io.github.dbstarll.utils.lang.EncryptUtils Maven / Gradle / Ivy
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package io.github.dbstarll.utils.lang;
import io.github.dbstarll.utils.lang.bytes.Bytes;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
/**
* 处理加解密相关的工具类.
*
* @author dbstar
*/
public final class EncryptUtils {
public static final String ALGORITHM_MD5 = "MD5";
public static final String ALGORITHM_SHA = "SHA";
/**
* 使用秘钥进行字节数组加密，保留原始字节数组不变，加密后结果填充到新创建的字节数组.
*
* @param data 待加密的字节数组
* @param encryptedKey 秘钥
* @return 加密后的字节数组
*/
public static byte[] encryptCopy(byte[] data, Bytes encryptedKey) {
return data == null ? null : encryptReplace(Arrays.copyOf(data, data.length), encryptedKey);
}
/**
* 使用秘钥进行字节数组加密，加密后数据直接替换原始字节数组.
*
* @param data 待加密的字节数组
* @param encryptedKey 秘钥
* @return 加密后的字节数组
*/
public static byte[] encryptReplace(byte[] data, Bytes encryptedKey) {
if (data != null) {
encrypt(data, 0, data.length, encryptedKey, 0);
}
return data;
}
/**
* 使用秘钥和位置进行字节数组加密.
*
* @param data 待加密的字节数组
* @param offset 待加密的字节数组的开始偏移位置
* @param length 待加密的字节数组从开始偏移位置开始的字节长度
* @param encryptedKey 秘钥
* @param position 位置
* @return 加密处理过的字节数
*/
public static int encrypt(byte[] data, int offset, int length, Bytes encryptedKey, long position) {
final byte[] bs = encryptedKey.get();
final int keyLen = bs.length;
final int end = offset + length;
int pos = (int) (position % keyLen);
for (int i = offset; i < end; i++) {
data[i] = (byte) (data[i] ^ bs[pos++ % keyLen]);
}
// other impl
// final int pos = (keyLen - (int) (position % keyLen)) % keyLen;
// for (int i = 0; i < keyLen; i++) {
// byte encryptByte = bs[i];
// for (int j = offset + (i + pos) % keyLen; j < end; j += keyLen) {
// data[j] = (byte) (data[j] ^ encryptByte);
// }
// }
return length;
}
/**
* 使用秘钥和位置进行字节加密.
*
* @param data 原始字节
* @param encryptedKey 秘钥
* @param position 位置
* @return 加密后字节
*/
public static byte getEncryptedByte(byte data, Bytes encryptedKey, long position) {
return getEncryptedByte(data, getEncryptByte(encryptedKey, position));
}
/**
* 使用秘钥字节进行字节加密.
*
* @param data 原始字节
* @param encryptByte 秘钥字节
* @return 加密后字节
*/
private static byte getEncryptedByte(byte data, byte encryptByte) {
return (byte) (data ^ encryptByte);
}
/**
* 获得指定位置的秘钥字节.
*
* @param encryptedKey 秘钥
* @param position 位置
* @return 指定位置的秘钥字节
*/
private static byte getEncryptByte(Bytes encryptedKey, long position) {
return encryptedKey.get((int) (position % encryptedKey.length()));
}
/**
* 对字节数组进行摘要.
*
* @param data the array of bytes.
* @param algorithm the name of the algorithm requested.
* @return the array of bytes for the resulting hash value.
* @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for
* the specified algorithm.
*/
public static byte[] digest(byte[] data, String algorithm) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance(algorithm);
md.update(data);
return md.digest();
}
/**
* 使用MD5对字节数组进行摘要.
*
* @param data the array of bytes.
* @return the array of bytes for the resulting hash value.
* @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for
* the specified algorithm.
*/
public static byte[] md5(byte[] data) throws NoSuchAlgorithmException {
return digest(data, ALGORITHM_MD5);
}
/**
* 使用SHA对字节数组进行摘要.
*
* @param data the array of bytes.
* @param strength SHA摘要力度
* @return the array of bytes for the resulting hash value.
* @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for
* the specified algorithm.
*/
public static byte[] sha(byte[] data, int strength) throws NoSuchAlgorithmException {
return digest(data, ALGORITHM_SHA + "-" + strength);
}
/**
* 使用SHA对字符串进行摘要.
*
* @param data string
* @param strength SHA摘要力度
* @return the array of bytes for the resulting hash value.
* @throws NoSuchAlgorithmException if no Provider supports a MessageDigestSpi implementation for
* the specified algorithm.
*/
public static byte[] sha(String data, int strength) throws NoSuchAlgorithmException {
return sha(data.getBytes(StandardCharsets.UTF_8), strength);
}
}