Question

我按照本教程加密和解密android / java中的简单字符串：

https://stackoverflow.com/questions/4319496/how-to-encrypt-and-decrypt-data-in-java 我做了一个密码学课：

public class Cryptography {

    public static SecretKey generateKey() throws NoSuchAlgorithmException {
        MessageDigest digest = MessageDigest.getInstance("SHA");
        digest.update("BhLKTyLoP YroUsRQT".getBytes());
        return new SecretKeySpec(digest.digest(), 0, 16, "AES");
    }

    public static byte[] encrypt(String message, SecretKey key) throws NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException, NoSuchPaddingException, InvalidKeyException, UnsupportedEncodingException {
        Cipher aes = Cipher.getInstance("AES/ECB/PKCS5Padding");
        aes.init(Cipher.ENCRYPT_MODE, key);
        return aes.doFinal(message.getBytes());
    }

    public static String decrypt(byte[] cipherText, SecretKey key) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        Cipher aes = Cipher.getInstance("AES/ECB/PKCS5Padding");
        aes.init(Cipher.DECRYPT_MODE, key);
        return new String(aes.doFinal(cipherText));
    }

}

我能够加密方法并给了我这个：

Encrypted username: [B@52aff408 
Encrypted password: [B@52aff6d8

但是，当我使用decrypt时：

SecretKey secret = Cryptography.generateKey();
Log.d("encryption", "Decrypted username: " + Cryptography.decrypt(encryptedUsername.getBytes(),secret)
                                + " Decrypted password: " +  Cryptography.decrypt(encyptedPassword.getBytes(),secret));

它给了我错误：

03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ java.lang.RuntimeException: error:0606506D:digital envelope routines:EVP_DecryptFinal_ex:wrong final block length
03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at org.apache.harmony.xnet.provider.jsse.NativeCrypto.EVP_CipherFinal_ex(Native Method)
03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at org.apache.harmony.xnet.provider.jsse.OpenSSLCipher.doFinalInternal(OpenSSLCipher.java:398)
03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at org.apache.harmony.xnet.provider.jsse.OpenSSLCipher.engineDoFinal(OpenSSLCipher.java:434)
03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at javax.crypto.Cipher.doFinal(Cipher.java:1111)
03-25 15:22:23.461    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at com.sblive.utils.Cryptography.decrypt(Cryptography.java:28)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at com.sblive.aufschoolbliz.GradeBookFragment$2.onClick(GradeBookFragment.java:99)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.view.View.performClick(View.java:4240)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.view.View$PerformClick.run(View.java:17721)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:730)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:92)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.os.Looper.loop(Looper.java:137)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5103)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:525)
03-25 15:22:23.465    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-25 15:22:23.469    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-25 15:22:23.469    2073-2073/com.sblive.aufschoolbliz W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)

Answer 1

加密用户名：[B @ 52aff408

加密密码：[B @ 52aff6d8

这些太小了。假设纯文本消息少于16个字节，那么由于PKCS填充，这些应该正好是16个字节。

您在某处遇到编码问题。可能是一个嵌入的null，当解释为字符串时会切断密文的末尾...

事实上，它们看起来像是在打印指针......

在解密期间获取“EVP_DecryptFinal_ex：错误的最终块长度”

1 个答案: