// GetMixData decrypts the private portion of a nymaddress.
func (ad *Address) GetMixData(keysLookup KeyFunc) (*AddressPrivate, error) {
pubkey := new([KeySize]byte)
copy(pubkey[:], ad.MixPubKey)
privkey := keysLookup(pubkey)
if privkey == nil {
return nil, ErrNoKey
}
sharedSecret := new([KeySize]byte)
addrKey := new([KeySize]byte)
copy(addrKey[:], ad.AddressKey)
curve25519.ScalarMult(sharedSecret, privkey, addrKey)
cr, err := lioness.New(sharedSecret[:]) // saves some bytes and is safe against tagging
if err != nil {
return nil, err
}
privmarshal, err := cr.Decrypt(ad.PrivateData)
if err != nil {
return nil, err
}
ap := new(AddressPrivate)
_, err = asn1.Unmarshal(privmarshal, ap)
if err != nil {
return nil, err
}
return ap, nil
}
// NewAddress generates a new nymaddress for nym/address from AddressTemplate.
// Only the first KeySize bytes of Nym are used, so use a hash of the true nym
// here.
func (tmp AddressTemplate) NewAddress(MailboxAddress, Nym []byte) ([]byte, error) {
xnym := make([]byte, KeySize)
copy(xnym, Nym)
Nym = xnym
mixAddress := tmp.MixCandidates.Expire(tmp.Expire).Rand() // Select a random mix
if mixAddress == nil {
return nil, ErrNoMix
}
pubKeyRand, privKeyRand, err := genKeyRandom()
if err != nil {
return nil, err
}
nonce, err := genNonce()
if err != nil {
return nil, err
}
nymaddr := new(Address)
nymaddr.MixAddress = []byte(mixAddress.Address)
nymaddr.MixPubKey = mixAddress.Pubkey
nymaddr.TokenPubKey = mixAddress.TokenKey
nymaddr.Expire = tmp.Expire
nymaddr.SingleUse = tmp.SingleUse
nymaddr.AddressKey = pubKeyRand[:]
nymprivate := new(AddressPrivate)
nymprivate.System = tmp.System
nymprivate.Expire = tmp.Expire
nymprivate.Address = MailboxAddress
nymprivate.SingleUse = tmp.SingleUse
nymprivate.MinDelay = tmp.MinDelay
nymprivate.MaxDelay = tmp.MaxDelay
nymprivate.Nonce = nonce[:]
// Calculate public key that the mix will encrypt TO
recPub, _ := tmp.genDetermKeys(nymprivate.Nonce, Nym)
nymprivate.ReceiverPubKey = recPub[:]
// Calculate symmetric key
symkey := tmp.genSymKey(nymprivate.Nonce, nymprivate.ReceiverPubKey, nymprivate.Address)
nymprivate.EncNym = encryptNym(symkey, Nym)
nymprivate.HMACHead = calcHmac(symkey, nymprivate.Nonce, nymprivate.ReceiverPubKey, nymprivate.EncNym)
privmarshal, err := asn1.Marshal(*nymprivate)
if err != nil {
return nil, err
}
mixPubKey := new([KeySize]byte)
sharedSecret := new([KeySize]byte)
copy(mixPubKey[:], nymaddr.MixPubKey)
curve25519.ScalarMult(sharedSecret, privKeyRand, mixPubKey)
cr, err := lioness.New(sharedSecret[:]) // saves some bytes and is safe against tagging
if err != nil {
return nil, err
}
privmarshalEnc, err := cr.Encrypt(privmarshal)
if err != nil {
return nil, err
}
nymaddr.PrivateData = privmarshalEnc
return asn1.Marshal(*nymaddr)
}
