Example #1
0
func Sign(msg []byte, seckey []byte) ([]byte, error) {
	nonce := randentropy.GetEntropyCSPRNG(32)

	var sig []byte = make([]byte, 65)
	var recid C.int

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

	var noncefp_ptr = &(*C.secp256k1_nonce_function_default)
	var ndata_ptr = unsafe.Pointer(&nonce[0])

	if C.secp256k1_ec_seckey_verify(seckey_ptr) != C.int(1) {
		return nil, errors.New("Invalid secret key")
	}

	ret := C.secp256k1_ecdsa_sign_compact(
		msg_ptr,
		sig_ptr,
		seckey_ptr,
		noncefp_ptr,
		ndata_ptr,
		&recid)

	sig[64] = byte(int(recid))

	if ret != C.int(1) {
		// nonce invalid, retry
		return Sign(msg, seckey)
	}

	return sig, nil

}
Example #2
0
func GenerateKeyPair() ([]byte, []byte) {

	pubkey_len := C.int(65)
	const seckey_len = 32

	var pubkey []byte = make([]byte, pubkey_len)
	var seckey []byte = randentropy.GetEntropyCSPRNG(seckey_len)

	var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0]))
	var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0]))

	ret := C.secp256k1_ec_pubkey_create(
		pubkey_ptr, &pubkey_len,
		seckey_ptr, 0) // uncompressed

	// or, see randFieldElement at https://golang.org/src/crypto/ecdsa/ecdsa.go#61
	// apparently not *every* 256 bit int is on the curve
	// XXX: is this the same as validating the privkey before calling create?
	if ret != C.int(1) {
		return GenerateKeyPair() //invalid secret, try again
	}
	return pubkey, seckey
}