Authenticating with the Valkey and Redis OSS AUTH command

Valkey and Redis OSS authentication tokens or passwords enable Valkey and Redis OSS to require a password before allowing clients to run commands, thereby improving data security. The AUTH is available for self-designed clusters only.

Overview of AUTH in ElastiCache with Valkey and Redis OSS

When you use the AUTH with your ElastiCache with Valkey or Redis OSS cluster, there are some refinements.

In particular, be aware of these AUTH token or password constraints when using AUTH:

To set up a strong token, we recommend that you follow a strict password policy, such as requiring the following:

Applying authentication to an ElastiCache with Valkey or Redis OSS cluster

You can require that users enter a token (password) on a token-protected Valkey or Redis OSS server. To do this, include the parameter --auth-token (API: AuthToken) with the correct token when you create your replication group or cluster. Also include it in all subsequent commands to the replication group or cluster.

The following AWS CLI operation creates a replication group with encryption in transit (TLS) enabled and the AUTH token This-is-a-sample-token. Replace the subnet group sng-test with a subnet group that exists.

For Linux, macOS, or Unix:

aws elasticache create-replication-group \
    --replication-group-id authtestgroup \
    --replication-group-description authtest \
    --engine redis \ 
    --cache-node-type cache.m4.large \
    --num-node-groups 1 \
    --replicas-per-node-group 2 \    
    --transit-encryption-enabled \
    --auth-token This-is-a-sample-token \
    --cache-subnet-group sng-test

For Windows:

aws elasticache create-replication-group ^
    --replication-group-id authtestgroup ^
    --replication-group-description authtest ^
    --engine redis ^ 
    --cache-node-type cache.m4.large ^
    --num-node-groups 1 ^
    --replicas-per-node-group 2 ^    
    --transit-encryption-enabled ^
    --auth-token This-is-a-sample-token ^
    --cache-subnet-group sng-test

Modifying the AUTH token on an existing cluster

To make it easier to update your authentication, you can modify the AUTH token used on a cluster. You can make this modification if the engine version is Valkey 7.2 or higher or Redis 5.0.6 or higher. ElastiCache must also have encryption in transit enabled.

Modifying the auth token supports two strategies: ROTATE and SET. The ROTATE strategy adds an additional AUTH token to the server while retaining the previous token. The SET strategy updates the server to support just a single AUTH token. Make these modification calls with the --apply-immediately parameter to apply changes immediately.

Rotating the AUTH token

To update a Valkey or Redis OSS server with a new AUTH token, call the ModifyReplicationGroup API with the --auth-token parameter as the new AUTH token and the --auth-token-update-strategy with the value ROTATE. After the ROTATE modification is complete, the cluster will support the previous AUTH token in addition to the one specified in the auth-token parameter. If no AUTH token was configured on the replication group before the AUTH token rotation, the cluster supports the AUTH token specified in the --auth-token parameter in addition to supporting connecting without authentication. See Setting the AUTH token to update the AUTH token to be required using update strategy SET.

If this modification is performed on a server that already supports two AUTH tokens, the oldest AUTH token will also be removed during this operation. This allows a server to support up to two most recent AUTH tokens at a given time.

At this point, you can proceed by updating the client to use the latest AUTH token. After the clients are updated, you can use the SET strategy for AUTH token rotation (explained in the following section) to exclusively start using the new token.

The following AWS CLI operation modifies a replication group to rotate the AUTH token This-is-the-rotated-token.

For Linux, macOS, or Unix:

aws elasticache modify-replication-group \
--replication-group-id authtestgroup \
--auth-token This-is-the-rotated-token \
--auth-token-update-strategy ROTATE \
--apply-immediately

For Windows:

aws elasticache modify-replication-group ^
--replication-group-id authtestgroup ^
--auth-token This-is-the-rotated-token ^
--auth-token-update-strategy ROTATE ^
--apply-immediately

Setting the AUTH token

To update a Valkey or Redis OSS server to support a single required AUTH token, call the ModifyReplicationGroup API operation with the --auth-token parameter with same value as the last AUTH token and the --auth-token-update-strategy parameter with the value SET. The SET strategy can only be used with a cluster that has 2 AUTH tokens or 1 optional AUTH token from using a ROTATE strategy before. After the modification is complete, the server supports only the AUTH token specified in the auth-token parameter.

The following AWS CLI operation modifies a replication group to set the AUTH token to This-is-the-set-token.

For Linux, macOS, or Unix:

aws elasticache modify-replication-group \
--replication-group-id authtestgroup \
--auth-token This-is-the-set-token \
--auth-token-update-strategy SET \
--apply-immediately

For Windows:

aws elasticache modify-replication-group ^
--replication-group-id authtestgroup ^
--auth-token This-is-the-set-token ^
--auth-token-update-strategy SET ^
--apply-immediately

Enabling authentication on an existing cluster

To enable authentication on an existing Valkey or Redis OSS server, call the ModifyReplicationGroup API operation. Call ModifyReplicationGroup with the --auth-token parameter as the new token and the --auth-token-update-strategy with the value ROTATE.

After the ROTATE modification is complete, the cluster supports the AUTH token specified in the --auth-token parameter in addition to supporting connecting without authentication. Once all client applications are updated to authenticate to Valkey or Redis OSS with the AUTH token, use the SET strategy to mark the AUTH token as required. Enabling authentication is only supported on Valkey and Redis OSS servers with encryption in transit (TLS) enabled.

Migrating from RBAC to AUTH

If you are authenticating users with Valkey or Redis OSS Role-Based Access Control (RBAC) as described in Role-Based Access Control (RBAC), and you want to migrate to AUTH, use the following procedures. You can migrate using either console or CLI.

To migrate from RBAC to AUTH using the AWS CLI

Use one of the following commands to configure a new optional AUTH token for your Valkey or Redis OSS replication group. Note that an optional Auth token will allow unauthenticated access to the replication group until the Auth token is marked as required, using the update strategy SET in the following step.

For Linux, macOS, or Unix:

aws elasticache modify-replication-group \
    --replication-group-id test \
    --remove-user-groups \
    --auth-token This-is-a-sample-token \
    --auth-token-update-strategy ROTATE \ 
    --apply-immediately 

For Windows:

aws elasticache modify-replication-group ^
    --replication-group-id test ^
    --remove-user-groups ^
    --auth-token This-is-a-sample-token ^
    --auth-token-update-strategy ROTATE ^ 
    --apply-immediately 

After executing the above command, you can update your Valkey or Redis OSS applications to authenticate to the ElastiCache replication group using the newly configured optional AUTH token. To complete the Auth token rotation, use the the update strategy SET in the subsequent command below. This will mark to the optional AUTH token as required. When the Auth token update completes, the replication group status will show as ACTIVE and all connections to this replication group will require authentication.

For Linux, macOS, or Unix:

aws elasticache modify-replication-group \
			--replication-group-id test \
			--auth-token This-is-a-sample-token \
			--auth-token-update-strategy SET \ 
			--apply-immediately 

For Windows:

aws elasticache modify-replication-group ^
			--replication-group-id test ^
			--remove-user-groups ^
			--auth-token This-is-a-sample-token ^
			--auth-token-update-strategy SET ^ 
			--apply-immediately

For more information, see Authenticating with the Valkey and Redis OSS AUTH command.