io.neow3j.transaction.Witness Maven / Gradle / Ivy
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package io.neow3j.transaction;
import io.neow3j.crypto.ECKeyPair;
import io.neow3j.crypto.ECKeyPair.ECPublicKey;
import io.neow3j.crypto.Sign.SignatureData;
import io.neow3j.script.InvocationScript;
import io.neow3j.script.ScriptBuilder;
import io.neow3j.script.VerificationScript;
import io.neow3j.serialization.BinaryReader;
import io.neow3j.serialization.BinaryWriter;
import io.neow3j.serialization.NeoSerializable;
import io.neow3j.serialization.exceptions.DeserializationException;
import io.neow3j.types.ContractParameter;
import java.io.IOException;
import java.util.List;
import java.util.Objects;
/**
* A script (invocation and verification script) used to validate a transaction.
* Usually, a witness is made up of a signature (invocation script) and a check-signature script
* (verification script) that together prove that the signer has witnessed the signed data.
*/
public class Witness extends NeoSerializable {
private InvocationScript invocationScript;
private VerificationScript verificationScript;
/**
* Constructs an empty witness.
*/
public Witness() {
invocationScript = new InvocationScript();
verificationScript = new VerificationScript();
}
/**
* Creates a new witness from the given invocation and verification script.
*
* @param invocationScript the invocation script
* @param verificationScript the verification script
* @see Witness#Witness(InvocationScript, VerificationScript)
*/
public Witness(byte[] invocationScript, byte[] verificationScript) {
this(new InvocationScript(invocationScript),
new VerificationScript(verificationScript));
}
/**
* Creates a new script from the given invocation and verification script.
*
* @param invocationScript the invocation script
* @param verificationScript the verification script
*/
public Witness(InvocationScript invocationScript, VerificationScript verificationScript) {
this.invocationScript = invocationScript;
this.verificationScript = verificationScript;
}
/**
* Creates a witness (invocation and verification scripts) from the given message, using the
* given keys for signing the message.
*
* @param messageToSign The message from which the signature is added to the invocation script.
* @param keyPair The key pair which is used for signing. The verification script is
* created from the public key.
* @return the constructed witness/script.
*/
public static Witness create(byte[] messageToSign, ECKeyPair keyPair) {
InvocationScript i = InvocationScript.fromMessageAndKeyPair(messageToSign, keyPair);
VerificationScript v = new VerificationScript(keyPair.getPublicKey());
return new Witness(i, v);
}
/**
* Creates a witness in which the invocation script contains the given signatures and the
* verification script checks the signatures according to the given public keys and signing
* threshold.
*
* @param signingThreshold The minimum number of signatures required for successful multi-sig
* verification.
* @param signatures The signatures to add to the invocation script.
* @param publicKeys The public keys to add to verification script.
* @return the witness.
*/
public static Witness createMultiSigWitness(int signingThreshold,
List signatures, List publicKeys) {
VerificationScript v = new VerificationScript(publicKeys, signingThreshold);
return createMultiSigWitness(signatures, v);
}
/**
* Constructs a witness with the given verification script and an invocation script
* containing the given signatures. The number of signatures must reach the signing threshold
* given in the verification script.
*
* @param signatures The signatures to add to the invocation script.
* @param verificationScript The verification script to use in the witness.
* @return the witness.
*/
public static Witness createMultiSigWitness(List signatures,
VerificationScript verificationScript) {
int signingThreshold = verificationScript.getSigningThreshold();
if (signatures.size() < signingThreshold) {
throw new IllegalArgumentException("Not enough signatures provided for the required " +
"signing threshold.");
}
return new Witness(
InvocationScript.fromSignatures(signatures.subList(0, signingThreshold)),
verificationScript);
}
/**
* Constructs a witness with an invocation script based on the provided parameters for the
* contract's verify method.
*
* This method is used if no signature is present, i.e. if the signer is a contract. In that
* case the invocation script is built based on the parameters of its verify method. No
* verification script is needed.
*
* @param verifyParams the parameters for the contract's verify method.
* @return the witness.
*/
public static Witness createContractWitness(List verifyParams) {
if (verifyParams.isEmpty()) {
return new Witness();
}
ScriptBuilder invocationScript = new ScriptBuilder();
verifyParams.forEach(invocationScript::pushParam);
return new Witness(invocationScript.toArray(), new byte[]{});
}
public InvocationScript getInvocationScript() {
return invocationScript;
}
public VerificationScript getVerificationScript() {
return verificationScript;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Witness)) return false;
Witness script = (Witness) o;
return Objects.equals(getInvocationScript(), script.getInvocationScript()) &&
Objects.equals(getVerificationScript(), script.getVerificationScript());
}
@Override
public int hashCode() {
return Objects.hash(getInvocationScript(), getVerificationScript());
}
@Override
public String toString() {
return "Script{" +
"invocationScript='" + invocationScript + '\'' +
", verificationScript='" + verificationScript + '\'' +
'}';
}
@Override
public void deserialize(BinaryReader reader) throws DeserializationException {
this.invocationScript = reader.readSerializable(InvocationScript.class);
this.verificationScript = reader.readSerializable(VerificationScript.class);
}
@Override
public void serialize(BinaryWriter writer) throws IOException {
invocationScript.serialize(writer);
verificationScript.serialize(writer);
}
@Override
public int getSize() {
return this.invocationScript.getSize() + this.verificationScript.getSize();
}
}