diff --git a/src/eblake2.erl b/src/eblake2.erl new file mode 100644 index 0000000..7f63a25 --- /dev/null +++ b/src/eblake2.erl @@ -0,0 +1,156 @@ +%%%============================================================================= +%%% @copyright (C) 2019, Hans Svensson +%%% @doc +%%% BLAKE2 implementation in Erlang - for details see: https://blake2.net +%%% @end +%%%============================================================================= +-module(eblake2). + +%% API exports +-export([ blake2b/2 + , blake2b/3 + ]). + +-define(MAXINT_64, 16#FFFFffffFFFFffff). + +%%==================================================================== +%% API functions +%%==================================================================== +-spec blake2b(HashLen :: integer(), Msg :: binary()) -> {ok, binary()}. +blake2b(HashLen, Msg) -> + blake2b(HashLen, Msg, <<>>). + +-spec blake2b(HashLen :: integer(), Msg :: binary(), Key :: binary()) -> {ok, binary()}. +blake2b(HashLen, Msg0, Key) -> + %% If message should be keyed, prepend message with padded key. + Msg = <<(pad(128, Key))/binary, Msg0/binary>>, + + %% Set up the initial state + Init = (16#01010000 + (byte_size(Key) bsl 8) + HashLen), + <> = blake_iv(), + H = <<(H0 bxor Init):64, H1_7/binary>>, + + %% Perform the compression - message will be chopped into 128-byte chunks. + State = blake2b_compress(H, Msg, 0), + + %% Just return the requested part of the hash + {ok, binary_part(to_little_endian(State), {0, HashLen})}. + +%%==================================================================== +%% Internal functions +%%==================================================================== +%% +blake2b_compress(H, <>, BCompr) when Rest /= <<>> -> + H1 = blake2b_compress(H, <>, BCompr + 128, false), + blake2b_compress(H1, Rest, BCompr + 128); +blake2b_compress(H, SmallChunk, BCompr) -> + Size = byte_size(SmallChunk), + FillSize = (128 - Size) * 8, + blake2b_compress(H, <>, BCompr + Size, true). + +blake2b_compress(H, Chunk0, BCompr, Last) -> + Chunk = to_big_endian(Chunk0), + <> = <>, + V12_ = V12 bxor (BCompr band ?MAXINT_64), + V13_ = V13 bxor ((BCompr bsr 64) band ?MAXINT_64), + V14_ = case Last of + false -> V14; + true -> V14 bxor ?MAXINT_64 + end, + V = <>, + + <> = + lists:foldl(fun(Round, Vx) -> blake2b_mix(Round, Chunk, Vx) end, V, lists:seq(0, 11)), + + <> = H, + <<((HInt bxor VLow) bxor VHigh):(8*64)>>. + +blake2b_mix(Rnd, Chunk, V) -> + <> = V, + <> = Chunk, + Ms = {M0, M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15}, + M = fun(Ix) -> element(Ix+1, Ms) end, + + [S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15] = sigma(Rnd rem 10), + + {Vx0, Vx4, Vx8, Vx12} = blake2b_mix(V0, V4, V8, V12, M(S0), M(S1)), + {Vx1, Vx5, Vx9, Vx13} = blake2b_mix(V1, V5, V9, V13, M(S2), M(S3)), + {Vx2, Vx6, Vx10, Vx14} = blake2b_mix(V2, V6, V10, V14, M(S4), M(S5)), + {Vx3, Vx7, Vx11, Vx15} = blake2b_mix(V3, V7, V11, V15, M(S6), M(S7)), + + {Vy0, Vy5, Vy10, Vy15} = blake2b_mix(Vx0, Vx5, Vx10, Vx15, M(S8), M(S9)), + {Vy1, Vy6, Vy11, Vy12} = blake2b_mix(Vx1, Vx6, Vx11, Vx12, M(S10), M(S11)), + {Vy2, Vy7, Vy8, Vy13} = blake2b_mix(Vx2, Vx7, Vx8, Vx13, M(S12), M(S13)), + {Vy3, Vy4, Vy9, Vy14} = blake2b_mix(Vx3, Vx4, Vx9, Vx14, M(S14), M(S15)), + + <>. + +blake2b_mix(Va, Vb, Vc, Vd, X, Y) -> + Va1 = (Va + Vb + X) band ?MAXINT_64, + Vd1 = rotr64(32, Vd bxor Va1), + + Vc1 = (Vc + Vd1) band ?MAXINT_64, + Vb1 = rotr64(24, Vb bxor Vc1), + + Va2 = (Va1 + Vb1 + Y) band ?MAXINT_64, + Vd2 = rotr64(16, Va2 bxor Vd1), + + Vc2 = (Vc1 + Vd2) band ?MAXINT_64, + Vb2 = rotr64(63, Vb1 bxor Vc2), + + {Va2, Vb2, Vc2, Vd2}. + +blake_iv() -> + IV0 = 16#6A09E667F3BCC908, + IV1 = 16#BB67AE8584CAA73B, + IV2 = 16#3C6EF372FE94F82B, + IV3 = 16#A54FF53A5F1D36F1, + IV4 = 16#510E527FADE682D1, + IV5 = 16#9B05688C2B3E6C1F, + IV6 = 16#1F83D9ABFB41BD6B, + IV7 = 16#5BE0CD19137E2179, + <>. + +sigma(N) -> + {_, Row} = lists:keyfind(N, 1, sigma()), Row. + +sigma() -> + [{0, [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]}, + {1, [14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3]}, + {2, [11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4]}, + {3, [ 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8]}, + {4, [ 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13]}, + {5, [ 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9]}, + {6, [12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11]}, + {7, [13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10]}, + {8, [ 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5]}, + {9, [10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0]}]. + +rotr64(N, I64) -> + <> = rotr641(N, <>), + I64rot. + +rotr641(16, <>) -> <>; +rotr641(24, <>) -> <>; +rotr641(32, <>) -> <>; +rotr641(63, <>) -> <>. + +pad(N, Bin) -> + case (N - (byte_size(Bin) rem N)) rem N of + 0 -> Bin; + Pad -> <> + end. + +to_big_endian(Bin) -> to_big_endian(Bin, <<>>). +to_big_endian(<<>>, Acc) -> Acc; +to_big_endian(<>, Acc) -> + to_big_endian(Rest, <>). + +to_little_endian(Bin) -> to_little_endian(Bin, <<>>). +to_little_endian(<<>>, Acc) -> Acc; +to_little_endian(<>, Acc) -> + to_little_endian(Rest, <>). +