QPQ-AG/enacl
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Do not create a new set of 0-bytes all the time.

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Rather than creating a set of <<0,…,0>> every time and then throwing it away,
we now reuse a constant. They are small enough they are still small-binaries, but a
process can keep them around and use them whenever it needs to go to the
low-level area.
This commit is contained in:
Jesper Louis Andersen 2015-08-29 20:54:37 +02:00
parent 310bb3cc77
commit 6bfa191f6b
1 changed files with 25 additions and 21 deletions
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46
src/enacl.erl
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@ -121,8 +121,12 @@
-define(CRYPTO_BOX_ZEROBYTES, 32).
-define(P_ZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 32 bytes of 0
-define(CRYPTO_BOX_BOXZEROBYTES, 16).
-define(P_BOXZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>).
-define(P_BOXZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 16 bytes
-define(CRYPTO_SECRETBOX_ZEROBYTES, 32).
-define(S_ZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 32 bytes
-define(CRYPTO_SECRETBOX_BOXZEROBYTES, 16).
-define(S_BOXZEROBYTES, <<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0>>). %% 16 bytes
-define(CRYPTO_STREAM_KEYBYTES, 32).
-define(CRYPTO_STREAM_NONCEBYTES, 24).
@ -130,11 +134,18 @@
verify() ->
true = equals(binary:copy(<<0>>, enacl_nif:crypto_box_ZEROBYTES()), ?P_ZEROBYTES),
true = equals(binary:copy(<<0>>, enacl_nif:crypto_box_BOXZEROBYTES()), ?P_BOXZEROBYTES),
true = equals(binary:copy(<<0>>, enacl_nif:crypto_secretbox_ZEROBYTES()), ?S_ZEROBYTES),
true = equals(binary:copy(<<0>>, enacl_nif:crypto_secretbox_BOXZEROBYTES()),
?S_BOXZEROBYTES),
Verifiers = [
{crypto_stream_KEYBYTES, ?CRYPTO_STREAM_KEYBYTES},
{crypto_stream_NONCEBYTES, ?CRYPTO_STREAM_NONCEBYTES},
{crypto_box_ZEROBYTES, ?CRYPTO_BOX_ZEROBYTES},
{crypto_box_BOXZEROBYTES, ?CRYPTO_BOX_BOXZEROBYTES}],
{crypto_box_BOXZEROBYTES, ?CRYPTO_BOX_BOXZEROBYTES},
{crypto_secretbox_ZEROBYTES, ?CRYPTO_SECRETBOX_ZEROBYTES},
{crypto_secretbox_BOXZEROBYTES, ?CRYPTO_SECRETBOX_BOXZEROBYTES}
],
run_verifiers(Verifiers).
run_verifiers([]) -> ok;
@ -263,10 +274,10 @@ box_beforenm(PK, SK) ->
box_afternm(Msg, Nonce, Key) ->
case iolist_size(Msg) of
K when K =< ?BOX_AFTERNM_SIZE ->
bump(enacl_nif:crypto_box_afternm_b([p_zerobytes(), Msg], Nonce, Key),
bump(enacl_nif:crypto_box_afternm_b([?P_ZEROBYTES, Msg], Nonce, Key),
?BOX_AFTERNM_REDUCTIONS, ?BOX_AFTERNM_SIZE, K);
_ ->
enacl_nif:crypto_box_afternm([p_zerobytes(), Msg], Nonce, Key)
enacl_nif:crypto_box_afternm([?P_ZEROBYTES, Msg], Nonce, Key)
end.
%% @doc box_open_afternm/3 works like `box_open/4` but uses a precomputed key
@ -285,13 +296,13 @@ box_open_afternm(CipherText, Nonce, Key) ->
case iolist_size(CipherText) of
K when K =< ?BOX_AFTERNM_SIZE ->
R =
case enacl_nif:crypto_box_open_afternm_b([p_box_zerobytes(), CipherText], Nonce, Key) of
case enacl_nif:crypto_box_open_afternm_b([?P_BOXZEROBYTES, CipherText], Nonce, Key) of
{error, Err} -> {error, Err};
Bin when is_binary(Bin) -> {ok, Bin}
end,
bump(R, ?BOX_AFTERNM_REDUCTIONS, ?BOX_AFTERNM_SIZE, K);
_ ->
case enacl_nif:crypto_box_open_afternm([p_box_zerobytes(), CipherText], Nonce, Key) of
case enacl_nif:crypto_box_open_afternm([?P_BOXZEROBYTES, CipherText], Nonce, Key) of
{error, Err} -> {error, Err};
Bin when is_binary(Bin) -> {ok, Bin}
end
@ -465,12 +476,12 @@ box_seal_open(SealedCipherText, PK, SK) ->
secretbox(Msg, Nonce, Key) ->
case iolist_size(Msg) of
K when K =< ?SECRETBOX_SIZE ->
bump(enacl_nif:crypto_secretbox_b([s_zerobytes(), Msg], Nonce, Key),
bump(enacl_nif:crypto_secretbox_b([?S_ZEROBYTES, Msg], Nonce, Key),
?SECRETBOX_REDUCTIONS,
?SECRETBOX_SIZE,
K);
_ ->
enacl_nif:crypto_secretbox([s_zerobytes(), Msg], Nonce, Key)
enacl_nif:crypto_secretbox([?S_ZEROBYTES, Msg], Nonce, Key)
end.
%% @doc secretbox_open/3 opens a sealed box.
%%
@ -486,14 +497,14 @@ secretbox(Msg, Nonce, Key) ->
secretbox_open(CipherText, Nonce, Key) ->
case iolist_size(CipherText) of
K when K =< ?SECRETBOX_SIZE ->
R = case enacl_nif:crypto_secretbox_open_b([s_box_zerobytes(), CipherText],
R = case enacl_nif:crypto_secretbox_open_b([?S_BOXZEROBYTES, CipherText],
Nonce, Key) of
{error, Err} -> {error, Err};
Bin when is_binary(Bin) -> {ok, Bin}
end,
bump(R, ?SECRETBOX_OPEN_REDUCTIONS, ?SECRETBOX_SIZE, K);
_ ->
case enacl_nif:crypto_secretbox_open([s_box_zerobytes(), CipherText], Nonce, Key) of
case enacl_nif:crypto_secretbox_open([?S_BOXZEROBYTES, CipherText], Nonce, Key) of
{error, Err} -> {error, Err};
Bin when is_binary(Bin) -> {ok, Bin}
end
@ -733,18 +744,11 @@ randombytes(N) ->
enacl_nif:randombytes(N).
%% Helpers
p_zerobytes() ->
binary:copy(<<0>>, enacl_nif:crypto_box_ZEROBYTES()).
p_box_zerobytes() ->
binary:copy(<<0>>, enacl_nif:crypto_box_BOXZEROBYTES()).
s_zerobytes() ->
binary:copy(<<0>>, enacl_nif:crypto_secretbox_ZEROBYTES()).
s_box_zerobytes() ->
binary:copy(<<0>>, enacl_nif:crypto_secretbox_BOXZEROBYTES()).
%% @doc bump/4 bumps a reduction budget linearly before returning the result
%% It is used for the on-scheduler variants of functions in order to make sure there
%% is a realistic apporach to handling the reduction counts of the system.
%% @end
bump(Res, Budget, Max, Sz) ->
Reds = (Budget * Sz) div Max,
erlang:bump_reductions(max(1, Reds)),