Adding an MD5SUM function to MS SQL.

public partial class UserDefinedFunctions
{
    [Microsoft.SqlServer.Server.SqlFunction(IsDeterministic = true, IsPrecise = false)]
    public static SqlString MD5Sum(SqlString S1)
    {
        MD5 md5 = System.Security.Cryptography.MD5.Create();
        byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(S1.Value);
        byte[] hash = md5.ComputeHash(inputBytes);

        // step 2, convert byte array to hex string
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < hash.Length; i++)
            sb.Append(hash[i].ToString("X2"));

        return new SqlString(sb.ToString());
    }
}

You will also need to following SQL To install the function

CREATE Function MD5Sum(@S1 nvarchar(512))
	RETURNS nvarchar(64) AS EXTERNAL NAME SqlExtensions.UserDefinedFunctions.MD5Sum
GO

You should be able to call the function in normal sql code like SELECT dbo.MD5SUM('test value')

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