// Generate a new stealth address
func new_stealth_address(prv_key []byte) {
sk, er := hex.DecodeString(*scankey)
if er != nil {
println(er.Error())
os.Exit(1)
}
if len(sk) != 33 || sk[0] != 2 && sk[0] != 3 {
println("scankey must be a compressed public key (33 bytes long)")
os.Exit(1)
}
if *prefix > 16 {
if *prefix > 24 {
fmt.Println("The stealth prefix cannot be bigger than 32", *prefix)
os.Exit(1)
}
fmt.Println("WARNING: You chose a prifix length of", *prefix)
fmt.Println("WARNING: Big prefixes endanger your anonymity.")
}
pub := btc.PublicFromPrivate(prv_key, true)
if pub == nil {
println("PublicFromPrivate error 2")
os.Exit(1)
}
sa := new(btc.StealthAddr)
sa.Version = btc.StealthAddressVersion(*testnet)
sa.Options = 0
copy(sa.ScanKey[:], sk)
sa.SpendKeys = make([][33]byte, 1)
copy(sa.SpendKeys[0][:], pub)
sa.Sigs = 1
sa.Prefix = make([]byte, 1+(byte(*prefix)+7)>>3)
if *prefix > 0 {
sa.Prefix[0] = byte(*prefix)
rand.Read(sa.Prefix[1:])
}
fmt.Println(sa.String())
}
func do_scan_stealth(p string, ignore_prefix bool) {
sa, _ := btc.NewStealthAddrFromString(p)
if sa == nil {
fmt.Println("Specify base58 encoded stealth address")
return
}
if sa.Version != btc.StealthAddressVersion(common.CFG.Testnet) {
fmt.Println("Incorrect version of the stealth address")
return
}
if len(sa.SpendKeys) != 1 {
fmt.Println("Currently only single spend keys are supported. This address has", len(sa.SpendKeys))
return
}
//fmt.Println("scankey", hex.EncodeToString(sa.ScanKey[:]))
if ignore_prefix {
sa.Prefix = []byte{0}
fmt.Println("Ignoring Prefix inside the address")
} else if len(sa.Prefix) == 0 {
fmt.Println("Prefix not present in the address")
} else {
fmt.Println("Prefix", sa.Prefix[0], hex.EncodeToString(sa.Prefix[1:]))
}
ds := wallet.FetchStealthKeys()
if len(ds) == 0 {
return
}
defer func() {
for i := range ds {
utils.ClearBuffer(ds[i])
}
}() // clear the keys in mem after all
var d []byte
for i := range ds {
if bytes.Equal(btc.PublicFromPrivate(ds[i], true), sa.ScanKey[:]) {
d = ds[i]
}
}
if d == nil {
fmt.Println("No matching secret found your wallet/stealth folder")
return
}
var pos []*btc.TxPrevOut
cs := make(map[uint64][]byte)
as := make(map[uint64]*btc.BtcAddr)
var ncnt uint
common.BlockChain.Unspent.ScanStealth(sa, func(eth, txid []byte, vout uint32, scr []byte) bool {
if len(scr) == 25 && scr[0] == 0x76 && scr[1] == 0xa9 && scr[2] == 0x14 && scr[23] == 0x88 && scr[24] == 0xac {
var h160 [20]byte
//yes := btc.NewUint256(txid).String()=="9cc90ff2528b49dfd9c53e5e90c98a1fd45d577af7f3a9e7a9f8a86b52fb0280"
c := btc.StealthDH(eth, d)
spen_exp := btc.DeriveNextPublic(sa.SpendKeys[0][:], c)
btc.RimpHash(spen_exp, h160[:])
if bytes.Equal(scr[3:23], h160[:]) {
po := new(btc.TxPrevOut)
copy(po.Hash[:], txid)
po.Vout = vout
pos = append(pos, po)
cs[po.UIdx()] = c
as[po.UIdx()] = btc.NewAddrFromHash160(h160[:], btc.AddrVerPubkey(common.CFG.Testnet))
}
ncnt++
/*fmt.Printf("%s with c=%s",
btc.NewAddrFromHash160(h160[:], btc.AddrVerPubkey(common.CFG.Testnet)).String(),
hex.EncodeToString(c))
fmt.Println()*/
return true
} else {
return false
}
})
fmt.Println(len(pos), "outputs, out of", ncnt, "notifications belonged to our wallet")
var unsp btc.AllUnspentTx
for i := range pos {
po, e := common.BlockChain.Unspent.UnspentGet(pos[i])
if e != nil {
println("UnspentGet:", e.Error())
println("This should not happen - please, report a bug.")
println("You can probably fix it by launching the client with -rescan")
os.Exit(1)
}
//fmt.Println(btc.NewUint256(pos[i].Hash[:]), pos[i].Vout+1, hex.EncodeToString(cs[pos[i].UIdx()]))
one := &btc.OneUnspentTx{
TxPrevOut: *pos[i],
Value: po.Value,
MinedAt: po.BlockHeight,
BtcAddr: as[pos[i].UIdx()],
StealthC: cs[pos[i].UIdx()]}
unsp = append(unsp, one)
}
sort.Sort(unsp)
os.RemoveAll("balance")
os.MkdirAll("balance/", 0770)
utxt, _ := os.Create("balance/unspent.txt")
fmt.Print(wallet.DumpBalance(unsp, utxt, true, false))
}
// Thanks @dabura667 - https://bitcointalk.org/index.php?topic=590349.msg6560332#msg6560332
func stealth_txout(sa *btc.StealthAddr, value uint64) (res []*btc.TxOut) {
if sa.Version != btc.StealthAddressVersion(*testnet) {
fmt.Println("ERROR: Unsupported version of a stealth address", sa.Version)
os.Exit(1)
}
if len(sa.SpendKeys) != 1 {
fmt.Println("ERROR: Currently only non-multisig stealth addresses are supported",
len(sa.SpendKeys))
os.Exit(1)
}
// Make two outpus
res = make([]*btc.TxOut, 2)
var e, ephemkey, pkscr []byte
var nonce, nonce_from uint32
var look4pref bool
sha := sha256.New()
// 6. create a new pub/priv keypair (lets call its pubkey "ephemkey" and privkey "e")
pick_different_e:
e = make([]byte, 32)
rand.Read(e)
defer utils.ClearBuffer(e)
ephemkey = btc.PublicFromPrivate(e, true)
if *verbose {
fmt.Println("e", hex.EncodeToString(e))
fmt.Println("ephemkey", hex.EncodeToString(ephemkey))
}
// 7. IF there is a prefix in the stealth address, brute force a nonce such
// that SHA256(nonce.concate(ephemkey)) first 4 bytes are equal to the prefix.
// IF NOT, then just run through the loop once and pickup a random nonce.
// (probably make the while condition include "or prefix = null" or something to that nature.
look4pref = len(sa.Prefix) > 0 && sa.Prefix[0] > 0
if look4pref {
fmt.Print("Prefix is ", sa.Prefix[0], ":", hex.EncodeToString(sa.Prefix[1:]), " - looking for nonce...")
}
binary.Read(rand.Reader, binary.LittleEndian, &nonce_from)
nonce = nonce_from
for {
binary.Write(sha, binary.LittleEndian, nonce)
sha.Write(ephemkey)
if sa.CheckPrefix(sha.Sum(nil)[:4]) {
break
}
sha.Reset()
nonce++
if nonce == nonce_from {
fmt.Println("EOF")
goto pick_different_e
}
if (nonce & 0xfffff) == 0 {
fmt.Print(".")
}
}
if look4pref {
fmt.Println(uint32(nonce - nonce_from))
}
// 8. Once you have the nonce and the ephemkey, you can create the first output, which is
pkscr = make([]byte, 40)
pkscr[0] = 0x6a // OP_RETURN
pkscr[1] = 38 // length
pkscr[2] = 0x06 // always 6
binary.LittleEndian.PutUint32(pkscr[3:7], nonce)
copy(pkscr[7:40], ephemkey)
res[0] = &btc.TxOut{Pk_script: pkscr}
// 9. Now use ECC multiplication to calculate e*Q where Q = scan_pubkey
// an e = privkey to ephemkey and then hash it.
c := btc.StealthDH(sa.ScanKey[:], e)
if *verbose {
fmt.Println("c", hex.EncodeToString(c))
}
// 10. That hash is now "c". use ECC multiplication and addition to
// calculate D + (c*G) where D = spend_pubkey, and G is the reference
// point for secp256k1. This will give you a new pubkey. (we'll call it D')
Dpr := btc.DeriveNextPublic(sa.SpendKeys[0][:], c)
if *verbose {
fmt.Println("Dpr", hex.EncodeToString(Dpr))
}
// 11. Create a normal P2KH output spending to D' as public key.
adr := btc.NewAddrFromPubkey(Dpr, btc.AddrVerPubkey(*testnet))
res[1] = &btc.TxOut{Value: value, Pk_script: adr.OutScript()}
fmt.Println("Sending to stealth", adr.String())
return
}