Welcome to this post, where we will delve into the various methods for authenticating applications to Google Cloud without the need to download service account keys. As security and best practices continue to evolve, it’s important to stay up-to-date on the latest options for authenticating your applications. In this post, we will explore the top five ways to accomplish this goal, providing a comprehensive understanding of the available options and their pros and cons. Whether you’re a beginner or an experienced developer, this post is designed to provide valuable insights that can help you make informed decisions about the best way to authenticate your applications to Google Cloud. So, let’s get started!
Introduction to Service Accounts and Service Account Keys
- In this section, we will introduce the concept of service accounts and service account keys. Service accounts are a way for applications to authenticate with Google Cloud APIs. They allow the application to identify itself and authorize API calls.
- Google Cloud APIs require every API call to be authorized. This means that the APIs require calls to identify who is making the call. This information is used for audit logs, quota, and billing.
- There are three ways to authorize API calls: API keys, user accounts, and service accounts. API keys are a string of letters and numbers that only identify the application. User accounts are for human users accessing resources. Service accounts represent an application or compute workload rather than a human user.
- Service accounts use a public-private RSA key pair for authentication, and there are no passwords. This means that you cannot log in as a service account via the browser.
- There are two types of service accounts: those created for your own applications, and default service accounts created when using certain services. For example, when you create a compute instance in a brand new project, the compute engine default service account is created and attached to the instance.
- We recommend creating custom service accounts tailored for the workload rather than relying on default service accounts for production workloads. For example, if you have an application that needs to read and write to Google Cloud Storage, you would create a custom service account with the necessary permissions for that task.
- When using a service account, you have the option to download a service account JSON file. This is the private key for the service account, however, we don’t recommend downloading key files if you can avoid it. This is because there are some risks associated with using service account keys, such as credential leakage, privilege escalation, and identity masking.
Example:
Consider an example of an application that needs to read and write data to a Google Cloud Storage bucket. To do this, the application needs to be authenticated with the Google Cloud Storage API. To accomplish this, you would create a custom service account with the necessary permissions for reading and writing to the bucket. Once the service account is created, the application can use the service account credentials to authenticate with the Google Cloud Storage API and read and write data to the bucket.
The Right Way to Authenticate Applications
- In this section, we will discuss the right way to authenticate applications. There are many ways to authenticate applications, but not all of them are secure or appropriate for different situations.
- We will focus on programmatically authenticating application code, which is the most common way for applications to authenticate with Google Cloud APIs.
- We will provide an overview of the available options for programmatically authenticating application code, such as using a service account, OAuth 2.0, or JSON Web Token (JWT). We will explain the pros and cons of each option and provide guidance on when to use them.
- It’s important to note that when we talk about APIs in this post, we are referring to Google Cloud API specifically. Authenticating to other Google APIs such as Google Maps Platform API or YouTube API may work differently.
Example:
Let’s consider an example of an application that needs to read data from a Google Cloud Storage bucket. To authenticate the application, you can choose between several options such as using a service account, OAuth 2.0, or JSON Web Token (JWT).
- Using a service account: This is the most straightforward option, but it requires the application to have access to the service account key. This can be risky if the key is not properly secured.
- OAuth 2.0: This option allows the application to authenticate using an access token. The user needs to grant permission for the application to access the data.
- JSON Web Token (JWT): This option requires the application to authenticate with a JSON Web Token (JWT) that is signed by a private key. This is a more secure option, but it requires additional setup.
In this example, it is recommended to use OAuth 2.0 as it is more secure and user-friendly, but it depends on the use-case.
Best Practices for Managing Service Account Keys
- In this section, we will discuss best practices for managing service account keys. Service account keys are private keys that are used to authenticate applications with Google Cloud APIs. These keys are sensitive and should be protected.
- We will highlight some of the risks associated with using service account keys, such as credential leakage, privilege escalation, and identity masking. Credential leakage can occur if a developer accidentally commits a key to a public code repository. Privilege escalation can occur if a bad actor gets access to a service account key and uses it to gain additional privileges. Identity masking can occur if a bad actor acts through a service account key, concealing their identity and actions.
- The main takeaway is that anyone with the service account JSON file can make API calls as that service account, so it is important to manage the keys properly.
Example:
Let’s consider an example of an application that needs to read and write data to a Google Cloud Storage bucket. To authenticate the application, you create a service account with the necessary permissions for reading and writing to the bucket. The private key of the service account is stored in a service account JSON file.
- To avoid credential leakage, you should store the key file in a secure location and make sure it is not committed to a public code repository.
- To avoid privilege escalation, you should limit the permissions of the service account to the minimum necessary for the application to function.
- To avoid identity masking, you should monitor the activity of the service account and investigate any suspicious activity.
It is important to understand that managing service account keys involves many security aspects and it’s important to follow best practices to ensure the safety of your data and resources.
Conclusion:
- We hope this post has provided a helpful overview of the top five ways to authenticate applications to Google Cloud without downloading service account keys. We’ve covered the basics of service accounts, the right way to authenticate applications, and best practices for managing service account keys.
- Our documentation goes into much more detail on what to consider and how to use specific authentication methods. It’s important to refer to the documentation when implementing the methods discussed in this post.
- If you have any further questions or need more information, please reach out to us. We’re here to help and support you in your journey to authenticate your applications to Google Cloud. Remember that security is a continuous process and you should always stay updated with the latest best practices.
Reference:
https://cloud.google.com/docs/authentication/provide-credentials-adc
