Android AESUtils 工具类与调用方法

加密类

package com.test.abc;

import android.annotation.SuppressLint;
import android.text.TextUtils;
import android.util.Base64;
import android.util.Log;

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 AESUtils {

    
    private final static String HEX = "0123456789ABCDEF";
    private static final String CBC_PKCS5_PADDING = "AES/CBC/PKCS5Padding";//AES是加密方式 CBC是工作模式 PKCS5Padding是填充模式
    private static final String AES = "AES";//AES 加密
    private static final String SHA1PRNG = "SHA1PRNG";// SHA1PRNG 强随机种子算法, 要区别4.2以上版本的调用方法

    /**
     * 返回固定的KEY
     * @return
     */
    public static String fixedKey(){
        String secret_key = "F2492E93586F768B1E9C80C10EBA1CA88AB6B16C";
        //"{\"activation_result\":-2,\"member_username\":\"qwe\",\"member_expirationtime\":0}";
        return  secret_key;
    }
    /**
     * 生成随机数，可以当做动态的密钥 加密和解密的密钥必须一致，不然将不能解密
     */
    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;
    }

    /**
     * 对密钥进行处理
     *
     * @param seed
     * @return
     * @throws Exception
     */
    @SuppressLint("DeletedProvider")
    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;
        if (sdk_version > 23) {  // Android  6.0 以上
            sr = SecureRandom.getInstance(SHA1PRNG, new CryptoProvider());
        } else if (android.os.Build.VERSION.SDK_INT >= 17) {   //4.2及以上
            sr = SecureRandom.getInstance(SHA1PRNG, "Crypto");
        } else {
            sr = SecureRandom.getInstance(SHA1PRNG);
        }


        // for Java
        // secureRandom = SecureRandom.getInstance(SHA1PRNG);
        sr.setSeed(seed);
        kgen.init(128, sr); //256 bits or 128 bits,192bits
        //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
     */
    public static String encrypt(String key, String cleartext) {
        if (TextUtils.isEmpty(cleartext)) {
            return cleartext;
        }
        try {
            byte[] result = encrypt(key, cleartext.getBytes());
            //            return Base64Encoder.encode(result);
            return new String(Base64.encode(result, Base64.DEFAULT));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 加密
     */
    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
     */
    public static String decrypt(String key, String encrypted) {
        if (TextUtils.isEmpty(encrypted)) {
            return encrypted;
        }
        try {
            //            byte[] enc = Base64Decoder.decodeToBytes(encrypted);
            byte[] enc = Base64.decode(encrypted, Base64.DEFAULT);
            byte[] result = decrypt(key, enc);
            return new String(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 解密
     */
    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;
    }

    //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");
        }
    }

}

调用方法

        String jsonData = "{\"activation_result\":-2,\"member_username\":\"qwe\",\"member_expirationtime\":0}";
        Log.e("MainActivity", "AES加密前json数据 ---->" + jsonData);
        Log.e("MainActivity", "AES加密前json数据长度 ---->" + jsonData.length());

        //生成一个动态key
        String secretKey = AESUtils.generateKey();
        Log.e("MainActivity", "AES动态secretKey ---->" + secretKey);

        //AES加密
        long start = System.currentTimeMillis();
        String encryStr = AESUtils.encrypt(secretKey, jsonData);
        long end = System.currentTimeMillis();
        Log.e("MainActivity", "AES加密耗时 cost time---->" + (end - start));
        Log.e("MainActivity", "AES加密后json数据 ---->" + encryStr);
        Log.e("MainActivity", "AES加密后json数据长度 ---->" + encryStr.length());

        //AES解密
        start = System.currentTimeMillis();
        String decryStr = AESUtils.decrypt(secretKey, encryStr);
        end = System.currentTimeMillis();
        Log.e("MainActivity", "AES解密耗时 cost time---->" + (end - start));
        Log.e("MainActivity", "AES解密后json数据 ---->" + decryStr);