Golang secp256k1_ecdsa_recover_compact Examples

Example #1

File: secp256.go Project: JmAbuDabi/skycoin

//recovers the public key from the signature
//recovery of pubkey means correct signature
func RecoverPubkey(msg []byte, sig []byte) []byte {
	if len(sig) != 65 {
		log.Panic()
	}

	var pubkey []byte = make([]byte, 33)

	var msg_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&msg[0]))
	var sig_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&sig[0]))
	var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))

	var pubkeylen C.int

	ret := C.secp256k1_ecdsa_recover_compact(
		msg_ptr, C.int(len(msg)),
		sig_ptr,
		pubkey_ptr, &pubkeylen,
		C.int(1), C.int(sig[64]),
	)

	if ret == 0 || int(pubkeylen) != 33 {
		return nil
	}

	return pubkey
}

Example #2

File: secp256.go Project: readevalprint/eris-db

//recovers the public key from the signature
//recovery of pubkey means correct signature
func RecoverPubkey(msg []byte, sig []byte) ([]byte, error) {
	if len(sig) != 65 {
		return nil, errors.New("Invalid signature length")
	}

	var pubkey []byte = make([]byte, 65)

	var msg_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&msg[0]))
	var sig_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&sig[0]))
	var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))

	var pubkeylen C.int

	ret := C.secp256k1_ecdsa_recover_compact(
		msg_ptr,
		sig_ptr,
		pubkey_ptr,
		&pubkeylen,
		C.int(0),
		C.int(sig[64]),
	)

	if ret == C.int(0) {
		return nil, errors.New("Failed to recover public key")
	} else if pubkeylen != C.int(65) {
		return nil, errors.New("Impossible Error: Invalid recovered public key length")
	} else {
		return pubkey, nil
	}
	return nil, errors.New("Impossible Error: func RecoverPubkey has reached an unreachable state")
}