feat: Add experimental support for Schnorr signatures

Author: peacekeeper

src/main/java/com/danubetech/keyformats/crypto/impl/secp256k1_ES256KS_PublicKeyVerifier.java

@@ -4,6 +4,7 @@
 import com.danubetech.keyformats.jose.JWSAlgorithm;
 import com.danubetech.keyformats.util.SchnorrUtil;
 import org.bitcoinj.crypto.ECKey;
+import org.bitcoinj.crypto.LazyECPoint;
 import org.web3j.crypto.Hash;
 
 import java.security.GeneralSecurityException;
@@ -21,7 +22,8 @@ public boolean verify(byte[] content, byte[] signature) throws GeneralSecurityEx
         // verify
 
         byte[] hash = Hash.sha3(content);
-        boolean verified = SchnorrUtil.schnorr_verify(hash, this.getPublicKey().getPubKey(), signature);
+        ECKey compressedPublicKey = ECKey.fromPublicOnly(new LazyECPoint(this.getPublicKey().getPubKeyPoint(), true).get(), true);
+        boolean verified = SchnorrUtil.schnorr_verify(hash, compressedPublicKey.getPubKey(), signature);
 
         // done
 

src/test/java/com/danubetech/keyformats/crypto/SignVerifyTest.java

@@ -7,11 +7,13 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
 
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class SignVerifyTest {
 
 	private static final byte[] CONTENT = "Hello World!".getBytes(StandardCharsets.UTF_8);
+	private static final byte[] OTHER_CONTENT = "Goodbye World!".getBytes(StandardCharsets.UTF_8);
 
 	private static final Map<PrivateKeySigner<?>, PublicKeyVerifier<?>> SIGNERS_VERIFIERS = Map.of(
 			PrivateKeySignerFactory.privateKeySignerForKey(Ed25519Test.jwkPrivate, JWSAlgorithm.EdDSA),
@@ -22,8 +24,8 @@ public class SignVerifyTest {
 			PublicKeyVerifierFactory.publicKeyVerifierForKey(secp256k1Test.jwkPublic, JWSAlgorithm.ES256KCC),
 			PrivateKeySignerFactory.privateKeySignerForKey(secp256k1Test.jwkPrivate, JWSAlgorithm.ES256KRR),
 			PublicKeyVerifierFactory.publicKeyVerifierForKey(secp256k1Test.jwkPublic, JWSAlgorithm.ES256KRR),
-			//PrivateKeySignerFactory.privateKeySignerForKey(secp256k1Test.jwkPrivate, JWSAlgorithm.ES256KS),
-			//PublicKeyVerifierFactory.publicKeyVerifierForKey(secp256k1Test.jwkPublic, JWSAlgorithm.ES256KS),
+			PrivateKeySignerFactory.privateKeySignerForKey(secp256k1Test.jwkPrivate, JWSAlgorithm.ES256KS),
+			PublicKeyVerifierFactory.publicKeyVerifierForKey(secp256k1Test.jwkPublic, JWSAlgorithm.ES256KS),
 			PrivateKeySignerFactory.privateKeySignerForKey(P_256Test.jwkPrivate, JWSAlgorithm.ES256),
 			PublicKeyVerifierFactory.publicKeyVerifierForKey(P_256Test.jwkPublic, JWSAlgorithm.ES256),
 			PrivateKeySignerFactory.privateKeySignerForKey(P_384Test.jwkPrivate, JWSAlgorithm.ES384),
@@ -39,6 +41,7 @@ public void testSignVerify() throws Exception {
 			PublicKeyVerifier<?> publicKeyVerifierFactory = pair.getValue();
 			byte[] signature = privateKeySigner.sign(CONTENT);
 			assertTrue(publicKeyVerifierFactory.verify(CONTENT, signature));
+			assertFalse(publicKeyVerifierFactory.verify(OTHER_CONTENT, signature));
 		}
 	}
 }