Rajeev Pentyala – Microsoft Power Platform

In one of my web application we are reading credentials from Web.config file’s Connection Strings section.

And we are encrypting the Connection Strings using aspnet_regiis.exe tool during deployments.

Below are the steps to Encrypt/Decryption of Config file using aspnet_regiis.exe tool

Encryption Command

• Open Visual Studio Command Prompt and run below commands.

   Encrypt Connection Strings  > aspnet_regiis.exe -pef “connectionStrings” “<Path of folder containing web.config file>”

Encrypt App Settings  > aspnet_regiis.exe -pef “appSettings” “<Path of folder containing web.config file>”

• Ex: If my web.config exists at wwwroot folder, below is the command to encrypt ‘connectionStrings’ section

     aspnet_regiis.exe -pef “connectionStrings” ” C:\inetpub\wwwroot\MyPublishedSite”

WebConfig – Path

Encryption – config file

Decryption Command

   Decrypt Connection Strings > aspnet_regiis.exe -pdf “connectionStrings” “<Path of folder containing web.config file>”

Decrypt App Settings > aspnet_regiis.exe -pdf “appSettings” “<Path of folder containing web.config file>”

How to read the encrypted values in your code?

• No need of any special statements in your code to the read the encrypted values.
• Your “ConfigurationManager” will take care (i.e., ConfigurationManager.AppSettings[“mypassword”] will return the actual value even if its encrypted)

Key points about Encryption/Decryption

• Encryption/Decryption is always specific to a machine.
• So you cannot decrypt a file on Machine 2 which has been encrypted on Machine 1 and ‘aspnet_regiis’ tool throws “Bad Data” error, if you attempt.

Bad Data – Decrypting config file

Reason and Fix for the “Bad Data” error:

• As mentioned earlier, Encryption/Decryption is always specific to a machine.
• In my case, I tried to Decrypt a file which was encrypted in my Test server, from my Local machine which resulted a “Bad Data” error.
• To fix the issue, I connected to “Test server” where the config file was originally encrypted, and decryption done successfully.

🙂