diff options
| -rw-r--r-- | lib/std/crypto/chacha20.zig | 51 |
1 files changed, 18 insertions, 33 deletions
diff --git a/lib/std/crypto/chacha20.zig b/lib/std/crypto/chacha20.zig index de9c1aab62..3b651bb2e4 100644 --- a/lib/std/crypto/chacha20.zig +++ b/lib/std/crypto/chacha20.zig @@ -34,67 +34,52 @@ const ChaCha20VecImpl = struct { }; } - inline fn chacha20Core(x: *BlockVec, input: BlockVec) void { - const rot8 = [_]i32{ 3, 0, 1, 2, 7, 4, 5, 6, 11, 8, 9, 10, 15, 12, 13, 14 }; - const rot16 = [_]i32{ 2, 3, 0, 1, 6, 7, 4, 5, 10, 11, 8, 9, 14, 15, 12, 13 }; + inline fn rot(x: Lane, comptime n: comptime_int) Lane { + return (x << @splat(4, @as(u5, n))) | (x >> @splat(4, @as(u5, 32 - n))); + } + inline fn chacha20Core(x: *BlockVec, input: BlockVec) void { x.* = input; var r: usize = 0; while (r < 20) : (r += 2) { x[0] +%= x[1]; x[3] ^= x[0]; - x[3] = @bitCast(Vector(4, u32), @shuffle(u8, @bitCast(Vector(16, u8), x[3]), undefined, rot16)); + x[3] = rot(x[3], 16); x[2] +%= x[3]; x[1] ^= x[2]; - - var t1 = x[1]; - x[1] <<= @splat(4, @as(u5, 12)); - t1 >>= @splat(4, @as(u5, 20)); - x[1] ^= t1; + x[1] = rot(x[1], 12); x[0] +%= x[1]; x[3] ^= x[0]; - x[0] = @shuffle(u32, x[0], undefined, Vector(4, i32){ 3, 0, 1, 2 }); - x[3] = @bitCast(Vector(4, u32), @shuffle(u8, @bitCast(Vector(16, u8), x[3]), undefined, rot8)); + x[0] = @shuffle(u32, x[0], undefined, [_]i32{ 3, 0, 1, 2 }); + x[3] = rot(x[3], 8); x[2] +%= x[3]; - x[3] = @shuffle(u32, x[3], undefined, Vector(4, i32){ 2, 3, 0, 1 }); + x[3] = @shuffle(u32, x[3], undefined, [_]i32{ 2, 3, 0, 1 }); x[1] ^= x[2]; - x[2] = @shuffle(u32, x[2], undefined, Vector(4, i32){ 1, 2, 3, 0 }); - - t1 = x[1]; - x[1] <<= @splat(4, @as(u5, 7)); - t1 >>= @splat(4, @as(u5, 25)); - x[1] ^= t1; + x[2] = @shuffle(u32, x[2], undefined, [_]i32{ 1, 2, 3, 0 }); + x[1] = rot(x[1], 7); x[0] +%= x[1]; x[3] ^= x[0]; - x[3] = @bitCast(Vector(4, u32), @shuffle(u8, @bitCast(Vector(16, u8), x[3]), undefined, rot16)); + x[3] = rot(x[3], 16); x[2] +%= x[3]; x[1] ^= x[2]; - - t1 = x[1]; - x[1] <<= @splat(4, @as(u5, 12)); - t1 >>= @splat(4, @as(u5, 20)); - x[1] ^= t1; + x[1] = rot(x[1], 12); x[0] +%= x[1]; x[3] ^= x[0]; - x[0] = @shuffle(u32, x[0], undefined, Vector(4, i32){ 1, 2, 3, 0 }); - x[3] = @bitCast(Vector(4, u32), @shuffle(u8, @bitCast(Vector(16, u8), x[3]), undefined, rot8)); + x[0] = @shuffle(u32, x[0], undefined, [_]i32{ 1, 2, 3, 0 }); + x[3] = rot(x[3], 8); x[2] +%= x[3]; - x[3] = @shuffle(u32, x[3], undefined, Vector(4, i32){ 2, 3, 0, 1 }); + x[3] = @shuffle(u32, x[3], undefined, [_]i32{ 2, 3, 0, 1 }); x[1] ^= x[2]; - x[2] = @shuffle(u32, x[2], undefined, Vector(4, i32){ 3, 0, 1, 2 }); - - t1 = x[1]; - x[1] <<= @splat(4, @as(u5, 7)); - t1 >>= @splat(4, @as(u5, 25)); - x[1] ^= t1; + x[2] = @shuffle(u32, x[2], undefined, [_]i32{ 3, 0, 1, 2 }); + x[1] = rot(x[1], 7); } } |