SQL Encrypt and decryption library in VB.Net

SQL Encrypt and decryption library (CodeProject)
This library allows a user to use functions in SQL server to encrypt and decrypt text.
Download source files - 55 Kb

Installation Instructions:

1) build the library
To use this COM Object with your SQL server 2000 or 2005 compile this project with Visual Studio 2005, and the dll will be in the bin\release folder.

2) Create a strong named assembly
This project already has a strong named key but you may swap it out with your own. Buy building the project it is already strong named. You may remove this but you will be responsible for putting it where it belongs so the COM client can find it.

3) move the file so SQL can see the COM Object
Take the EncryptDecrypt.dll and copy that to your SQL servers binn folder. This is usually in the C:\Program Files\Microsoft SQL Server\MSSQL\Binn folder.

4) Generate a type library
Once you have copied the file you will need to register the component to make it visable to a COM client. You do this using the Regasm utility

Regasm /tlb:EncryptDecrypt binn\EncryptDecrypt.dll

5) Register the assembly in the GAC
In order for any COM clinet to see the .NET assembly, we need to register the assembly in the Global Assembly Cache, use the GACUTIl utility to register the assembly with the GAC

GACUTIL /i binn\EncryptDecrypt.dll

6) Install the functions to SQL
Open the EncryptDecryptFunctions.sql in your Query Analyzer select the database you wish to install the functions into, and execute the SQL script. This script will create 4 functions EncryptTextNoPWD, EncryptTextWPWD, DecryptTextNoPwd, and DecryptTextWPWD

The following are examples on how to use the functions in your SQL

--Encrypt text using the internal password
select dbo.EncryptStringnoPWD('test')
--Decrypt the encrypted text using the internal password
Select dbo.DecryptStringNoPWD('NzevW30d2I9egnLSz+PDvw==')

--Encrypt text using a user supplied password of ‘froggy’
select dbo.EncryptStringwPWD('test','froggy')
--Decrypt encrypted using a user supplied password of ‘froggy’
Select dbo.DecryptStringWPWD('eKO76BsvLSJMWK7kF6Mfpw==','froggy')