Calculate a MD5 hash from a string

Question

I use the following C# code to calculate a MD5 hash from a string. It works well and generates a 32-character hex string like this: 900150983cd24fb0d6963f7d28e17f72

Answer 1

Here is my utility function for UTF8, which can be replaced with ASCII if desired:

    public static byte[] MD5Hash(string message)
    {
        return MD5.Create().ComputeHash(Encoding.UTF8.GetBytes(message));
    }

Answer 2

Idk anything about 16 character hex strings....

using System;
using System.Security.Cryptography;
using System.Text;

But here is mine for creating MD5 hash in one line.

string hash = BitConverter.ToString(MD5.Create().ComputeHash(Encoding.ASCII.GetBytes("THIS STRING TO MD5"))).Replace("-","");

Answer 3

// given, a password in a string
string password = @"1234abcd";

// byte array representation of that string
byte[] encodedPassword = new UTF8Encoding().GetBytes(password);

// need MD5 to calculate the hash
byte[] hash = ((HashAlgorithm) CryptoConfig.CreateFromName("MD5")).ComputeHash(encodedPassword);

// string representation (similar to UNIX format)
string encoded = BitConverter.ToString(hash)
   // without dashes
   .Replace("-", string.Empty)
   // make lowercase
   .ToLower();

// encoded contains the hash you want

Answer 4

I'd like to offer an alternative that appears to perform at least 10% faster than craigdfrench's answer in my tests (.NET 4.7.2):

public static string GetMD5Hash(string text)
{
    using ( var md5 = MD5.Create() )
    {
        byte[] computedHash = md5.ComputeHash( Encoding.UTF8.GetBytes(text) );
        return new System.Runtime.Remoting.Metadata.W3cXsd2001.SoapHexBinary(computedHash).ToString();
    }
}

If you prefer to have using System.Runtime.Remoting.Metadata.W3cXsd2001; at the top, the method body can be made an easier to read one-liner:

using ( var md5 = MD5.Create() )
{
    return new SoapHexBinary( md5.ComputeHash( Encoding.UTF8.GetBytes(text) ) ).ToString();
}

Obvious enough, but for completeness, in OP's context it would be used as:

sSourceData = "MySourceData";
tmpHash = GetMD5Hash(sSourceData);