Zig 0.17.0-dev (Split by item)

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blake2bLong

argon2.blake2bLong

fn blake2bLong(out: []u8, in: []const u8) void

File

lib/std/crypto/argon2.zig:144

Code

fn blake2bLong(out: []u8, in: []const u8) void {
    const H = Blake2b512;
    var outlen_bytes: [4]u8 = undefined;
    mem.writeInt(u32, &outlen_bytes, @as(u32, @intCast(out.len)), .little);

    var out_buf: [H.digest_length]u8 = undefined;

    if (out.len <= H.digest_length) {
        var h = H.init(.{ .expected_out_bits = out.len * 8 });
        h.update(&outlen_bytes);
        h.update(in);
        h.final(&out_buf);
        @memcpy(out, out_buf[0..out.len]);
        return;
    }

    var h = H.init(.{});
    h.update(&outlen_bytes);
    h.update(in);
    h.final(&out_buf);
    var out_slice = out;
    out_slice[0 .. H.digest_length / 2].* = out_buf[0 .. H.digest_length / 2].*;
    out_slice = out_slice[H.digest_length / 2 ..];

    var in_buf: [H.digest_length]u8 = undefined;
    while (out_slice.len > H.digest_length) {
        in_buf = out_buf;
        H.hash(&in_buf, &out_buf, .{});
        out_slice[0 .. H.digest_length / 2].* = out_buf[0 .. H.digest_length / 2].*;
        out_slice = out_slice[H.digest_length / 2 ..];
    }
    in_buf = out_buf;
    H.hash(&in_buf, &out_buf, .{ .expected_out_bits = out_slice.len * 8 });
    @memcpy(out_slice, out_buf[0..out_slice.len]);
}