org.apache.commons.compress.archivers.sevenz.AES256SHA256Decoder Maven / Gradle / Ivy

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Apache Commons Compress defines an API for working with compression and archive formats. These include bzip2, gzip, pack200, LZMA, XZ, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.
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/*
 *  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.commons.compress.archivers.sevenz;

import java.io.IOException;
import java.io.InputStream;
import java.security.GeneralSecurityException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.compress.PasswordRequiredException;

class AES256SHA256Decoder extends CoderBase {
    @Override
    InputStream decode(final String archiveName, final InputStream in, final long uncompressedLength,
            final Coder coder, final byte[] passwordBytes) throws IOException {
        return new InputStream() {
            private boolean isInitialized = false;
            private CipherInputStream cipherInputStream = null;
                
            private CipherInputStream init() throws IOException {
                if (isInitialized) {
                    return cipherInputStream;
                }
                final int byte0 = 0xff & coder.properties[0];
                final int numCyclesPower = byte0 & 0x3f;
                final int byte1 = 0xff & coder.properties[1];
                final int ivSize = ((byte0 >> 6) & 1) + (byte1 & 0x0f);
                final int saltSize = ((byte0 >> 7) & 1) + (byte1 >> 4);
                if (2 + saltSize + ivSize > coder.properties.length) {
                    throw new IOException("Salt size + IV size too long in " + archiveName);
                }
                final byte[] salt = new byte[saltSize];
                System.arraycopy(coder.properties, 2, salt, 0, saltSize);
                final byte[] iv = new byte[16];
                System.arraycopy(coder.properties, 2 + saltSize, iv, 0, ivSize);

                if (passwordBytes == null) {
                    throw new PasswordRequiredException(archiveName);
                }
                final byte[] aesKeyBytes;
                if (numCyclesPower == 0x3f) {
                    aesKeyBytes = new byte[32];
                    System.arraycopy(salt, 0, aesKeyBytes, 0, saltSize);
                    System.arraycopy(passwordBytes, 0, aesKeyBytes, saltSize,
                                     Math.min(passwordBytes.length, aesKeyBytes.length - saltSize));
                } else {
                    final MessageDigest digest;
                    try {
                        digest = MessageDigest.getInstance("SHA-256");
                    } catch (final NoSuchAlgorithmException noSuchAlgorithmException) {
                        throw new IOException("SHA-256 is unsupported by your Java implementation",
                            noSuchAlgorithmException);
                    }
                    final byte[] extra = new byte[8];
                    for (long j = 0; j < (1L << numCyclesPower); j++) {
                        digest.update(salt);
                        digest.update(passwordBytes);
                        digest.update(extra);
                        for (int k = 0; k < extra.length; k++) {
                            ++extra[k];
                            if (extra[k] != 0) {
                                break;
                            }
                        }
                    }
                    aesKeyBytes = digest.digest();
                }

                final SecretKey aesKey = new SecretKeySpec(aesKeyBytes, "AES");
                try {
                    final Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
                    cipher.init(Cipher.DECRYPT_MODE, aesKey, new IvParameterSpec(iv));
                    cipherInputStream = new CipherInputStream(in, cipher);
                    isInitialized = true;
                    return cipherInputStream;
                } catch (final GeneralSecurityException generalSecurityException) {
                    throw new IOException("Decryption error " +
                        "(do you have the JCE Unlimited Strength Jurisdiction Policy Files installed?)",
                        generalSecurityException);
                    }
            }
                
            @Override
            public int read() throws IOException {
                return init().read();
            }
                
            @Override
            public int read(final byte[] b, final int off, final int len) throws IOException {
                return init().read(b, off, len);
            }
                
            @Override
            public void close() {
            }
        };
    }
}