Managing HSM users with CloudHSM Management Utility (CMU) - AWS CloudHSM

Managing HSM users with CloudHSM Management Utility (CMU)

In AWS CloudHSM, you must use CloudHSM CLI or CloudHSM Management Utility (CMU) command line tools to create and manage the users on your HSM. CloudHSM CLI is designed to be used with the latest SDK, while the CMU is designed to be used with previous SDKs.

Understanding HSM users

Most operations that you perform on the HSM require the credentials of an HSM user. The HSM authenticates each HSM user and each HSM user has a type that determines which operations you can perform on the HSM as that user.


HSM users are distinct from IAM users. IAM users who have the correct credentials can create HSMs by interacting with resources through the AWS API. After the HSM is created, you must use HSM user credentials to authenticate operations on the HSM.

Precrypto officer (PRECO)

In both the cloud management utility (CMU) and the key management utility (KMU), the PRECO is a temporary user that exists only on the first HSM in an AWS CloudHSM cluster. The first HSM in a new cluster contains an PRECO user indicating that this cluster has never been activated. To activate a cluster, you execute the cloudhsm-cli and run the cluster activate command. log in to the HSM and change the PRECO's password. When you change the password, this user becomes the crypto officer (CO).

Crypto officer (CO)

In both the cloud management utility (CMU) and the key management utility (KMU), a crypto officer (CO) can perform user management operations. For example, they can create and delete users and change user passwords. For more information about CO users, see the HSM user permissions table. When you activate a new cluster, the user changes from a Precrypto Officer (PRECO) to a crypto officer (CO).-->

Crypto user (CU)

A crypto user (CU) can perform the following key management and cryptographic operations.

  • Key management – Create, delete, share, import, and export cryptographic keys.

  • Cryptographic operations – Use cryptographic keys for encryption, decryption, signing, verifying, and more.

For more information, see the HSM user permissions table.

Appliance user (AU)

The appliance user (AU) can perform cloning and synchronization operations on your cluster's HSMs. AWS CloudHSM uses the AU to synchronize the HSMs in an AWS CloudHSM cluster. The AU exists on all HSMs provided by AWS CloudHSM, and has limited permissions. For more information, see the HSM user permissions table.

AWS cannot perform any operations on your HSMs . AWS cannot view or modify your users or keys and cannot perform any cryptographic operations using those keys.

HSM user permissions table

The following table lists HSM operations sorted by the type of HSM user or session that can perform the operation.

Crypto officer (CO) Crypto User (CU) Appliance User (AU) Unauthenticated Session
Get basic cluster info¹ Yes Yes Yes Yes
Change own password Yes Yes Yes Not applicable
Change any user's password Yes No No No
Add, remove users Yes No No No
Get sync status² Yes Yes Yes No
Extract, insert masked objects³ Yes Yes Yes No
Key management functions⁴ No Yes No No
Encrypt, decrypt No Yes No No
Sign, verify No Yes No No
Generate digests and HMACs No Yes No No
  • [1] Basic cluster information includes the number of HSMs in the cluster and each HSM's IP address, model, serial number, device ID, firmware ID, etc.

  • [2] The user can get a set of digests (hashes) that correspond to the keys on the HSM. An application can compare these sets of digests to understand the synchronization status of HSMs in a cluster.

  • [3] Masked objects are keys that are encrypted before they leave the HSM. They cannot be decrypted outside of the HSM. They are only decrypted after they are inserted into an HSM that is in the same cluster as the HSM from which they were extracted. An application can extract and insert masked objects to synchronize the HSMs in a cluster.

  • [4] Key management functions include creating, deleting, wrapping, unwrapping, and modifying the attributes of keys.