AES CBC 加密解密(偏移量)
程序员文章站
2022-05-28 22:13:54
参考文章:AES加密解密(ECB模式)使用固定的keypackage com.eshore.cloud.utils;import android.text.TextUtils;import android.util.Base64;import java.security.Provider;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;im...
参考文章:AES加密解密(ECB模式)
工具:在线AES加密解密
使用固定的key
package com.eshore.cloud.utils;
import android.text.TextUtils;
import android.util.Base64;
import java.security.Provider;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AesUtil {
//偏移量
public static final String VIPARA = "XXX"; //AES 为16位. DES 为8bytes
//AES是加密方式 CBC是工作模式 PKCS5Padding是填充模式
private static final String CBC_PKCS5_PADDING = "AES/CBC/PKCS5Padding";
//AES 加密
private static final String AES = "AES";
// SHA1PRNG 强随机种子算法, 要区别4.2以上版本的调用方法
private static final String SHA1PRNG = "SHA1PRNG";
//编码方式
public static final String CODE_TYPE = "UTF-8";
/**
* 加密
*
* @param key
* @param cleartext
* @return
*/
public static String encrypt(String key, String cleartext) {
if (TextUtils.isEmpty(cleartext)) {
return cleartext;
}
try {
byte[] result = encrypt(key, cleartext.getBytes(CODE_TYPE));
return new String(Base64.encode(result, Base64.NO_WRAP),CODE_TYPE);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static byte[] encrypt(String key, byte[] clear) throws Exception {
IvParameterSpec zeroIv = new IvParameterSpec(VIPARA.getBytes(CODE_TYPE));
/*byte[] raw = getRawKey(key.getBytes("utf-8"));
SecretKeySpec skeySpec = new SecretKeySpec(raw, AES);*/
byte[] raw = key.getBytes(CODE_TYPE);
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance(CBC_PKCS5_PADDING);
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, zeroIv);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
/**
* 解密
*
* @param key
* @param encrypted
* @return
*/
public static String decrypt(String key, String encrypted) {
if (TextUtils.isEmpty(encrypted)) {
return encrypted;
}
try {
byte[] enc = Base64.decode(encrypted.getBytes(CODE_TYPE), Base64.NO_WRAP);
byte[] result = decrypt(key, enc);
return new String(result);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static byte[] decrypt(String key, byte[] encrypted) throws Exception {
IvParameterSpec zeroIv = new IvParameterSpec(VIPARA.getBytes(CODE_TYPE));
/* byte[] raw = getRawKey(key.getBytes());
SecretKeySpec skeySpec = new SecretKeySpec(raw, AES);*/
byte[] raw = key.getBytes(CODE_TYPE);
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance(CBC_PKCS5_PADDING);
cipher.init(Cipher.DECRYPT_MODE, skeySpec, zeroIv);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
}
使用动态的key:
package com.iefeel.tool;
import android.text.TextUtils;
import android.util.Base64;
import java.security.Provider;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class AesUtil {
private final static String HEX = "0123456789ABCDEF";
//AES是加密方式 CBC是工作模式 PKCS5Padding是填充模式
private static final String CBC_PKCS5_PADDING = "AES/CBC/PKCS5Padding";
//AES 加密
private static final String AES = "AES";
// SHA1PRNG 强随机种子算法, 要区别4.2以上版本的调用方法
private static final String SHA1PRNG = "SHA1PRNG";
/**
* @return 动态生成秘钥
*/
public static String generateKey() {
try {
SecureRandom localSecureRandom = SecureRandom.getInstance(SHA1PRNG);
byte[] bytes_key = new byte[20];
localSecureRandom.nextBytes(bytes_key);
String str_key = toHex(bytes_key);
return str_key;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 对秘钥进行处理
*
* @param seed 动态生成的秘钥
* @return
* @throws Exception
*/
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance(AES);
//for android
SecureRandom sr = null;
// 在4.2以上版本中,SecureRandom获取方式发生了改变
int sdk_version = android.os.Build.VERSION.SDK_INT;
// Android 6.0 以上
if (sdk_version > 23) {
sr = SecureRandom.getInstance(SHA1PRNG, new CryptoProvider());
//4.2及以上
} else if (android.os.Build.VERSION.SDK_INT >= 17) {
sr = SecureRandom.getInstance(SHA1PRNG, "Crypto");
} else {
sr = SecureRandom.getInstance(SHA1PRNG);
}
// for Java
// secureRandom = SecureRandom.getInstance(SHA1PRNG);
sr.setSeed(seed);
//256 bits or 128 bits,192bits
kgen.init(128, sr);
//AES中128位密钥版本有10个加密循环,192比特密钥版本有12个加密循环,256比特密钥版本则有14个加密循环。
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
/**
* 加密
*
* @param key
* @param cleartext
* @return
*/
public static String encrypt(String key, String cleartext) {
if (TextUtils.isEmpty(cleartext)) {
return cleartext;
}
try {
byte[] result = encrypt(key, cleartext.getBytes());
return new String(Base64.encode(result, Base64.DEFAULT));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private static byte[] encrypt(String key, byte[] clear) throws Exception {
byte[] raw = getRawKey(key.getBytes());
SecretKeySpec skeySpec = new SecretKeySpec(raw, AES);
Cipher cipher = Cipher.getInstance(CBC_PKCS5_PADDING);
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
/**
* 解密
*
* @param key
* @param encrypted
* @return
*/
public static String decrypt(String key, String encrypted) {
if (TextUtils.isEmpty(encrypted)) {
return encrypted;
}
try {
byte[] enc = Base64.decode(encrypted, Base64.DEFAULT);
byte[] result = decrypt(key, enc);
return new String(result);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private static byte[] decrypt(String key, byte[] encrypted) throws Exception {
byte[] raw = getRawKey(key.getBytes());
SecretKeySpec skeySpec = new SecretKeySpec(raw, AES);
Cipher cipher = Cipher.getInstance(CBC_PKCS5_PADDING);
cipher.init(Cipher.DECRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
// ----------------------------------------------- 辅助方法 ------------------------------------
//二进制转字符
public static String toHex(byte[] buf) {
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2 * buf.length);
for (int i = 0; i < buf.length; i++) {
appendHex(result, buf[i]);
}
return result.toString();
}
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
}
// 增加 CryptoProvider 类
public static class CryptoProvider extends Provider {
/**
* Creates a Provider and puts parameters
*/
public CryptoProvider() {
super("Crypto", 1.0, "HARMONY (SHA1 digest; SecureRandom; SHA1withDSA signature)");
put("SecureRandom.SHA1PRNG",
"org.apache.harmony.security.provider.crypto.SHA1PRNG_SecureRandomImpl");
put("SecureRandom.SHA1PRNG ImplementedIn", "Software");
}
}
}
本文地址:https://blog.csdn.net/tantion/article/details/107404940
上一篇: SQL Server基础之登陆触发器
下一篇: 设计模式随笔