package zero

// This file implements range-based zeroing, which as of Go 1.5 is optimized using a Duff's device.
import "math/big"

// Bytes sets all bytes in the passed slice to zero. This is used to explicitly
// clear private key material from memory.
//
// In general, prefer to use the fixed-sized zeroing functions (Bytea*) when
// zeroing bytes as they are much more efficient than the variable sized zeroing
// func Hash.
func Bytes(b []byte) {
	for i := range b {
		b[i] = 0
	}
}

// BigInt sets all bytes in the passed big int to zero and then sets the value to 0. This differs from simply setting
// the value in that it specifically clears the underlying bytes whereas simply setting the value does not. This is
// mostly useful to forcefully clear private keys.
func BigInt(x *big.Int) {
	b := x.Bits()
	for i := range b {
		b[i] = 0
	}
	x.SetInt64(0)
}