J2ME AES解密错误(org.bouncycastle.crypto.InvalidCipherTextException:pad block corrupted)

时间:2010-12-01 11:41:20

标签: java-me aes encryption bouncycastle midlet

我正在使用具有弹性城堡的AES算法进行加密和解密

我的加密和解密工作正常,但是当我的纯文字大小更大时,它会给我错误

甚至有时它会提供非解密数据

public static boolean setEncryptionKey(String keyText)
{
    byte[] keyBytes = keyText.getBytes();

    key = new KeyParameter(keyBytes);
    engine = new AESFastEngine();
    cipher = new PaddedBufferedBlockCipher(engine);

    return true;
}

加密

public static String encryptString(String plainText)
{

        byte[] plainArray = plainText.getBytes();

        cipher.init(true, key);
        byte[] cipherBytes = new byte[cipher.getOutputSize(plainArray.length)];
        int cipherLength = cipher.processBytes(plainArray, 0, plainArray.length, cipherBytes, 0);
        cipher.doFinal(cipherBytes, cipherLength);
        String cipherString = new String(cipherBytes);
        return cipherString;
    }

解密:

public static String decryptString(String encryptedText)
{

        byte[] cipherBytes = encryptedText.getBytes();
        cipher.init(false, key);
        byte[] decryptedBytes = new byte[cipher.getOutputSize(cipherBytes.length)];
        int decryptedLength = cipher.processBytes(cipherBytes, 0, cipherBytes.length, decryptedBytes, 0);
        cipher.doFinal(decryptedBytes, decryptedLength);
        String decryptedString = new String(decryptedBytes);

        int index = decryptedString.indexOf("\u0000");
        if (index >= 0)
        {
            decryptedString = decryptedString.substring(0, index);
        }
        return decryptedString;
    }

此解密给我以下错误

org.bouncycastle.crypto.InvalidCipherTextException: pad block corrupted
        at org.bouncycastle.crypto.paddings.PKCS7Padding.padCount(+30)
        at org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher.doFinal(+190)
        at com.NewCrypto.decryptString(NewCrypto.java:103)
        at com.New_Midlet.startApp(New_Midlet.java:23)
        at javax.microedition.midlet.MIDletProxy.startApp(MIDletProxy.java:44)
        at com.sun.midp.midlet.Scheduler.schedule(Scheduler.java:375)
        at com.sun.midp.main.Main.runLocalClass(Main.java:477)
        at com.sun.midp.main.Main.main(+80)

可能是什么问题?

1 个答案:

答案 0 :(得分:2)

该行

String cipherString = new String(cipherBytes);

是一个错误。 cipherBytes是具有任意值的字节数组,不能使用任何Java字符串解码器转换为字符串。您应该将密码作为字节数组发送/保存。如果你必须使它成为一个字符串,那么你将不得不使用编码器。通常使用Base64编码器,Base16(十六进制)也是如此。您可以使用Apache Commons Codec或我最喜欢的Harder Base64 codec