java - Android 加密和解密错误 - javax.crypto.IllegalBlockSizeException : last block incomplete in decryption

Question

我在以下代码中遇到解密问题。我有一个加密的字符串被发送到 setData()。我正在尝试解密加密的字符串(数据)。我不断收到的错误是

javax.crypto.IllegalBlockSizeException: last block incomplete in decryption

byte[] data;
String key = "tkg96827pco74510";

byte[] encryptedOut;
String decryptedOut;

Key aesKey;
Cipher cipher;

public void setData(String dataIn){
    this.data = dataIn.getBytes();
    try {
        aesKey = new SecretKeySpec(key.getBytes(), "AES");
        cipher = Cipher.getInstance("AES");

    }catch(Exception e){
        System.out.println("SET DATA ERROR - " + e);
    }
}
public void encrypt() {
    try{
        cipher.init(Cipher.ENCRYPT_MODE, aesKey);
        encryptedOut = cipher.doFinal(data);
    }catch(Exception e){
        System.out.println(e);
    }
}

public void decrypt(){
    try {
        cipher.init(Cipher.DECRYPT_MODE, aesKey);
        decryptedOut = new String(cipher.doFinal(data));

    }catch(Exception e){
        System.out.println("Decrypt Error: " + e);
    }
}

public byte[] getEncrypted() {
   return encryptedOut;
}

public String getDecrypted(){
    return decryptedOut;
}

Answer 1

问题是由这一行引起的:

decryptedOut = new String(cipher.doFinal(data));

这里您将传递原始数据进行解密。但您应该在此处传递 encryptedOut。

所以解决方案是:

decryptedOut = new String(cipher.doFinal(encryptedOut));

是的，请传递一些编码机制将 String 转换为 byteArray，反之亦然，例如 "UTF-8"。

所以正确的行是:

decryptedOut = new String(cipher.doFinal(encryptedOut),"UTF-8");

假设您已经完成了这样的字节转换:

this.data = dataIn.getBytes("UTF-8");