get_registered_users() ->
    Servers = ejabberd_config:get_vh_by_auth_method(odbc),
    lists:flatmap(
      fun(Server) ->
          get_vh_registered_users(Server)
      end, Servers).

get_vh_registered_users(Server) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:list_users(LServer) of
    {selected, ["username"], Res} ->
        [{U, LServer} || {U} <- Res];
    _ ->
        []
    end.

get_vh_registered_users(Server, Opts) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:list_users(LServer, Opts) of
    {selected, ["username"], Res} ->
        [{U, LServer} || {U} <- Res];
    _ ->
        []
    end.

get_vh_registered_users_number(Server) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:users_number(LServer) of
    {selected, [_], [{Res}]} ->
        list_to_integer(Res);
    _ ->
        0
    end.

get_vh_registered_users_number(Server, Opts) ->
    LServer = jlib:nameprep(Server),
    case catch odbc_queries:users_number(LServer, Opts) of
    {selected, [_], [{Res}]} ->
        list_to_integer(Res);
    _Other ->
        0
    end.

get_password(User, Server) ->
    case jlib:nodeprep(User) of
    error ->
        false;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        case catch odbc_queries:get_password(LServer, Username) of
        {selected, ["password"], [{Password}]} ->
            Password;
        _ ->
            false
        end
    end.

get_password_s(User, Server) ->
    case jlib:nodeprep(User) of
    error ->
        "";
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        case catch odbc_queries:get_password(LServer, Username) of
        {selected, ["password"], [{Password}]} ->
            Password;
        _ ->
            ""
        end
    end.

%% @spec (User, Server) -> true | false | {error, Error}
is_user_exists(User, Server) ->
    case jlib:nodeprep(User) of
    error ->
        false;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        try odbc_queries:get_password(LServer, Username) of
        {selected, ["password"], [{_Password}]} ->
            true; %% Account exists
        {selected, ["password"], []} ->
            false; %% Account does not exist
        {error, Error} ->
            {error, Error} %% Typical error is that table doesn't exist
        catch
        _:B ->
            {error, B} %% Typical error is database not accessible
        end
    end.

%% @spec (User, Server) -> ok | error
%% @doc Remove user.
%% Note: it may return ok even if there was some problem removing the user.
remove_user(User, Server) ->
    case jlib:nodeprep(User) of
    error ->
        error;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        LServer = jlib:nameprep(Server),
        catch odbc_queries:del_user(LServer, Username),
        ok
    end.

%% @spec (User, Server, Password) -> ok | error | not_exists | not_allowed
%% @doc Remove user if the provided password is correct.
remove_user(User, Server, Password) ->
    case jlib:nodeprep(User) of
    error ->
        error;
    LUser ->
        Username = ejabberd_odbc:escape(LUser),
        Pass = ejabberd_odbc:escape(Password),
        LServer = jlib:nameprep(Server),
        F = fun() ->
            Result = odbc_queries:del_user_return_password(
                   LServer, Username, Pass),
            case Result of
                {selected, ["password"], [{Password}]} ->
                ok;
                {selected, ["password"], []} ->
                not_exists;
                _ ->
                not_allowed
            end
        end,
        {atomic, Result} = odbc_queries:sql_transaction(LServer, F),
        Result
    end.