org.dromara.hutool.crypto.openssl.SaltMagic Maven / Gradle / Ivy
/*
* Copyright (c) 2013-2024 Hutool Team and hutool.cn
*
* Licensed 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.dromara.hutool.crypto.openssl;
import org.dromara.hutool.core.array.ArrayUtil;
import org.dromara.hutool.core.io.IORuntimeException;
import org.dromara.hutool.core.lang.Assert;
import org.dromara.hutool.core.text.StrUtil;
import org.dromara.hutool.core.util.ByteUtil;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
/**
* 加盐值魔数
* 用于在OpenSSL生成的密文中,提取加盐值等相关信息
*
* @author looly
* @since 6.0.0
*/
public class SaltMagic {
/**
* 加盐值长度
*/
public final static byte SALT_LEN = 8;
/**
* OpenSSL's magic initial bytes.
*/
public static final byte[] SALTED_MAGIC = "Salted__".getBytes(StandardCharsets.US_ASCII);
/**
* 获取魔术值和随机盐的长度:16(128位)
*/
public static final int MAGIC_SALT_LENGTH = SALTED_MAGIC.length + SALT_LEN;
/**
* 获取去除头部盐的加密数据
*
* @param encryptedData 密文
* @return 实际密文
*/
public static byte[] getData(final byte[] encryptedData) {
if (ArrayUtil.startWith(encryptedData, SALTED_MAGIC)) {
return Arrays.copyOfRange(encryptedData, SALTED_MAGIC.length + SALT_LEN, encryptedData.length);
}
return encryptedData;
}
/**
* 获取流中的加盐值
* 不关闭流
*
* @param in 流
* @return salt
* @throws IORuntimeException IO异常
*/
public static byte[] getSalt(final InputStream in) throws IORuntimeException {
final byte[] headerBytes = new byte[SALTED_MAGIC.length];
try{
final int readHeaderSize = in.read(headerBytes);
if (readHeaderSize < headerBytes.length ||
!Arrays.equals(SALTED_MAGIC, headerBytes)) {
throw new IORuntimeException("Unexpected magic header " + StrUtil.utf8Str(headerBytes));
}
final byte[] salt = new byte[SALT_LEN];
final int readSaltSize = in.read(salt);
if (readSaltSize < salt.length) {
throw new IORuntimeException("Unexpected salt: " + StrUtil.utf8Str(salt));
}
return salt;
} catch (final IOException e){
throw new IORuntimeException(e);
}
}
/**
* 获取8位salt随机数
*
* @param encryptedData 密文
* @return salt随机数
*/
public static byte[] getSalt(final byte[] encryptedData) {
if (ArrayUtil.startWith(encryptedData, SALTED_MAGIC)) {
return Arrays.copyOfRange(encryptedData, SALTED_MAGIC.length, MAGIC_SALT_LENGTH);
}
return null;
}
/**
* 为加密后的数据添加Magic头,生成的密文格式为:
*
* Salted__[salt][data]
*
*
* @param data 数据
* @param salt 加盐值,必须8位,{@code null}表示返回原文
* @return 密文
*/
public static byte[] addMagic(final byte[] data, final byte[] salt) {
if (null == salt) {
return data;
}
Assert.isTrue(SALT_LEN == salt.length);
return ByteUtil.concat(SALTED_MAGIC, salt, data);
}
/**
* 获取Magic头,生成的密文格式为:
*
* Salted__[salt]
*
*
* @param salt 加盐值,必须8位,不能为{@code null}
* @return Magic头
*/
public static byte[] getSaltedMagic(final byte[] salt) {
return ByteUtil.concat(SALTED_MAGIC, salt);
}
}