NetHSM: Fixing `list-users` With Invalid Username Errors
Introduction
This article delves into a specific bug encountered while using NetHSM with the nitropy tool. The issue arises when attempting to list users via the list-users command, particularly when usernames contain hyphens. While user creation might succeed through the API, the list-users command throws an error due to a validation mismatch. This article provides a detailed explanation, reproduction steps, and potential solutions to address this inconsistency.
Bug Description
When using NetHSM as a backend, a user created with a name containing a hyphen (e.g., n-admin) can be successfully added. The user is even listed when querying the /api/v1/users endpoint directly. However, attempting to list users using the nitropy nethsm list-users command results in the following error:
An unhandled exception occurred
Exception encountered: ApiValueError("Invalid value `Development~n-admin`, must match regular expression `^([a-zA-Z0-9]+~)?[a-zA-Z0-9]+
NetHSM: Fixing `list-users` With Invalid Username Errors
NetHSM: Fixing `list-users` With Invalid Username Errors
at ('args[0]', 1, 'user')")
This error indicates that the list-users command enforces a stricter username validation than the user creation process itself. Specifically, it appears to reject usernames containing hyphens (-). This discrepancy is problematic because it allows for the creation of users that cannot be properly managed or viewed through the nitropy tool. The core issue lies in the inconsistency between the validation rules applied during user creation and those applied when listing users. Ideally, either the user creation process should prevent the creation of usernames with invalid characters, or the list-users command should be updated to handle these usernames gracefully. The current behavior leads to a confusing user experience where users can be created but not fully managed via the command-line tool.
Root Cause Analysis
The root cause of this issue is a discrepancy in validation logic. The API endpoint responsible for creating users (/api/v1/users) likely has less restrictive validation rules compared to the list-users command within nitropy. The list-users command seems to be using a regular expression (^([a-zA-Z0-9]+~)?[a-zA-Z0-9]+$) to validate usernames, which explicitly disallows hyphens. This regular expression checks if the username starts with an optional namespace followed by a tilde (~) and then requires one or more alphanumeric characters. The absence of hyphen (-) in the character class [a-zA-Z0-9] is the key reason for the validation failure.
The inconsistency might stem from different development teams working on the backend API and the nitropy tool, leading to divergent validation rules. Alternatively, the list-users validation might have been introduced later without proper synchronization with the user creation process. Regardless of the origin, the inconsistency needs to be addressed to ensure a consistent and reliable user experience. It is crucial to align the validation rules across all components of the system to prevent unexpected errors and ensure that users can manage their accounts effectively. This can be achieved by either updating the regular expression in the list-users command to allow hyphens or by adding stricter validation to the user creation API to prevent the creation of usernames that are incompatible with the nitropy tool.
Proposed Solutions
Several solutions can be proposed to address this issue. Each has its trade-offs, and the best approach depends on the overall design goals of NetHSM:
- Relax Validation in
list-users: Modify the regular expression used by the list-users command to allow hyphens in usernames. This is the simplest solution and would immediately resolve the error. However, it assumes that hyphens in usernames do not cause any other issues within the NetHSM system.
- Enforce Validation on User Creation: Implement stricter validation on the user creation API to prevent the creation of usernames with hyphens. This approach ensures consistency but might require changes to existing user creation workflows. Users might need to rename existing accounts to comply with the new rules.
- Hybrid Approach: Implement stricter validation on user creation and provide a migration path for existing users with invalid usernames. This is the most comprehensive solution, ensuring consistency while minimizing disruption to existing users. A migration script could be provided to automatically rename accounts with invalid usernames.
- Provide Clear Error Messages: Improve the error message returned by the
list-users command to clearly indicate that the username contains invalid characters. This would help users understand the issue and take corrective action.
The preferred solution would likely be a combination of options 2 and 4. Enforcing validation on user creation prevents future inconsistencies, while providing clear error messages helps users understand and resolve existing issues. Option 3, the hybrid approach, is also a good choice if a significant number of users already have usernames with hyphens. It would provide a smoother transition to the new validation rules.
Local Reproduction
To reproduce this issue locally, follow these steps:
-
Run a local NetHSM container:
docker run --rm -it -p 8443:8443 --name local-hsm -d docker.io/nitrokey/nethsm:testing
2. Provision the container:
```bash
nitropy nethsm --host localhost:8443 --username admin --password adminadmin --no-verify-tls \
provision \
--unlock-passphrase unlockunlock \
--admin-passphrase adminadmin \
<<-EOF
unlockunlock2
adminadmin
EOF
-
Create a user with a hyphen in the username:
nitropy nethsm --host localhost:8443 --username admin --password adminadmin --no-verify-tls add-user --user-id "n-admin" --passphrase adminadmin --namespace Development --create-namespace --role Administrator --real-name "N Admin"
4. Attempt to list users:
```bash
nitropy nethsm --host localhost:8443 --username admin --password adminadmin --no-verify-tls list-users
This will reproduce the error described above.
Detailed Reproduction Steps Explained
Let's break down these reproduction steps to ensure clarity:
-
Step 1: Run Local Container: This step initiates a Docker container running NetHSM. The command docker run is used to create and start a new container. The flags used are:
--rm: Automatically removes the container when it exits.-it: Allocates a pseudo-TTY connected to the container and keeps STDIN open, allowing interactive access.-p 8443:8443: Maps port 8443 on the host machine to port 8443 on the container, enabling access to the NetHSM API.--name local-hsm: Assigns the name local-hsm to the container for easy reference.-d: Runs the container in detached mode (in the background).docker.io/nitrokey/nethsm:testing: Specifies the Docker image to use for the container. In this case, it's the testing tag of the nitrokey/nethsm image.
-
Step 2: Provision Container: This step provisions the newly created NetHSM container using the nitropy tool. Provisioning involves setting up the initial configuration, including unlock and admin passphrases. The nitropy nethsm provision command is used with the following options:
--host localhost:8443: Specifies the address of the NetHSM instance.--username admin: Specifies the administrative username.--password adminadmin: Specifies the administrative password.--no-verify-tls: Disables TLS certificate verification (for testing purposes only; do not use in production).--unlock-passphrase unlockunlock: Sets the unlock passphrase for the HSM.--admin-passphrase adminadmin: Sets the admin passphrase for the HSM.- The
<<-EOF ... EOF block provides the unlock and admin passphrases as input to the provision command.
-
Step 3: Create n-admin: This step creates a new user named n-admin with a hyphen in the username. The nitropy nethsm add-user command is used with these options:
- `--user-id
