请求数据解密（Java）

ISV在收到AIoT创新工厂转发的请求内容后，进行数据解密计算工具类如下：

  1. import org.apache.commons.codec.binary.Base64;
  2. import javax.crypto.Cipher;
  3. import javax.crypto.KeyGenerator;
  4. import javax.crypto.spec.IvParameterSpec;
  5. import javax.crypto.spec.SecretKeySpec;
  6. import java.nio.charset.Charset;
  7. import java.security.NoSuchAlgorithmException;
  8. import java.util.Arrays;
  10. public class IsvEncryptor {
  12.     private static final Charset CHARSET = Charset.forName("utf-8");
  13.     private final static int     BLOCK_SIZE = 32;
  14.     private byte[]         aesKey;
  15.     private String         accountId;
  16.     /**ask getPaddingBytes key固定长度**/
  17.     private static final Integer AES_ENCODE_KEY_LENGTH = 43;
  19.     static {
  20.         KeyGenerator keyGenForAES = null;
  21.         try {
  22.             keyGenForAES = KeyGenerator.getInstance("AES");
  23.         } catch (NoSuchAlgorithmException e) {
  24.             e.printStackTrace();
  25.         }
  26.         keyGenForAES.init(128);
  27.     }
  29.     /**
  30.      * 构造函数
  31.      * @param encodingAesKey     秘钥
  32.      * @param openAccountId      OpenAccountId
  33.      * @throws RuntimeException  执行失败，请查看该异常的错误信息
  34.      */
  35.     public IsvEncryptor(String encodingAesKey, String openAccountId) throws RuntimeException {
  36.         if (null==encodingAesKey ||  encodingAesKey.length() != AES_ENCODE_KEY_LENGTH) {
  37.             throw new RuntimeException("不合法的aesKey");
  38.         }
  39.         this.accountId = openAccountId;
  40.         aesKey = Base64.decodeBase64(encodingAesKey + "=");
  41.     }
  43.     /*
  44.      * 对密文进行解密.
  45.      * @param text 需要解密的密文
  46.      * @return 解密得到的明文
  47.      */
  48.     public String decrypt(String text) throws RuntimeException {
  49.         byte[] originalArr;
  50.         try {
  51.             Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
  52.             SecretKeySpec keySpec = new SecretKeySpec(aesKey, "AES");
  53.             IvParameterSpec iv = new IvParameterSpec(Arrays.copyOfRange(aesKey, 0, 16));
  54.             cipher.init(Cipher.DECRYPT_MODE, keySpec, iv);
  55.             byte[] encrypted = Base64.decodeBase64(text);
  56.             originalArr = cipher.doFinal(encrypted);
  57.         } catch (Exception e) {
  58.             throw new RuntimeException("计算解密文字错误");
  59.         }
  61.         String plainText;
  62.         String fromAccountid;
  63.         try {
  64.             byte[] bytes = removePaddingBytes(originalArr);
  65.             byte[] networkOrder = Arrays.copyOfRange(bytes, 16, 20);
  66.             int plainTextLegth = bytes2int(networkOrder);
  67.             plainText = new String(Arrays.copyOfRange(bytes, 20, 20 + plainTextLegth), CHARSET);
  68.             fromAccountid = new String(Arrays.copyOfRange(bytes, 20 + plainTextLegth, bytes.length), CHARSET);
  69.         } catch (Exception e) {
  70.             throw new RuntimeException("计算解密文字长度不匹配");
  71.         }
  72.         if (!fromAccountid.equals(accountId)) {
  73.             throw new RuntimeException("计算解密文字accountId不匹配");
  74.         }
  75.         return plainText;
  76.     }
  78.     private static byte[] removePaddingBytes(byte[] decrypted) {
  79.         int pad = (int) decrypted[decrypted.length - 1];
  80.         if (pad < 1 || pad > BLOCK_SIZE) {
  81.             pad = 0;
  82.         }
  83.         return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
  84.     }
  86.     private static int bytes2int(byte[] byteArr) {
  87.         int count = 0;
  88.         for (int i = 0; i < 4; i++) {
  89.             count <<= 8;
  90.             count |= byteArr[i] & 0xff;
  91.         }
  92.         return count;
  93.     }
  94. }