Azure Identity Authentication and Configuration Guide

Azure Identity provides a comprehensive authentication and authorization solution for cloud applications. It allows you to manage access to your Azure resources securely.

To get started with Azure Identity, you'll need to create an Azure AD tenant. This can be done through the Azure portal. You can also use the Azure CLI or PowerShell to create a tenant.

Azure Identity supports multiple authentication protocols, including OAuth 2.0 and OpenID Connect. These protocols enable secure authentication and authorization for your cloud applications.

You can configure Azure Identity using the Azure portal, Azure CLI, or PowerShell. The Azure portal provides a user-friendly interface for managing Azure Identity settings.

You can authenticate with Azure Identity using multiple methods.

One method is to use the DefaultAzureCredential, which is demonstrated in the Azure Security Key Vault Secrets client library example.

To use the DefaultAzureCredential in a development machine, you need to configure environment settings by setting the variables AZURE_CLIENT_ID, AZURE_TENANT_ID, and AZURE_CLIENT_SECRET to the appropriate values for your service principal.

Another method is to use the ClientSecretCredential, which is used to authenticate a service principal with a client secret, as shown in the Azure Storage Blobs client library example.

You can also use the CertificateCredential to authenticate a service principal with a certificate, as demonstrated in the Azure Security Key Vault Keys client library example.

Alternatively, you can use the InteractiveBrowserCredential to authenticate a user by launching the system's default browser, as shown in the Azure Storage Blobs client library example.

Note that if a default browser is not available in the system, or the current application does not have permissions to create a process, authentication will fail with an AuthenticationFailedException.

To configure your Azure Identity setup, you'll need to understand the different credential types and how to set them up. Credentials default to authenticating to the Microsoft Entra endpoint for Azure Public Cloud.

You can configure credentials to authenticate to other clouds, such as Azure Government or a private cloud, by using the authority argument. AzureAuthorityHosts defines authorities for well-known clouds.

If the authority for your cloud isn't listed in AzureAuthorityHosts, you can explicitly specify its URL. Alternatively, you can set the AZURE_AUTHORITY_HOST environment variable to the URL of your cloud's authority.

To install the Azure Identity client library for .NET, you'll need to install the package using NuGet. The DefaultAzureCredential is a good starting point for most scenarios, as it determines the appropriate credential type based on the environment it's executing in.

Here are some environment variables that you can use to configure DefaultAzureCredential and EnvironmentCredential:

To install the Azure Identity client library for .NET, you'll need to use NuGet.

Install the package using NuGet to get started.

The Azure Identity client library for .NET is available for installation with NuGet, which is a package manager for .NET projects.

This library can be installed using NuGet, making it easy to get started with Azure Identity in your .NET projects.

To authenticate using the Azure CLI, run the command az login. This will sign you in to the Azure CLI, allowing you to use your account to authenticate calls in your app.

The Azure CLI will launch your default web browser to authenticate you, unless you're on a system without a default browser, in which case it will use the device code authentication flow.

You can also force the Azure CLI to use the device code flow by specifying the --use-device-code argument with the az login command.

Alternatively, you can use the Azure Developer CLI to authenticate, by running the command azd auth login. This will also launch your default web browser to authenticate you, unless you're on a system without a default browser, in which case it will use the device code authentication flow.

You can force the Azure Developer CLI to use the device code flow by specifying the --use-device-code argument with the azd auth login command.

Cloud configuration is crucial for accessing resources in different clouds, such as Azure Government or a private cloud. Credentials default to authenticating to the Microsoft Entra endpoint for Azure Public Cloud.

To access resources in other clouds, you can configure credentials with the authority argument. AzureAuthorityHosts defines authorities for well-known clouds, including Azure Public Cloud, Azure Government, and Azure China Cloud.

If the authority for your cloud isn't listed in AzureAuthorityHosts, you can explicitly specify its URL. For example, to access Azure Government, you can use the authority URL https://login.microsoftonline.us/.

Alternatively, you can set the AZURE_AUTHORITY_HOST environment variable to the URL of your cloud's authority. This approach is useful when configuring multiple credentials to authenticate to the same cloud.

Here's a list of well-known clouds and their corresponding authority URLs:

Not all credentials require this configuration. Credentials that authenticate through a developer tool, such as AzureCliCredential, use that tool's configuration.

As of version 1.14.0, DefaultAzureCredential attempts to authenticate with all developer credentials until one succeeds, regardless of any errors previous developer credentials experienced.

This means that if a developer credential fails to get a token, DefaultAzureCredential will continue to the next credential in the flow.

Deployed service credentials, on the other hand, stop the flow with a thrown exception if they're able to attempt token retrieval but don't receive one.

Prior to version 1.14.0, developer credentials would similarly stop the authentication flow if token retrieval failed, but this is no longer the case.

This change allows for trying all of the developer credentials on your machine while having predictable deployed behavior.

To authenticate with a certificate, you'll need to provide the path to a PEM or PKCS12 certificate file including a private key. This file is required.

The certificate file can be a PFX or PEM-encoded file, and it must include the private key. If the file is PFX-encoded, you'll also need to provide the password protecting the certificate file.

There are a few variables to consider when setting up certificate authentication:

Here are the required variables for certificate authentication:

If you're using a PFX-encoded certificate file, you'll also need to provide the password.

During local development, it's common for developers to use their own accounts to authenticate calls to Azure services. This is where the Azure Identity library comes in, supporting authentication through developer tools to simplify local development.

The library provides several credential implementations that are thread-safe, allowing a single credential instance to be used by multiple service clients. This makes it easy to switch between different development environments.

Here's a list of some of the credential implementations provided by the Azure Identity library:

You can also use Azure Developer CLI, Azure PowerShell, or Visual Studio Code to authenticate in a development environment.

During local development, developers often use their own accounts to authenticate calls to Azure services. This can be a hassle, but the Azure Identity library is here to help.

The library supports authenticating through developer tools, making local development a breeze. You can use the Azure CLI, Azure Developer CLI, Azure PowerShell, or even Visual Studio Code to authenticate.

Here are some credential options you can use:

Note that you can also use environment variables like AZURE_CLIENT_ID, AZURE_USERNAME, and AZURE_PASSWORD to authenticate. For example, you can use the AZURE_CLIENT_ID variable to store the ID of a Microsoft Entra application.

Async development is a game-changer for Azure users.

Async credentials are available in the azure.identity library, which includes a set of async APIs. To use them, you must first install an async transport, such as aiohttp.

You can authenticate with async credentials using libraries like azure-keyvault-secrets. For example, you can use the asynchronous SecretClient to authenticate with an asynchronous credential.

Async credentials should be closed when they're no longer needed. Each async credential is an async context manager and defines an async close method.

Here are some examples of libraries that support authenticating with TokenCredential and the Azure Identity library:

Thread safety is crucial in development, especially when dealing with credential instances.

All credential instance methods are thread-safe, ensuring that recommendations to reuse credential instances are always safe, even across threads.

This thread safety guarantee is a result of careful design and implementation.

It allows developers to focus on other aspects of their code without worrying about thread-related issues.

Credential instance methods are independent of each other, making them safe to use in multithreaded environments.

This independence ensures that one method's execution won't interfere with another's, preventing potential bugs and errors.

As a result, developers can safely reuse credential instances across threads, streamlining their code and improving overall efficiency.

This thread safety feature is a significant advantage in development, allowing for more complex and scalable applications.

Error handling is crucial when working with Azure Identity. Credentials raise CredentialUnavailableError when they're unable to attempt authentication because they lack required data or state.

This can happen when the configuration of EnvironmentCredential is incomplete. Credentials also raise azure.core.exceptions.ClientAuthenticationError when they fail to authenticate, which has a message attribute describing why authentication failed.

The message attribute collects error messages from each credential in the chain when raised by DefaultAzureCredential or ChainedTokenCredential. To handle specific Microsoft Entra ID errors, refer to the Microsoft Entra ID error code documentation.

To distinguish failures from failures in the service client, Azure Identity classes raise the AuthenticationFailedException with details on the error source in the exception message and possibly the error message.

Troubleshooting is an essential part of error handling.

To troubleshoot authentication errors, look for the AuthenticationFailedException, which is raised by Azure Identity classes. This exception provides details on the error source in the exception message and possibly the error message.

When an AuthenticationFailedException is raised, it's often due to a failed token request from the credential. This can happen on the first call to the service or when the token needs to be refreshed.

To distinguish between failures in the service client and authentication errors, check the exception message for details on the error source.

For more details on dealing with specific errors, refer to the Microsoft Entra ID error code documentation or the Azure Active Directory documentation on authorization error codes.

Here are some common error sources to look out for:

The "Fixed" section of our article highlights some notable improvements in error handling and troubleshooting.

AzureCliCredential has been improved to raise a CredentialUnavailableError when the CLI times out, and it can now kill timed out subprocesses.

This is a significant enhancement that can help prevent errors and make troubleshooting easier.

Reduced retry delay for ManagedIdentityCredential on Azure VMs is another important fix.

This change can help improve performance and reduce the likelihood of errors in these environments.

InteractiveBrowserCredential now functions in more WSL environments, thanks to the fix in issue #17615.

This is a welcome improvement for users who rely on WSL for their development work.

Azure Identity has a rich history, with the first release of Azure Active Directory (Azure AD) dating back to 2011. It was initially designed to provide identity and access management capabilities for Azure services.

In 2014, Azure AD was rebranded to Azure Active Directory. This change marked a significant milestone in its evolution, enabling it to support more features and services.

Azure AD B2C was introduced in 2015, allowing developers to create consumer-focused identity experiences. This feature was a major addition to Azure Identity, enabling businesses to provide seamless authentication for their customers.

The Azure AD B2C feature was further enhanced in 2017, with the introduction of custom policies. This update allowed developers to create custom authentication flows, giving them more control over the identity experience.

In 2019, Azure Identity introduced the concept of conditional access, which enables organizations to enforce security policies based on user identity and behavior. This feature has been a game-changer for many businesses, helping them to stay secure in a rapidly changing threat landscape.

Since then, Azure Identity has continued to evolve, with regular updates and new features being added.