Hello and welcome to this lecture where I want to highlight how you can access AWS CloudHSM.  

More often than not in AWS, access to resources can be controlled by IAM controls, however, CloudHSM is slightly different.  Instead of using IAM users, the service has its own users and security held on the HSMs themselves utilizing a role-based access control method.  Do bear in mind, however, you will still need permissions from within IAM to use the CloudHSM service.   As you might expect, there are different types of users with different levels of controls as to what actions they can perform on the module.  So let’s take a look.  

The types of users available on the HSM are as follows:

• Precrypto Office (PRECO).
• Crypto Office (CO).
• Crypto User (CU).
• Appliance User (AU).

After you have created your HSM cluster, the first HSM you connect to will be provisioned with the Precrypto Office (PRECO) user with a default username and password.  This is a temporary user with temporary credentials of read-only access to the cluster.  Using the PRECO user you must activate your cluster. As a part of the activation process of your cluster you will need to change the PRECO password, and by doing so your PRECO user will then become the Crypto Office (CO) user.  

The Crypto Office (CO) user contains a more advanced permission set than that of the PRECO user.  The CO has the ability to carry out user management tasks, such as the creation and deletion of users, in addition to changing users' passwords.  It can also perform some administrative level operations as well, including:

• The ability to zeroise data on the HSM, which will delete certificated, keys and any other data on the HSM.
• Obtain HSM details such as the different HSM IP address in the cluster, the models, and serial numbers.
• View and determine the synchronization status across your cluster.

A Crypto User (CU) is used predominantly to perform the cryptographic operations and key management functions with your CloudHSM cluster, these include: 

• Create, delete, import/export, and share cryptographic keys.
• Perform encryption and decryption, plus signing and verifying.

Also, much like the CO, CUs are also able to zeroise data and basic cluster information such as IP address and serial number and retrieve cluster synchronization status.

The Appliance User (AU) performs cloning and synchronization across your cluster and it exists on all HSMs.  The CloudHSM calls upon the AU to ensure the synchronization of your HSMs within your cluster is maintained.  

Here is a summary of the different user types used on the HSMs. (Image source: https://docs.aws.amazon.com/cloudhsm/latest/userguide/manage-hsm-users.html#user-permissions-table)

The hardware security modules are designed with physical tamper detection and response processes.  This means that if the HSM detected any kind of physical breach or tampering of the device, it would begin key deletion across the hardware. 

In addition to this, the HSMs are also designed with protection against brute force login attacks.  This means that if you were to incorrectly enter the wrong passwords for a Crypto User, then that HSM would lock out that user, and would have to be unlocked by a Crypto Officer.