Secure access keys - AWS Identity and Access Management
Auditing access keys

Secure access keys

Anyone who has your access keys has the same level of access to your AWS resources that you do. Consequently, AWS goes to significant lengths to protect your access keys, and, in keeping with our shared-responsibility model, you should as well.

Expand the following sections for guidance to help you protect your access keys.

Note

Your organization may have different security requirements and policies than those described in this topic. The suggestions provided here are intended as general guidelines.

One of the best ways to protect your account is to not have access keys for your AWS account root user. Unless you must have root user access keys (which is rare), it is best not to generate them. Instead, create an administrative user in AWS IAM Identity Center for daily administrative tasks.For information about how to create an administrative user in IAM Identity Center, see Getting started in the IAM Identity Center User Guide.

If you already have root user access keys for your account, we recommend the following: Find places in your applications where you are currently using access keys (if any), and replace the root user access keys with IAM user access keys. Then disable and remove the root user access keys. For more information about how to update access keys, see Update access keys

In many scenarios, you don't need long-term access keys that never expire (as you have with an IAM user). Instead, you can create IAM roles and generate temporary security credentials. Temporary security credentials consist of an access key ID and a secret access key, but they also include a security token that indicates when the credentials expire.

Long-term access keys, such as those associated with IAM users and the root user, remain valid until you manually revoke them. However, temporary security credentials obtained through IAM roles and other features of the AWS Security Token Service expire after a short period of time. Use temporary security credentials to help reduce your risk in case credentials are accidentally exposed.

Use an IAM role and temporary security credentials in these scenarios:

  • You have an application or AWS CLI scripts running on an Amazon EC2 instance. Don't use access keys directly in your application. Don't pass access keys to the application, embed them in the application, or let the application read access keys from any source. Instead, define an IAM role that has appropriate permissions for your application and launch the Amazon Elastic Compute Cloud (Amazon EC2) instance with roles for EC2. Doing this associates an IAM role with the Amazon EC2 instance. This practice also enables the application to get temporary security credentials that it can in turn use to make programmatic calls to AWS. The AWS SDKs and the AWS Command Line Interface (AWS CLI) can get temporary credentials from the role automatically.

  • You need to grant cross-account access. Use an IAM role to establish trust between accounts, and then grant users in one account limited permissions to access the trusted account. For more information, see IAM tutorial: Delegate access across AWS accounts using IAM roles.

  • You have a mobile app. Don't embed access keys with the app, even in encrypted storage. Instead, use Amazon Cognito to manage user identities in your app. This service lets you authenticate users using Login with Amazon, Facebook, Google, or any OpenID Connect (OIDC)–compatible identity provider. You can then use the Amazon Cognito credentials provider to manage credentials that your app uses to make requests to AWS.

  • You want to federate into AWS and your organization supports SAML 2.0. If you work for an organization that has an identity provider that supports SAML 2.0, configure the provider to use SAML. You can use SAML to exchange authentication information with AWS and get back a set of temporary security credentials. For more information, see SAML 2.0 federation.

  • You want to federate into AWS and your organization has an on-premises identity store. If users can authenticate inside your organization, you can write an application that can issue them temporary security credentials for access to AWS resources. For more information, see Enable custom identity broker access to the AWS console.

Note

Are you using an Amazon EC2 instance with an application that requires programmatic access to AWS resources? If so, use IAM roles for EC2.

If you must create access keys for programmatic access to AWS, create them for IAM users, granting the users only the permissions they require.

Observe these precautions to help protect IAM user access keys:

  • Don't embed access keys directly into code. The AWS SDKs and the AWS Command Line Tools enable you to put access keys in known locations so that you don't have to keep them in code.

    Put access keys in one of the following locations:

    • The AWS credentials file. The AWS SDKs and AWS CLI automatically use the credentials that you store in the AWS credentials file.

      For information about using the AWS credentials file, see the documentation for your SDK. Examples include Set AWS Credentials and Region in the AWS SDK for Java Developer Guide and Configuration and credential files in the AWS Command Line Interface User Guide.

      To store credentials for the AWS SDK for .NET and the AWS Tools for Windows PowerShell, we recommend that you use the SDK Store. For more information, see Using the SDK Store in the AWS SDK for .NET Developer Guide.

    • Environment variables. On a multi-tenant system, choose user environment variables, not system environment variables.

      For more information about using environment variables to store credentials, see Environment Variables in the AWS Command Line Interface User Guide.

  • Use different access keys for different applications. Do this so that you can isolate the permissions and revoke the access keys for individual applications if they are exposed. Having separate access keys for different applications also generates distinct entries in AWS CloudTrail log files. This configuration makes it easier for you to determine which application performed specific actions.

  • Update access keys when needed. If there is a risk that the access key could be compromised, update the access key and delete the previous access key. For details, see Update access keys

  • Remove unused access keys. If a user leaves your organization, remove the corresponding IAM user so that the user can no longer access your resources. To find out when an access key was last used, use the GetAccessKeyLastUsed API (AWS CLI command: aws iam get-access-key-last-used).

  • Use temporary credentials and configure multi-factor authentication for your most sensitive API operations. With IAM policies, you can specify which API operations a user is allowed to call. In some cases, you might want the additional security of requiring users to be authenticated with AWS MFA before you allow them to perform particularly sensitive actions. For example, you might have a policy that allows a user to perform the Amazon EC2 RunInstances, DescribeInstances, and StopInstances actions. But you might want to restrict a destructive action like TerminateInstances and ensure that users can perform that action only if they authenticate with an AWS MFA device. For more information, see Secure API access with MFA.

You can access a limited set of AWS services and features using the AWS mobile app. The mobile app helps you support incident response while on the go. For more information and to download the app, see AWS Console Mobile Application.

You can sign in to the mobile app using your console password or your access keys. As a best practice, do not use root user access keys. Instead, we strongly recommend that in addition to using a password or biometric lock on your mobile device, you create an IAM user specifically for managing AWS resources using the mobile app. If you lose your mobile device, you can remove the IAM user's access.

To sign in using access keys (mobile app)

  1. Open the app on your mobile device.

  2. If this is the first time that you're adding an identity to the device, choose Add an identity and then choose Access keys.

    If you have already signed in using another identity, choose the menu icon and choose Switch identity. Then choose Sign in as a different identity and then Access keys.

  3. On the Access keys page, enter your information:

    • Access key ID – Enter your access key ID.

    • Secret access key – Enter your secret access key.

    • Identity name – Enter the name of the identity that will appear in the mobile app. This does not need to match your IAM user name.

    • Identity PIN – Create a personal identification number (PIN) that you will use for future sign-ins.

      Note

      If you enable biometrics for the AWS mobile app, you will be prompted to use your fingerprint or facial recognition for verification instead of the PIN. If the biometrics fail, you might be prompted for the PIN instead.

  4. Choose Verify and add keys.

    You can now access a select set of your resources using the mobile app.

The following topics provide guidance for setting up the AWS SDKs and the AWS CLI to use access keys:

Auditing access keys

You can review the AWS access keys in your code to determine whether the keys are from an account that you own. You can pass an access key ID using the aws sts get-access-key-info AWS CLI command or the GetAccessKeyInfo AWS API operation.

The AWS CLI and AWS API operations return the ID of the AWS account to which the access key belongs. Access key IDs beginning with AKIA are long-term credentials for an IAM user or an AWS account root user. Access key IDs beginning with ASIA are temporary credentials that are created using AWS STS operations. If the account in the response belongs to you, you can sign in as the root user and review your root user access keys. Then, you can pull a credentials report to learn which IAM user owns the keys. To learn who requested the temporary credentials for an ASIA access key, view the AWS STS events in your CloudTrail logs.

For security purposes, you can review AWS CloudTrail logs to learn who performed an action in AWS. You can use the sts:SourceIdentity condition key in the role trust policy to require users to specify an identity when they assume a role. For example, you can require that IAM users specify their own user name as their source identity. This can help you determine which user performed a specific action in AWS. For more information, see sts:SourceIdentity.

This operation does not indicate the state of the access key. The key might be active, inactive, or deleted. Active keys might not have permissions to perform an operation. Providing a deleted access key might return an error that the key doesn't exist.