Implement the ECKeyPairGenerator initialize func

Aim to solve openj9 issue 18320.
DefaultSignatureAlgorithm test run in those
Redhat OS based machines, FIPS version of
openssl is used in those machines. So, a 192
size of EC key pair generator is not allowed
by the native code in FIPS version of openssl
, then a Java implementation is used.

However, there are lacking of implementation
of initialize function in ECKeyPairGenerator
file.

This PR implements the initialize function in
ECKeyPairGenerator file.

test/jdk/sun/security/tools/keytool/fakegen/DefaultSignatureAlgorithm.java

@@ -74,8 +74,9 @@ private static void check(String keyAlg, int keySize,
         String sigAlgParam = requestedSigAlg == null
                 ? ""
                 : (" -sigalg " + requestedSigAlg);
+        System.out.println("starting...");
         genkeypair(alias,
-                "-keyalg " + keyAlg + " -keysize " + keySize + sigAlgParam)
+                "-keyalg " + keyAlg + " -keysize " + keySize + sigAlgParam + " -debug -J-Djdk.nativeCryptoTrace=true")
             .shouldHaveExitValue(0);
 
         KeyStore ks = KeyStore.getInstance(

test/jdk/sun/security/tools/keytool/fakegen/jdk.crypto.ec/sun/security/ec/ECKeyPairGenerator.java

@@ -27,6 +27,7 @@
 import java.security.*;
 import java.security.spec.AlgorithmParameterSpec;
 import java.security.spec.ECParameterSpec;
+import java.security.spec.ECGenParameterSpec;
 import java.security.spec.ECPoint;
 
 import sun.security.util.ECUtil;
@@ -51,7 +52,28 @@ public void initialize(int keySize, SecureRandom random) {
     @Override
     public void initialize(AlgorithmParameterSpec params, SecureRandom random)
             throws InvalidAlgorithmParameterException {
-        throw new UnsupportedOperationException();
+        ECParameterSpec ecSpec = null;
+
+        if (params instanceof ECParameterSpec) {
+            ECParameterSpec ecParams = (ECParameterSpec) params;
+            ecSpec = ECUtil.getECParameterSpec(null, ecParams);
+            if (ecSpec == null) {
+                throw new InvalidAlgorithmParameterException(
+                    "Unsupported curve: " + params);
+            }
+        } else if (params instanceof ECGenParameterSpec) {
+            String name = ((ECGenParameterSpec) params).getName();
+            ecSpec = ECUtil.getECParameterSpec(null, name);
+            if (ecSpec == null) {
+                throw new InvalidAlgorithmParameterException(
+                    "Unknown curve name: " + name);
+            }
+        } else {
+            throw new InvalidAlgorithmParameterException(
+                "ECParameterSpec or ECGenParameterSpec required for EC");
+        }
+
+        this.keySize = ecSpec.getCurve().getField().getFieldSize();
     }
 
     @Override