WSS: SOAP Message Security Header for .NET

Example.cs

public class Example
{
    public WebServiceResponseObject CallWebService()
    {
        var client = new YourWebserviceClient();

        try
        {
            client.Open();

            using (OperationContextScope scope = new OperationContextScope(client.InnerChannel))
            {
                MessageHeaders messageHeadersElement = OperationContext.Current.OutgoingMessageHeaders;
                messageHeadersElement.Add(new SecurityHeader("username", "password"));
                var result = client.DoThing();
                return result;
            }

        }
        catch (Exception ex)
        {
            // show the error
            throw;
        }
        finally
        {
            client.Close();
        }
    }
}

SecurityHeader.cs

public class SecurityHeader : System.ServiceModel.Channels.MessageHeader
{
    public string username;
    public string password;
    public string passwordDigest;
    public string created;
    public string nonce;
    public SecurityHeader(string username, string password)
    {
        string noncePhrase = Guid.NewGuid().ToString();
        var created = System.DateTime.UtcNow.ToString("o");
        this.username = username;
        this.password = password;
        this.created = created;
        this.nonce = ToBase64(noncePhrase);
        this.passwordDigest = GetHashedString(noncePhrase + created + password);
    }
    protected override void OnWriteStartHeader(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Channels.MessageVersion messageVersion)
    {
        writer.WriteStartElement("o", Name, Namespace);
        writer.WriteXmlnsAttribute("o", Namespace);
    }

    protected override void OnWriteHeaderContents(System.Xml.XmlDictionaryWriter writer, System.ServiceModel.Channels.MessageVersion messageVersion)
    {
        var xml =
            "<wsse:UsernameToken wsu:Id=\"" + this.username + "\" xmlns:wsse=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd\" xmlns:wsu=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd\">" +
                "<wsse:Username>" + this.username + "</wsse:Username>" +
                "<wsse:Password Type=\"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordDigest\">" + this.passwordDigest + "</wsse:Password>" +
                "<wsse:Nonce>" + this.nonce + "</wsse:Nonce>" +
                "<wsu:Created>" + this.created + "</wsu:Created>" +
            "</wsse:UsernameToken>";

        writer.WriteRaw(xml);

    }
    protected string GetHashedString(string phrase)
    {
        var hasher = new SHA256CryptoServiceProvider();
        byte[] hashedDataBytes = hasher.ComputeHash(Encoding.UTF8.GetBytes(phrase));
        return Convert.ToBase64String(hashedDataBytes);
    }
    protected string ToBase64(string phrase)
    {
        byte[] hashedDataBytes = Encoding.UTF8.GetBytes(phrase);
        return Convert.ToBase64String(hashedDataBytes);
    }
    public override string Name
    {
        get { return "Security"; }
    }

    public override string Namespace
    {
        get { return "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"; }
    }
}