Rotate SSL/TLS Certificates for Database Instances

Risk Level: High (not acceptable risk)

Ensure that the SSL/TLS certificates configured for your Amazon Relational Database Service (RDS) database instances are replaced every few years as part of AWS cloud standard maintenance and security discipline.

Security

To maintain Amazon RDS database security and avoid interruption of the applications that are using RDS and/or Aurora databases, rotate the required SSL/TLS certificates and update the deprecated Certificate Authority (CA) certificates at the Amazon RDS instance level.

Audit

To determine if the CA certificates configured your Amazon RDS database instances are expired or about to expire soon, perform the following operations:

Using AWS Console

01 Sign in to the AWS Management Console.

02 Navigate to Amazon RDS console at https://console.aws.amazon.com/rds/.

03 In the navigation panel, under Amazon RDS, choose Databases.

04 Click on the name of the Amazon RDS database instance that you want to examine. To identify RDS database instances, check the database role available in the Role column (i.e. Instance).

05 Select the Connectivity & security tab and check the Certificate authority date attribute value to determine the date after which the configured CA certificate is no longer valid. If the Certificate Authority (CA) certificate is about to expire soon, the certificate configured for the selected Amazon RDS database instance needs to be changed (rotated).

06 Repeat steps no. 4 and 5 for each Amazon RDS database instance available within the current AWS region.

07 Change the AWS cloud region from the navigation bar and repeat the Audit process for other regions.

Using AWS CLI

01 Run describe-db-instances command (OSX/Linux/UNIX) with custom query filters to list the names of all the Amazon RDS database instances available in the selected AWS region:

aws rds describe-db-instances
  --region us-east-1
  --output table
  --query 'DBInstances[*].DBInstanceIdentifier'

02 The command output should return a table with the requested database instance names:

--------------------------------
|     DescribeDBInstances      |
+------------------------------+
|  cc-project5-mysql-database  |
|  cc-prod-postgres-database   |
+------------------------------+

03 Run describe-db-instances command (OSX/Linux/UNIX) using the name of the Amazon RDS database instance that you want to examine as the identifier parameter and custom query filters to describe the name of the Certificate Authority (CA) certificate configured for the selected database instance:

aws rds describe-db-instances
  --region us-east-1
  --db-instance-identifier cc-project5-mysql-database
  --query 'DBInstances[*].CACertificateIdentifier'

04 The command output should return the requested CA certificate name:

[
	"rds-ca-2015"
]

05 Run describe-certificates command (OSX/Linux/UNIX) using the name of the Certificate Authority (CA) certificate returned at the previous step as the identifier parameter, to describe the date after which the specified CA certificate is no longer valid:

aws rds describe-certificates
  --region us-east-1
  --certificate-identifier "rds-ca-2015"
  --query 'Certificates[*].ValidTill'

06 The command output should return the expiration for the specified certificate:

[
	"2020-03-05T21:54:04Z"
]

Check the date returned by the describe-certificates command output to determine the specified CA certificate validity. If the associated certificate is about to expire soon, the Certificate Authority (CA) certificate configured for the selected Amazon RDS database instance needs to be changed (rotated).

07 Repeat steps no. 3 – 6 for each Amazon RDS database instance available in the selected AWS region.

08 Change the AWS cloud region by updating the --region command parameter value and repeat the Audit process for other regions.

Remediation / Resolution

To rotate Certificate Authority (CA) certificates configured for your Amazon RDS database instances, perform the following operations:

Note: Before you reconfigure your RDS database instances to use the new CA certificate, make sure that you update your clients or applications connecting to your RDS databases to use the new certificates. If your database client knows how to handle certificate chains, you can download the root certificate and use it for all AWS regions. If not, you need to download a certificate that is specific to the region where your database instance is provisioned.

Using AWS CloudFormation

01 CloudFormation template (JSON):

{
	"AWSTemplateFormatVersion": "2010-09-09",
	"Description": "Rotate SSL/TLS Certificates for Database Instances",
	"Parameters": {
		"DBInstanceName": {
			"Default": "mysql-database-instance",
			"Description": "RDS database instance name",
			"Type": "String",
			"MinLength": "1",
			"MaxLength": "63",
			"AllowedPattern": "^[0-9a-zA-Z-/]*$",
			"ConstraintDescription": "Must begin with a letter and must not end with a hyphen or contain two consecutive hyphens."
		},
		"DBInstanceClass": {
			"Default": "db.t3.medium",
			"Description": "DB instance class/type",
			"Type": "String",
			"ConstraintDescription": "Must provide a valid DB instance type."
		},
		"DBAllocatedStorage": {
			"Default": "20",
			"Description": "The size of the database (GiB)",
			"Type": "Number",
			"MinValue": "20",
			"MaxValue": "65536",
			"ConstraintDescription": "Must be between 20 and 65536 GiB."
		},
		"DBName": {
			"Default": "mysqldb",
			"Description": "Database name",
			"Type": "String",
			"MinLength": "1",
			"MaxLength": "64",
			"AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
			"ConstraintDescription": "Must begin with a letter and contain only alphanumeric characters."
		},
		"DBUsername": {
			"Description": "Master username for database access",
			"Type": "String",
			"MinLength": "1",
			"MaxLength": "16",
			"AllowedPattern": "[a-zA-Z][a-zA-Z0-9]*",
			"ConstraintDescription": "Must begin with a letter and contain only alphanumeric characters."
		},
		"DBPassword": {
			"NoEcho": "true",
			"Description": "Password for database access",
			"Type": "String",
			"MinLength": "8",
			"MaxLength": "41",
			"AllowedPattern": "[a-zA-Z0-9]*",
			"ConstraintDescription": "Must contain only alphanumeric characters."
		}
	},
	"Resources": {
		"RDSInstance": {
			"Type": "AWS::RDS::DBInstance",
			"Properties": {
				"DBInstanceIdentifier": {
					"Ref": "DBInstanceName"
				},
				"DBName": {
					"Ref": "DBName"
				},
				"MasterUsername": {
					"Ref": "DBUsername"
				},
				"MasterUserPassword": {
					"Ref": "DBPassword"
				},
				"DBInstanceClass": {
					"Ref": "DBInstanceClass"
				},
				"AllocatedStorage": {
					"Ref": "DBAllocatedStorage"
				},
				"Engine": "MySQL",
				"EngineVersion": "5.7.36",
				"CACertificateIdentifier": "rds-ca-2019"
			}
		}
	}
}

02 CloudFormation template (YAML):

AWSTemplateFormatVersion: '2010-09-09'
	Description: Rotate SSL/TLS Certificates for Database Instances
	Parameters:
	DBInstanceName:
		Default: mysql-database-instance
		Description: RDS database instance name
		Type: String
		MinLength: '1'
		MaxLength: '63'
		AllowedPattern: ^[0-9a-zA-Z-/]*$
		ConstraintDescription: Must begin with a letter and must not end with a hyphen
		or contain two consecutive hyphens.
	DBInstanceClass:
		Default: db.t3.medium
		Description: DB instance class/type
		Type: String
		ConstraintDescription: Must provide a valid DB instance type.
	DBAllocatedStorage:
		Default: '20'
		Description: The size of the database (GiB)
		Type: Number
		MinValue: '20'
		MaxValue: '65536'
		ConstraintDescription: Must be between 20 and 65536 GiB.
	DBName:
		Default: mysqldb
		Description: Database name
		Type: String
		MinLength: '1'
		MaxLength: '64'
		AllowedPattern: '[a-zA-Z][a-zA-Z0-9]*'
		ConstraintDescription: Must begin with a letter and contain only alphanumeric
		characters.
	DBUsername:
		Description: Master username for database access
		Type: String
		MinLength: '1'
		MaxLength: '16'
		AllowedPattern: '[a-zA-Z][a-zA-Z0-9]*'
		ConstraintDescription: Must begin with a letter and contain only alphanumeric
		characters.
	DBPassword:
		NoEcho: 'true'
		Description: Password for database access
		Type: String
		MinLength: '8'
		MaxLength: '41'
		AllowedPattern: '[a-zA-Z0-9]*'
		ConstraintDescription: Must contain only alphanumeric characters.
	Resources:
	RDSInstance:
		Type: AWS::RDS::DBInstance
		Properties:
		DBInstanceIdentifier: !Ref 'DBInstanceName'
		DBName: !Ref 'DBName'
		MasterUsername: !Ref 'DBUsername'
		MasterUserPassword: !Ref 'DBPassword'
		DBInstanceClass: !Ref 'DBInstanceClass'
		AllocatedStorage: !Ref 'DBAllocatedStorage'
		Engine: MySQL
		EngineVersion: 5.7.36
		CACertificateIdentifier: rds-ca-2019

Using Terraform (AWS Provider)

01 Terraform configuration file (.tf):

terraform {
	required_providers {
		aws = {
			source  = "hashicorp/aws"
			version = "~> 4.0"
		}
	}

	required_version = ">= 0.14.9"
}

provider "aws" {
	profile = "default"
	region  = "us-east-1"
}

resource "aws_db_instance" "rds-database-instance" {
	allocated_storage     = 30
	engine                = "mysql"
	engine_version        = "5.7"
	instance_class        = "db.t3.medium"
	name                  = "[database-name]"
	username              = "[master-username]"
	password              = "[master-password]"
	parameter_group_name  = "default.mysql5.7"
	ca_cert_identifier    = "rds-ca-2019"
}

Using AWS Console

01 Sign in to the AWS Management Console.

02 Navigate to Amazon RDS console at https://console.aws.amazon.com/rds/.

03 In the navigation panel, under Amazon RDS, choose Databases.

04 Select the Amazon RDS database instance that you want to reconfigure and choose Modify.

05 On the Modify DB instance: <instance-name> configuration page, perform the following actions:

In the Connectivitysection, select the newest Certificate Authority (CA) certificate from the Certificate authority dropdown list to replace the CA certificate that is going to be deprecated soon.
Choose Continue and review the configuration changes that you want to apply, available in the Summary of modifications section.
In the Scheduling of modifications section, perform one of the following actions based on your workload requirements:
- Select Apply during the next scheduled maintenance window to apply the changes automatically during the next scheduled maintenance window.
- Select Apply immediately to apply the changes right away. With this option any pending modifications will be asynchronously applied as soon as possible, regardless of the maintenance window configured for the selected database instance. Note that any changes available in the pending modifications queue are also applied. If any of the pending modifications require downtime, choosing this option can cause unexpected downtime for your database application.
Choose Modify DB instance to apply the configuration changes.

06 Repeat steps no. 4 and 5 for each Amazon RDS database instance available in the selected AWS region.

07 Change the AWS cloud region from the navigation bar and repeat the Remediation process for other regions.

Using AWS CLI

01 Run modify-db-instance command (OSX/Linux/UNIX) to replace (rotate) the Certificate Authority (CA) certificate configured for the selected Amazon RDS database instance. The following command request example makes use of --apply-immediately parameter to apply the configuration changes asynchronously and as soon as possible. Any changes available in the pending modifications queue are also applied with this request. If any of the pending modifications require downtime, choosing this option can cause unexpected downtime for your RDS database application. If you skip adding the --apply-immediately parameter to the command request, Amazon RDS will apply your changes during the next maintenance window:

aws rds modify-db-instance
  --region us-east-1
  --db-instance-identifier cc-project5-mysql-database
  --ca-certificate-identifier "rds-ca-2019"
  --apply-immediately

02 The command output should return the configuration metadata for the modified database instance:

{
	"DBInstance": {
		"PubliclyAccessible": true,
		"MasterUsername": "ccadmin",
		"MonitoringInterval": 0,
		"LicenseModel": "general-public-license",
		"VpcSecurityGroups": [
			{
				"Status": "active",
				"VpcSecurityGroupId": "sg-0abcd1234abcd1234"
			}
		],
		"InstanceCreateTime": "2021-05-12T08:00:00.677Z",
		"CopyTagsToSnapshot": true,
		"OptionGroupMemberships": [
			{
				"Status": "in-sync",
				"OptionGroupName": "default:mysql-5-7"
			}
		],
		"Engine": "mysql",
		"MultiAZ": false,
		"DBSecurityGroups": [],
		"DBParameterGroups": [
			{
				"DBParameterGroupName": "default.mysql5.7",
				"ParameterApplyStatus": "in-sync"
			}
		],
		"PerformanceInsightsEnabled": true,
		"AutoMinorVersionUpgrade": true,
		"PreferredBackupWindow": "06:02-06:32",
		"DBSubnetGroup": {
			"Subnets": [
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-abcd1234",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1d"
					}
				},
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-1234abcd",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1e"
					}
				},
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-abcdabcd",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1b"
					}
				},
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-12341234",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1a"
					}
				},
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-abcd1234",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1f"
					}
				},
				{
					"SubnetStatus": "Active",
					"SubnetIdentifier": "subnet-1234abcd",
					"SubnetOutpost": {},
					"SubnetAvailabilityZone": {
						"Name": "us-east-1c"
					}
				}
			],
			"DBSubnetGroupName": "default-vpc-abcdabcd",
			"VpcId": "vpc-abcdabcd",
			"DBSubnetGroupDescription": "Created from the AWS Management Console",
			"SubnetGroupStatus": "Complete"
		},
		"ReadReplicaDBInstanceIdentifiers": [],
		"AllocatedStorage": 70,
		"DBInstanceArn": "arn:aws:rds:us-east-1:123456789012:db:cc-project5-mysql-database",
		"BackupRetentionPeriod": 7,
		"PreferredMaintenanceWindow": "thu:03:27-thu:03:57",
		"Endpoint": {
			"HostedZoneId": "ABCDABCDABCD",
			"Port": 3306,
			"Address": "cc-project5-mysql-database.abcdabcdabcd.us-east-1.rds.amazonaws.com"
		},
		"DBInstanceStatus": "available",
		"IAMDatabaseAuthenticationEnabled": true,
		"EngineVersion": "5.7.30",
		"DeletionProtection": true,
		"AvailabilityZone": "us-east-1a",
		"DomainMemberships": [],
		"StorageType": "gp2",
		"DbiResourceId": "db-ABCDABCDABCDABCDABCDABCDAB",
		"CACertificateIdentifier": "rds-ca-2015",
		"StorageEncrypted": true,
		"AssociatedRoles": [],
		"DBInstanceClass": "db.t3.medium",
		"DbInstancePort": 0,
		"DBInstanceIdentifier": "cc-project5-mysql-database"
	}
}

03 Repeat steps no. 1 and 2 for each Amazon RDS database instance available in the selected AWS region.

04 Change the AWS cloud region by updating the --region command parameter value and repeat the Remediation process for other regions.

References

AWS Documentation
Using SSL/TLS to encrypt a connection to a DB instance
Rotating your SSL/TLS certificate
Modifying an Amazon RDS DB instance

AWS Command Line Interface (CLI) Documentation
rds
describe-db-instances
modify-db-instance

Publication date Oct 19, 2023

Audit

Using AWS Console

Using AWS CLI

Remediation / Resolution

Using AWS CloudFormation

Using Terraform (AWS Provider)

Using AWS Console

Using AWS CLI

References

Related RDS rules