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This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig standard library. Public Function

hkdfExpandLabel

Public Function
std.crypto.tls.hkdfExpandLabel
pub fn hkdfExpandLabel(
    comptime Hkdf: type,
    key: [Hkdf.prk_length]u8,
    label: []const u8,
    context: []const u8,
    comptime len: usize,
) [len]u8

Params

  • Hkdf: type
  • key: [Hkdf.prk_length]u8
  • label: []const u8
  • context: []const u8
  • len: usize

File

crypto/tls.zig:558
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pub fn hkdfExpandLabel(
    comptime Hkdf: type,
    key: [Hkdf.prk_length]u8,
    label: []const u8,
    context: []const u8,
    comptime len: usize,
) [len]u8 {
    const max_label_len = 255;
    const max_context_len = 255;
    const tls13 = "tls13 ";
    var buf: [2 + 1 + tls13.len + max_label_len + 1 + max_context_len]u8 = undefined;
    mem.writeInt(u16, buf[0..2], len, .big);
    buf[2] = @as(u8, @intCast(tls13.len + label.len));
    buf[3..][0..tls13.len].* = tls13.*;
    var i: usize = 3 + tls13.len;
    @memcpy(buf[i..][0..label.len], label);
    i += label.len;
    buf[i] = @as(u8, @intCast(context.len));
    i += 1;
    @memcpy(buf[i..][0..context.len], context);
    i += context.len;

    var result: [len]u8 = undefined;
    Hkdf.expand(&result, buf[0..i], key);
    return result;
}