8318328: DHKEM should check XDH name in case-insensitive mode

src/java.base/share/classes/com/sun/crypto/provider/DHKEM.java

@@ -353,9 +353,9 @@ private Params paramsFromKey(Key k) throws InvalidKeyException {
             }
         } else if (k instanceof XECKey xkey
                 && xkey.getParams() instanceof NamedParameterSpec ns) {
-            if (ns.getName().equals("X25519")) {
+            if (ns.getName().equalsIgnoreCase("X25519")) {
                 return Params.X25519;
-            } else if (ns.getName().equals("X448")) {
+            } else if (ns.getName().equalsIgnoreCase("X448")) {
                 return Params.X448;
             }
         }

src/jdk.crypto.ec/share/classes/sun/security/ec/XDHPrivateKeyImpl.java

@@ -104,7 +104,7 @@ public Optional<byte[]> getScalar() {
 
     @Override
     public PublicKey calculatePublicKey() {
-        XECParameters params = paramSpec.getName().equals("X25519")
+        XECParameters params = paramSpec.getName().equalsIgnoreCase("X25519")
                 ? XECParameters.X25519
                 : XECParameters.X448;
         try {

test/jdk/com/sun/crypto/provider/DHKEM/NameSensitiveness.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8318328
+ * @summary DHKEM should check XDH name in case-insensitive mode
+ * @library /test/lib
+ * @modules java.base/com.sun.crypto.provider
+ */
+import javax.crypto.KEM;
+import java.math.BigInteger;
+import java.security.KeyPairGenerator;
+import java.security.interfaces.XECPublicKey;
+import java.security.spec.AlgorithmParameterSpec;
+import java.security.spec.NamedParameterSpec;
+
+public class NameSensitiveness {
+    public static void main(String[] args) throws Exception {
+        var g = KeyPairGenerator.getInstance("XDH");
+        g.initialize(NamedParameterSpec.X25519);
+        var pk1 = (XECPublicKey) g.generateKeyPair().getPublic();
+        var pk2 = new XECPublicKey() {
+            public BigInteger getU() {
+                return pk1.getU();
+            }
+            public AlgorithmParameterSpec getParams() {
+                return new NamedParameterSpec("x25519"); // lowercase!!!
+            }
+            public String getAlgorithm() {
+                return pk1.getAlgorithm();
+            }
+            public String getFormat() {
+                return pk1.getFormat();
+            }
+            public byte[] getEncoded() {
+                return pk1.getEncoded();
+            }
+        };
+        var kem = KEM.getInstance("DHKEM");
+        kem.newEncapsulator(pk2);
+    }
+}