How to do a checksum on Windows?

Is there a way to do a checksum on windows machines like on unix/li开发者_运维知识库nux machines?

I cannot download any 3rd party tools and wondering if there was something similar natively?

---

You can get get the MD5 hash of the file. You would essentially parse the file and pass it into this function as a string. e.g.

 public string GetMD5Hash(string input)
    {
        System.Security.Cryptography.MD5CryptoServiceProvider x = new System.Security.Cryptography.MD5CryptoServiceProvider();
        byte[] bs = System.Text.Encoding.UTF8.GetBytes(input);
        bs = x.ComputeHash(bs);
        System.Text.StringBuilder s = new System.Text.StringBuilder();
        foreach (byte b in bs)
        {
            s.Append(b.ToString("x2").ToLower());
        }
        string password = s.ToString();
        return password;
    }

(taken from here)

...or as a file:

protected string GetMD5HashFromFile(string fileName)
{
  FileStream file = new FileStream(fileName, FileMode.Open);
  MD5 md5 = new MD5CryptoServiceProvider();
  byte[] retVal = md5.ComputeHash(file);
  file.Close();

  StringBuilder sb = new StringBuilder();
  for (int i = 0; i < retVal.Length; i++)
  {
    sb.Append(retVal[i].ToString("x2"));
  }
  return sb.ToString();
}

Taken from here Calculate MD5 Checksum for File

---

For modern versions of windows, you can run a command line (much like you mentioned 'Like Unix machines, etc').

The tool is called FCIV and you can download from Microsoft Here. https://www.microsoft.com/en-us/download/details.aspx?id=11533

To Run it its pretty easy...

FCIV -md5 -sha1 C:\path\to\my\file

MD5                              SHA1
------------------------------------------------------------------------------------------
8a3d1ae852c3d2f255ea9a732a539721 9747e6afa6d6fcb94fe3bf86ead91683c26d1aca c:\path\to\my\file

Im pretty sure that in powershell you can parse that response as a PSObject.

---

Here's a powershell 1 liner that will return 'true' if the file's checksum matches. Just replace $filePath, $hash, and encryption type as appropriate.

certUtil -hashfile $filePath SHA256 | Select-String -Pattern '^.{2}\s' | % {($_ -Replace ' ', '')  -eq "$hash"}