address.go

package wotsp

import (
	"encoding/binary"
	"fmt"
)

// Address describes a hash address, i.e. where a hash is calculated. It is used
// to randomize each hash function call to prevent multi-target attacks on the
// used hash function.
type Address struct {
	data [32]byte
}

// SetLayer sets the Layer field of a W-OTS+ address to the given value.
func (a *Address) SetLayer(l uint32) {
	binary.BigEndian.PutUint32(a.data[0:], l)
}

// SetTree sets the Tree field of a W-OTS+ address to the given value.
func (a *Address) SetTree(t uint64) {
	binary.BigEndian.PutUint64(a.data[4:], t)
}

// SetType sets the Type field of a W-OTS+ address to the given value.
func (a *Address) SetType(t uint32) {
	binary.BigEndian.PutUint32(a.data[12:], t)
}

// SetOTS sets the OTS field of a W-OTS+ address to the given value.
func (a *Address) SetOTS(o uint32) {
	binary.BigEndian.PutUint32(a.data[16:], o)
}

func (a *Address) setChain(c uint32) {
	binary.BigEndian.PutUint32(a.data[20:], c)
}

func (a *Address) setHash(h uint32) {
	binary.BigEndian.PutUint32(a.data[24:], h)
}

func (a *Address) setKeyAndMask(km uint32) {
	binary.BigEndian.PutUint32(a.data[28:], km)
}

// ToBytes serializes an address to a byte slice.
func (a *Address) ToBytes() []byte {
	return a.data[:]
}

// AddressFromBytes deserializes a byte slice into a new W-OTS+ address. The
// given byte slice must have a length of 32.
func AddressFromBytes(data []byte) (a Address, err error) {
	if len(data) != 32 {
		err = fmt.Errorf("raw address must have length 32 (has length %d)", len(data))
		return
	}

	copy(a.data[:], data)

	return
}