totp_check/2

src/utools.erl

@@ -7,6 +7,7 @@
 -export([rand_chars/1]).
 -export([rand_hash/0]).
 -export([totp/1, totp/2]).
+-export([totp_check/2]).
 -export([totp_generate/0]).
 
 b32_decode({<<V, "======">>, Bits}) ->
@@ -93,13 +94,18 @@ rand_hash() ->
   {ok, R} = rand_chars(64),
   {ok, binary:encode_hex(crypto:hash(sha256, <<"utools:rand_hash(", R/binary, ")">>))}.
 
-totp_generate() ->
-  rand_chars(16).
+totp(<<Secret/binary>>) ->
+  totp(Secret, erlang:timestamp()).
 
-totp(<<Token/binary>>) ->
-  totp(Token, erlang:timestamp()).
-
-totp(<<Token/binary>>, {M, S, _}) ->
+totp(<<Secret/binary>>, {M, S, _}) ->
   T = (M * 1000000 + S) / 30,
   Time = trunc(T),
-  hotp(Token, Time).
+  hotp(Secret, Time).
+
+totp_check(<<Token/binary>>, <<Secret/binary>>) ->
+  {M, S, _} = erlang:timestamp(),
+  TL = [totp(Secret, {M, S - 30, 0}), totp(Secret, {M, S, 0}), totp(Secret, {M, S + 30, 0})],
+  {ok, lists:member({ok, Token}, TL)}.
+
+totp_generate() ->
+  rand_chars(16).