// this function signs either a message or a raw hash
func sign_message() {
var hash []byte
var signkey *btc.PrivateAddr
signkey = address_to_key(*signaddr)
if signkey == nil {
println("You do not have a private key for", *signaddr)
return
}
if *signhash != "" {
hash, er := hex.DecodeString(*signhash)
if er != nil {
println("Incorrect content of -hash parameter")
println(er.Error())
return
} else if len(hash) > 0 {
txsig := new(btc.Signature)
txsig.HashType = 0x01
r, s, e := btc.EcdsaSign(signkey.Key, hash)
if e != nil {
println(e.Error())
return
}
txsig.R.Set(r)
txsig.S.Set(s)
fmt.Println("PublicKey:", hex.EncodeToString(signkey.BtcAddr.Pubkey))
fmt.Println(hex.EncodeToString(txsig.Bytes()))
return
}
}
var msg []byte
if *message == "" {
msg, _ = ioutil.ReadAll(os.Stdin)
} else {
msg = []byte(*message)
}
hash = make([]byte, 32)
if litecoin {
ltc.HashFromMessage(msg, hash)
} else {
btc.HashFromMessage(msg, hash)
}
btcsig := new(btc.Signature)
var sb [65]byte
sb[0] = 27
if signkey.IsCompressed() {
sb[0] += 4
}
r, s, e := btc.EcdsaSign(signkey.Key, hash)
if e != nil {
println(e.Error())
return
}
btcsig.R.Set(r)
btcsig.S.Set(s)
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(signkey.IsCompressed()), signkey.BtcAddr.Version)
if sa.Hash160 == signkey.BtcAddr.Hash160 {
fmt.Println(base64.StdEncoding.EncodeToString(sb[:]))
return
}
rpk = btcsig.RecoverPublicKey(hash[:], 1)
sa = btc.NewAddrFromPubkey(rpk.Bytes(signkey.IsCompressed()), signkey.BtcAddr.Version)
if sa.Hash160 == signkey.BtcAddr.Hash160 {
sb[0]++
fmt.Println(base64.StdEncoding.EncodeToString(sb[:]))
return
}
println("Something went wrong. The message has not been signed.")
}
func main() {
var msg []byte
flag.Parse()
if *help || *addr == "" || *sign == "" {
flag.PrintDefaults()
return
}
ad, er := btc.NewAddrFromString(*addr)
if !*litecoin && ad != nil && ad.Version == ltc.AddrVerPubkey(false) {
*litecoin = true
}
if er != nil {
println("Address:", er.Error())
flag.PrintDefaults()
return
}
nv, btcsig, er := btc.ParseMessageSignature(*sign)
if er != nil {
println("ParseMessageSignature:", er.Error())
return
}
if *mess != "" {
msg = []byte(*mess)
} else if *mfil != "" {
msg, er = ioutil.ReadFile(*mfil)
if er != nil {
println(er.Error())
return
}
} else {
if *verb {
fmt.Println("Enter the message:")
}
msg, _ = ioutil.ReadAll(os.Stdin)
}
if *unix {
if *verb {
fmt.Println("Enforcing Unix text format")
}
msg = bytes.Replace(msg, []byte{'\r'}, nil, -1)
}
hash := make([]byte, 32)
if *litecoin {
ltc.HashFromMessage(msg, hash)
} else {
btc.HashFromMessage(msg, hash)
}
compressed := false
if nv >= 31 {
if *verb {
fmt.Println("compressed key")
}
nv -= 4
compressed = true
}
pub := btcsig.RecoverPublicKey(hash[:], int(nv-27))
if pub != nil {
pk := pub.Bytes(compressed)
ok := btc.EcdsaVerify(pk, btcsig.Bytes(), hash)
if ok {
sa := btc.NewAddrFromPubkey(pk, ad.Version)
if ad.Hash160 != sa.Hash160 {
fmt.Println("BAD signature for", ad.String())
if bytes.IndexByte(msg, '\r') != -1 {
fmt.Println("You have CR chars in the message. Try to verify with -u switch.")
}
os.Exit(1)
} else {
fmt.Println("Signature OK")
}
} else {
println("BAD signature")
os.Exit(1)
}
} else {
println("BAD, BAD, BAD signature")
os.Exit(1)
}
}