--- a/src/share/classes/com/sun/crypto/provider/CipherBlockChaining.java	Fri Nov 10 04:05:13 2017 +0000
+++ b/src/share/classes/com/sun/crypto/provider/CipherBlockChaining.java	Fri Nov 10 04:12:11 2017 +0000
@@ -186,29 +186,15 @@
                 byte[] plain, int plainOffset)
     {
         int i;
-        byte[] cipherOrig=null;
         int endIndex = cipherOffset + cipherLen;
 
-        if (cipher==plain && (cipherOffset >= plainOffset)
-            && ((cipherOffset - plainOffset) < blockSize)) {
-            // Save the original ciphertext blocks, so they can be
-            // stored in the feedback register "r".
-            // This is necessary because in this constellation, a
-            // ciphertext block (or parts of it) will be overridden by
-            // the plaintext result.
-            cipherOrig = cipher.clone();
-        }
         for (; cipherOffset < endIndex;
              cipherOffset += blockSize, plainOffset += blockSize) {
             embeddedCipher.decryptBlock(cipher, cipherOffset, k, 0);
             for (i = 0; i < blockSize; i++) {
                 plain[i+plainOffset] = (byte)(k[i] ^ r[i]);
             }
-            if (cipherOrig==null) {
-                System.arraycopy(cipher, cipherOffset, r, 0, blockSize);
-            } else {
-                System.arraycopy(cipherOrig, cipherOffset, r, 0, blockSize);
-            }
+            System.arraycopy(cipher, cipherOffset, r, 0, blockSize);
         }
         return cipherLen;
     }

--- a/src/share/classes/com/sun/crypto/provider/CipherCore.java	Fri Nov 10 04:05:13 2017 +0000
+++ b/src/share/classes/com/sun/crypto/provider/CipherCore.java	Fri Nov 10 04:12:11 2017 +0000
@@ -608,8 +608,12 @@
                     System.arraycopy(buffer, len, buffer, 0, buffered);
                 }
             } else { // len > buffered
-                if (buffered == 0) {
+                if ((input != output) && (buffered == 0)) {
                     // all to-be-processed data are from 'input'
+                    // however, note that if 'input' and 'output' are the same,
+                    // then they can't be passed directly to the underlying cipher
+                    // engine operations as data may be overwritten before they
+                    // are read.
                     if (decrypting) {
                         outLen = cipher.decrypt(input, inputOffset, len, output, outputOffset);
                     } else {
@@ -620,12 +624,16 @@
                 } else {
                     // assemble the data using both 'buffer' and 'input'
                     byte[] in = new byte[len];
-                    System.arraycopy(buffer, 0, in, 0, buffered);
                     int inConsumed = len - buffered;
-                    System.arraycopy(input, inputOffset, in, buffered, inConsumed);
-                    buffered = 0;
-                    inputOffset += inConsumed;
-                    inputLen -= inConsumed;
+                    if (buffered != 0) {
+                        System.arraycopy(buffer, 0, in, 0, buffered);
+                        buffered = 0;
+                    }
+                    if (inConsumed != 0) {
+                        System.arraycopy(input, inputOffset, in, len - inConsumed, inConsumed);
+                        inputOffset += inConsumed;
+                        inputLen -= inConsumed;
+                    }
                     if (decrypting) {
                         outLen = cipher.decrypt(in, 0, len, output, outputOffset);
                     } else {
@@ -780,11 +788,18 @@
                  " when decrypting with padded cipher");
         }
 
-        // prepare the final input avoiding copying if possible
+        /*
+         * prepare the final input, assemble a new buffer if any
+         * of the following is true:
+         *  - 'input' and 'output' are the same buffer
+         *  - there are internally buffered bytes
+         *  - doing encryption and padding is needed
+         */
         byte[] finalBuf = input;
         int finalOffset = inputOffset;
         int finalBufLen = inputLen;
-        if ((buffered != 0) || (!decrypting && padding != null)) {
+        if ((input == output) || (buffered != 0) ||
+            (!decrypting && padding != null)) {
             if (decrypting || padding == null) {
                 paddingLen = 0;
             }

--- a/src/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java	Fri Nov 10 04:05:13 2017 +0000
+++ b/src/share/classes/com/sun/crypto/provider/DESedeWrapCipher.java	Fri Nov 10 04:12:11 2017 +0000
@@ -50,6 +50,9 @@
         (byte) 0x79, (byte) 0xe8, (byte) 0x21, (byte) 0x05
     };
 
+    private static final int CHECKSUM_LEN = 8;
+    private static final int IV_LEN = 8;
+
     /*
      * internal cipher object which does the real work.
      */
@@ -135,7 +138,7 @@
         // can only return an upper-limit if not initialized yet.
         int result = 0;
         if (decrypting) {
-            result = inputLen - 16;
+            result = inputLen - 16; // CHECKSUM_LEN + IV_LEN;
         } else {
             result = inputLen + 16;
         }
@@ -215,7 +218,7 @@
         if (opmode == Cipher.WRAP_MODE) {
             decrypting = false;
             if (params == null) {
-                iv = new byte[8];
+                iv = new byte[IV_LEN];
                 if (random == null) {
                     random = SunJCE.RANDOM;
                 }
@@ -453,14 +456,15 @@
         }
 
         byte[] cks = getChecksum(keyVal);
-        byte[] out = new byte[iv.length + keyVal.length + cks.length];
+        byte[] in = new byte[keyVal.length + CHECKSUM_LEN];
+        System.arraycopy(keyVal, 0, in, 0, keyVal.length);
+        System.arraycopy(cks, 0, in, keyVal.length, CHECKSUM_LEN);
 
-        System.arraycopy(keyVal, 0, out, iv.length, keyVal.length);
-        System.arraycopy(cks, 0, out, iv.length+keyVal.length, cks.length);
-        cipher.encrypt(out, iv.length, keyVal.length+cks.length,
-                       out, iv.length);
+        byte[] out = new byte[iv.length + in.length];
+        System.arraycopy(iv, 0, out, 0, iv.length);
 
-        System.arraycopy(iv, 0, out, 0, iv.length);
+        cipher.encrypt(in, 0, in.length, out, iv.length);
+
         // reverse the array content
         for (int i = 0; i < out.length/2; i++) {
             byte temp = out[i];
@@ -474,7 +478,8 @@
             // should never happen
             throw new RuntimeException("Internal cipher key is corrupted");
         }
-        cipher.encrypt(out, 0, out.length, out, 0);
+        byte[] out2 = new byte[out.length];
+        cipher.encrypt(out, 0, out.length, out2, 0);
 
         // restore cipher state to prior to this call
         try {
@@ -484,7 +489,7 @@
             // should never happen
             throw new RuntimeException("Internal cipher key is corrupted");
         }
-        return out;
+        return out2;
     }
 
     /**
@@ -524,25 +529,26 @@
             buffer[i] = buffer[buffer.length-1-i];
             buffer[buffer.length-1-i] = temp;
         }
-        iv = new byte[IV2.length];
+        iv = new byte[IV_LEN];
         System.arraycopy(buffer, 0, iv, 0, iv.length);
         cipher.init(true, cipherKey.getAlgorithm(), cipherKey.getEncoded(),
                     iv);
-        cipher.decrypt(buffer, iv.length, buffer.length-iv.length,
-                       buffer, iv.length);
-        int origLen = buffer.length - iv.length - 8;
-        byte[] cks = getChecksum(buffer, iv.length, origLen);
-        int offset = iv.length + origLen;
-        for (int i = 0; i < cks.length; i++) {
-            if (buffer[offset + i] != cks[i]) {
+        byte[] buffer2 = new byte[buffer.length - iv.length];
+        cipher.decrypt(buffer, iv.length, buffer2.length,
+                       buffer2, 0);
+        int keyValLen = buffer2.length - CHECKSUM_LEN;
+        byte[] cks = getChecksum(buffer2, 0, keyValLen);
+        int offset = keyValLen;
+        for (int i = 0; i < CHECKSUM_LEN; i++) {
+            if (buffer2[offset + i] != cks[i]) {
                 throw new InvalidKeyException("Checksum comparison failed");
             }
         }
         // restore cipher state to prior to this call
         cipher.init(decrypting, cipherKey.getAlgorithm(),
                     cipherKey.getEncoded(), IV2);
-        byte[] out = new byte[origLen];
-        System.arraycopy(buffer, iv.length, out, 0, out.length);
+        byte[] out = new byte[keyValLen];
+        System.arraycopy(buffer2, 0, out, 0, keyValLen);
         return ConstructKeys.constructKey(out, wrappedKeyAlgorithm,
                                           wrappedKeyType);
     }
@@ -558,7 +564,7 @@
             throw new RuntimeException("SHA1 message digest not available");
         }
         md.update(in, offset, len);
-        byte[] cks = new byte[8];
+        byte[] cks = new byte[CHECKSUM_LEN];
         System.arraycopy(md.digest(), 0, cks, 0, cks.length);
         return cks;
     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/com/sun/crypto/provider/Cipher/AES/TestCopySafe.java	Fri Nov 10 04:12:11 2017 +0000
@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2013, 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 8026943
+ * @summary Verify that same buffer can be used as input and output when
+ * using Cipher objects.
+ * @author Valerie Peng
+ */
+import java.security.*;
+import java.security.spec.*;
+
+import java.util.Arrays;
+
+import javax.crypto.*;
+import javax.crypto.spec.*;
+
+public class TestCopySafe {
+
+    private static boolean DEBUG = false;
+    private static int INPUT_LENGTH = 160; // must be multiple of block size
+    private static byte[] PT = new byte[INPUT_LENGTH];
+    private static SecretKey KEY = new SecretKeySpec(new byte[16], "AES");
+    private static byte[] IV = new byte[16];
+
+    private static int[] OFFSETS = { 1, 8, 17 };
+
+    private static final String[] MODES = {
+        "ECB", "CBC", "PCBC", "CTR", "CTS",
+        "CFB", "CFB8", "CFB16", "CFB24", "CFB32", "CFB40",
+        "CFB48", "CFB56", "CFB64",
+        "OFB", "OFB8", "OFB16", "OFB24", "OFB32", "OFB40",
+        "OFB48", "OFB56", "OFB64"
+    };
+
+    public static void main(String[] argv) throws Exception {
+
+        Provider p = Security.getProvider("SunJCE");
+
+        AlgorithmParameterSpec params = null;
+        boolean result = true;
+        for (String mode : MODES) {
+            String transformation = "AES/" + mode + "/NoPadding";
+            boolean isGCM = (mode == "GCM");
+            if (isGCM) {
+                params = new GCMParameterSpec(128, IV);
+            } else if (mode != "ECB") {
+                params = new IvParameterSpec(IV);
+            }
+            Cipher c = Cipher.getInstance(transformation, p);
+            System.out.println("Testing " + transformation + ":");
+            for (int offset : OFFSETS) {
+                System.out.print("=> offset " + offset + ": ");
+                try {
+                    test(c, params, offset, isGCM);
+                    System.out.println("Passed");
+                } catch(Exception ex) {
+                    ex.printStackTrace();
+                    result = false;
+                    continue;
+                }
+            }
+        }
+        if (!result) {
+            throw new Exception("One or more test failed");
+        }
+    }
+
+    private static void test(Cipher c, AlgorithmParameterSpec params,
+        int offset, boolean isGCM) throws Exception {
+
+        // Test encryption first
+        if (isGCM) {
+            // re-init with only key value first to bypass the
+            // Key+IV-uniqueness check for GCM encryption
+            c.init(Cipher.ENCRYPT_MODE, KEY);
+        }
+        c.init(Cipher.ENCRYPT_MODE, KEY, params);
+        byte[] answer = c.doFinal(PT);
+        byte[] pt2 = Arrays.copyOf(PT, answer.length + offset);
+
+        // #1: outOfs = inOfs = 0
+        if (isGCM) {
+            c.init(Cipher.ENCRYPT_MODE, KEY);
+            c.init(Cipher.ENCRYPT_MODE, KEY, params);
+        }
+        c.doFinal(pt2, 0, PT.length, pt2, 0);
+        if (!isTwoArraysEqual(pt2, 0, answer, 0, answer.length)) {
+            throw new Exception("Enc#1 diff check failed!");
+        } else if (DEBUG) {
+            System.out.println("Enc#1 diff check passed");
+        }
+
+        // #2: inOfs = 0, outOfs = offset
+        System.arraycopy(PT, 0, pt2, 0, PT.length);
+        if (isGCM) {
+            c.init(Cipher.ENCRYPT_MODE, KEY);
+            c.init(Cipher.ENCRYPT_MODE, KEY, params);
+        }
+        c.doFinal(pt2, 0, PT.length, pt2, offset);
+        if (!isTwoArraysEqual(pt2, offset, answer, 0, answer.length)) {
+            throw new Exception("Enc#2 diff check failed");
+        } else if (DEBUG) {
+            System.out.println("Enc#2 diff check passed");
+        }
+
+        // #3: inOfs = offset, outOfs = 0
+        System.arraycopy(PT, 0, pt2, offset, PT.length);
+        if (isGCM) {
+            c.init(Cipher.ENCRYPT_MODE, KEY);
+            c.init(Cipher.ENCRYPT_MODE, KEY, params);
+        }
+        c.doFinal(pt2, offset, PT.length, pt2, 0);
+        if (!isTwoArraysEqual(pt2, 0, answer, 0, answer.length)) {
+            throw new Exception("Enc#3 diff check failed");
+        } else if (DEBUG) {
+            System.out.println("Enc#3 diff check passed");
+        }
+
+       // Test decryption now, we should get back PT as a result
+        c.init(Cipher.DECRYPT_MODE, KEY, params);
+        pt2 = Arrays.copyOf(answer, answer.length + offset);
+
+        // #1: outOfs = inOfs = 0
+        c.doFinal(pt2, 0, answer.length, pt2, 0);
+        if (!isTwoArraysEqual(pt2, 0, PT, 0, PT.length)) {
+            throw new Exception("Dec#1 diff check failed!");
+        } else if (DEBUG) {
+            System.out.println("Dec#1 diff check passed");
+        }
+
+        // #2: inOfs = 0, outOfs = offset
+        System.arraycopy(answer, 0, pt2, 0, answer.length);
+        c.doFinal(pt2, 0, answer.length, pt2, offset);
+        if (!isTwoArraysEqual(pt2, offset, PT, 0, PT.length)) {
+            throw new Exception("Dec#2 diff check failed");
+        } else if (DEBUG) {
+            System.out.println("Dec#2 diff check passed");
+        }
+
+        // #3: inOfs = offset, outOfs = 0
+        System.arraycopy(answer, 0, pt2, offset, answer.length);
+        c.doFinal(pt2, offset, answer.length, pt2, 0);
+        if (!isTwoArraysEqual(pt2, 0, PT, 0, PT.length)) {
+            throw new Exception("Dec#3 diff check failed");
+        } else if (DEBUG) {
+            System.out.println("Dec#3 diff check passed");
+        }
+    }
+
+    private static boolean isTwoArraysEqual(byte[] a, int aOff, byte[] b, int bOff,
+        int len) {
+        for (int i = 0; i < len; i++) {
+            if (a[aOff + i] != b[bOff + i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+}
+