8258915: Temporary buffer cleanup

Reviewed-by: valeriep

src/java.base/share/classes/sun/security/util/DerOutputStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2021, 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
@@ -169,6 +169,17 @@ extends ByteArrayOutputStream implements DerEncoder {
         write(buf, 0, buf.length);
     }
 
+    /**
+     * Marshals a DER integer on the output stream.
+     *
+     * @param i the integer in bytes, equivalent to BigInteger::toByteArray.
+     */
+    public void putInteger(byte[] buf) throws IOException {
+        write(DerValue.tag_Integer);
+        putLength(buf.length);
+        write(buf, 0, buf.length);
+    }
+
     /**
      * Marshals a DER integer on the output stream.
      * @param i the integer in the form of an Integer.
@@ -575,4 +586,8 @@ extends ByteArrayOutputStream implements DerEncoder {
     public void derEncode(OutputStream out) throws IOException {
         out.write(toByteArray());
     }
+
+    byte[] buf() {
+        return buf;
+    }
 }

src/java.base/share/classes/sun/security/util/DerValue.java

@@ -286,6 +286,22 @@ public class DerValue {
         this(tag, buffer.clone(), true);
     }
 
+    /**
+     * Wraps an DerOutputStream. All bytes currently written
+     * into the stream will become the content of the newly
+     * created DerValue.
+     *
+     * Attention: do not reset the DerOutputStream after this call.
+     * No array copying is made.
+     *
+     * @param tag the tag
+     * @param out the DerOutputStream
+     * @returns a new DerValue using out as its content
+     */
+    public static DerValue wrap(byte tag, DerOutputStream out) {
+        return new DerValue(tag, out.buf(), 0, out.size(), false);
+    }
+
     /**
      * Parse an ASN.1/BER encoded datum. The entire encoding must hold exactly
      * one datum, including its tag and length.
@@ -1072,10 +1088,15 @@ public class DerValue {
      * @return DER-encoded value, including tag and length.
      */
     public byte[] toByteArray() throws IOException {
+        data.pos = data.start; // Compatibility. At head.
+        // Minimize content duplication by writing out tag and length only
         DerOutputStream out = new DerOutputStream();
-        encode(out);
-        data.pos = data.start; // encode go last, should go back
-        return out.toByteArray();
+        out.write(tag);
+        out.putLength(end - start);
+        int headLen = out.size();
+        byte[] result = Arrays.copyOf(out.buf(), end - start + headLen);
+        System.arraycopy(buffer, start, result, headLen, end - start);
+        return result;
     }
 
     /**
@@ -1216,4 +1237,8 @@ public class DerValue {
         }
         return result.toArray(new DerValue[0]);
     }
+
+    public void clear() {
+        Arrays.fill(buffer, start, end, (byte)0);
+    }
 }

src/java.base/share/classes/sun/security/util/ECUtil.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2021, 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
@@ -25,6 +25,8 @@
 
 package sun.security.util;
 
+import jdk.internal.access.SharedSecrets;
+
 import java.io.IOException;
 import java.math.BigInteger;
 import java.security.*;
@@ -122,8 +124,11 @@ public final class ECUtil {
             throws InvalidKeySpecException {
         KeyFactory keyFactory = getKeyFactory();
         PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(encoded);
-
-        return (ECPrivateKey)keyFactory.generatePrivate(keySpec);
+        try {
+            return (ECPrivateKey) keyFactory.generatePrivate(keySpec);
+        } finally {
+            SharedSecrets.getJavaSecuritySpecAccess().clearEncodedKeySpec(keySpec);
+        }
     }
 
     public static ECPrivateKey generateECPrivateKey(BigInteger s,

src/java.base/share/classes/sun/security/util/KeyUtil.java

@@ -47,6 +47,7 @@ import javax.crypto.spec.DHParameterSpec;
 import javax.crypto.spec.DHPublicKeySpec;
 import java.math.BigInteger;
 import java.security.spec.NamedParameterSpec;
+import java.util.Arrays;
 
 import sun.security.jca.JCAUtil;
 
@@ -82,8 +83,12 @@ public final class KeyUtil {
         if (key instanceof SecretKey) {
             SecretKey sk = (SecretKey)key;
             String format = sk.getFormat();
-            if ("RAW".equals(format) && sk.getEncoded() != null) {
-                size = (sk.getEncoded().length * 8);
+            if ("RAW".equals(format)) {
+                byte[] encoded = sk.getEncoded();
+                if (encoded != null) {
+                    size = (encoded.length * 8);
+                    Arrays.fill(encoded, (byte)0);
+                }
             }   // Otherwise, it may be a unextractable key of PKCS#11, or
                 // a key we are not able to handle.
         } else if (key instanceof RSAKey) {