575 lines
26 KiB
Java
575 lines
26 KiB
Java
/* ====================================================================
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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==================================================================== */
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package org.apache.poi.poifs.crypt;
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import java.nio.charset.Charset;
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import java.security.DigestException;
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import java.security.GeneralSecurityException;
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import java.security.Key;
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import java.security.MessageDigest;
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import java.security.Provider;
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import java.security.Security;
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import java.security.spec.AlgorithmParameterSpec;
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import java.util.Arrays;
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import java.util.Locale;
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import javax.crypto.Cipher;
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import javax.crypto.Mac;
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import javax.crypto.SecretKey;
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import javax.crypto.spec.IvParameterSpec;
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import javax.crypto.spec.RC2ParameterSpec;
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import org.apache.poi.EncryptedDocumentException;
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import org.apache.poi.util.Internal;
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import org.apache.poi.util.LittleEndian;
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import org.apache.poi.util.LittleEndianConsts;
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import org.apache.poi.util.StringUtil;
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/**
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* Helper functions used for standard and agile encryption
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*/
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@Internal
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public class CryptoFunctions {
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/**
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* <p><cite>2.3.4.7 ECMA-376 Document Encryption Key Generation (Standard Encryption)<br/>
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* 2.3.4.11 Encryption Key Generation (Agile Encryption)</cite></p>
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*
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* <p>The encryption key for ECMA-376 document encryption [ECMA-376] using agile
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* encryption MUST be generated by using the following method, which is derived from PKCS #5:
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* <a href="https://www.ietf.org/rfc/rfc2898.txt">Password-Based Cryptography Version 2.0 [RFC2898]</a>.</p>
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*
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* <p>Let H() be a hashing algorithm as determined by the PasswordKeyEncryptor.hashAlgorithm
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* element, H_n be the hash data of the n-th iteration, and a plus sign (+) represent concatenation.
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* The password MUST be provided as an array of Unicode characters. Limitations on the length of the
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* password and the characters used by the password are implementation-dependent.
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* The initial password hash is generated as follows:</p>
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*
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*
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* <pre>H_0 = H(salt + password)</pre>
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*
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* <p>The salt used MUST be generated randomly. The salt MUST be stored in the
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* PasswordKeyEncryptor.saltValue element contained within the \EncryptionInfo stream as
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* specified in section 2.3.4.10. The hash is then iterated by using the following approach:</p>
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*
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* <pre>H_n = H(iterator + H_n-1)</pre>
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*
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* <p>where iterator is an unsigned 32-bit value that is initially set to 0x00000000 and then incremented
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* monotonically on each iteration until PasswordKey.spinCount iterations have been performed.
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* The value of iterator on the last iteration MUST be one less than PasswordKey.spinCount.</p>
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*
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* <p>For POI, H_final will be calculated by {@link #generateKey(byte[],HashAlgorithm,byte[],int)}</p>
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*
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* @param password
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* @param hashAlgorithm
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* @param salt
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* @param spinCount
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* @return the hashed password
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*/
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public static byte[] hashPassword(String password, HashAlgorithm hashAlgorithm, byte salt[], int spinCount) {
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return hashPassword(password, hashAlgorithm, salt, spinCount, true);
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}
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/**
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* Generalized method for read and write protection hash generation.
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* The difference is, read protection uses the order iterator then hash in the hash loop, whereas write protection
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* uses first the last hash value and then the current iterator value
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*
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* @param password
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* @param hashAlgorithm
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* @param salt
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* @param spinCount
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* @param iteratorFirst if true, the iterator is hashed before the n-1 hash value,
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* if false the n-1 hash value is applied first
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* @return the hashed password
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*/
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public static byte[] hashPassword(String password, HashAlgorithm hashAlgorithm, byte salt[], int spinCount, boolean iteratorFirst) {
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// If no password was given, use the default
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if (password == null) {
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password = Decryptor.DEFAULT_PASSWORD;
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}
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MessageDigest hashAlg = getMessageDigest(hashAlgorithm);
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hashAlg.update(salt);
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byte[] hash = hashAlg.digest(StringUtil.getToUnicodeLE(password));
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byte[] iterator = new byte[LittleEndianConsts.INT_SIZE];
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byte[] first = (iteratorFirst ? iterator : hash);
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byte[] second = (iteratorFirst ? hash : iterator);
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try {
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for (int i = 0; i < spinCount; i++) {
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LittleEndian.putInt(iterator, 0, i);
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hashAlg.reset();
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hashAlg.update(first);
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hashAlg.update(second);
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hashAlg.digest(hash, 0, hash.length); // don't create hash buffer everytime new
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}
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} catch (DigestException e) {
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throw new EncryptedDocumentException("error in password hashing");
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}
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return hash;
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}
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/**
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* <p><cite>2.3.4.12 Initialization Vector Generation (Agile Encryption)</cite></p>
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*
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* <p>Initialization vectors are used in all cases for agile encryption. An initialization vector MUST be
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* generated by using the following method, where H() is a hash function that MUST be the same as
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* specified in section 2.3.4.11 and a plus sign (+) represents concatenation:</p>
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* <ul>
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* <li>If a blockKey is provided, let IV be a hash of the KeySalt and the following value:<br/>
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* {@code blockKey: IV = H(KeySalt + blockKey)}</li>
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* <li>If a blockKey is not provided, let IV be equal to the following value:<br/>
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* {@code KeySalt:IV = KeySalt}</li>
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* <li>If the number of bytes in the value of IV is less than the the value of the blockSize attribute
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* corresponding to the cipherAlgorithm attribute, pad the array of bytes by appending 0x36 until
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* the array is blockSize bytes. If the array of bytes is larger than blockSize bytes, truncate the
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* array to blockSize bytes.</li>
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* </ul>
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**/
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public static byte[] generateIv(HashAlgorithm hashAlgorithm, byte[] salt, byte[] blockKey, int blockSize) {
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byte iv[] = salt;
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if (blockKey != null) {
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MessageDigest hashAlgo = getMessageDigest(hashAlgorithm);
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hashAlgo.update(salt);
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iv = hashAlgo.digest(blockKey);
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}
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return getBlock36(iv, blockSize);
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}
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/**
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* <p><cite>2.3.4.11 Encryption Key Generation (Agile Encryption)</cite></p>
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*
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* <p>The final hash data that is used for an encryption key is then generated by using the following
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* method:</p>
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*
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* <pre>H_final = H(H_n + blockKey)</pre>
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*
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* <p>where blockKey represents an array of bytes used to prevent two different blocks from encrypting
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* to the same cipher text.</p>
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*
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* <p>If the size of the resulting H_final is smaller than that of PasswordKeyEncryptor.keyBits, the key
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* MUST be padded by appending bytes with a value of 0x36. If the hash value is larger in size than
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* PasswordKeyEncryptor.keyBits, the key is obtained by truncating the hash value.</p>
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*
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* @param passwordHash
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* @param hashAlgorithm
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* @param blockKey
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* @param keySize
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* @return intermediate key
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*/
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public static byte[] generateKey(byte[] passwordHash, HashAlgorithm hashAlgorithm, byte[] blockKey, int keySize) {
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MessageDigest hashAlgo = getMessageDigest(hashAlgorithm);
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hashAlgo.update(passwordHash);
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byte[] key = hashAlgo.digest(blockKey);
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return getBlock36(key, keySize);
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}
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/**
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* Initialize a new cipher object with the given cipher properties and no padding
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* If the given algorithm is not implemented in the JCE, it will try to load it from the bouncy castle
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* provider.
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*
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* @param key the secrect key
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* @param cipherAlgorithm the cipher algorithm
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* @param chain the chaining mode
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* @param vec the initialization vector (IV), can be null
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* @param cipherMode Cipher.DECRYPT_MODE or Cipher.ENCRYPT_MODE
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* @return the requested cipher
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* @throws GeneralSecurityException
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* @throws EncryptedDocumentException if the initialization failed or if an algorithm was specified,
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* which depends on a missing bouncy castle provider
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*/
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public static Cipher getCipher(SecretKey key, CipherAlgorithm cipherAlgorithm, ChainingMode chain, byte[] vec, int cipherMode) {
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return getCipher(key, cipherAlgorithm, chain, vec, cipherMode, null);
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}
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/**
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* Initialize a new cipher object with the given cipher properties
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* If the given algorithm is not implemented in the JCE, it will try to load it from the bouncy castle
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* provider.
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*
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* @param key the secrect key
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* @param cipherAlgorithm the cipher algorithm
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* @param chain the chaining mode
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* @param vec the initialization vector (IV), can be null
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* @param cipherMode Cipher.DECRYPT_MODE or Cipher.ENCRYPT_MODE
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* @param padding the padding (null = NOPADDING, ANSIX923Padding, PKCS5Padding, PKCS7Padding, ISO10126Padding, ...)
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* @return the requested cipher
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* @throws GeneralSecurityException
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* @throws EncryptedDocumentException if the initialization failed or if an algorithm was specified,
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* which depends on a missing bouncy castle provider
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*/
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public static Cipher getCipher(Key key, CipherAlgorithm cipherAlgorithm, ChainingMode chain, byte[] vec, int cipherMode, String padding) {
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int keySizeInBytes = key.getEncoded().length;
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if (padding == null) padding = "NoPadding";
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try {
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// Ensure the JCE policies files allow for this sized key
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if (Cipher.getMaxAllowedKeyLength(cipherAlgorithm.jceId) < keySizeInBytes*8) {
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throw new EncryptedDocumentException("Export Restrictions in place - please install JCE Unlimited Strength Jurisdiction Policy files");
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}
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Cipher cipher;
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if (cipherAlgorithm == CipherAlgorithm.rc4) {
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cipher = Cipher.getInstance(cipherAlgorithm.jceId);
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} else if (cipherAlgorithm.needsBouncyCastle) {
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registerBouncyCastle();
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cipher = Cipher.getInstance(cipherAlgorithm.jceId + "/" + chain.jceId + "/" + padding, "BC");
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} else {
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cipher = Cipher.getInstance(cipherAlgorithm.jceId + "/" + chain.jceId + "/" + padding);
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}
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if (vec == null) {
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cipher.init(cipherMode, key);
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} else {
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AlgorithmParameterSpec aps;
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if (cipherAlgorithm == CipherAlgorithm.rc2) {
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aps = new RC2ParameterSpec(key.getEncoded().length*8, vec);
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} else {
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aps = new IvParameterSpec(vec);
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}
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cipher.init(cipherMode, key, aps);
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}
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return cipher;
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} catch (GeneralSecurityException e) {
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throw new EncryptedDocumentException(e);
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}
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}
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/**
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* Returns a new byte array with a truncated to the given size.
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* If the hash has less then size bytes, it will be filled with 0x36-bytes
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*
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* @param hash the to be truncated/filled hash byte array
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* @param size the size of the returned byte array
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* @return the padded hash
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*/
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private static byte[] getBlock36(byte[] hash, int size) {
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return getBlockX(hash, size, (byte)0x36);
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}
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/**
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* Returns a new byte array with a truncated to the given size.
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* If the hash has less then size bytes, it will be filled with 0-bytes
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*
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* @param hash the to be truncated/filled hash byte array
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* @param size the size of the returned byte array
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* @return the padded hash
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*/
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public static byte[] getBlock0(byte[] hash, int size) {
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return getBlockX(hash, size, (byte)0);
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}
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private static byte[] getBlockX(byte[] hash, int size, byte fill) {
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if (hash.length == size) return hash;
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byte[] result = new byte[size];
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Arrays.fill(result, fill);
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System.arraycopy(hash, 0, result, 0, Math.min(result.length, hash.length));
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return result;
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}
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public static MessageDigest getMessageDigest(HashAlgorithm hashAlgorithm) {
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try {
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if (hashAlgorithm.needsBouncyCastle) {
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registerBouncyCastle();
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return MessageDigest.getInstance(hashAlgorithm.jceId, "BC");
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} else {
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return MessageDigest.getInstance(hashAlgorithm.jceId);
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}
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} catch (GeneralSecurityException e) {
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throw new EncryptedDocumentException("hash algo not supported", e);
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}
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}
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public static Mac getMac(HashAlgorithm hashAlgorithm) {
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try {
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if (hashAlgorithm.needsBouncyCastle) {
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registerBouncyCastle();
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return Mac.getInstance(hashAlgorithm.jceHmacId, "BC");
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} else {
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return Mac.getInstance(hashAlgorithm.jceHmacId);
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}
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} catch (GeneralSecurityException e) {
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throw new EncryptedDocumentException("hmac algo not supported", e);
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}
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}
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@SuppressWarnings("unchecked")
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public static void registerBouncyCastle() {
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if (Security.getProvider("BC") != null) {
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return;
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}
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try {
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ClassLoader cl = Thread.currentThread().getContextClassLoader();
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String bcProviderName = "org.bouncycastle.jce.provider.BouncyCastleProvider";
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Class<Provider> clazz = (Class<Provider>)cl.loadClass(bcProviderName);
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Security.addProvider(clazz.newInstance());
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} catch (Exception e) {
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throw new EncryptedDocumentException("Only the BouncyCastle provider supports your encryption settings - please add it to the classpath.", e);
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}
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}
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private static final int INITIAL_CODE_ARRAY[] = {
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0xE1F0, 0x1D0F, 0xCC9C, 0x84C0, 0x110C, 0x0E10, 0xF1CE,
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0x313E, 0x1872, 0xE139, 0xD40F, 0x84F9, 0x280C, 0xA96A,
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0x4EC3
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};
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private static final byte PAD_ARRAY[] = {
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(byte)0xBB, (byte)0xFF, (byte)0xFF, (byte)0xBA, (byte)0xFF,
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(byte)0xFF, (byte)0xB9, (byte)0x80, (byte)0x00, (byte)0xBE,
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(byte)0x0F, (byte)0x00, (byte)0xBF, (byte)0x0F, (byte)0x00
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};
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private static final int ENCRYPTION_MATRIX[][] = {
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/* char 1 */ {0xAEFC, 0x4DD9, 0x9BB2, 0x2745, 0x4E8A, 0x9D14, 0x2A09},
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/* char 2 */ {0x7B61, 0xF6C2, 0xFDA5, 0xEB6B, 0xC6F7, 0x9DCF, 0x2BBF},
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/* char 3 */ {0x4563, 0x8AC6, 0x05AD, 0x0B5A, 0x16B4, 0x2D68, 0x5AD0},
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/* char 4 */ {0x0375, 0x06EA, 0x0DD4, 0x1BA8, 0x3750, 0x6EA0, 0xDD40},
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/* char 5 */ {0xD849, 0xA0B3, 0x5147, 0xA28E, 0x553D, 0xAA7A, 0x44D5},
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/* char 6 */ {0x6F45, 0xDE8A, 0xAD35, 0x4A4B, 0x9496, 0x390D, 0x721A},
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/* char 7 */ {0xEB23, 0xC667, 0x9CEF, 0x29FF, 0x53FE, 0xA7FC, 0x5FD9},
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/* char 8 */ {0x47D3, 0x8FA6, 0x0F6D, 0x1EDA, 0x3DB4, 0x7B68, 0xF6D0},
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/* char 9 */ {0xB861, 0x60E3, 0xC1C6, 0x93AD, 0x377B, 0x6EF6, 0xDDEC},
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/* char 10 */ {0x45A0, 0x8B40, 0x06A1, 0x0D42, 0x1A84, 0x3508, 0x6A10},
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/* char 11 */ {0xAA51, 0x4483, 0x8906, 0x022D, 0x045A, 0x08B4, 0x1168},
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/* char 12 */ {0x76B4, 0xED68, 0xCAF1, 0x85C3, 0x1BA7, 0x374E, 0x6E9C},
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/* char 13 */ {0x3730, 0x6E60, 0xDCC0, 0xA9A1, 0x4363, 0x86C6, 0x1DAD},
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/* char 14 */ {0x3331, 0x6662, 0xCCC4, 0x89A9, 0x0373, 0x06E6, 0x0DCC},
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/* char 15 */ {0x1021, 0x2042, 0x4084, 0x8108, 0x1231, 0x2462, 0x48C4}
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};
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/**
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* Create the verifier for xor obfuscation (method 1)
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*
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* @see <a href="http://msdn.microsoft.com/en-us/library/dd926947.aspx">2.3.7.1 Binary Document Password Verifier Derivation Method 1</a>
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* @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
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* @see <a href="http://www.ecma-international.org/news/TC45_current_work/Office Open XML Part 4 - Markup Language Reference.pdf">Part 4 - Markup Language Reference - Ecma International - 3.2.12 fileSharing</a>
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*
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* @param password the password
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* @return the verifier (actually a short value)
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*/
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public static int createXorVerifier1(String password) {
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byte[] arrByteChars = toAnsiPassword(password);
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// SET Verifier TO 0x0000
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short verifier = 0;
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if (!"".equals(password)) {
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// FOR EACH PasswordByte IN PasswordArray IN REVERSE ORDER
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for (int i = arrByteChars.length-1; i >= 0; i--) {
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// SET Verifier TO Intermediate3 BITWISE XOR PasswordByte
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verifier = rotateLeftBase15Bit(verifier);
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verifier ^= arrByteChars[i];
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}
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// as we haven't prepended the password length into the input array
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// we need to do it now separately ...
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verifier = rotateLeftBase15Bit(verifier);
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verifier ^= arrByteChars.length;
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// RETURN Verifier BITWISE XOR 0xCE4B
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verifier ^= 0xCE4B; // (0x8000 | ('N' << 8) | 'K')
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}
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return verifier & 0xFFFF;
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}
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/**
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* This method generates the xor verifier for word documents < 2007 (method 2).
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* Its output will be used as password input for the newer word generations which
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* utilize a real hashing algorithm like sha1.
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*
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* @param password the password
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* @return the hashed password
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*
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* @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
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* @see <a href="http://blogs.msdn.com/b/vsod/archive/2010/04/05/how-to-set-the-editing-restrictions-in-word-using-open-xml-sdk-2-0.aspx">How to set the editing restrictions in Word using Open XML SDK 2.0</a>
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* @see <a href="http://www.aspose.com/blogs/aspose-blogs/vladimir-averkin/archive/2007/08/20/funny-how-the-new-powerful-cryptography-implemented-in-word-2007-turns-it-into-a-perfect-tool-for-document-password-removal.html">Funny: How the new powerful cryptography implemented in Word 2007 turns it into a perfect tool for document password removal.</a>
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*/
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public static int createXorVerifier2(String password) {
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//Array to hold Key Values
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byte[] generatedKey = new byte[4];
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//Maximum length of the password is 15 chars.
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final int maxPasswordLength = 15;
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if (!"".equals(password)) {
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// Truncate the password to 15 characters
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password = password.substring(0, Math.min(password.length(), maxPasswordLength));
|
|
|
|
byte[] arrByteChars = toAnsiPassword(password);
|
|
|
|
// Compute the high-order word of the new key:
|
|
|
|
// --> Initialize from the initial code array (see below), depending on the passwords length.
|
|
int highOrderWord = INITIAL_CODE_ARRAY[arrByteChars.length - 1];
|
|
|
|
// --> For each character in the password:
|
|
// --> For every bit in the character, starting with the least significant and progressing to (but excluding)
|
|
// the most significant, if the bit is set, XOR the keys high-order word with the corresponding word from
|
|
// the Encryption Matrix
|
|
for (int i = 0; i < arrByteChars.length; i++) {
|
|
int tmp = maxPasswordLength - arrByteChars.length + i;
|
|
for (int intBit = 0; intBit < 7; intBit++) {
|
|
if ((arrByteChars[i] & (0x0001 << intBit)) != 0) {
|
|
highOrderWord ^= ENCRYPTION_MATRIX[tmp][intBit];
|
|
}
|
|
}
|
|
}
|
|
|
|
// Compute the low-order word of the new key:
|
|
int verifier = createXorVerifier1(password);
|
|
|
|
// The byte order of the result shall be reversed [password "Example": 0x64CEED7E becomes 7EEDCE64],
|
|
// and that value shall be hashed as defined by the attribute values.
|
|
|
|
LittleEndian.putShort(generatedKey, 0, (short)verifier);
|
|
LittleEndian.putShort(generatedKey, 2, (short)highOrderWord);
|
|
}
|
|
|
|
return LittleEndian.getInt(generatedKey);
|
|
}
|
|
|
|
/**
|
|
* This method generates the xored-hashed password for word documents < 2007.
|
|
*/
|
|
public static String xorHashPassword(String password) {
|
|
int hashedPassword = createXorVerifier2(password);
|
|
return String.format(Locale.ROOT, "%1$08X", hashedPassword);
|
|
}
|
|
|
|
/**
|
|
* Convenience function which returns the reversed xored-hashed password for further
|
|
* processing in word documents 2007 and newer, which utilize a real hashing algorithm like sha1.
|
|
*/
|
|
public static String xorHashPasswordReversed(String password) {
|
|
int hashedPassword = createXorVerifier2(password);
|
|
|
|
return String.format(Locale.ROOT, "%1$02X%2$02X%3$02X%4$02X"
|
|
, ( hashedPassword >>> 0 ) & 0xFF
|
|
, ( hashedPassword >>> 8 ) & 0xFF
|
|
, ( hashedPassword >>> 16 ) & 0xFF
|
|
, ( hashedPassword >>> 24 ) & 0xFF
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Create the xor key for xor obfuscation, which is used to create the xor array (method 1)
|
|
*
|
|
* @see <a href="http://msdn.microsoft.com/en-us/library/dd924704.aspx">2.3.7.2 Binary Document XOR Array Initialization Method 1</a>
|
|
* @see <a href="http://msdn.microsoft.com/en-us/library/dd905229.aspx">2.3.7.4 Binary Document Password Verifier Derivation Method 2</a>
|
|
*
|
|
* @param password the password
|
|
* @return the xor key
|
|
*/
|
|
public static int createXorKey1(String password) {
|
|
// the xor key for method 1 is part of the verifier for method 2
|
|
// so we simply chop it from there
|
|
return createXorVerifier2(password) >>> 16;
|
|
}
|
|
|
|
/**
|
|
* Creates an byte array for xor obfuscation (method 1)
|
|
*
|
|
* @see <a href="http://msdn.microsoft.com/en-us/library/dd924704.aspx">2.3.7.2 Binary Document XOR Array Initialization Method 1</a>
|
|
* @see <a href="http://docs.libreoffice.org/oox/html/binarycodec_8cxx_source.html">Libre Office implementation</a>
|
|
*
|
|
* @param password the password
|
|
* @return the byte array for xor obfuscation
|
|
*/
|
|
public static byte[] createXorArray1(String password) {
|
|
if (password.length() > 15) password = password.substring(0, 15);
|
|
byte passBytes[] = password.getBytes(Charset.forName("ASCII"));
|
|
|
|
// this code is based on the libre office implementation.
|
|
// The MS-OFFCRYPTO misses some infos about the various rotation sizes
|
|
byte obfuscationArray[] = new byte[16];
|
|
System.arraycopy(passBytes, 0, obfuscationArray, 0, passBytes.length);
|
|
System.arraycopy(PAD_ARRAY, 0, obfuscationArray, passBytes.length, PAD_ARRAY.length-passBytes.length+1);
|
|
|
|
int xorKey = createXorKey1(password);
|
|
|
|
// rotation of key values is application dependent - Excel = 2 / Word = 7
|
|
int nRotateSize = 2;
|
|
|
|
byte baseKeyLE[] = { (byte)(xorKey & 0xFF), (byte)((xorKey >>> 8) & 0xFF) };
|
|
for (int i=0; i<obfuscationArray.length; i++) {
|
|
obfuscationArray[i] ^= baseKeyLE[i&1];
|
|
obfuscationArray[i] = rotateLeft(obfuscationArray[i], nRotateSize);
|
|
}
|
|
|
|
return obfuscationArray;
|
|
}
|
|
|
|
/**
|
|
* The provided Unicode password string is converted to a ANSI string
|
|
*
|
|
* @param password the password
|
|
* @return the ansi bytes
|
|
*
|
|
* @see <a href="http://www.ecma-international.org/news/TC45_current_work/Office%20Open%20XML%20Part%204%20-%20Markup%20Language%20Reference.pdf">Part 4 - Markup Language Reference - Ecma International - section 3.2.29 (workbookProtection)</a>
|
|
*/
|
|
private static byte[] toAnsiPassword(String password) {
|
|
// TODO: charset conversion (see ecma spec)
|
|
|
|
// Get the single-byte values by iterating through the Unicode characters.
|
|
// For each character, if the low byte is not equal to 0, take it.
|
|
// Otherwise, take the high byte.
|
|
byte[] arrByteChars = new byte[password.length()];
|
|
|
|
for (int i = 0; i < password.length(); i++) {
|
|
int intTemp = password.charAt(i);
|
|
byte lowByte = (byte)(intTemp & 0xFF);
|
|
byte highByte = (byte)((intTemp >>> 8) & 0xFF);
|
|
arrByteChars[i] = (lowByte != 0 ? lowByte : highByte);
|
|
}
|
|
|
|
return arrByteChars;
|
|
}
|
|
|
|
private static byte rotateLeft(byte bits, int shift) {
|
|
return (byte)(((bits & 0xff) << shift) | ((bits & 0xff) >>> (8 - shift)));
|
|
}
|
|
|
|
private static short rotateLeftBase15Bit(short verifier) {
|
|
/*
|
|
* IF (Verifier BITWISE AND 0x4000) is 0x0000
|
|
* SET Intermediate1 TO 0
|
|
* ELSE
|
|
* SET Intermediate1 TO 1
|
|
* ENDIF
|
|
*/
|
|
short intermediate1 = (short)(((verifier & 0x4000) == 0) ? 0 : 1);
|
|
/*
|
|
* SET Intermediate2 TO Verifier MULTIPLED BY 2
|
|
* SET most significant bit of Intermediate2 TO 0
|
|
*/
|
|
short intermediate2 = (short)((verifier<<1) & 0x7FFF);
|
|
/*
|
|
* SET Intermediate3 TO Intermediate1 BITWISE OR Intermediate2
|
|
*/
|
|
short intermediate3 = (short)(intermediate1 | intermediate2);
|
|
return intermediate3;
|
|
}
|
|
}
|