8337692: Better TLS connection support

Reviewed-by: abakhtin, andrew
Backport-of: 73aa304234f2ec17abbb640b7f2d0503cf1bfc91

Author: martinuy

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

@@ -384,7 +384,7 @@ private byte[] doFinal() throws BadPaddingException,
                 byte[] decryptBuffer = RSACore.convert(buffer, 0, bufOfs);
                 paddingCopy = RSACore.rsa(decryptBuffer, privateKey, false);
                 result = padding.unpad(paddingCopy);
-                if (result == null && !forTlsPremasterSecret) {
+                if (!forTlsPremasterSecret && result == null) {
                     throw new BadPaddingException
                             ("Padding error in decryption");
                 }
@@ -404,6 +404,34 @@ private byte[] doFinal() throws BadPaddingException,
         }
     }
 
+    // TLS master secret decode version of the doFinal() method.
+    private byte[] doFinalForTls(int clientVersion, int serverVersion)
+            throws BadPaddingException, IllegalBlockSizeException {
+        if (bufOfs > buffer.length) {
+            throw new IllegalBlockSizeException("Data must not be longer "
+                    + "than " + buffer.length + " bytes");
+        }
+        byte[] paddingCopy = null;
+        byte[] result = null;
+        try {
+            byte[] decryptBuffer = RSACore.convert(buffer, 0, bufOfs);
+
+            paddingCopy = RSACore.rsa(decryptBuffer, privateKey, false);
+            result = padding.unpadForTls(paddingCopy, clientVersion,
+                    serverVersion);
+
+            return result;
+        } finally {
+            Arrays.fill(buffer, 0, bufOfs, (byte)0);
+            bufOfs = 0;
+            if (paddingCopy != null
+                    && paddingCopy != buffer    // already cleaned
+                    && paddingCopy != result) { // DO NOT CLEAN, THIS IS RESULT
+                Arrays.fill(paddingCopy, (byte)0);
+            }
+        }
+    }
+
     // see JCE spec
     protected byte[] engineUpdate(byte[] in, int inOfs, int inLen) {
         update(in, inOfs, inLen);
@@ -476,38 +504,34 @@ protected Key engineUnwrap(byte[] wrappedKey, String algorithm,
         byte[] encoded = null;
 
         update(wrappedKey, 0, wrappedKey.length);
-        try {
-            encoded = doFinal();
-        } catch (BadPaddingException | IllegalBlockSizeException e) {
-            // BadPaddingException cannot happen for TLS RSA unwrap.
-            // In that case, padding error is indicated by returning null.
-            // IllegalBlockSizeException cannot happen in any case,
-            // because of the length check above.
-            throw new InvalidKeyException("Unwrapping failed", e);
-        }
-
         try {
             if (isTlsRsaPremasterSecret) {
                 if (!forTlsPremasterSecret) {
                     throw new IllegalStateException(
                             "No TlsRsaPremasterSecretParameterSpec specified");
                 }
-
-                // polish the TLS premaster secret
-                encoded = KeyUtil.checkTlsPreMasterSecretKey(
-                        ((TlsRsaPremasterSecretParameterSpec) spec).getClientVersion(),
-                        ((TlsRsaPremasterSecretParameterSpec) spec).getServerVersion(),
-                        random, encoded, encoded == null);
+                TlsRsaPremasterSecretParameterSpec parameterSpec =
+                        (TlsRsaPremasterSecretParameterSpec) spec;
+                encoded = doFinalForTls(parameterSpec.getClientVersion(),
+                        parameterSpec.getServerVersion());
+            } else {
+                encoded = doFinal();
             }
-
             return ConstructKeys.constructKey(encoded, algorithm, type);
+
+        } catch (BadPaddingException | IllegalBlockSizeException e) {
+            // BadPaddingException cannot happen for TLS RSA unwrap.
+            // Neither padding error nor server version error is indicated
+            // for TLS, but a fake unwrapped value is returned.
+            // IllegalBlockSizeException cannot happen in any case,
+            // because of the length check above.
+            throw new InvalidKeyException("Unwrapping failed", e);
         } finally {
             if (encoded != null) {
                 Arrays.fill(encoded, (byte) 0);
             }
         }
     }
-
     // see JCE spec
     protected int engineGetKeySize(Key key) throws InvalidKeyException {
         RSAKey rsaKey = RSAKeyFactory.toRSAKey(key);

src/java.base/share/classes/sun/security/rsa/RSAPadding.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -327,48 +327,103 @@ private byte[] padV15(byte[] data, int ofs, int len) {
      * Note that we want to make it a constant-time operation
      */
     private byte[] unpadV15(byte[] padded) {
-        int k = 0;
-        boolean bp = false;
+        int paddedLength = padded.length;
 
-        if (padded[k++] != 0) {
-            bp = true;
-        }
-        if (padded[k++] != type) {
-            bp = true;
+        if (paddedLength < 2) {
+            return null;
         }
-        int p = 0;
-        while (k < padded.length) {
+
+        // The following check ensures that the lead byte is zero and
+        // the second byte is equivalent to the padding type.  The
+        // bp (bad padding) variable throughout this unpadding process will
+        // be updated and remain 0 if good padding, 1 if bad.
+        int p0 = padded[0];
+        int p1 = padded[1];
+        int bp = (-(p0 & 0xff) | ((p1 - type) | (type - p1))) >>> 31;
+
+        int padLen = 0;
+        int k = 2;
+        // Walk through the random, nonzero padding bytes.  For each padding
+        // byte bp and padLen will remain zero.  When the end-of-padding
+        // byte (0x00) is reached then padLen will be set to the index of the
+        // first byte of the message content.
+        while (k < paddedLength) {
             int b = padded[k++] & 0xff;
-            if ((b == 0) && (p == 0)) {
-                p = k;
-            }
-            if ((k == padded.length) && (p == 0)) {
-                bp = true;
-            }
-            if ((type == PAD_BLOCKTYPE_1) && (b != 0xff) &&
-                    (p == 0)) {
-                bp = true;
+            padLen += (k * (1 - ((-(b | padLen)) >>> 31)));
+            if (k == paddedLength) {
+                bp = bp | (1 - ((-padLen) >>> 31));
             }
+            bp = bp | (1 - (-(((type - PAD_BLOCKTYPE_1) & 0xff) |
+                    padLen | (1 - ((b - 0xff) >>> 31))) >>> 31));
         }
-        int n = padded.length - p;
-        if (n > maxDataSize) {
-            bp = true;
-        }
+        int n = paddedLength - padLen;
+        // So long as n <= maxDataSize, bp will remain zero
+        bp = bp | ((maxDataSize - n) >>> 31);
 
         // copy useless padding array for a constant-time method
-        byte[] padding = new byte[p];
-        System.arraycopy(padded, 0, padding, 0, p);
+        byte[] padding = new byte[padLen + 2];
+        for (int i = 0; i < padLen; i++) {
+            padding[i] = padded[i];
+        }
 
         byte[] data = new byte[n];
-        System.arraycopy(padded, p, data, 0, n);
+        for (int i = 0; i < n; i++) {
+            data[i] = padded[padLen + i];
+        }
 
-        if (bp) {
+        if ((bp | padding[bp]) != 0) {
+            // using the array padding here hoping that this way
+            // the compiler does not eliminate the above useless copy
             return null;
         } else {
             return data;
         }
     }
 
+    public byte[] unpadForTls(byte[] padded, int clientVersion,
+            int serverVersion) {
+        int paddedLength = padded.length;
+
+        // bp is positive if the padding is bad and 0 if it is good so far
+        int bp = (((int) padded[0] | ((int)padded[1] - PAD_BLOCKTYPE_2)) &
+                0xFFF);
+
+        int k = 2;
+        while (k < paddedLength - 49) {
+            int b = padded[k++] & 0xFF;
+            bp = bp | (1 - (-b >>> 31)); // if (padded[k] == 0) bp |= 1;
+        }
+        bp |= ((int)padded[k++] & 0xFF);
+        int encodedVersion = ((padded[k] & 0xFF) << 8) | (padded[k + 1] & 0xFF);
+
+        int bv1 = clientVersion - encodedVersion;
+        bv1 |= -bv1;
+        int bv3 = serverVersion - encodedVersion;
+        bv3 |= -bv3;
+        int bv2 = (0x301 - clientVersion);
+
+        bp |= ((bv1 & (bv2 | bv3)) >>> 28);
+
+        byte[] data = Arrays.copyOfRange(padded, paddedLength - 48,
+                paddedLength);
+        if (random == null) {
+            random = JCAUtil.getSecureRandom();
+        }
+
+        byte[] fake = new byte[48];
+        random.nextBytes(fake);
+
+        bp = (-bp >> 24);
+
+        // Now bp is 0 if the padding and version number were good and
+        // -1 otherwise.
+        for (int i = 0; i < 48; i++) {
+            data[i] = (byte)((~bp & data[i]) | (bp & fake[i]));
+        }
+
+        return data;
+    }
+
     /**
      * PKCS#1 v2.0 OAEP padding (MGF1).
      * Paragraph references refer to PKCS#1 v2.1 (June 14, 2002)

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

@@ -288,19 +288,31 @@ public static byte[] checkTlsPreMasterSecretKey(
             tmp = encoded;
         }
 
+        // At this point tmp.length is 48
         int encodedVersion =
                 ((tmp[0] & 0xFF) << 8) | (tmp[1] & 0xFF);
-        int check1 = 0;
-        int check2 = 0;
-        int check3 = 0;
-        if (clientVersion != encodedVersion) check1 = 1;
-        if (clientVersion > 0x0301) check2 = 1;
-        if (serverVersion != encodedVersion) check3 = 1;
-        if ((check1 & (check2 | check3)) == 1) {
-            return replacer;
-        } else {
-            return tmp;
+
+        // The following code is a time-constant version of
+        // if ((clientVersion != encodedVersion) ||
+        //    ((clientVersion > 0x301) && (serverVersion != encodedVersion))) {
+        //        return replacer;
+        // } else { return tmp; }
+        int check1 = (clientVersion - encodedVersion) |
+                (encodedVersion - clientVersion);
+        int check2 = 0x0301 - clientVersion;
+        int check3 = (serverVersion - encodedVersion) |
+                (encodedVersion - serverVersion);
+
+        check1 = (check1 & (check2 | check3)) >> 24;
+
+        // Now check1 is either 0 or -1
+        check2 = ~check1;
+
+        for (int i = 0; i < 48; i++) {
+            tmp[i] = (byte) ((tmp[i] & check2) | (replacer[i] & check1));
         }
+
+        return tmp;
     }
 
     /**