• ValidationSummary controls look at the ErrorMessage field to figure out what to display, so always use ErrorMessage in a verbose enough way that it will be helpful from a ValidationSummary control.
• If you need a shorter message to display inline (i.e., where the validation control is on the form, as opposed to the ValidationSummary) use the body of the control to define it.

In the past, I've used RequiredFieldValidator controls on my web forms to remind users that certain fields are required. I would set the ErrorMessage to something vanilla like, "This field is required", or even something simpler like "*" (an asterisk) if I didn't have much room on the form to display more prose for an error.

A friend was recently testing a new feature that I'd built for our sales team and she had a hard time seeing the little red asterisks that were showing up next to required fields. It felt to her as though she was pushing the submit button on the form but nothing was happening. It was clear that a ValidationSummary control would be helpful, especially if placed close to the submit button for the form.

I've been a bit lazy in the past about using ValidationSummary controls, partially because most of my forms are simple enough that they feel a bit redundant. But on a more complicated form, they can be very helpful to guide users back to the places on the form where there's problems.

So I threw one of those puppies on the form and immediately saw that there was a problem - my error message was set to "*", which meant that my validation summary was pretty useless - it just displayed a bunch of red asterisks! And in places where I'd used the prose, "This field is required", well that was pretty useless as an error message in the summary.

After a bit of research and experimentation, I discovered that the ValidationSummary control looks at the ErrorMessage property on each validation control in order to figure out what to display in the summary. So it's important to use ErrorMessage with a summary in mind! Don't use text like "*" or "This field is required". Be more specific so the user can find her way up to the problem field, as in, "PostalCode is required".

But if you make ErrorMessage verbose so that it's helpful in a summary, it may make your form really ugly when displayed inline next to the control being validated. The trick is to use the body of the validation control element to specify the inline error message. Then you end up with two messages: a verbose one that's used in your summary, and a more localized, brief message that shows up right next to the control being validated. Note the asterisk that's in the body of the RequiredFieldValidator below:

<asp:RequiredFieldValidator
      ErrorMessage="Zip/postal code is required"
      ControlToValidate='txtPostalCode'
      ValidationGroup='BasicInfo'
      Display="Dynamic"
      runat='server'>*</asp:RequiredFieldValidator>

I've learned a lesson from all of this. In the future when I use validation controls I'll always provide a summary-friendly message in the ErrorMessage field, and if I need something different (typically shorter) to display inline, I'll put it in the body of the validation control element.

Hope this helps!

At Consumer Reports, we have always believed that scientific testing is the best way to evaluate products. We also use a statistically-valid survey methodology to measure consumer experiences. In preparing our September security reports, we employed both methods as we have for many decades. Some additional notes on this column:

• The story was not, as you state, "filled with data sourced to eMarketer." That service provided just two pieces of data, namely the current number of Internet- and broadband-using U.S. Households
• Using a separate credit card for online transactions avoids having to cancel your main card should fraud occur.
• We test software against modified versions of actual malware because such threats are what security software will often be called upon to recognize on the job.

Finally, a note about your claim that Consumer Reports was invited to respond. Your e-mail to us requesting a comment was time-stamped on the same Saturday evening as your column is labeled as having posted. That left fewer than six hours to respond, on a weekend. It would have been helpful to have had more time.

So I put together a simple class that holds an XmlDocument and implements ISerializable and called it SerializableXmlDocument. I'm sharing the source code here in the hopes that

a) somebody will find it useful, and

b) somebody smarter than I am will point out how I screwed it up and help me make it better.

SerializableXmlDocument includes implicit conversion operators to make it easy to convert to/from an XmlDocument. It holds the actual document in a property called Value. This "isomorph" pattern is one that I picked up from Craig.

While writing this code, I also wrote a helpful extension method for getting a byte array out of a MemoryStream that is exactly the length of the data written to the stream so far (CopyUpToSeekPointer). So don't go looking in the docs for MemoryStream for this method :) This is obviously not the most efficient way to consume bytes written to a MemoryStream since it copies the data into a new byte array, but it's very convenient in many scenarios.

Here is SerializableXmlDocument.cs:

using System;
using System.Runtime.Serialization;
using System.Xml;
using System.IO;

namespace Pluralsight.Samples
{
    [Serializable]
    public class SerializableXmlDocument : ISerializable
    {
        public SerializableXmlDocument() { }
        public SerializableXmlDocument(XmlDocument value)
        {
            this.Value = value;
        }

        public XmlDocument Value { get; set; }

        #region ISerializable implementation
        public SerializableXmlDocument(SerializationInfo info,
                                       StreamingContext context)
        {
            byte[] serializedData = (byte[])info.GetValue("doc",
                typeof(byte[]));
            if (null != serializedData)
                this.Value = Deserialize(serializedData);
        }

        public void GetObjectData(SerializationInfo info,
                                  StreamingContext context)
        {
            byte[] serializedData = null;
            if (null != Value)
                serializedData = Serialize(Value);
            info.AddValue("doc", serializedData);
        }
        #endregion

        #region implicit conversion to/from XmlDocument
        public static implicit operator SerializableXmlDocument(
            XmlDocument doc)
        {
            return new SerializableXmlDocument(doc);
        }
        public static implicit operator XmlDocument(
            SerializableXmlDocument sdoc)
        {
            return sdoc.Value;
        }
        #endregion

        #region Xml serialization helper methods
        private static byte[] Serialize(XmlDocument doc)
        {
            MemoryStream stream = new MemoryStream();
            doc.Save(stream);
            return stream.CopyUpToSeekPointer();
        }
        private static XmlDocument Deserialize(byte[] serializedData)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(new MemoryStream(serializedData, false));
            return doc;
        }
        #endregion
    }
}

...and here's the CopyUpToSeekPointer extension method for MemoryStream:

using System;
using System.IO;

namespace Pluralsight.Samples
{
    public static class MemoryStreamExtensionMethods
    {
        public static byte[] CopyUpToSeekPointer(
            this MemoryStream stream)
        {
            // copy only the part of the buffer
            // that contains the serialized document
            long length = stream.Position;
            byte[] buffer = stream.GetBuffer();
            byte[] result = new byte[length];
            for (int i = 0; i < length; ++i)
                result[i] = buffer[i];
            return result;
        }
    }
}

...and here's a sample object that uses SerializableXmlDocument:

using System;

namespace Pluralsight.Samples
{
    [Serializable]
    public class Item
    {
        public string Name { get; set; }
        public SerializableXmlDocument Data { get; set; }

        public void Print()
        {
            Console.WriteLine("Name: {0}", Name);
            Console.WriteLine(Data.Value.OuterXml);
        }
    }
}

...and here's a sample program that creates an instance of Item, serializes it, then deserializes it, printing diagnostics along the way to show that it's working properly.

using System;
using System.Xml;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using Pluralsight.Samples;

class DemoProgram
{
    static void Main(string[] args)
    {
        XmlDocument doc = new XmlDocument();
        doc.LoadXml("<root><child>text</child></root>");

        Item item = new Item
        {
            Name = "Testing 123",
            Data = doc,
        };

        // print object before serialization
        item.Print();

        BinaryFormatter formatter = new BinaryFormatter();
        MemoryStream stream = new MemoryStream();
        formatter.Serialize(stream, item);

        byte[] serializedItem = stream.CopyUpToSeekPointer();

        Console.WriteLine("Serialized data (base64): {0}",
            Convert.ToBase64String(serializedItem));

        item = (Item)formatter.Deserialize(
            new MemoryStream(serializedItem, false));

        // print object after deserialization
        item.Print();
    }
}

Here's the output of the previous sample program:

Flame away!

ASP.NET's health monitoring system does list the inner exceptions (apparently up to a maximum depth of two, from spelunking the code with reflector), but it does not emit the stack traces for these exceptions, which would be really helpful. I've spent some time this morning trying to figure out how I'd customize things to emit this, and it looks like what I'd have to do is catch the exception and generate a custom WebEvent that overrides ToString(bool, bool) and does everything that WebRequestErrorEvent does, but also generate the inner stack trace.

That seems a bit ugly. A search for "ASP.NET web event inner exception stack trace" yielded no interesting results, so if you've dealt with this and have a cleaner solution, let me know. I'll post my solution once I get it worked out.

• Certified Information Systems Auditor (CISA) : http://www.isaca.org/cisa/
• Certified Information Systems Security Professional : https://www.isc2.org/cissp

Are You Ready ?
A few basic questions to ask yourself to gauge how ready you are:

• Do I meet the spirit, and not just the letter, of the experience requirements ?
• Has there been sufficient diversity in my experience ?

Five Step Approach to CISA or CISSP Exam Preparation

1. Perform an initial benchmark and assessment of your readiness
2. Read a “survey” level preparation guide cover to cover
3. Perform a secondary benchmark, and compare your readiness
4. Review official, or “deep dive”, preparation materials on areas identified as your weaknesses
5. Re-benchmark, and repeat targeted reviews until ready

CISA and CISSP Preparation

We've probably all heard that you can't secure what you can't see and that statement is even more profound when it comes to virtual environments.  This is because it is extremely challenging to see what is going on at a micro vs. macro level within a virtual environments network.  The virtualization vendors such as VMWare and Citrix have provided embedded tools into their management consoles that show a macro level of visibility but its not enough to identify security events in the environment.  Take a look at the attached picture.  It simply shows VMWare's ability to monitor virtual network performance statistics from a bits per second perspective.

<-Click To Enlarge

With only this level of detail how can one determine which network applications are causing spikes.  Is it FTP traffic that is occuring at a high volume at an unuseal time of day?  If that were occuring, could that be indicative of either a breach or some sort of problem? What if FTP isn't even an authorized service in the virtual environment but there is a high volume of it?  Did someone install a rouge FTP service so they could steal information from the server at will?

These types of questions can't really be answered without a micro level of detail into the packets flowing in, out and within the virtual environment.  Now, what I am highlighting is not security in the traditional sense of prevention but using visibility as a means to first identify, then pin point the source of an issue so that it can properly be mitigated.  Having constant visibility can also ensure that other security products in the environment are performing as expected.  What if a Montego HyperSwitch with firewalling enabled is configured with many policies but someone forgot to create an FTP block policy.  One could think they are protected from rouge FTP services transmiting data out of the network, but without constant visibility monitoring, can you be certain?

Some vendors, namely Reflex Security will get you to believe that their IPS / IDS solution that is inline and running in the virtual environment is the right and only approach.  Or they will tell you to hang a virtual IDS off a span port in the virtual environment and you will at least have visibility into the attacks that are taking place.  Well, sure... You now have attack visibility but at the performance cost of your virtual environment.  Signature matching technologies are great, I'm a huge believer; however they don't scale very well in shared computing environments such as virtual ones.  IDS systems also don't typically track protocol and network service (FTP, HTTP, etc.) utilizations; which is another important part of visibility.

So, what do we do to gain visibility without the performance headache?  Well, for starters its probably best to put your IDS/IPS solutions in the physical environment where performance will be less of a concern.  In fact, you can span a virtual switch's traffic out to a physical NIC as easy as you can to a virtual one.  So why do it virtual and have to pay a 60% CPU utilization tax?  Another solution is to IDS inspect only the things you care about.  Why IDS inspect SSL traffic if you know your solution can't unencrypt SSL.  Its just a waste of compute cycles isnt it?  Policy based switching helps you with directing only the things you care about to an IDS (attack visualization product).  Montego's HyperSwitch also can help you with the traffic redirection of only the things you care about.

Another method of visibility which I tend to be a fan of is one of packet analysis (aka NetFlow).  NetFlow was invented by Cisco some time ago and has gained popularity in the physical world and definately has a use in the virtual world.  NetFlow is lightweight.  Let me say that again, its light weight!  It only sends a summation of packet detail to an analytical engine which can do some number crunching, packet comparison, etc. etc. to make some sense out of whats going on.  Lancope, an Atlanta based visibility company that provides Network Visibility, Security Visibility and User Visibility has this tool on their website that is a Netflow Bandwidth calculator.  You'll see from playing with this ( http://www.lancope.com/netflowcalculator.aspx ) calculator that it doesn't consume a lot of network bandwidth to transmit these network accounting records.  It also doesn't cause a lot of CPU overhead to send these records to an analytical engine sitting somewhere in the network.

Lancope's analytical engines have the ability to do the following for you within your virtual environment:

...and probably a slew of other things I'm not aware of.  A screen shot of their product is bellow:

<- Click to enlarge

You'll notice from the screenshot that you are able to visualize who is talking to who, how much traffic they have sent and received and something called a concern index (not seen on this screenshot).

Now, a concern index is a number that increases as Lancopes analytical engines monitor suspicious activity on a session.  A high counter can be indicative of a security problem.  Its another way of identifying (visualizing) compromised hosts (virtual machines) without having to do signature matching like a heavy weight IPS engine.  Example:  Lets say you have a VM that has a BOT on it and is "owned".  The Lancope product is monitoring this long life session.  Let's say that session is established for several hours or maybe even days or months.  Lets also say that the conversation appears to be mostly unidirectional from a public ip address not belonging to your enterprise.  Lancope would increase a the concern index on this since this server hasn't typically had this type of behavior.  Once the concern index reached a certain level it could then fire off an email, send you a text message or something saying:  Warning, Warning, Danger, Danger Will Robinson!!! You're virtual server may be infected with a BOT, please investigate immediately!!!

This example is VISIBILITY which helps you with SECURITY.  There are a number of other things you can do with NetFlow and Lancope products that have less to do with security and more to do with operational efficiencies.  Things like, helping you answer questions of:  How do I know what network applications are taking up the most bandwidth?  When should I move those applications over to a server with more horsepower?  When did these VM's vmotion over here and was there a traffic condition / CPU condition that caused that to occur?  I could go on and on but thats a topic for another blog entry.

So, my suggestion is to take a look at what NetFlow has to offer.  Montego Networks supports NetFlow transmission and Lancope supports NetFlow analytics and with both you can regain what was lost visibility.

I hope this was helpful to you all!

-John Peterson

We've probably all heard that you can't secure what you can't see and that statement is even more profound when it comes to virtual environments.  This is because it is extremely challenging to see what is going on at a micro vs. macro level within a virtual environments network.  The virtualization vendors such as VMWare and Citrix have provided embedded tools into their management consoles that show a macro level of visibility but its not enough to identify security events in the environment.  Take a look at the attached picture.  It simply shows VMWare's ability to monitor virtual network performance statistics from a bits per second perspective.

<-Click To Enlarge

With only this level of detail how can one determine which network applications are causing spikes.  Is it FTP traffic that is occuring at a high volume at an unuseal time of day?  If that were occuring, could that be indicative of either a breach or some sort of problem? What if FTP isn't even an authorized service in the virtual environment but there is a high volume of it?  Did someone install a rouge FTP service so they could steal information from the server at will?

These types of questions can't really be answered without a micro level of detail into the packets flowing in, out and within the virtual environment.  Now, what I am highlighting is not security in the traditional sense of prevention but using visibility as a means to first identify, then pin point the source of an issue so that it can properly be mitigated.  Having constant visibility can also ensure that other security products in the environment are performing as expected.  What if a Montego HyperSwitch with firewalling enabled is configured with many policies but someone forgot to create an FTP block policy.  One could think they are protected from rouge FTP services transmiting data out of the network, but without constant visibility monitoring, can you be certain?

Some vendors, namely Reflex Security will get you to believe that their IPS / IDS solution that is inline and running in the virtual environment is the right and only approach.  Or they will tell you to hang a virtual IDS off a span port in the virtual environment and you will at least have visibility into the attacks that are taking place.  Well, sure... You now have attack visibility but at the performance cost of your virtual environment.  Signature matching technologies are great, I'm a huge believer; however they don't scale very well in shared computing environments such as virtual ones.  IDS systems also don't typically track protocol and network service (FTP, HTTP, etc.) utilizations; which is another important part of visibility.

So, what do we do to gain visibility without the performance headache?  Well, for starters its probably best to put your IDS/IPS solutions in the physical environment where performance will be less of a concern.  In fact, you can span a virtual switch's traffic out to a physical NIC as easy as you can to a virtual one.  So why do it virtual and have to pay a 60% CPU utilization tax?  Another solution is to IDS inspect only the things you care about.  Why IDS inspect SSL traffic if you know your solution can't unencrypt SSL.  Its just a waste of compute cycles isnt it?  Policy based switching helps you with directing only the things you care about to an IDS (attack visualization product).  Montego's HyperSwitch also can help you with the traffic redirection of only the things you care about.

Another method of visibility which I tend to be a fan of is one of packet analysis (aka NetFlow).  NetFlow was invented by Cisco some time ago and has gained popularity in the physical world and definately has a use in the virtual world.  NetFlow is lightweight.  Let me say that again, its light weight!  It only sends a summation of packet detail to an analytical engine which can do some number crunching, packet comparison, etc. etc. to make some sense out of whats going on.  Lancope, an Atlanta based visibility company that provides Network Visibility, Security Visibility and User Visibility has this tool on their website that is a Netflow Bandwidth calculator.  You'll see from playing with this ( http://www.lancope.com/netflowcalculator.aspx ) calculator that it doesn't consume a lot of network bandwidth to transmit these network accounting records.  It also doesn't cause a lot of CPU overhead to send these records to an analytical engine sitting somewhere in the network.

Lancope's analytical engines have the ability to do the following for you within your virtual environment:

...and probably a slew of other things I'm not aware of.  A screen shot of their product is bellow:

<- Click to enlarge

You'll notice from the screenshot that you are able to visualize who is talking to who, how much traffic they have sent and received and something called a concern index (not seen on this screenshot).

Now, a concern index is a number that increases as Lancopes analytical engines monitor suspicious activity on a session.  A high counter can be indicative of a security problem.  Its another way of identifying (visualizing) compromised hosts (virtual machines) without having to do signature matching like a heavy weight IPS engine.  Example:  Lets say you have a VM that has a BOT on it and is "owned".  The Lancope product is monitoring this long life session.  Let's say that session is established for several hours or maybe even days or months.  Lets also say that the conversation appears to be mostly unidirectional from a public ip address not belonging to your enterprise.  Lancope would increase a the concern index on this since this server hasn't typically had this type of behavior.  Once the concern index reached a certain level it could then fire off an email, send you a text message or something saying:  Warning, Warning, Danger, Danger Will Robinson!!! You're virtual server may be infected with a BOT, please investigate immediately!!!

This example is VISIBILITY which helps you with SECURITY.  There are a number of other things you can do with NetFlow and Lancope products that have less to do with security and more to do with operational efficiencies.  Things like, helping you answer questions of:  How do I know what network applications are taking up the most bandwidth?  When should I move those applications over to a server with more horsepower?  When did these VM's vmotion over here and was there a traffic condition / CPU condition that caused that to occur?  I could go on and on but thats a topic for another blog entry.

So, my suggestion is to take a look at what NetFlow has to offer.  Montego Networks supports NetFlow transmission and Lancope supports NetFlow analytics and with both you can regain what was lost visibility.

I hope this was helpful to you all!

-John Peterson

My goal is to fix the width of each column at design time, and any field that contains text that may be longer than my fixed width should wrap around, taking up more vertical space in the table. If you are trying to accomplish this goal, you might find these tips helpful.

1) Set up a CssClass for the GridView itself and include the table-layout:fixed style. This tells the browser that you're going to specify the width of each cell. You may also want to include the overall width of the grid here as I mention in (3).

2) The first row of the table sets the width for each cell, and that's usually the HEADER row, not the item row, so use either HeaderStyle-CssClass or HeaderStyle-Width to set the width of the cell. I wasted a lot of time trying to set the width using the ItemStyle.

3) Make certain the table itself is wide enough to hold all of the cells. I added up all of my cell widths and used that to set the width via the CssClass attribute on the GridView.

Using these guidelines, I'm having much better luck controlling the layout of my GridView controls. I hope this simple advise helps someone else!