Skip to main content

Can you keep a secret?

A lot of applications store sensitive security related data inside their configuration. Things like API keys, database connection information, even passwords are directly accesible inside the app.config or web.config of a .NET application. Last week a colleague mentioned that they uploaded a project to GitHub accidently exposing the root AWS password for their Amazon account. Whooops!

With ASP.NET Core, Microsoft tries to solve this kind of problems with the introduction of the SecretManager command-line tool. This tool allows you to store these sensitive values in a secure way without exposing them through source control.

If you want to enable it, add the following entry to the “tools” section of project.json:

"Microsoft.Extensions.SecretManager.Tools": {
  "version": "1.0.0-preview1-final",
  "imports": "portable-net45+win8+dnxcore50"
}

You also need a unique identifier that links your project to the secret manager. Therefore add a userSecretsId for your project in its project.json file:

image
Now we can use the Secret Manager tool from a command window to set a secret:
dotnet user-secrets set MySecretKey MySecretValue
image

You can then reference the secret values stored by the secret manager by adding a reference to the Microsoft.Extensions.Configuration.UserSecrets package. Now we can add the “AddUserSecrets()” method to our Startup.cs file:

image

Probably you only want to do this during development, so wrap it inside an if block:

image

This will overwrite any configuration options loaded from a configuration file with the contents of the secret store. 

Remark: The secret store actually isn’t too secret, its just a set of JSON files hidden in your user profile folder.  It only prevents you from checking in these values into source control.

Popular posts from this blog

DevToys–A swiss army knife for developers

As a developer there are a lot of small tasks you need to do as part of your coding, debugging and testing activities.  DevToys is an offline windows app that tries to help you with these tasks. Instead of using different websites you get a fully offline experience offering help for a large list of tasks. Many tools are available. Here is the current list: Converters JSON <> YAML Timestamp Number Base Cron Parser Encoders / Decoders HTML URL Base64 Text & Image GZip JWT Decoder Formatters JSON SQL XML Generators Hash (MD5, SHA1, SHA256, SHA512) UUID 1 and 4 Lorem Ipsum Checksum Text Escape / Unescape Inspector & Case Converter Regex Tester Text Comparer XML Validator Markdown Preview Graphic Color B

Help! I accidently enabled HSTS–on localhost

I ran into an issue after accidently enabling HSTS for a website on localhost. This was not an issue for the original website that was running in IIS and had a certificate configured. But when I tried to run an Angular app a little bit later on http://localhost:4200 the browser redirected me immediately to https://localhost . Whoops! That was not what I wanted in this case. To fix it, you need to go the network settings of your browser, there are available at: chrome://net-internals/#hsts edge://net-internals/#hsts brave://net-internals/#hsts Enter ‘localhost’ in the domain textbox under the Delete domain security policies section and hit Delete . That should do the trick…

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.