Android Apache 编解码器 Base64 错误

Question

我正在尝试实现一个更高级的密码散列算法 (PBKDF2)，它使用 java util 库中的 Base64 类，但由于此类已过时，我需要获取支持更新的 Apache Codecs 库Base64 类。令人惊奇的是，在普通的 java 类上它可以完美地工作，但是当我在 android 活动中使用同一段代码时，它给了我一个错误，说我试图从 Base64 调用的方法不存在！

我认为这里的问题是，在活动中，Base64 是从具有过时版本的 Base64 的 util 库中调用的。 下面是代码示例。

import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import java.security.SecureRandom;
import org.apache.commons.codec.binary.Base64;

public class Password {
    // The higher the number of iterations the more 
    // expensive computing the hash is for us and
    // also for an attacker.
    private final int iterations = 20 * 1000;
    private final int saltLen = 32;
    private final int desiredKeyLen = 256;

    /**
     * Computes a salted PBKDF2 hash of given plaintext password
     * suitable for storing in a database.
     * Empty passwords are not supported.
     */
    public String getSaltedHash(String password) throws Exception {
        byte[] salt = SecureRandom.getInstance("SHA1PRNG").generateSeed(saltLen);
        // store the salt with the password
        return Base64.encodeBase64String(salt) + "$" + hash(password, salt);
    }

    /**
     * Checks whether given plaintext password corresponds
     * to a stored salted hash of the password.
     */
    public boolean check(String password, String stored) throws Exception {
        String[] saltAndPass = stored.split("\\$");
        if (saltAndPass.length != 2) {
            throw new IllegalStateException(
                    "The stored password have the form 'salt$hash'");
        }
        String hashOfInput = hash(password, Base64.decodeBase64(saltAndPass[0]));
        return hashOfInput.equals(saltAndPass[1]);
    }

    // using PBKDF2 from Sun, an alternative is https://github.com/wg/scrypt
    // cf. http://www.unlimitednovelty.com/2012/03/dont-use-bcrypt.html
    private String hash(String password, byte[] salt) throws Exception {
        if (password == null || password.length() == 0)
            throw new IllegalArgumentException("Empty passwords are not supported.");
        SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
        SecretKey key = f.generateSecret(new PBEKeySpec(
                password.toCharArray(), salt, iterations, desiredKeyLen)
        );
        return Base64.encodeBase64String(key.getEncoded());
    }

    public static void main(String[] args) throws Exception {

        Password passwordHash = new Password();
        String password = passwordHash.getSaltedHash("password");
        String password2 = passwordHash.getSaltedHash("password");
        System.out.println("P1-HASH: " + password);
        System.out.println("P2-HASH: " + password2);

        System.out.println(passwordHash.check("password", password2));
    }

}

Answer 1

该方法似乎被称为encodeToString。我真的不知道您在哪里找到了您的特定方法，但没有记录在案；我想你只是指错了类。