Android(安卓)N中不再支持“Crypto”的解决方案

这个问题的相关说明你可以看看这篇博文。
按照官方说明，我写了一个工具类，下面是代码：
/** * AES 加密工具类，适配Android7.0，相对老的加密工具，提升了安全性 */public class AESUtil {    /** iv大小(位) **/    private static final int IV_SIZE = 16;    /** 密钥大小(位) **/    private static final int KEY_SIZE = 32;    /** iv文件名 **/    private static final String IV_FILE_NAME = "AES_IV";    /** salt文件名 **/    private static final String SALT_FILE_NAME = "AES_SALT";    // iv文件和salt文件位于外置储存卡的Android/data/com.example.name(你的App的包名)/files/Download目录下，文件名如上面所示    /**     * 生成一个安全的密钥     * @param password 生成密钥的seed     * @param keySizeInBytes 密钥大小(位)     * @return 密钥     */    private static SecretKey deriveKeySecurely(Context context, String password, int keySizeInBytes) {        // Use this to derive the key from the password:        KeySpec keySpec = new PBEKeySpec(password.toCharArray(), retrieveSalt(context),                100 /* iterationCount */, keySizeInBytes * 8 /* key size in bits */);        try {            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");            byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();            return new SecretKeySpec(keyBytes, "AES");        } catch (Exception e) {            throw new RuntimeException("Deal with exceptions properly!", e);        }    }    private static byte[] retrieveIv(Context context) {        byte[] iv = new byte[IV_SIZE];        // Ideally your data should have been encrypted with a random iv. This creates a random iv        // if not present, in order to encrypt our mock data.        readFromFileOrCreateRandom(context, IV_FILE_NAME, iv);        return iv;    }    private static byte[] retrieveSalt(Context context) {        // Salt must be at least the same size as the key.        byte[] salt = new byte[KEY_SIZE];        // Create a random salt if encrypting for the first time, and save it for future use.        readFromFileOrCreateRandom(context, SALT_FILE_NAME, salt);        return salt;    }    private static void readFromFileOrCreateRandom(Context context, String fileName, byte[] bytes) {        if (fileExists(context, fileName)) {            readBytesFromFile(context, fileName, bytes);            return;        }        SecureRandom sr = new SecureRandom();        sr.nextBytes(bytes);        writeToFile(context, fileName, bytes);    }    private static boolean fileExists(Context context, String fileName) {        File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName);        return file.exists();    }    @SuppressWarnings("unused")    private static void removeFile(Context context, String fileName) {        File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName);        //noinspection ResultOfMethodCallIgnored        file.delete();    }    private static void writeToFile(Context context, String fileName, byte[] bytes) {        File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName);        try {            FileOutputStream fos = new FileOutputStream(file);            fos.write(bytes);        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();            throw new RuntimeException("Couldn't write to " + fileName, e);        }    }    private static void readBytesFromFile(Context context, String fileName, byte[] bytes) {        File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), fileName);        try {            FileInputStream fis = new FileInputStream(file);            int numBytes = 0;            while (numBytes < bytes.length) {                int n = fis.read(bytes, numBytes, bytes.length - numBytes);                if (n <= 0) {                    throw new RuntimeException("Couldn't read from " + fileName);                }                numBytes += n;            }        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();            throw new RuntimeException("Couldn't read from " + fileName, e);        }    }    private static byte[] encryptOrDecrypt(            byte[] data, SecretKey key, byte[] iv, boolean isEncrypt) {        try {            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7PADDING");            cipher.init(isEncrypt ? Cipher.ENCRYPT_MODE : Cipher.DECRYPT_MODE, key,                    new IvParameterSpec(iv));            return cipher.doFinal(data);        } catch (GeneralSecurityException e) {            throw new RuntimeException("This is unconceivable!", e);        }    }    private static byte[] encryptData(byte[] data, byte[] iv, SecretKey key) {        return encryptOrDecrypt(data, key, iv, true);    }    private static byte[] decryptData(byte[] data, byte[] iv, SecretKey key) {        return encryptOrDecrypt(data, key, iv, false);    }    // 本工具类唯一提供的两个公共方法，用来加密和加密数据    /**     * 加密数据     * @param data 待加密的数据     * @param password 密钥     * @return 已加密的数据     */    public static byte[] encrypt(Context context, String data, String password) {        return encryptData(data.getBytes(), retrieveIv(context), deriveKeySecurely(context, password, KEY_SIZE));    }    /**     * 解密数据     * @param data 待解密的数据     * @param password 密钥     * @return 已解密的数据     */    public static byte[] decrypt(Context context, byte[] data, String password) {        return decryptData(data, retrieveIv(context), deriveKeySecurely(context, password, KEY_SIZE));    }
使用方法：
调用AESUtil.encrypt(Context context, String data, String password)来加密数据，调用AESUtil.decrypt(Context context, byte[] data, String password)来解密数据。
Enjoy it
转载地址： http://celerysoft.github.io/2016-09-14.html
更多相关文章

随机推荐
