Unidev Tech Blog

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Most users of popular libraries like jQuery tend to use a few jQuery plugins also. One project I’ve worked on has 10 jQuery plugins, plus a few scripts that are common across all pages on the site. Each script has to be downloaded, parsed, and executed before your page loads in full. So, a proliferation of Javascript includes on your pages can dramatically slow down load time, but this doesn’t have to be the case.

Another issue that often occurs when working with Javascript and CSS is some browsers are overzealous with their caching, which can result in telling someone to refresh a page to see if it’s working, and while it might work for you, their browser decided to cache the old script, making your changes not appear.

In this post, I will outline a few techniques to help alleviate a few of these problems.

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A common operation in many systems is bulk loading of data into a database, be it from another system, a flat file, or generated output, which may or may not involve updating existing records. A lesser known class in .Net, SqlBulkCopy, and a new feature in SQL Server 2008, MERGE can greatly increase the speed of these operations.

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With the several high profile security breaches so far this year, security is on the forefront of most developers minds, or it should be. Though, if one has never coded good authentication code before, it can be a rather daunting task. The Internet is rife with poor advice, old advice, or just plain wrong advice. This post will attempt to help demystify some of tools and techniques of building authentication systems.

Most authentication services have different requirements. For example, you would expect there to be more security logging into your bank than into your blogging software. At a point, you have to establish what is good enough for the data your authentication you’re protecting. Users are more likely to not use your system for every additional hoop they have to jump thorough, but if they view the data as worth it, they might be willing to be further inconvenienced (For example, two-factor authentication with a key fob for logging into a bank)

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Problem:

When trying to start the debugger in SQL Server Management Studio, I received the error: Unable to start T-SQL Debugging.  Could not attach to SQL Server process on ‘%dbservername%’.  Click Help for more information.

Solution:

Configure the database engine service with a Domain user account, or more specifically, an account that can be authenticated from the machine that is running Management Studio.  I noticed in a Wireshark trace on my pc that a NTLM call was being made with the account of the database engine service.

I had a spreadsheet with tens of thousands of mailing addresses. One of the columns was  the ZIP code for each address row.  Some of those ZIP codes were in the ZIP + 4 format (12345-6789) and others were not.  Those others were 3, 4 or 5 digit numbers.  When the data was put into the spreadsheet, Excel removed the leading zeroes from some ZIP codes (like “00345” truncated to “345”).

I used the Import functionality in SQL Server Management Studio 2005 to put the data from the Excel spreadsheet into a table.  Without modifying the spreadsheet data the import would place a NULL into each row that had a 3,4 or 5 digit ZIP code, while keeping the ZIP + 4 codes correctly.

To get both “5-Digit” and “Zip Plus Four” ZIP codes into the same database column I needed to make Excel see them as text. To do this I made a new column next to my ZIP Codes with this style of formula:                =TEXT(B2,”00000″)

This causes the data to have at least 5 digits and leading zeroes if less than five  digits. Next I copied this new column and then used “Paste Special” with the “Values” option to replace my original ZIP code column. Saving the spreadsheet and executing a SQL Server import of the XLS file, all ZIP codes were then correct.

I also found that using the “Format Cells” functionality with the Special “Zip Code” setting only changes how the data appears. It does not change the underlying data. For example “345” shows as “00345” but if you look at the actual data, it remains unchanged. So just doing Excel formating did not work when importing in to a SQL Server database.

By George Zheng

When we deploy one of our web sites to a 64 bit web server, we get following error: “Could not load file or assembly ‘apachefop.net’ or one of its dependencies. An attempt was made to load a program with an incorrect format.”

This web site is using fop.net to generate the PDF for printing. After investigation, we realize the fop.net can’t run on IIS with 64-bit version of ASP.NET.

IIS 6.0 on a 64-bit hardware supports both the 32-bit version of ASP.NET and the 64-bit version of ASP.NET. However IIS 6.0 does not support running both modes at the same time on a 64-bit version of Windows.  Here are the steps to run the 32-bit version of ASP.NET 2.0 on IIS:

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command to enable the 32-bit mode:
   cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 1
3. Type the following command to install the version of ASP.NET 2.0 (32-bit) and to install the script maps at the IIS root and under:
   %SYSTEMROOT%\Microsoft.NET\Framework\v2.0.50727\aspnet_regiis.exe -i
4. Make sure that the status of ASP.NET version 2.0.50727 (32-bit) is set to Allowed in the Web service extension list in Internet Information Services Manager.

Useful Links

How to switch between the 32-bit versions of ASP.NET 1.1 and the 64-bit version of ASP.NET 2.0 on a 64-bit version of Windows

The past few weeks have been challenging in an interesting and fun way. We are on track to release version 2.6 of our Content Management System and finally decided it was time to overhaul our security framework. We are moving from a simple role based architecture to a framework that supports the following:

• Roles
• Permissions
• Ability to assign Permissions to Roles
• Ability to assign Supplemental Permissions to Users external of Roles
• Ability to assign Roles to Users
• Ability to grant/deny access down to the control level
• Reverse capability of locking individual elements down by assigning Roles/Permissions to user created elements

In working on this there have been LOTS of questions as you can imagine. Here are a few resources I found useful and/or interesting while working on this implementation.

• I am a regular reader of the .NET Security Blog and found the CAS and CLR discussions pertaining to .NET 4 interesting.
• I found a nice way to get a flattened hierarchy of controls on a page over at the Vault of Thoughts. We implemented something similar but with a few additions.
• Here is a good read on general role based security.

Derek Bemis