undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/com/sun/crypto/provider/Cipher/TextLength/SameBufferOverwrite.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2020, 2024, 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.
+ */
+
+import javax.crypto.Cipher;
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKey;
+import java.security.AlgorithmParameters;
+import java.util.Arrays;
+
+
+/*
+ * @test
+ * @summary Verify when decrypting over an existing buffer than padding does not
+ * overwrite past what the plaintext length is.
+ *
+ */
+
+public class SameBufferOverwrite {
+
+    private SecretKey skey;
+    private Cipher c;
+    private int start = 17, end = 17;  // default
+
+    SameBufferOverwrite(String algo, String transformation)
+        throws Exception {
+
+        KeyGenerator kg = KeyGenerator.getInstance(algo,
+                            System.getProperty("test.provider.name", "SunJCE"));
+        skey = kg.generateKey();
+        c = Cipher.getInstance(transformation,
+                            System.getProperty("test.provider.name", "SunJCE"));
+    }
+
+    /*
+     * Run the test
+     */
+    void test() throws Exception {
+        byte[] in = new byte[end + (c.getBlockSize() - (end % c.getBlockSize()))];
+        Arrays.fill(in, (byte)8);
+        int len = start;
+        AlgorithmParameters params = null;
+
+        System.out.println("Testing transformation: " + c.getAlgorithm() +
+            ",  byte length from " + start + " to " + end);
+        while (end >= len) {
+            // encrypt
+            c.init(Cipher.ENCRYPT_MODE, skey, params);
+            byte[] out = c.doFinal(in, 0, len);
+            System.out.println("  enc = " + byteToHex(out));
+            System.out.println("  => enc " + len + " bytes, ret " +
+                (out == null ? "null" : (out.length + " byte")));
+
+            // decrypt
+            params = c.getParameters();
+            c.init(Cipher.DECRYPT_MODE, skey, params);
+            int rLen = c.doFinal(out, 0, out.length, in);
+            System.out.println("  dec = " + byteToHex(in));
+            System.out.println("  => dec " + out.length + " bytes, ret " +
+                rLen + " byte");
+            // check if more than rLen bytes are written into 'in'
+            for (int j = rLen; j < in.length; j++) {
+                if (in[j] != (byte) 8) {
+                    throw new Exception("Value check failed at index " + j);
+                }
+            }
+            System.out.println(" Test Passed:  len = " + len);
+            len++;
+
+            // Because GCM doesn't allow params reuse
+            if (c.getAlgorithm().contains("GCM")) {
+                params = null;
+            }
+        }
+    }
+
+    /**
+     * Builder method for the test to run data lengths from the start value to
+     * the end value.  To do one length, have start and end equal that number.
+     * @param start starting data length
+     * @param end ending data length
+     */
+    SameBufferOverwrite iterate(int start, int end) {
+        this.start = start;
+        this.end = end;
+        return this;
+    }
+
+    public static void main(String args[]) throws Exception {
+        new SameBufferOverwrite("AES", "AES/GCM/NoPadding").iterate(1, 25).
+            test();
+        new SameBufferOverwrite("AES", "AES/CTR/NoPadding").iterate(1, 25).
+            test();
+        new SameBufferOverwrite("AES", "AES/CBC/PKCS5Padding").iterate(1, 25).
+            test();
+        new SameBufferOverwrite("AES", "AES/ECB/PKCS5Padding").iterate(1, 25).
+            test();
+        new SameBufferOverwrite("DES", "DES/CBC/PKCS5Padding").iterate(1, 17).
+            test();
+        new SameBufferOverwrite("DESede", "DESede/CBC/PKCS5Padding").iterate(1, 17).
+            test();
+    }
+
+    private static String byteToHex(byte[] barray) {
+        StringBuilder s = new StringBuilder();
+        for (byte b : barray) {
+            s.append(String.format("%02x", b));
+        }
+        return s.toString();
+    }
+}