HTTP摘要验证-在多个HTTP请求之间共享MD5实例

Question

I have my own HTTP request class which I am using it as a client to send an HTTP requests to some remote servers. I am implementing an HTTP digest authentication and using MD5 instance in order to preform the hash algorithm . I would like to know what is the efficient way to store the MD5 instance ? I thought about these options:

1. Every request will hold a MD5 instance, so every time that request are being sent we will do : m_md5 = MD5.Create();

   How expensive is the 'Create' process ?

2. The MD5 instance will be static and will be store out of the request class and we will use the MD5.Create() just once and all the request instance will use the same MD5 instance.Note that a lot of threads are creating instances of the HTTP request class. Is it thread-safe ?

Thnaks.

Answer 1

As Oguz Ozgul Said the second optiond doesn't possible since MD5 doesn't thread-safeas we can see here :

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe