C3rd

I encountered again on how to generate MD5 File Hash in C# and compare generated C# file hash to PHP md5_file() function. This is to make sure the file integrity are maintained on copying files. It took me while to find the function but I know I have created one of my previous projects. And this time, I will post here in my blog for future use. Hehehe! For C#:

public static string md5_file(string fileName)
{
    FileStream file = new FileStream(fileName, FileMode.Open);
    MD5 md5 = new MD5CryptoServiceProvider();
    int length = (int)file.Length;  // get file length
    byte[] buffer = new byte[length];      // create buffer
    int count;                      // actual number of bytes read
    int sum = 0;                    // total number of bytes read

    // read until Read method returns 0 (end of the stream has been reached)
    while ((count = file.Read(buffer, sum, length - sum)) > 0)
        sum += count;  // sum is a buffer offset for next reading
    byte[] retVal = md5.ComputeHash(buffer);
    file.Close();

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

<?php

echo md5_file($filename_with_fullpath);

?>