emqx4.3/plugins/emysql/src/emysql_auth.erl

-module(emysql_auth).

-export([make_auth/2, make_new_auth/3, password_old/2, password_new/2]).

%%--------------------------------------------------------------------
%% Macros
%%--------------------------------------------------------------------
-define(LONG_PASSWORD, 1).
-define(LONG_FLAG, 4).
-define(PROTOCOL_41, 512).
-define(TRANSACTIONS, 8192).
-define(SECURE_CONNECTION, 32768).
-define(CONNECT_WITH_DB, 8).
-define(MAX_PACKET_SIZE, 1000000).

password_old(Password, Salt) ->
    {P1, P2} = hash(Password),
    {S1, S2} = hash(Salt),
    Seed1 = P1 bxor S1,
    Seed2 = P2 bxor S2,
    List = rnd(9, Seed1, Seed2),
    {L, [Extra]} = lists:split(8, List),
    list_to_binary(lists:map(fun (E) -> E bxor (Extra - 64) end, L)).

%% part of do_old_auth/4, which is part of mysql_init/4
make_auth(User, Password) ->
    Caps = ?LONG_PASSWORD bor ?LONG_FLAG bor ?TRANSACTIONS,
    Maxsize = 0,
    UserB = list_to_binary(User),
    PasswordB = Password,
    <<Caps:16/little, Maxsize:24/little, UserB/binary, 0:8,
    PasswordB/binary>>.

%% part of do_new_auth/4, which is part of mysql_init/4
make_new_auth(User, Password, Database) ->
    DBCaps = case Database of
		 none ->
		     0;
		 _ ->
		     ?CONNECT_WITH_DB
	     end,
    Caps = ?LONG_PASSWORD bor ?LONG_FLAG bor ?TRANSACTIONS bor
	?PROTOCOL_41 bor ?SECURE_CONNECTION bor DBCaps,
    Maxsize = ?MAX_PACKET_SIZE,
    UserB = list_to_binary(User),
    PasswordL = size(Password),
    DatabaseB = case Database of
		    none ->
			<<>>;
		    _ ->
			list_to_binary(Database)
		end,
    <<Caps:32/little, Maxsize:32/little, 8:8, 0:23/integer-unit:8,
    UserB/binary, 0:8, PasswordL:8, Password/binary, DatabaseB/binary>>.

hash(S) ->
    hash(S, 1345345333, 305419889, 7).

hash([C | S], N1, N2, Add) ->
    N1_1 = N1 bxor (((N1 band 63) + Add) * C + N1 * 256),
    N2_1 = N2 + ((N2 * 256) bxor N1_1),
    Add_1 = Add + C,
    hash(S, N1_1, N2_1, Add_1);
hash([], N1, N2, _Add) ->
    Mask = (1 bsl 31) - 1,
    {N1 band Mask , N2 band Mask}.

rnd(N, Seed1, Seed2) ->
    Mod = (1 bsl 30) - 1,
    rnd(N, [], Seed1 rem Mod, Seed2 rem Mod).

rnd(0, List, _, _) ->
    lists:reverse(List);
rnd(N, List, Seed1, Seed2) ->
    Mod = (1 bsl 30) - 1,
    NSeed1 = (Seed1 * 3 + Seed2) rem Mod,
    NSeed2 = (NSeed1 + Seed2 + 33) rem Mod,
    Float = (float(NSeed1) / float(Mod))*31,
    Val = trunc(Float)+64,
    rnd(N - 1, [Val | List], NSeed1, NSeed2).


dualmap(_F, [], []) ->
    [];
dualmap(F, [E1 | R1], [E2 | R2]) ->
    [F(E1, E2) | dualmap(F, R1, R2)].

bxor_binary(B1, B2) ->
    list_to_binary(dualmap(fun (E1, E2) ->
				   E1 bxor E2
			   end, binary_to_list(B1), binary_to_list(B2))).

password_new(Password, Salt) ->
    Stage1 = crypto:sha(Password),
    Stage2 = crypto:sha(Stage1),
    Res = crypto:sha_final(
	    crypto:sha_update(
	      crypto:sha_update(crypto:sha_init(), Salt),
	      Stage2)
	   ),
    bxor_binary(Res, Stage1).