BouncyCastle RSA实现

Question

这是我实现的1024位(可以更改) RSA。我做错什么了吗？

public class Rsa:IEncryption
{
    public AsymmetricCipherKeyPair Keys { get;private set; }

    private readonly Pkcs1Encoding _engine;

    public Rsa()
    {
        Keys = GenerateKeys();
        _engine = new Pkcs1Encoding(new RsaEngine());
    }

    public byte[] Encrypt(byte[] buffer)
    {
        return Encrypt(buffer, 0, buffer.Length);
    }

    public byte[] Decrypt(byte[] buffer)
    {
        return Decrypt(buffer, 0, buffer.Length);
    }

    public byte[] Encrypt(byte[] buffer, int offSet, int length)
    {
        return RsaProcessor(buffer, offSet, length, Keys.Public);
    }

    public byte[] Decrypt(byte[] buffer, int offSet, int length)
    {
        return RsaProcessor(buffer, offSet, length,Keys.Private);
    }

    private byte[] RsaProcessor(byte[] data,int offset,int length, AsymmetricKeyParameter key)
    {
        _engine.Init(!key.IsPrivate, key);

        var blockSize = _engine.GetInputBlockSize();

        var result = new List<byte>();
        for (var i = offset; i < offset+length; i += blockSize)
        {
            var currentSize = Math.Min(blockSize, offset + length - i);
            result.AddRange(_engine.ProcessBlock(data, i, currentSize));
        }
        return result.ToArray();
    }

    public static AsymmetricCipherKeyPair GenerateKeys()
    {
        var rsaKeyParams = new RsaKeyGenerationParameters(BigInteger.ProbablePrime(512, new Random()),
                                                          new SecureRandom(), 1024, 25); //Unsure about the certinaty parameter
        var keyGen = new RsaKeyPairGenerator();
        keyGen.Init(rsaKeyParams);

        return keyGen.GenerateKeyPair();
    }
}

Answer 1

风格

• 几乎所有参数和方法的命名都很好。
• RsaProcessor()听起来像个名词。根据命名指南，你应该用动词或动词短语来命名你的方法。也许像Process()这样的简单名称在这里就足够了。

在RsaProcessor()方法中，我建议将其介绍为Boolean forEncryption。就这样，这一行的意思

_engine.Init(!key.IsPrivate，key);

会很明显的。

private byte[] Process(byte[] data, int offset, int length, AsymmetricKeyParameter key)
{
    Boolean forEncryption = !key.IsPrivate;

    _engine.Init(forEncryption , key);

    var blockSize = _engine.GetInputBlockSize();

    var result = new List<byte>();
    for (var i = offset; i < offset+length; i += blockSize)
    {
        var currentSize = Math.Min(blockSize, offset + length - i);
        result.AddRange(_engine.ProcessBlock(data, i, currentSize));
    }
    return result.ToArray();
}

否则，您的代码看起来很好。

关于您的Unsure about the certinaty parameter，请参阅https://stackoverflow.com/a/3087161/2655508

RSA密钥生成需要素数。然而，不可能产生绝对素数。和其他密码库一样，BC使用可能的素数。确定性表示你有多确定你希望这个数字是素数。任何超过80的东西都会大大减慢密钥生成速度。