Question

我已经有一个包含名为User的表的数据库，该表包含表盐，密码等...

盐柱的数据长度为43
密码列包含88长度的数据

我的数据库是由symfony(ORM+FOSUserBundle)使用sha512创建的。

我正在尝试获取salt和密码，并将它们从桌面java应用程序存储到数据库中，所以我尝试了这个类：

import com.google.common.io.BaseEncoding;
import org.slf4j.Logger;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import com.google.common.primitives.Bytes;
import org.slf4j.LoggerFactory;

public class SHA512 {
    private static final Logger log = LoggerFactory.getLogger(SHA512.class);
    private static final String ALGORITHM = "SHA-512";
    private static final int ITERATIONS = 5000;
    private static final int SALT_SIZE = 43;


    /**
     * Private constructor.
     */
    private SHA512() {
    }

    public static void main(String[] args) {
        String password = "0000";

        try {

            byte[] salt = generateSalt();
            log.info("Password {}. hash algorithm {}, iterations {}, salt {}", password, ALGORITHM, ITERATIONS,
                    BaseEncoding.base64().encode(salt));
            byte[] hash = calculateHash(password, salt);
            boolean correct = verifyPassword(hash, password, salt);

            log.info("Entered password is correct: {}", correct);
        } catch (NoSuchAlgorithmException | UnsupportedEncodingException ex) {
            log.error(ex.getMessage(), ex);
        }
    }


    private static byte[] generateSalt() {
        SecureRandom random = new SecureRandom();
        byte[] salt = new byte[SALT_SIZE];
        random.nextBytes(salt);

        return salt;
    }

    private static byte[] calculateHash(String password, byte[] salt) throws NoSuchAlgorithmException,
            UnsupportedEncodingException {
        MessageDigest md = MessageDigest.getInstance(ALGORITHM);
        md.reset();
        md.update(Bytes.concat(password.getBytes("UTF-8"), salt));
        byte[] hash = md.digest();

        for (int i = 0; i < ITERATIONS; i++) {
            md.reset();
            hash = md.digest(hash);
        }
        return hash;
    }

    private static boolean verifyPassword(byte[] originalHash, String password, byte[] salt) throws
            NoSuchAlgorithmException, UnsupportedEncodingException {
        byte[] comparisonHash = calculateHash(password, salt);

        log.info("hash 1: {}", BaseEncoding.base64().encode(originalHash));
        log.info("hash 2: {}", BaseEncoding.base64().encode(comparisonHash));

        return comparePasswords(originalHash, comparisonHash);
    }

    /**
     * Compares the two byte arrays in length-constant time using XOR.
     *
     * @param originalHash   The original password hash
     * @param comparisonHash The comparison password hash
     * @return True if both match, false otherwise
     */
    private static boolean comparePasswords(byte[] originalHash, byte[] comparisonHash) {
        int diff = originalHash.length ^ comparisonHash.length;
        for (int i = 0; i < originalHash.length && i < comparisonHash.length; i++) {
            diff |= originalHash[i] ^ comparisonHash[i];
        }

        return diff == 0;
    }
}

我需要一个长度为43的盐，但BaseEncoding.base64().encode(salt)输出盐，长度等于60。我将SALT_SIZE修改为30并且BaseEncoding.base64().encode(salt)输出长度等于40的salt但是，当我添加一个用户使用该盐并生成哈希时，我无法从我的Web应用程序登录此用户（已经说FOSUserBundle控制认证和编码/解码算法）

Answer 1

如果我正确阅读，您的摘要编码器实施中会出错。

参考点：

<强> MessageDigestPasswordEncoder.php

<强> BasePasswordEncoder.php

当您请求手动生成摘要时，基本上有两个步骤：

哈希结束：password + { + salt + }
对于每次额外的迭代：对previous digest + salt的concat进行哈希处理（请注意，此步骤不会添加{或}字符）

所以，我在你的实现中看到了两个问题：

我认为你没有在迭代＃0中包含{和}
您未在以后的任何迭代中包含salt

希望这有点帮助...

如何在数据库中持久保存具有指定长度的salt

1 个答案: