Secret management refers to the tools and practices used to manage digital authentication credentials (like API keys, tokens, passwords, and certificates). These secrets are used to protect access to sensitive data and services, making their management critical for security.
We should assume any repo we work on may go public at any time and protect our secrets, even if the repo is initially private.
In modern software development, applications often need to interact with other software components, APIs, and services. These interactions often require authentication, which is typically handled using secrets. If these secrets are not managed properly, they can be exposed, leading to potential security breaches.
- Centralized Secret Storage: Store all secrets in a centralized, encrypted location. This reduces the risk of secrets being lost or exposed.
- Access Control: Implement strict access control policies. Only authorized entities should have access to secrets.
- Rotation of Secrets: Regularly change secrets to reduce the risk if a secret is compromised.
- Audit Trails: Keep a record of when and who accessed which secret. This can help in identifying suspicious activities.
- Automated Secret Management: Automate the processes of secret creation, rotation, and deletion. This reduces the risk of human error.
Remember, the goal of secret management is to protect sensitive information from unauthorized access and potential security threats.
The general approach is to keep secrets in separate configuration files that are not checked in to the repo. Add the files to the .gitignore to prevent that they're checked in.
Each developer maintains their own local version of the file or, if required, circulate them via private channels e.g. a Teams chat.
In a production system, assuming Azure, create the secrets in the environment of the running process. We can do this by manually editing the 'Applications Settings' section of the resource, but a script using the Azure CLI to do the same is a useful time-saving utility. See az webapp config appsettings for more details.
It's best practice to maintain separate secrets configurations for each environment that you run. e.g. dev, test, prod, local etc
The secrets-per-branch recipe describes a simple way to manage separate secrets configurations for each environment.
Note: even if the secret was only pushed to a feature branch and never merged, it's still a part of the git history. Follow these instructions to remove any sensitive data and/or regenerate any keys and other sensitive information added to the repo. If a key or secret made it into the code base, rotate the key/secret so that it's no longer active
The care taken to protect our secrets applies both to how we get and store them, but also to how we use them.
- Don't log secrets
- Don't put them in reporting
- Don't send them to other applications, as part of URLs, forms, or in any other way other than to make a request to the service that requires that secret
The techniques outlined below provide good security and a common pattern for a wide range of languages. They rely on the fact that Azure keeps application settings (the environment) encrypted until your app runs.
They do not prevent secrets from existing in plaintext in memory at runtime. In particular, for garbage collected languages those values may exist for longer than the lifetime of the variable, and may be visible when debugging a memory dump of the process.
If you are working on an application with enhanced security requirements you should consider using additional techniques to maintain encryption on secrets throughout the application lifetime.
Always rotate encryption keys on a regular basis.
These techniques make the loading of secrets transparent to the developer.
For .NET SDK (version 2.0 or higher) we have dotnet secrets
, a tool provided by the .NET SDK that allows you to manage and protect sensitive information, such as API keys, connection strings, and other secrets, during development. The secrets are stored securely on your machine and can be accessed by your .NET applications.
# Initialize dotnet secret
dotnet user-secrets init
# Adding secret
# dotnet user-secrets set <KEY> <VALUE>
dotnet user-secrets set ExternalServiceApiKey my-api-key-12345
# Update Secret
dotnet user-secrets set ExternalServiceApiKey updated-api-key-67890
To access the secrets;
using Microsoft.Extensions.Configuration;
var builder = new ConfigurationBuilder()
.AddUserSecrets<Startup>();
var configuration = builder.Build();
var externalServiceApiKey = configuration["ExternalServiceApiKey"];
When deploying your application to production, it's essential to ensure that your secrets are securely managed. Here are some deployment-related implications:
-
Remove Development Secrets: Before deploying to production, remove any development secrets from your application configuration. You can use environment variables or a more secure secret management solution like Azure Key Vault or AWS Secrets Manager in production.
-
Secure Deployment: Ensure that your production server is secure, and access to secrets is controlled. Never store secrets directly in source code or configuration files.
-
Key Rotation: Consider implementing a secret rotation policy to regularly update your secrets in production.
Use the file
attribute of the appSettings element to load secrets from a local file.
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings file="..\..\secrets.config">
…
</appSettings>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
</startup>
…
</configuration>
Access secrets:
static void Main(string[] args)
{
String mySecret = System.Configuration.ConfigurationManager.AppSettings["mySecret"];
}
When running in Azure, ConfigurationManager will load these settings from the process environment. We don't need to upload secrets files to the server or change any code.
Store secrets in environment variables or in a .env
file
$ cat .env
MY_SECRET=mySecret
Use the dotenv package to load and access environment variables
require('dotenv').config()
let mySecret = process.env("MY_SECRET")
Store secrets in environment variables or in a .env
file
$ cat .env
MY_SECRET=mySecret
Use the dotenv package to load and access environment variables
import os
from dotenv import load_dotenv
load_dotenv()
my_secret = os.getenv('MY_SECRET')
Another good library for reading environment variables is environs
from environs import Env
env = Env()
env.read_env()
my_secret = os.environ["MY_SECRET"]
Databricks has the option of using dbutils as a secure way to retrieve credentials and not reveal them within the notebooks running on Databricks
The following steps lay out a clear pathway to creating new secrets and then utilizing them within a notebook on Databricks:
- Install and configure the Databricks CLI on your local machine
- Get the Databricks personal access token
- Create a scope for the secrets
- Create secrets
Automated credential scanning can be performed on the code regardless of the programming language.