| /* ==================================================================== |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You under the Apache License, Version 2.0 |
| (the "License"); you may not use this file except in compliance with |
| the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| ==================================================================== */ |
| |
| package org.apache.poi.poifs.crypt.cryptoapi; |
| |
| import java.io.IOException; |
| |
| import org.apache.poi.EncryptedDocumentException; |
| import org.apache.poi.poifs.crypt.ChainingMode; |
| import org.apache.poi.poifs.crypt.CipherAlgorithm; |
| import org.apache.poi.poifs.crypt.CipherProvider; |
| import org.apache.poi.poifs.crypt.HashAlgorithm; |
| import org.apache.poi.poifs.crypt.standard.StandardEncryptionHeader; |
| import org.apache.poi.util.LittleEndianInput; |
| |
| public class CryptoAPIEncryptionHeader extends StandardEncryptionHeader { |
| |
| public CryptoAPIEncryptionHeader(LittleEndianInput is) throws IOException { |
| super(is); |
| } |
| |
| protected CryptoAPIEncryptionHeader(CryptoAPIEncryptionHeader other) { |
| super(other); |
| } |
| |
| protected CryptoAPIEncryptionHeader(CipherAlgorithm cipherAlgorithm, |
| HashAlgorithm hashAlgorithm, int keyBits, int blockSize, |
| ChainingMode chainingMode) { |
| super(cipherAlgorithm, hashAlgorithm, keyBits, blockSize, chainingMode); |
| } |
| |
| @Override |
| public void setKeySize(int keyBits) { |
| // Microsoft Base Cryptographic Provider is limited up to 40 bits |
| // http://msdn.microsoft.com/en-us/library/windows/desktop/aa375599(v=vs.85).aspx |
| boolean found = false; |
| for (int size : getCipherAlgorithm().allowedKeySize) { |
| if (size == keyBits) { |
| found = true; |
| break; |
| } |
| } |
| if (!found) { |
| throw new EncryptedDocumentException("invalid keysize "+keyBits+" for cipher algorithm "+getCipherAlgorithm()); |
| } |
| super.setKeySize(keyBits); |
| if (keyBits > 40) { |
| setCspName("Microsoft Enhanced Cryptographic Provider v1.0"); |
| } else { |
| setCspName(CipherProvider.rc4.cipherProviderName); |
| } |
| } |
| |
| @Override |
| public CryptoAPIEncryptionHeader copy() { |
| return new CryptoAPIEncryptionHeader(this); |
| } |
| } |