io.neow3j.crypto

Class Sign

java.lang.Object

io.neow3j.crypto.Sign

public class Sign
extends java.lang.Object

Transaction signing logic.

Originally adapted from the BitcoinJ ECKey implementation.

Class from web3j project, and adapted to neow3j project (with NEO requirements).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Sign.SignatureData

Constructor Summary

Constructors

Constructor and Description
Sign()

Method Summary

Modifier and Type	Method and Description
static ECKeyPair.ECPublicKey	publicKeyFromPrivate(ECKeyPair.ECPrivateKey privKey) Returns public key from the given private key.
static org.bouncycastle.math.ec.ECPoint	publicPointFromPrivateKey(ECKeyPair.ECPrivateKey privKey) Returns public key point from the given private key.
static ECKeyPair.ECPublicKey	recoverFromSignature(int recId, ECDSASignature sig, byte[] message) Given the components of a signature and a selector value, recover and return the public key that generated the signature according to the algorithm in SEC1v2 section 4.1.6.
static java.lang.String	recoverSigningAddress(byte[] message, Sign.SignatureData signatureData) Recovers the address that created the given signature on the given message.
static ECKeyPair.ECPublicKey	signedMessageToKey(byte[] message, Sign.SignatureData signatureData) Given an arbitrary piece of text and an NEO message signature encoded in bytes, returns the public key that was used to sign it.
static Sign.SignatureData	signMessage(byte[] message, ECKeyPair keyPair)
static Sign.SignatureData	signMessage(byte[] message, ECKeyPair keyPair, boolean needToHash)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Sign

public Sign()

Method Detail

signMessage

public static Sign.SignatureData signMessage(byte[] message,
                                             ECKeyPair keyPair)

signMessage

public static Sign.SignatureData signMessage(byte[] message,
                                             ECKeyPair keyPair,
                                             boolean needToHash)

recoverFromSignature

public static ECKeyPair.ECPublicKey recoverFromSignature(int recId,
                                                         ECDSASignature sig,
                                                         byte[] message)

Given the components of a signature and a selector value, recover and return the public key that generated the signature according to the algorithm in SEC1v2 section 4.1.6.

The recId is an index from 0 to 3 which indicates which of the 4 possible keys is the correct one. Because the key recovery operation yields multiple potential keys, the correct key must either be stored alongside the signature, or you must be willing to try each recId in turn until you find one that outputs the key you are expecting.

If this method returns null it means recovery was not possible and recId should be iterated.

Given the above two points, a correct usage of this method is inside a for loop from 0 to 3, and if the output is null OR a key that is not the one you expect, you try again with the next recId.

Parameters:

recId - Which possible key to recover.

sig - the R and S components of the signature, wrapped.

message - Hash of the data that was signed.

Returns:

An ECKey containing only the public part, or null if recovery wasn't possible.

signedMessageToKey

public static ECKeyPair.ECPublicKey signedMessageToKey(byte[] message,
                                                       Sign.SignatureData signatureData)
                                                throws java.security.SignatureException

Given an arbitrary piece of text and an NEO message signature encoded in bytes, returns the public key that was used to sign it. This can then be compared to the expected public key to determine if the signature was correct.

Parameters:

message - encoded message.

signatureData - The message signature components

Returns:

the public key used to sign the message

Throws:

java.security.SignatureException - If the public key could not be recovered or if there was a signature format error.

publicKeyFromPrivate

public static ECKeyPair.ECPublicKey publicKeyFromPrivate(ECKeyPair.ECPrivateKey privKey)

Returns public key from the given private key.

Parameters:

privKey - the private key to derive the public key from

Returns:

BigInteger encoded public key

publicPointFromPrivateKey

public static org.bouncycastle.math.ec.ECPoint publicPointFromPrivateKey(ECKeyPair.ECPrivateKey privKey)

Returns public key point from the given private key.

Parameters:

privKey - The private key as BigInteger

Returns:

The ECPoint object representation of the public key based on the given private key

recoverSigningAddress

public static java.lang.String recoverSigningAddress(byte[] message,
                                                     Sign.SignatureData signatureData)
                                              throws java.security.SignatureException

Recovers the address that created the given signature on the given message.

If the message is a Neo transaction, then make sure that it was serialized without the verification and invocation script attached (i.e. without the signature).

Parameters:

signatureData - The signature.

message - The message for which the signature was created.

Returns:

the address that produced the signature data from the transaction.

Throws:

java.security.SignatureException - throws if the signature is invalid.