| /* |
| * Copyright (c) 1996, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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. |
| */ |
| |
| |
| package sun.security.ssl; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.IOException; |
| import java.util.Hashtable; |
| import java.util.Arrays; |
| |
| import java.security.*; |
| import javax.crypto.*; |
| import javax.crypto.spec.IvParameterSpec; |
| import javax.crypto.spec.GCMParameterSpec; |
| |
| import java.nio.*; |
| |
| import sun.security.ssl.CipherSuite.*; |
| import static sun.security.ssl.CipherSuite.*; |
| import static sun.security.ssl.CipherSuite.CipherType.*; |
| |
| import sun.misc.HexDumpEncoder; |
| |
| |
| /** |
| * This class handles bulk data enciphering/deciphering for each SSLv3 |
| * message. This provides data confidentiality. Stream ciphers (such |
| * as RC4) don't need to do padding; block ciphers (e.g. DES) need it. |
| * |
| * Individual instances are obtained by calling the static method |
| * newCipherBox(), which should only be invoked by BulkCipher.newCipher(). |
| * |
| * In RFC 2246, with bock ciphers in CBC mode, the Initialization |
| * Vector (IV) for the first record is generated with the other keys |
| * and secrets when the security parameters are set. The IV for |
| * subsequent records is the last ciphertext block from the previous |
| * record. |
| * |
| * In RFC 4346, the implicit Initialization Vector (IV) is replaced |
| * with an explicit IV to protect against CBC attacks. RFC 4346 |
| * recommends two algorithms used to generated the per-record IV. |
| * The implementation uses the algorithm (2)(b), as described at |
| * section 6.2.3.2 of RFC 4346. |
| * |
| * The usage of IV in CBC block cipher can be illustrated in |
| * the following diagrams. |
| * |
| * (random) |
| * R P1 IV C1 |
| * | | | | |
| * SIV---+ |-----+ |-... |----- |------ |
| * | | | | | | | | |
| * +----+ | +----+ | +----+ | +----+ | |
| * | Ek | | + Ek + | | Dk | | | Dk | | |
| * +----+ | +----+ | +----+ | +----+ | |
| * | | | | | | | | |
| * |----| |----| SIV--+ |----| |-... |
| * | | | | |
| * IV C1 R P1 |
| * (discard) |
| * |
| * CBC Encryption CBC Decryption |
| * |
| * NOTE that any ciphering involved in key exchange (e.g. with RSA) is |
| * handled separately. |
| * |
| * @author David Brownell |
| * @author Andreas Sterbenz |
| */ |
| final class CipherBox { |
| |
| // A CipherBox that implements the identity operation |
| final static CipherBox NULL = new CipherBox(); |
| |
| /* Class and subclass dynamic debugging support */ |
| private static final Debug debug = Debug.getInstance("ssl"); |
| |
| // the protocol version this cipher conforms to |
| private final ProtocolVersion protocolVersion; |
| |
| // cipher object |
| private final Cipher cipher; |
| |
| /** |
| * secure random |
| */ |
| private SecureRandom random; |
| |
| /** |
| * fixed IV, the implicit nonce of AEAD cipher suite, only apply to |
| * AEAD cipher suites |
| */ |
| private final byte[] fixedIv; |
| |
| /** |
| * the key, reserved only for AEAD cipher initialization |
| */ |
| private final Key key; |
| |
| /** |
| * the operation mode, reserved for AEAD cipher initialization |
| */ |
| private final int mode; |
| |
| /** |
| * the authentication tag size, only apply to AEAD cipher suites |
| */ |
| private final int tagSize; |
| |
| /** |
| * the record IV length, only apply to AEAD cipher suites |
| */ |
| private final int recordIvSize; |
| |
| /** |
| * cipher type |
| */ |
| private final CipherType cipherType; |
| |
| /** |
| * Fixed masks of various block size, as the initial decryption IVs |
| * for TLS 1.1 or later. |
| * |
| * For performance, we do not use random IVs. As the initial decryption |
| * IVs will be discarded by TLS decryption processes, so the fixed masks |
| * do not hurt cryptographic strength. |
| */ |
| private static Hashtable<Integer, IvParameterSpec> masks; |
| |
| /** |
| * NULL cipherbox. Identity operation, no encryption. |
| */ |
| private CipherBox() { |
| this.protocolVersion = ProtocolVersion.DEFAULT; |
| this.cipher = null; |
| this.cipherType = STREAM_CIPHER; |
| this.fixedIv = new byte[0]; |
| this.key = null; |
| this.mode = Cipher.ENCRYPT_MODE; // choose at random |
| this.random = null; |
| this.tagSize = 0; |
| this.recordIvSize = 0; |
| } |
| |
| /** |
| * Construct a new CipherBox using the cipher transformation. |
| * |
| * @exception NoSuchAlgorithmException if no appropriate JCE Cipher |
| * implementation could be found. |
| */ |
| private CipherBox(ProtocolVersion protocolVersion, BulkCipher bulkCipher, |
| SecretKey key, IvParameterSpec iv, SecureRandom random, |
| boolean encrypt) throws NoSuchAlgorithmException { |
| try { |
| this.protocolVersion = protocolVersion; |
| this.cipher = JsseJce.getCipher(bulkCipher.transformation); |
| this.mode = encrypt ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE; |
| |
| if (random == null) { |
| random = JsseJce.getSecureRandom(); |
| } |
| this.random = random; |
| this.cipherType = bulkCipher.cipherType; |
| |
| /* |
| * RFC 4346 recommends two algorithms used to generated the |
| * per-record IV. The implementation uses the algorithm (2)(b), |
| * as described at section 6.2.3.2 of RFC 4346. |
| * |
| * As we don't care about the initial IV value for TLS 1.1 or |
| * later, so if the "iv" parameter is null, we use the default |
| * value generated by Cipher.init() for encryption, and a fixed |
| * mask for decryption. |
| */ |
| if (iv == null && bulkCipher.ivSize != 0 && |
| mode == Cipher.DECRYPT_MODE && |
| protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| iv = getFixedMask(bulkCipher.ivSize); |
| } |
| |
| if (cipherType == AEAD_CIPHER) { |
| // AEAD must completely initialize the cipher for each packet, |
| // and so we save initialization parameters for packet |
| // processing time. |
| |
| // Set the tag size for AEAD cipher |
| tagSize = bulkCipher.tagSize; |
| |
| // Reserve the key for AEAD cipher initialization |
| this.key = key; |
| |
| fixedIv = iv.getIV(); |
| if (fixedIv == null || |
| fixedIv.length != bulkCipher.fixedIvSize) { |
| throw new RuntimeException("Improper fixed IV for AEAD"); |
| } |
| |
| // Set the record IV length for AEAD cipher |
| recordIvSize = bulkCipher.ivSize - bulkCipher.fixedIvSize; |
| |
| // DON'T initialize the cipher for AEAD! |
| } else { |
| // CBC only requires one initialization during its lifetime |
| // (future packets/IVs set the proper CBC state), so we can |
| // initialize now. |
| |
| // Zeroize the variables that only apply to AEAD cipher |
| this.tagSize = 0; |
| this.fixedIv = new byte[0]; |
| this.recordIvSize = 0; |
| this.key = null; |
| |
| // Initialize the cipher |
| cipher.init(mode, key, iv, random); |
| } |
| } catch (NoSuchAlgorithmException e) { |
| throw e; |
| } catch (Exception e) { |
| throw new NoSuchAlgorithmException |
| ("Could not create cipher " + bulkCipher, e); |
| } catch (ExceptionInInitializerError e) { |
| throw new NoSuchAlgorithmException |
| ("Could not create cipher " + bulkCipher, e); |
| } |
| } |
| |
| /* |
| * Factory method to obtain a new CipherBox object. |
| */ |
| static CipherBox newCipherBox(ProtocolVersion version, BulkCipher cipher, |
| SecretKey key, IvParameterSpec iv, SecureRandom random, |
| boolean encrypt) throws NoSuchAlgorithmException { |
| if (cipher.allowed == false) { |
| throw new NoSuchAlgorithmException("Unsupported cipher " + cipher); |
| } |
| |
| if (cipher == B_NULL) { |
| return NULL; |
| } else { |
| return new CipherBox(version, cipher, key, iv, random, encrypt); |
| } |
| } |
| |
| /* |
| * Get a fixed mask, as the initial decryption IVs for TLS 1.1 or later. |
| */ |
| private static IvParameterSpec getFixedMask(int ivSize) { |
| if (masks == null) { |
| masks = new Hashtable<Integer, IvParameterSpec>(5); |
| } |
| |
| IvParameterSpec iv = masks.get(ivSize); |
| if (iv == null) { |
| iv = new IvParameterSpec(new byte[ivSize]); |
| masks.put(ivSize, iv); |
| } |
| |
| return iv; |
| } |
| |
| /* |
| * Encrypts a block of data, returning the size of the |
| * resulting block. |
| */ |
| int encrypt(byte[] buf, int offset, int len) { |
| if (cipher == null) { |
| return len; |
| } |
| |
| try { |
| int blockSize = cipher.getBlockSize(); |
| if (cipherType == BLOCK_CIPHER) { |
| len = addPadding(buf, offset, len, blockSize); |
| } |
| |
| if (debug != null && Debug.isOn("plaintext")) { |
| try { |
| HexDumpEncoder hd = new HexDumpEncoder(); |
| |
| System.out.println( |
| "Padded plaintext before ENCRYPTION: len = " |
| + len); |
| hd.encodeBuffer( |
| new ByteArrayInputStream(buf, offset, len), |
| System.out); |
| } catch (IOException e) { } |
| } |
| |
| |
| if (cipherType == AEAD_CIPHER) { |
| try { |
| return cipher.doFinal(buf, offset, len, buf, offset); |
| } catch (IllegalBlockSizeException | BadPaddingException ibe) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "Cipher error in AEAD mode in JCE provider " + |
| cipher.getProvider().getName(), ibe); |
| } |
| } else { |
| int newLen = cipher.update(buf, offset, len, buf, offset); |
| if (newLen != len) { |
| // catch BouncyCastle buffering error |
| throw new RuntimeException("Cipher buffering error " + |
| "in JCE provider " + cipher.getProvider().getName()); |
| } |
| return newLen; |
| } |
| } catch (ShortBufferException e) { |
| // unlikely to happen, we should have enough buffer space here |
| throw new ArrayIndexOutOfBoundsException(e.toString()); |
| } |
| } |
| |
| /* |
| * Encrypts a ByteBuffer block of data, returning the size of the |
| * resulting block. |
| * |
| * The byte buffers position and limit initially define the amount |
| * to encrypt. On return, the position and limit are |
| * set to last position padded/encrypted. The limit may have changed |
| * because of the added padding bytes. |
| */ |
| int encrypt(ByteBuffer bb, int outLimit) { |
| |
| int len = bb.remaining(); |
| |
| if (cipher == null) { |
| bb.position(bb.limit()); |
| return len; |
| } |
| |
| int pos = bb.position(); |
| |
| int blockSize = cipher.getBlockSize(); |
| if (cipherType == BLOCK_CIPHER) { |
| // addPadding adjusts pos/limit |
| len = addPadding(bb, blockSize); |
| bb.position(pos); |
| } |
| |
| if (debug != null && Debug.isOn("plaintext")) { |
| try { |
| HexDumpEncoder hd = new HexDumpEncoder(); |
| |
| System.out.println( |
| "Padded plaintext before ENCRYPTION: len = " |
| + len); |
| hd.encodeBuffer(bb.duplicate(), System.out); |
| |
| } catch (IOException e) { } |
| } |
| |
| /* |
| * Encrypt "in-place". This does not add its own padding. |
| */ |
| ByteBuffer dup = bb.duplicate(); |
| if (cipherType == AEAD_CIPHER) { |
| try { |
| int outputSize = cipher.getOutputSize(dup.remaining()); |
| if (outputSize > bb.remaining()) { |
| // need to expand the limit of the output buffer for |
| // the authentication tag. |
| // |
| // DON'T worry about the buffer's capacity, we have |
| // reserved space for the authentication tag. |
| if (outLimit < pos + outputSize) { |
| // unlikely to happen |
| throw new ShortBufferException( |
| "need more space in output buffer"); |
| } |
| bb.limit(pos + outputSize); |
| } |
| int newLen = cipher.doFinal(dup, bb); |
| if (newLen != outputSize) { |
| throw new RuntimeException( |
| "Cipher buffering error in JCE provider " + |
| cipher.getProvider().getName()); |
| } |
| return newLen; |
| } catch (IllegalBlockSizeException | |
| BadPaddingException | ShortBufferException ibse) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "Cipher error in AEAD mode in JCE provider " + |
| cipher.getProvider().getName(), ibse); |
| } |
| } else { |
| int newLen; |
| try { |
| newLen = cipher.update(dup, bb); |
| } catch (ShortBufferException sbe) { |
| // unlikely to happen |
| throw new RuntimeException("Cipher buffering error " + |
| "in JCE provider " + cipher.getProvider().getName()); |
| } |
| |
| if (bb.position() != dup.position()) { |
| throw new RuntimeException("bytebuffer padding error"); |
| } |
| |
| if (newLen != len) { |
| // catch BouncyCastle buffering error |
| throw new RuntimeException("Cipher buffering error " + |
| "in JCE provider " + cipher.getProvider().getName()); |
| } |
| return newLen; |
| } |
| } |
| |
| |
| /* |
| * Decrypts a block of data, returning the size of the |
| * resulting block if padding was required. |
| * |
| * For SSLv3 and TLSv1.0, with block ciphers in CBC mode the |
| * Initialization Vector (IV) for the first record is generated by |
| * the handshake protocol, the IV for subsequent records is the |
| * last ciphertext block from the previous record. |
| * |
| * From TLSv1.1, the implicit IV is replaced with an explicit IV to |
| * protect against CBC attacks. |
| * |
| * Differentiating between bad_record_mac and decryption_failed alerts |
| * may permit certain attacks against CBC mode. It is preferable to |
| * uniformly use the bad_record_mac alert to hide the specific type of |
| * the error. |
| */ |
| int decrypt(byte[] buf, int offset, int len, |
| int tagLen) throws BadPaddingException { |
| if (cipher == null) { |
| return len; |
| } |
| |
| try { |
| int newLen; |
| if (cipherType == AEAD_CIPHER) { |
| try { |
| newLen = cipher.doFinal(buf, offset, len, buf, offset); |
| } catch (IllegalBlockSizeException ibse) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "Cipher error in AEAD mode in JCE provider " + |
| cipher.getProvider().getName(), ibse); |
| } |
| } else { |
| newLen = cipher.update(buf, offset, len, buf, offset); |
| if (newLen != len) { |
| // catch BouncyCastle buffering error |
| throw new RuntimeException("Cipher buffering error " + |
| "in JCE provider " + cipher.getProvider().getName()); |
| } |
| } |
| if (debug != null && Debug.isOn("plaintext")) { |
| try { |
| HexDumpEncoder hd = new HexDumpEncoder(); |
| |
| System.out.println( |
| "Padded plaintext after DECRYPTION: len = " |
| + newLen); |
| hd.encodeBuffer( |
| new ByteArrayInputStream(buf, offset, newLen), |
| System.out); |
| } catch (IOException e) { } |
| } |
| |
| if (cipherType == BLOCK_CIPHER) { |
| int blockSize = cipher.getBlockSize(); |
| newLen = removePadding( |
| buf, offset, newLen, tagLen, blockSize, protocolVersion); |
| |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| if (newLen < blockSize) { |
| throw new BadPaddingException("invalid explicit IV"); |
| } |
| } |
| } |
| return newLen; |
| } catch (ShortBufferException e) { |
| // unlikely to happen, we should have enough buffer space here |
| throw new ArrayIndexOutOfBoundsException(e.toString()); |
| } |
| } |
| |
| |
| /* |
| * Decrypts a block of data, returning the size of the |
| * resulting block if padding was required. position and limit |
| * point to the end of the decrypted/depadded data. The initial |
| * limit and new limit may be different, given we may |
| * have stripped off some padding bytes. |
| * |
| * @see decrypt(byte[], int, int) |
| */ |
| int decrypt(ByteBuffer bb, int tagLen) throws BadPaddingException { |
| |
| int len = bb.remaining(); |
| |
| if (cipher == null) { |
| bb.position(bb.limit()); |
| return len; |
| } |
| |
| try { |
| /* |
| * Decrypt "in-place". |
| */ |
| int pos = bb.position(); |
| ByteBuffer dup = bb.duplicate(); |
| int newLen; |
| if (cipherType == AEAD_CIPHER) { |
| try { |
| newLen = cipher.doFinal(dup, bb); |
| } catch (IllegalBlockSizeException ibse) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "Cipher error in AEAD mode \"" + ibse.getMessage() + |
| " \"in JCE provider " + cipher.getProvider().getName()); |
| } |
| } else { |
| newLen = cipher.update(dup, bb); |
| if (newLen != len) { |
| // catch BouncyCastle buffering error |
| throw new RuntimeException("Cipher buffering error " + |
| "in JCE provider " + cipher.getProvider().getName()); |
| } |
| } |
| |
| // reset the limit to the end of the decryted data |
| bb.limit(pos + newLen); |
| |
| if (debug != null && Debug.isOn("plaintext")) { |
| try { |
| HexDumpEncoder hd = new HexDumpEncoder(); |
| |
| System.out.println( |
| "Padded plaintext after DECRYPTION: len = " |
| + newLen); |
| |
| hd.encodeBuffer( |
| (ByteBuffer)bb.duplicate().position(pos), System.out); |
| } catch (IOException e) { } |
| } |
| |
| /* |
| * Remove the block padding. |
| */ |
| if (cipherType == BLOCK_CIPHER) { |
| int blockSize = cipher.getBlockSize(); |
| bb.position(pos); |
| newLen = removePadding(bb, tagLen, blockSize, protocolVersion); |
| |
| // check the explicit IV of TLS v1.1 or later |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| if (newLen < blockSize) { |
| throw new BadPaddingException("invalid explicit IV"); |
| } |
| |
| // reset the position to the end of the decrypted data |
| bb.position(bb.limit()); |
| } |
| } |
| return newLen; |
| } catch (ShortBufferException e) { |
| // unlikely to happen, we should have enough buffer space here |
| throw new ArrayIndexOutOfBoundsException(e.toString()); |
| } |
| } |
| |
| private static int addPadding(byte[] buf, int offset, int len, |
| int blockSize) { |
| int newlen = len + 1; |
| byte pad; |
| int i; |
| |
| if ((newlen % blockSize) != 0) { |
| newlen += blockSize - 1; |
| newlen -= newlen % blockSize; |
| } |
| pad = (byte) (newlen - len); |
| |
| if (buf.length < (newlen + offset)) { |
| throw new IllegalArgumentException("no space to pad buffer"); |
| } |
| |
| /* |
| * TLS version of the padding works for both SSLv3 and TLSv1 |
| */ |
| for (i = 0, offset += len; i < pad; i++) { |
| buf [offset++] = (byte) (pad - 1); |
| } |
| return newlen; |
| } |
| |
| /* |
| * Apply the padding to the buffer. |
| * |
| * Limit is advanced to the new buffer length. |
| * Position is equal to limit. |
| */ |
| private static int addPadding(ByteBuffer bb, int blockSize) { |
| |
| int len = bb.remaining(); |
| int offset = bb.position(); |
| |
| int newlen = len + 1; |
| byte pad; |
| int i; |
| |
| if ((newlen % blockSize) != 0) { |
| newlen += blockSize - 1; |
| newlen -= newlen % blockSize; |
| } |
| pad = (byte) (newlen - len); |
| |
| /* |
| * Update the limit to what will be padded. |
| */ |
| bb.limit(newlen + offset); |
| |
| /* |
| * TLS version of the padding works for both SSLv3 and TLSv1 |
| */ |
| for (i = 0, offset += len; i < pad; i++) { |
| bb.put(offset++, (byte) (pad - 1)); |
| } |
| |
| bb.position(offset); |
| bb.limit(offset); |
| |
| return newlen; |
| } |
| |
| /* |
| * A constant-time check of the padding. |
| * |
| * NOTE that we are checking both the padding and the padLen bytes here. |
| * |
| * The caller MUST ensure that the len parameter is a positive number. |
| */ |
| private static int[] checkPadding( |
| byte[] buf, int offset, int len, byte pad) { |
| |
| if (len <= 0) { |
| throw new RuntimeException("padding len must be positive"); |
| } |
| |
| // An array of hits is used to prevent Hotspot optimization for |
| // the purpose of a constant-time check. |
| int[] results = {0, 0}; // {missed #, matched #} |
| for (int i = 0; i <= 256;) { |
| for (int j = 0; j < len && i <= 256; j++, i++) { // j <= i |
| if (buf[offset + j] != pad) { |
| results[0]++; // mismatched padding data |
| } else { |
| results[1]++; // matched padding data |
| } |
| } |
| } |
| |
| return results; |
| } |
| |
| /* |
| * A constant-time check of the padding. |
| * |
| * NOTE that we are checking both the padding and the padLen bytes here. |
| * |
| * The caller MUST ensure that the bb parameter has remaining. |
| */ |
| private static int[] checkPadding(ByteBuffer bb, byte pad) { |
| |
| if (!bb.hasRemaining()) { |
| throw new RuntimeException("hasRemaining() must be positive"); |
| } |
| |
| // An array of hits is used to prevent Hotspot optimization for |
| // the purpose of a constant-time check. |
| int[] results = {0, 0}; // {missed #, matched #} |
| bb.mark(); |
| for (int i = 0; i <= 256; bb.reset()) { |
| for (; bb.hasRemaining() && i <= 256; i++) { |
| if (bb.get() != pad) { |
| results[0]++; // mismatched padding data |
| } else { |
| results[1]++; // matched padding data |
| } |
| } |
| } |
| |
| return results; |
| } |
| |
| /* |
| * Typical TLS padding format for a 64 bit block cipher is as follows: |
| * xx xx xx xx xx xx xx 00 |
| * xx xx xx xx xx xx 01 01 |
| * ... |
| * xx 06 06 06 06 06 06 06 |
| * 07 07 07 07 07 07 07 07 |
| * TLS also allows any amount of padding from 1 and 256 bytes as long |
| * as it makes the data a multiple of the block size |
| */ |
| private static int removePadding(byte[] buf, int offset, int len, |
| int tagLen, int blockSize, |
| ProtocolVersion protocolVersion) throws BadPaddingException { |
| |
| // last byte is length byte (i.e. actual padding length - 1) |
| int padOffset = offset + len - 1; |
| int padLen = buf[padOffset] & 0xFF; |
| |
| int newLen = len - (padLen + 1); |
| if ((newLen - tagLen) < 0) { |
| // If the buffer is not long enough to contain the padding plus |
| // a MAC tag, do a dummy constant-time padding check. |
| // |
| // Note that it is a dummy check, so we won't care about what is |
| // the actual padding data. |
| checkPadding(buf, offset, len, (byte)(padLen & 0xFF)); |
| |
| throw new BadPaddingException("Invalid Padding length: " + padLen); |
| } |
| |
| // The padding data should be filled with the padding length value. |
| int[] results = checkPadding(buf, offset + newLen, |
| padLen + 1, (byte)(padLen & 0xFF)); |
| if (protocolVersion.v >= ProtocolVersion.TLS10.v) { |
| if (results[0] != 0) { // padding data has invalid bytes |
| throw new BadPaddingException("Invalid TLS padding data"); |
| } |
| } else { // SSLv3 |
| // SSLv3 requires 0 <= length byte < block size |
| // some implementations do 1 <= length byte <= block size, |
| // so accept that as well |
| // v3 does not require any particular value for the other bytes |
| if (padLen > blockSize) { |
| throw new BadPaddingException("Invalid SSLv3 padding"); |
| } |
| } |
| return newLen; |
| } |
| |
| /* |
| * Position/limit is equal the removed padding. |
| */ |
| private static int removePadding(ByteBuffer bb, |
| int tagLen, int blockSize, |
| ProtocolVersion protocolVersion) throws BadPaddingException { |
| |
| int len = bb.remaining(); |
| int offset = bb.position(); |
| |
| // last byte is length byte (i.e. actual padding length - 1) |
| int padOffset = offset + len - 1; |
| int padLen = bb.get(padOffset) & 0xFF; |
| |
| int newLen = len - (padLen + 1); |
| if ((newLen - tagLen) < 0) { |
| // If the buffer is not long enough to contain the padding plus |
| // a MAC tag, do a dummy constant-time padding check. |
| // |
| // Note that it is a dummy check, so we won't care about what is |
| // the actual padding data. |
| checkPadding(bb.duplicate(), (byte)(padLen & 0xFF)); |
| |
| throw new BadPaddingException("Invalid Padding length: " + padLen); |
| } |
| |
| // The padding data should be filled with the padding length value. |
| int[] results = checkPadding( |
| (ByteBuffer)bb.duplicate().position(offset + newLen), |
| (byte)(padLen & 0xFF)); |
| if (protocolVersion.v >= ProtocolVersion.TLS10.v) { |
| if (results[0] != 0) { // padding data has invalid bytes |
| throw new BadPaddingException("Invalid TLS padding data"); |
| } |
| } else { // SSLv3 |
| // SSLv3 requires 0 <= length byte < block size |
| // some implementations do 1 <= length byte <= block size, |
| // so accept that as well |
| // v3 does not require any particular value for the other bytes |
| if (padLen > blockSize) { |
| throw new BadPaddingException("Invalid SSLv3 padding"); |
| } |
| } |
| |
| /* |
| * Reset buffer limit to remove padding. |
| */ |
| bb.position(offset + newLen); |
| bb.limit(offset + newLen); |
| |
| return newLen; |
| } |
| |
| /* |
| * Dispose of any intermediate state in the underlying cipher. |
| * For PKCS11 ciphers, this will release any attached sessions, and |
| * thus make finalization faster. |
| */ |
| void dispose() { |
| try { |
| if (cipher != null) { |
| // ignore return value. |
| cipher.doFinal(); |
| } |
| } catch (Exception e) { |
| // swallow all types of exceptions. |
| } |
| } |
| |
| /* |
| * Does the cipher use CBC mode? |
| * |
| * @return true if the cipher use CBC mode, false otherwise. |
| */ |
| boolean isCBCMode() { |
| return cipherType == BLOCK_CIPHER; |
| } |
| |
| /* |
| * Does the cipher use AEAD mode? |
| * |
| * @return true if the cipher use AEAD mode, false otherwise. |
| */ |
| boolean isAEADMode() { |
| return cipherType == AEAD_CIPHER; |
| } |
| |
| /* |
| * Is the cipher null? |
| * |
| * @return true if the cipher is null, false otherwise. |
| */ |
| boolean isNullCipher() { |
| return cipher == null; |
| } |
| |
| /* |
| * Gets the explicit nonce/IV size of the cipher. |
| * |
| * The returned value is the SecurityParameters.record_iv_length in |
| * RFC 4346/5246. It is the size of explicit IV for CBC mode, and the |
| * size of explicit nonce for AEAD mode. |
| * |
| * @return the explicit nonce size of the cipher. |
| */ |
| int getExplicitNonceSize() { |
| switch (cipherType) { |
| case BLOCK_CIPHER: |
| // For block ciphers, the explicit IV length is of length |
| // SecurityParameters.record_iv_length, which is equal to |
| // the SecurityParameters.block_size. |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| return cipher.getBlockSize(); |
| } |
| break; |
| case AEAD_CIPHER: |
| return recordIvSize; |
| // It is also the length of sequence number, which is |
| // used as the nonce_explicit for AEAD cipher suites. |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Applies the explicit nonce/IV to this cipher. This method is used to |
| * decrypt an SSL/TLS input record. |
| * |
| * The returned value is the SecurityParameters.record_iv_length in |
| * RFC 4346/5246. It is the size of explicit IV for CBC mode, and the |
| * size of explicit nonce for AEAD mode. |
| * |
| * @param authenticator the authenticator to get the additional |
| * authentication data |
| * @param contentType the content type of the input record |
| * @param bb the byte buffer to get the explicit nonce from |
| * |
| * @return the explicit nonce size of the cipher. |
| */ |
| int applyExplicitNonce(Authenticator authenticator, byte contentType, |
| ByteBuffer bb) throws BadPaddingException { |
| switch (cipherType) { |
| case BLOCK_CIPHER: |
| // sanity check length of the ciphertext |
| int tagLen = (authenticator instanceof MAC) ? |
| ((MAC)authenticator).MAClen() : 0; |
| if (tagLen != 0) { |
| if (!sanityCheck(tagLen, bb.remaining())) { |
| throw new BadPaddingException( |
| "ciphertext sanity check failed"); |
| } |
| } |
| |
| // For block ciphers, the explicit IV length is of length |
| // SecurityParameters.record_iv_length, which is equal to |
| // the SecurityParameters.block_size. |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| return cipher.getBlockSize(); |
| } |
| break; |
| case AEAD_CIPHER: |
| if (bb.remaining() < (recordIvSize + tagSize)) { |
| throw new BadPaddingException( |
| "invalid AEAD cipher fragment"); |
| } |
| |
| // initialize the AEAD cipher for the unique IV |
| byte[] iv = Arrays.copyOf(fixedIv, |
| fixedIv.length + recordIvSize); |
| bb.get(iv, fixedIv.length, recordIvSize); |
| bb.position(bb.position() - recordIvSize); |
| GCMParameterSpec spec = new GCMParameterSpec(tagSize * 8, iv); |
| try { |
| cipher.init(mode, key, spec, random); |
| } catch (InvalidKeyException | |
| InvalidAlgorithmParameterException ikae) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "invalid key or spec in GCM mode", ikae); |
| } |
| |
| // update the additional authentication data |
| byte[] aad = authenticator.acquireAuthenticationBytes( |
| contentType, bb.remaining() - recordIvSize - tagSize); |
| cipher.updateAAD(aad); |
| |
| return recordIvSize; |
| // It is also the length of sequence number, which is |
| // used as the nonce_explicit for AEAD cipher suites. |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Applies the explicit nonce/IV to this cipher. This method is used to |
| * decrypt an SSL/TLS input record. |
| * |
| * The returned value is the SecurityParameters.record_iv_length in |
| * RFC 4346/5246. It is the size of explicit IV for CBC mode, and the |
| * size of explicit nonce for AEAD mode. |
| * |
| * @param authenticator the authenticator to get the additional |
| * authentication data |
| * @param contentType the content type of the input record |
| * @param buf the byte array to get the explicit nonce from |
| * @param offset the offset of the byte buffer |
| * @param cipheredLength the ciphered fragment length of the output |
| * record, it is the TLSCiphertext.length in RFC 4346/5246. |
| * |
| * @return the explicit nonce size of the cipher. |
| */ |
| int applyExplicitNonce(Authenticator authenticator, |
| byte contentType, byte[] buf, int offset, |
| int cipheredLength) throws BadPaddingException { |
| |
| ByteBuffer bb = ByteBuffer.wrap(buf, offset, cipheredLength); |
| |
| return applyExplicitNonce(authenticator, contentType, bb); |
| } |
| |
| /* |
| * Creates the explicit nonce/IV to this cipher. This method is used to |
| * encrypt an SSL/TLS output record. |
| * |
| * The size of the returned array is the SecurityParameters.record_iv_length |
| * in RFC 4346/5246. It is the size of explicit IV for CBC mode, and the |
| * size of explicit nonce for AEAD mode. |
| * |
| * @param authenticator the authenticator to get the additional |
| * authentication data |
| * @param contentType the content type of the input record |
| * @param fragmentLength the fragment length of the output record, it is |
| * the TLSCompressed.length in RFC 4346/5246. |
| * |
| * @return the explicit nonce of the cipher. |
| */ |
| byte[] createExplicitNonce(Authenticator authenticator, |
| byte contentType, int fragmentLength) { |
| |
| byte[] nonce = new byte[0]; |
| switch (cipherType) { |
| case BLOCK_CIPHER: |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| // For block ciphers, the explicit IV length is of length |
| // SecurityParameters.record_iv_length, which is equal to |
| // the SecurityParameters.block_size. |
| // |
| // Generate a random number as the explicit IV parameter. |
| nonce = new byte[cipher.getBlockSize()]; |
| random.nextBytes(nonce); |
| } |
| break; |
| case AEAD_CIPHER: |
| // To be unique and aware of overflow-wrap, sequence number |
| // is used as the nonce_explicit of AEAD cipher suites. |
| nonce = authenticator.sequenceNumber(); |
| |
| // initialize the AEAD cipher for the unique IV |
| byte[] iv = Arrays.copyOf(fixedIv, |
| fixedIv.length + nonce.length); |
| System.arraycopy(nonce, 0, iv, fixedIv.length, nonce.length); |
| GCMParameterSpec spec = new GCMParameterSpec(tagSize * 8, iv); |
| try { |
| cipher.init(mode, key, spec, random); |
| } catch (InvalidKeyException | |
| InvalidAlgorithmParameterException ikae) { |
| // unlikely to happen |
| throw new RuntimeException( |
| "invalid key or spec in GCM mode", ikae); |
| } |
| |
| // update the additional authentication data |
| byte[] aad = authenticator.acquireAuthenticationBytes( |
| contentType, fragmentLength); |
| cipher.updateAAD(aad); |
| break; |
| } |
| |
| return nonce; |
| } |
| |
| /* |
| * Is this cipher available? |
| * |
| * This method can only be called by CipherSuite.BulkCipher.isAvailable() |
| * to test the availability of a cipher suites. Please DON'T use it in |
| * other places, otherwise, the behavior may be unexpected because we may |
| * initialize AEAD cipher improperly in the method. |
| */ |
| Boolean isAvailable() { |
| // We won't know whether a cipher for a particular key size is |
| // available until the cipher is successfully initialized. |
| // |
| // We do not initialize AEAD cipher in the constructor. Need to |
| // initialize the cipher to ensure that the AEAD mode for a |
| // particular key size is supported. |
| if (cipherType == AEAD_CIPHER) { |
| try { |
| Authenticator authenticator = |
| new Authenticator(protocolVersion); |
| byte[] nonce = authenticator.sequenceNumber(); |
| byte[] iv = Arrays.copyOf(fixedIv, |
| fixedIv.length + nonce.length); |
| System.arraycopy(nonce, 0, iv, fixedIv.length, nonce.length); |
| GCMParameterSpec spec = new GCMParameterSpec(tagSize * 8, iv); |
| |
| cipher.init(mode, key, spec, random); |
| } catch (Exception e) { |
| return Boolean.FALSE; |
| } |
| } // Otherwise, we have initialized the cipher in the constructor. |
| |
| return Boolean.TRUE; |
| } |
| |
| /** |
| * Sanity check the length of a fragment before decryption. |
| * |
| * In CBC mode, check that the fragment length is one or multiple times |
| * of the block size of the cipher suite, and is at least one (one is the |
| * smallest size of padding in CBC mode) bigger than the tag size of the |
| * MAC algorithm except the explicit IV size for TLS 1.1 or later. |
| * |
| * In non-CBC mode, check that the fragment length is not less than the |
| * tag size of the MAC algorithm. |
| * |
| * @return true if the length of a fragment matches above requirements |
| */ |
| private boolean sanityCheck(int tagLen, int fragmentLen) { |
| if (!isCBCMode()) { |
| return fragmentLen >= tagLen; |
| } |
| |
| int blockSize = cipher.getBlockSize(); |
| if ((fragmentLen % blockSize) == 0) { |
| int minimal = tagLen + 1; |
| minimal = (minimal >= blockSize) ? minimal : blockSize; |
| if (protocolVersion.v >= ProtocolVersion.TLS11.v) { |
| minimal += blockSize; // plus the size of the explicit IV |
| } |
| |
| return (fragmentLen >= minimal); |
| } |
| |
| return false; |
| } |
| |
| } |
