Question

我正在使用this library来保存加密到SharedPreferences的用户名和密码（非常确定没有应用可以访问我的SharedPreferences，但无论如何这都是必需的。）

我做了这段代码，因为我还需要使用自己的IV和密钥：

public class EncryptionHandler {
    private final static String PREFS_FILE_NAME = "SAVED_CREDENTIALS";
    private final static String MSG_FORMAT = "%s;%s";

    public static void saveCredentials(Context context, String username, String password) {
        try {
            String formattedMsg = String.format(MSG_FORMAT, username, password);

            String encryptedMsg = new String(AESCrypt.encrypt(getKeySpec(), getIV(), stringToBytes(formattedMsg)));

            //save encryptedMsg to SharedPreferences
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static byte[] stringToBytes(String msg) {
        return msg.getBytes(Charset.forName("UTF-8"));
    }

    public static LoginCredentials getSavedCredentials(Context context) {
        try {
            String encryptedMsg = getSharedPreferences(context).getString(PREFS_FILE_NAME, "");
            String messageAfterDecrypt = new String(AESCrypt.decrypt(getKeySpec(), getIV(), stringToBytes(encryptedMsg)));

            String[] split = messageAfterDecrypt.split(";");

            //irrelevant code

            return credentials;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    private static byte[] ivBytes = {0x00, 0x12, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x23, 0x52, 0x00, 0x00, 0x00, 0x00};

    private static SecretKeySpec secretKeySpec = new SecretKeySpec(ivBytes, "AES");

    private static SecretKeySpec getKeySpec() throws Exception {
        return secretKeySpec;
    }

    private static byte[] getIV() {
        return ivBytes;
    }
}

Related questions建议使用Base64，但我确实需要使用AESCrypt（它已经在iOS应用程序上工作，所以我必须做同样的事情）。

我得到的例外是：

javax.crypto.IllegalBlockSizeException: error:1e06b07b:Cipher functions:EVP_DecryptFinal_ex:WRONG_FINAL_BLOCK_LENGTH
    at com.android.org.conscrypt.NativeCrypto.EVP_CipherFinal_ex(Native Method)
    at com.android.org.conscrypt.OpenSSLCipher$EVP_CIPHER.doFinalInternal(OpenSSLCipher.java:568)
    at com.android.org.conscrypt.OpenSSLCipher.engineDoFinal(OpenSSLCipher.java:350)
    at javax.crypto.Cipher.doFinal(Cipher.java:1502)
    at com.scottyab.aescrypt.AESCrypt.decrypt(AESCrypt.java:158)
    at com.mypackage.encryption.EncryptionHandler.getSavedCredentials(EncryptionHandler.java:48)

当我尝试读取和解密时，此行中发生异常：

String messageAfterDecrypt = new String(AESCrypt.decrypt(getKeySpec(), getIV(), stringToBytes(encryptedMsg)));

修改：

我明白做new String(someBytes)没有意义，所以我也尝试将字节转换为Base64：

public static void saveCredentials(Context context, String username, String password) {
    try {
        String formattedMsg = String.format(MSG_FORMAT, username, password);
        byte[] bytes = stringToBytes(formattedMsg);
        byte[] encryptedBytes = AESCrypt.encrypt(getKeySpec(), getIV(), bytes);
        String encryptedMsg = Base64.encodeToString(encryptedBytes, Base64.NO_WRAP);

        //save to sharedpreferences
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private static byte[] stringToBytes(String msg) {
    byte[] bytes = msg.getBytes(Charset.forName("UTF-8"));

    return bytes;
}

public static LoginCredentials getSavedCredentials(Context context) {
    try {
        String base64Msg = getSharedPreferences(context).getString(PREFS_FILE_NAME, "");
        byte[] bytes = Base64.decode(base64Msg, Base64.NO_WRAP);
        byte[] decryptedBytes = AESCrypt.decrypt(getKeySpec(), getIV(), bytes);

        String messageAfterDecrypt = ????;

        //...
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

我没有收到错误，但我不知道如何获得最终的解密消息（行String messageAfterDecrypt = ????;）

尝试使用AESCrypt时出现javax.crypto.IllegalBlockSizeException

0 个答案: