IAM database authentication for MySQL and PostgreSQL

You can authenticate to your DB instance using AWS Identity and Access Management (IAM) database authentication. IAM database authentication works with MySQL and PostgreSQL. With this authentication method, you don't need to use a password when you connect to a DB instance. Instead, you use an authentication token.

An authentication token is a unique string of characters that Amazon RDS generates on request. Authentication tokens are generated using AWS Signature Version 4. Each token has a lifetime of 15 minutes. You don't need to store user credentials in the database, because authentication is managed externally using IAM. You can also still use standard database authentication.

IAM database authentication provides the following benefits:

• Network traffic to and from the database is encrypted using Secure Socket Layer (SSL) or Transport Layer Security (TLS). For more information about using SSL/TLS with Amazon RDS, see Using SSL/TLS to encrypt a connection to a DB instance.

• You can use IAM to centrally manage access to your database resources, instead of managing access individually on each DB instance.

• For applications running on Amazon EC2, you can use profile credentials specific to your EC2 instance to access your database instead of a password, for greater security.

Topics

• Availability for IAM database authentication
• Limitations for IAM database authentication
• MySQL recommendations for IAM database authentication
• Enabling and disabling IAM database authentication
• Creating and using an IAM policy for IAM database access
• Creating a database account using IAM authentication
• Connecting to your DB instance using IAM authentication

Availability for IAM database authentication

IAM database authentication is available for the following database engines:

• MySQL 8.0, minor version 8.0.16 or higher

• MySQL 5.7, minor version 5.7.16 or higher

• MySQL 5.6, minor version 5.6.34 or higher

• PostgreSQL 13, all minor versions

• PostgreSQL 12, all minor versions

• PostgreSQL 11, all minor versions

• PostgreSQL 10, minor version 10.6 or higher

• PostgreSQL 9.6, minor version 9.6.11 or higher

• PostgreSQL 9.5, minor version 9.5.15 or higher

Limitations for IAM database authentication

When using IAM database authentication, the following limitations apply:

• The maximum number of connections per second for your DB instance might be limited depending on its DB instance class and your workload.

• Currently, IAM database authentication doesn't support all global condition context keys.

  For more information about global condition context keys, see AWS global condition context keys in the IAM User Guide.

• Currently, IAM database authentication isn't supported for CNAMEs.

• For PostgreSQL, if the IAM role (rds_iam) is added to the master user, IAM authentication takes precedence over Password authentication so the master user has to log in as an IAM user.

MySQL recommendations for IAM database authentication

We recommend the following when using the MySQL DB engine:

• Use IAM database authentication as a mechanism for temporary, personal access to databases.

• Use IAM database authentication only for workloads that can be easily retried.

• Use IAM database authentication when your application requires fewer than 200 new IAM database authentication connections per second.

  The database engines that work with Amazon RDS don't impose any limits on authentication attempts per second. However, when you use IAM database authentication, your application must generate an authentication token. Your application then uses that token to connect to the DB instance. If you exceed the limit of maximum new connections per second, then the extra overhead of IAM database authentication can cause connection throttling. The extra overhead can cause even existing connections to drop. For information about the maximum total connections for MySQL, see Maximum MySQL and MariaDB connections.