如何使用Java中的BouncyCastle API加密和解密密码？ [英] How to encrypt and salt the password using BouncyCastle API in Java?

问题描述

加密我很新，我正在使用 BouncyCasetle API 加密密码，并将其存储在数据库。对于加密我正在使用 SHA-1 算法，我想要使用密码来防止它再次发生字典攻击。

I am fairly new to cryptography and I am using BouncyCasetle API to encrypt password and store it in the database. For encryption I am using SHA-1 algorithm and I want to salt the password to prevent it agains dictionary attacks.

任何帮助将不胜感激。

推荐答案

我建议使用基于密码的密钥推导函数而不是基本的哈希函数。这样的东西：

I'd recommend use of a Password-Based Key Derivation Function instead of a basic hash function for this. Something like this:

// tuning parameters

// these sizes are relatively arbitrary
int seedBytes = 20;
int hashBytes = 20;

// increase iterations as high as your performance can tolerate
// since this increases computational cost of password guessing
// which should help security
int iterations = 1000;

// to save a new password:

SecureRandom rng = new SecureRandom();
byte[] salt = rng.generateSeed(seedBytes);

Pkcs5S2ParametersGenerator kdf = new Pkcs5S2ParametersGenerator();
kdf.init(passwordToSave.getBytes("UTF-8"), salt, iterations);

byte[] hash =
    ((KeyParameter) kdf.generateDerivedMacParameters(8*hashBytes)).getKey();

// now save salt and hash

// to check a password, given the known previous salt and hash:

kdf = new Pkcs5S2ParametersGenerator();
kdf.init(passwordToCheck.getBytes("UTF-8"), salt, iterations);

byte[] hashToCheck =
    ((KeyParameter) kdf.generateDerivedMacParameters(8*hashBytes)).getKey();

// if the bytes of hashToCheck don't match the bytes of hash
// that means the password is invalid

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