android之AES加密解密

package cn.example.aes;

import android.util.Base64;

import java.security.MessageDigest;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class AESCrypt {

/** 加密key*/
private final String SEED_16_CHARACTERAes = "aaaaaaaaaaaaaaaa";
/** 解密key*/
private final String SEED_16_CHARACTERDes = "bbbbbbbbbbbbbbbb";

public AESCrypt(){
}

/** 获取偏移向量*/
public AlgorithmParameterSpec getIV() {
// 偏移向量初始化（要求为16位）
byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
IvParameterSpec ivParameterSpec;
ivParameterSpec = new IvParameterSpec(iv);
return ivParameterSpec;
}

/** 加密*/
public String encrypt(String plainText) throws Exception {
MessageDigest digest = MessageDigest.getInstance("SHA-256");
digest.update(SEED_16_CHARACTERAes.getBytes("UTF-8"));
byte[] keyBytes = new byte[32];
System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
AlgorithmParameterSpec spec = getIV();
cipher.init(Cipher.ENCRYPT_MODE, key, spec);
byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
String encryptedText = new String(Base64.encode(encrypted,Base64.DEFAULT), "UTF-8");
return encryptedText;
}
/** 解密*/
public String decrypt(String cryptedText) throws Exception {
MessageDigest digest = MessageDigest.getInstance("SHA-256");
digest.update(SEED_16_CHARACTERDes.getBytes("UTF-8"));
byte[] keyBytes = new byte[32];
System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
AlgorithmParameterSpec spec = getIV();
cipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
byte[] decrypted = cipher.doFinal(bytes);
String decryptedText = new String(decrypted, "UTF-8");
return decryptedText;
}
}