// Verify the secret key's range and if a test message signed with it verifies OK // Returns nil if averything looks OK func VerifyKeyPair(priv []byte, publ []byte) error { const TestMessage = "Just some test message..." hash := Sha2Sum([]byte(TestMessage)) pub_key, e := NewPublicKey(publ) if e != nil { return e } var key ecdsa.PrivateKey key.D = new(big.Int).SetBytes(priv) key.PublicKey = pub_key.PublicKey if key.D.Cmp(big.NewInt(0)) == 0 { return errors.New("pubkey value is zero") } if key.D.Cmp(secp256k1.N) != -1 { return errors.New("pubkey value is too big") } r, s, err := ecdsa.Sign(rand.Reader, &key, hash[:]) if err != nil { return errors.New("ecdsa.Sign failed: " + err.Error()) } ok := ecdsa.Verify(&key.PublicKey, hash[:], r, s) if !ok { return errors.New("ecdsa.Sign Verify") } return nil }
// Signs a specified transaction input func (tx *Tx) Sign(in int, pk_script []byte, hash_type byte, pubkey, priv_key []byte) error { if in >= len(tx.TxIn) { return errors.New("tx.Sign() - input index overflow") } pub_key, er := NewPublicKey(pubkey) if er != nil { return er } // Load the key (private and public) var key ecdsa.PrivateKey key.D = new(big.Int).SetBytes(priv_key) key.PublicKey = pub_key.PublicKey //Calculate proper transaction hash h := tx.SignatureHash(pk_script, in, hash_type) // Sign r, s, er := EcdsaSign(&key, h) if er != nil { return er } rb := r.Bytes() sb := s.Bytes() if rb[0] >= 0x80 { rb = append([]byte{0x00}, rb...) } if sb[0] >= 0x80 { sb = append([]byte{0x00}, sb...) } // Output the signing result into a buffer, in format expected by bitcoin protocol busig := new(bytes.Buffer) busig.WriteByte(0x30) busig.WriteByte(byte(4 + len(rb) + len(sb))) busig.WriteByte(0x02) busig.WriteByte(byte(len(rb))) busig.Write(rb) busig.WriteByte(0x02) busig.WriteByte(byte(len(sb))) busig.Write(sb) busig.WriteByte(0x01) // hash type // Output the signature and the public key into tx.ScriptSig buscr := new(bytes.Buffer) buscr.WriteByte(byte(busig.Len())) buscr.Write(busig.Bytes()) buscr.WriteByte(byte(len(pubkey))) buscr.Write(pubkey) // assign sign script ot the tx: tx.TxIn[in].ScriptSig = buscr.Bytes() return nil // no error }
func UnmarshalCertificate(data []byte) Certificate { priv := new(big.Int).SetBytes(data[:28]) pub := UnmarshalPublicCertificate(data[28:]) cert := new(ecdsa.PrivateKey) cert.D = priv cert.PublicKey = *pub return cert }
func (pk *PrivateKey) parseECDSAPrivateKey(data []byte) (err error) { ecdsaPub := pk.PublicKey.PublicKey.(*ecdsa.PublicKey) ecdsaPriv := new(ecdsa.PrivateKey) ecdsaPriv.PublicKey = *ecdsaPub buf := bytes.NewBuffer(data) d, _, err := readMPI(buf) if err != nil { return } ecdsaPriv.D = new(big.Int).SetBytes(d) pk.PrivateKey = ecdsaPriv pk.Encrypted = false pk.encryptedData = nil return nil }
// Verify the secret key's range and al if a test message signed with it verifies OK func verify_key(priv []byte, publ []byte) bool { const TestMessage = "Just some test message..." hash := btc.Sha2Sum([]byte(TestMessage)) pub_key, e := btc.NewPublicKey(publ) if e != nil { println("NewPublicKey:", e.Error(), "\007") os.Exit(1) } var key ecdsa.PrivateKey key.D = new(big.Int).SetBytes(priv) key.PublicKey = pub_key.PublicKey if key.D.Cmp(big.NewInt(0)) == 0 { println("pubkey value is zero") return false } if key.D.Cmp(maxKeyVal) != -1 { println("pubkey value is too big", hex.EncodeToString(publ)) return false } r, s, err := ecdsa.Sign(rand.Reader, &key, hash[:]) if err != nil { println("ecdsa.Sign:", err.Error()) return false } ok := ecdsa.Verify(&key.PublicKey, hash[:], r, s) if !ok { println("The key pair does not verify!") return false } return true }
func multisig_sign() { tx := raw_tx_from_file(*rawtx) if tx == nil { println("ERROR: Cannot decode the raw multisig transaction") println("Always use -msign <addr> along with -raw multi2sign.txt") return } ad2s, e := btc.NewAddrFromString(*multisign) if e != nil { println("BTC addr:", e.Error()) return } var privkey *ecdsa.PrivateKey //var compr bool for i := range publ_addrs { if publ_addrs[i].Hash160 == ad2s.Hash160 { privkey = new(ecdsa.PrivateKey) pub, e := btc.NewPublicKey(publ_addrs[i].Pubkey) if e != nil { println("PubKey:", e.Error()) return } privkey.PublicKey = pub.PublicKey privkey.D = new(big.Int).SetBytes(priv_keys[i][:]) //compr = compressed_key[i] break } } if privkey == nil { println("You do not know a key for address", ad2s.String()) return } for i := range tx.TxIn { ms, er := btc.NewMultiSigFromScript(tx.TxIn[i].ScriptSig) if er != nil { println("WARNING: Input", i, "- not multisig:", er.Error()) continue } hash := tx.SignatureHash(ms.P2SH(), i, btc.SIGHASH_ALL) //fmt.Println("Input number", i, len(ms.Signatures), " - hash to sign:", hex.EncodeToString(hash)) btcsig := &btc.Signature{HashType: 0x01} btcsig.R, btcsig.S, e = btc.EcdsaSign(privkey, hash) if e != nil { println(e.Error()) return } ms.Signatures = append(ms.Signatures, btcsig) tx.TxIn[i].ScriptSig = ms.Bytes() } // Now re-order the signatures as they shall be: for i := range tx.TxIn { ms, er := btc.NewMultiSigFromScript(tx.TxIn[i].ScriptSig) if er != nil { //println(er.Error()) continue } hash := tx.SignatureHash(ms.P2SH(), i, btc.SIGHASH_ALL) //fmt.Println("Input number", i, " - hash to sign:", hex.EncodeToString(hash)) //fmt.Println(" ... number of signatures:", len(ms.Signatures)) var sigs []*btc.Signature for ki := range ms.PublicKeys { //pk := btc.NewPublicKey(ms.PublicKeys[ki]) //fmt.Println(ki, hex.EncodeToString(ms.PublicKeys[ki])) var sig *btc.Signature for si := range ms.Signatures { if btc.EcdsaVerify(ms.PublicKeys[ki], ms.Signatures[si].Bytes(), hash) { //fmt.Println("Key number", ki, "has signature number", si) sig = ms.Signatures[si] break } } if sig != nil { sigs = append(sigs, sig) } else if *verbose { fmt.Println("WARNING: Key number", ki, "has no matching signature") } if !*allowextramsigns && uint(len(sigs)) >= ms.SigsNeeded { break } } if len(ms.Signatures) > len(sigs) { fmt.Println("WARNING: Some signatures are obsolete and will be removed", len(ms.Signatures), "=>", len(sigs)) } else if len(ms.Signatures) < len(sigs) { fmt.Println("It appears that same key is re-used.", len(sigs)-len(ms.Signatures), "more signatures were added") } ms.Signatures = sigs tx.TxIn[i].ScriptSig = ms.Bytes() } write_tx_file(tx) }
// prepare a signed transaction func make_signed_tx() { // Make an empty transaction tx := new(btc.Tx) tx.Version = 1 tx.Lock_time = 0 // Select as many inputs as we need to pay the full amount (with the fee) var btcsofar uint64 var inpcnt uint for inpcnt = 0; inpcnt < uint(len(unspentOuts)); inpcnt++ { uo := UO(unspentOuts[inpcnt]) // add the input to our transaction: tin := new(btc.TxIn) tin.Input = *unspentOuts[inpcnt] tin.Sequence = 0xffffffff tx.TxIn = append(tx.TxIn, tin) btcsofar += uo.Value if btcsofar >= spendBtc+feeBtc { break } } changeBtc = btcsofar - (spendBtc + feeBtc) fmt.Printf("Spending %d out of %d outputs...\n", inpcnt+1, len(unspentOuts)) // Build transaction outputs: tx.TxOut = make([]*btc.TxOut, len(sendTo)) for o := range sendTo { tx.TxOut[o] = &btc.TxOut{Value: sendTo[o].amount, Pk_script: sendTo[o].addr.OutScript()} } if changeBtc > 0 { // Add one more output (with the change) tx.TxOut = append(tx.TxOut, &btc.TxOut{Value: changeBtc, Pk_script: get_change_addr().OutScript()}) } //fmt.Println("Unsigned:", hex.EncodeToString(tx.Serialize())) for in := range tx.TxIn { uo := UO(unspentOuts[in]) var found bool for j := range publ_addrs { if publ_addrs[j].Owns(uo.Pk_script) { pub_key, e := btc.NewPublicKey(publ_addrs[j].Pubkey) if e != nil { println("NewPublicKey:", e.Error(), "\007") os.Exit(1) } // Load the key (private and public) var key ecdsa.PrivateKey key.D = new(big.Int).SetBytes(priv_keys[j][:]) key.PublicKey = pub_key.PublicKey //Calculate proper transaction hash h := tx.SignatureHash(uo.Pk_script, in, btc.SIGHASH_ALL) //fmt.Println("SignatureHash:", btc.NewUint256(h).String()) // Sign r, s, err := ecdsa.Sign(rand.Reader, &key, h) if err != nil { println("Sign:", err.Error(), "\007") os.Exit(1) } rb := r.Bytes() sb := s.Bytes() if rb[0] >= 0x80 { // I thinnk this is needed, thought I am not quite sure... :P rb = append([]byte{0x00}, rb...) } if sb[0] >= 0x80 { // I thinnk this is needed, thought I am not quite sure... :P sb = append([]byte{0x00}, sb...) } // Output the signing result into a buffer, in format expected by bitcoin protocol busig := new(bytes.Buffer) busig.WriteByte(0x30) busig.WriteByte(byte(4 + len(rb) + len(sb))) busig.WriteByte(0x02) busig.WriteByte(byte(len(rb))) busig.Write(rb) busig.WriteByte(0x02) busig.WriteByte(byte(len(sb))) busig.Write(sb) busig.WriteByte(0x01) // hash type // Output the signature and the public key into tx.ScriptSig buscr := new(bytes.Buffer) buscr.WriteByte(byte(busig.Len())) buscr.Write(busig.Bytes()) buscr.WriteByte(byte(len(publ_addrs[j].Pubkey))) buscr.Write(publ_addrs[j].Pubkey) // assign: tx.TxIn[in].ScriptSig = buscr.Bytes() found = true break } } if !found { fmt.Println("You do not have private key for input number", hex.EncodeToString(uo.Pk_script), "\007") os.Exit(1) } } rawtx := tx.Serialize() tx.Hash = btc.NewSha2Hash(rawtx) hs := tx.Hash.String() fmt.Println(hs) f, _ := os.Create(hs[:8] + ".txt") if f != nil { f.Write([]byte(hex.EncodeToString(rawtx))) f.Close() fmt.Println("Transaction data stored in", hs[:8]+".txt") } f, _ = os.Create("balance/unspent.txt") if f != nil { for j := uint(0); j < uint(len(unspentOuts)); j++ { if j > inpcnt { fmt.Fprintln(f, unspentOuts[j], unspentOutsLabel[j]) } } fmt.Println(inpcnt, "spent output(s) removed from 'balance/unspent.txt'") var addback int for out := range tx.TxOut { for j := range publ_addrs { if publ_addrs[j].Owns(tx.TxOut[out].Pk_script) { fmt.Fprintf(f, "%s-%03d # %.8f / %s\n", tx.Hash.String(), out, float64(tx.TxOut[out].Value)/1e8, publ_addrs[j].String()) addback++ } } } f.Close() if addback > 0 { f, _ = os.Create("balance/" + hs + ".tx") if f != nil { f.Write(rawtx) f.Close() } fmt.Println(addback, "new output(s) appended to 'balance/unspent.txt'") } } }
func sign_message() { ad2s, e := btc.NewAddrFromString(*signaddr) if e != nil { println(e.Error()) return } var privkey *ecdsa.PrivateKey for i := range publ_addrs { if publ_addrs[i].Hash160 == ad2s.Hash160 { privkey = new(ecdsa.PrivateKey) pub, e := btc.NewPublicKey(publ_addrs[i].Pubkey) if e != nil { println(e.Error()) return } privkey.PublicKey = pub.PublicKey privkey.D = new(big.Int).SetBytes(priv_keys[i][:]) break } } if privkey == nil { println("You do not have a private key for", ad2s.String()) return } var msg []byte if *message == "" { msg, _ = ioutil.ReadAll(os.Stdin) } else { msg = []byte(*message) } hash := make([]byte, 32) btc.HashFromMessage(msg, hash) btcsig := new(btc.Signature) var sb [65]byte sb[0] = 27 if !*uncompressed { sb[0] += 4 } btcsig.R, btcsig.S, e = ecdsa_Sign(privkey, hash) if e != nil { println(e.Error()) return } rd := btcsig.R.Bytes() sd := btcsig.S.Bytes() copy(sb[1+32-len(rd):], rd) copy(sb[1+64-len(sd):], sd) rpk := btcsig.RecoverPublicKey(hash[:], 0) sa := btc.NewAddrFromPubkey(rpk.Bytes(!*uncompressed), ad2s.Version) if sa.Hash160 == ad2s.Hash160 { fmt.Println(base64.StdEncoding.EncodeToString(sb[:])) return } rpk = btcsig.RecoverPublicKey(hash[:], 1) sa = btc.NewAddrFromPubkey(rpk.Bytes(!*uncompressed), ad2s.Version) if sa.Hash160 == ad2s.Hash160 { sb[0]++ fmt.Println(base64.StdEncoding.EncodeToString(sb[:])) return } println("Something went wrong. The message has not been signed.") }
// this function signs either a message or a raw transaction hash func sign_message() { var hash []byte if *signhash != "" { var er error hash, er = hex.DecodeString(*signhash) if er != nil { println("Incorrect content of -hash parameter") println(er.Error()) return } } ad2s, e := btc.NewAddrFromString(*signaddr) if e != nil { println(e.Error()) if *signhash != "" { println("Always use -sign <addr> along with -hash <msghash>") } return } var privkey *ecdsa.PrivateKey var compr bool for i := range publ_addrs { if publ_addrs[i].Hash160 == ad2s.Hash160 { privkey = new(ecdsa.PrivateKey) pub, e := btc.NewPublicKey(publ_addrs[i].Pubkey) if e != nil { println(e.Error()) return } privkey.PublicKey = pub.PublicKey privkey.D = new(big.Int).SetBytes(priv_keys[i][:]) compr = compressed_key[i] // Sign raw hash? if hash != nil { txsig := new(btc.Signature) txsig.HashType = 0x01 txsig.R, txsig.S, e = btc.EcdsaSign(privkey, hash) if e != nil { println(e.Error()) return } fmt.Println("PublicKey:", hex.EncodeToString(publ_addrs[i].Pubkey)) fmt.Println(hex.EncodeToString(txsig.Bytes())) return } break } } if privkey == nil { println("You do not have a private key for", ad2s.String()) return } var msg []byte if *message == "" { msg, _ = ioutil.ReadAll(os.Stdin) } else { msg = []byte(*message) } hash = make([]byte, 32) btc.HashFromMessage(msg, hash) btcsig := new(btc.Signature) var sb [65]byte sb[0] = 27 if compr { sb[0] += 4 } btcsig.R, btcsig.S, e = btc.EcdsaSign(privkey, hash) if e != nil { println(e.Error()) return } rd := btcsig.R.Bytes() sd := btcsig.S.Bytes() copy(sb[1+32-len(rd):], rd) copy(sb[1+64-len(sd):], sd) rpk := btcsig.RecoverPublicKey(hash[:], 0) sa := btc.NewAddrFromPubkey(rpk.Bytes(compr), ad2s.Version) if sa.Hash160 == ad2s.Hash160 { fmt.Println(base64.StdEncoding.EncodeToString(sb[:])) return } rpk = btcsig.RecoverPublicKey(hash[:], 1) sa = btc.NewAddrFromPubkey(rpk.Bytes(compr), ad2s.Version) if sa.Hash160 == ad2s.Hash160 { sb[0]++ fmt.Println(base64.StdEncoding.EncodeToString(sb[:])) return } println("Something went wrong. The message has not been signed.") }