8186654: Poor quality of sun.security.util.Cache.EqualByteArray.hashCode()
Reviewed-by: coffeys
--- a/src/java.base/share/classes/sun/security/util/Cache.java Tue Oct 03 23:42:08 2017 -0700
+++ b/src/java.base/share/classes/sun/security/util/Cache.java Wed Oct 04 01:08:36 2017 -0700
@@ -164,7 +164,7 @@
public static class EqualByteArray {
private final byte[] b;
- private volatile int hash;
+ private int hash;
public EqualByteArray(byte[] b) {
this.b = b;
@@ -172,12 +172,8 @@
public int hashCode() {
int h = hash;
- if (h == 0) {
- h = b.length + 1;
- for (int i = 0; i < b.length; i++) {
- h += (b[i] & 0xff) * 37;
- }
- hash = h;
+ if (h == 0 && b.length > 0) {
+ hash = h = Arrays.hashCode(b);
}
return h;
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/sun/security/util/Cache/EbaHash.java Wed Oct 04 01:08:36 2017 -0700
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2017, 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 8186654
+ * @summary Transpositions of an array result in the same
+ * EqualByteArray.hashCode()
+ * @modules java.base/sun.security.util
+ */
+
+import sun.security.util.Cache;
+
+public class EbaHash {
+ public static void main(String[] args) throws Throwable {
+ int h1 = new Cache.EqualByteArray(new byte[] {1,2,3}).hashCode();
+ int h2 = new Cache.EqualByteArray(new byte[] {2,3,1}).hashCode();
+ int h3 = new Cache.EqualByteArray(new byte[] {3,1,2}).hashCode();
+ if (h1 == h2 && h2 == h3) {
+ throw new RuntimeException("Transpositions of an array" +
+ " resulted in the same hashCode()");
+ }
+ }
+}