PKCS#11 Setup#


You can either get the NetHSM PKCS#11 module as a precompiled binary or compile it from source.

Precompiled Binaries#

  1. Download the module file corresponding to your system from the releases page of the repository.

  2. Copy the module file to the directory where your PKCS#11 applications expect to find it.

Compile From Source#

  1. Install the Rust toolchain.

  2. Download and extract the source from the releases page or clone the repository.

  3. Run cargo build --release in the source directory.


By default the module searches for configuration files in:

  • /etc/nitrokey/p11nethsm.conf

  • /usr/local/etc/nitrokey/p11nethsm.conf

  • $HOME/.config/nitrokey/p11nethsm.conf

If multiple files are present the configurations will be merged so that the slots of all the config files will be used by the module.

You can manually set the config file location (only this one will be read) with the env variable P11NETHSM_CONFIG_FILE (e.g. P11NETHSM_CONFIG_FILE=./p11nethsm.conf).

Configuration File Format#

The configuration is yaml-formatted:

# Set this option to true to enable the compatibility option for the C_SetAttributeValue() function.
# This allows the applications using the Java Sun PKCS11 module (like EJBCA) to generate keys.
# When using this, the names given to the keys will be ignored and the keys will have random names.
# Under the hood it will store in memory the name given to the key when calling C_SetAttributeValue(). When a certificate is uploaded it will check if the name was previously passed to C_SetAttributeValue() and translate it to the real name on the NetHSM.
enable_set_attribute_value: false

# Optional log level, acceptable  values are Trace, Debug, Info, Warn and Error
log_level: Debug

# By default, the module logs to both syslog and stderr, trying the sockets /dev/log, /var/run/syslog and finally /var/run/log
# A custom socket can be configured:
syslog_socket: /var/nethsm/log
# Instead of a socket, a custom UDP or TCP syslog can be configured:
# syslog_udp:
#    to_addr: 127.0.0:1:514
#    from_addr: 127.0.0:1:4789
# syslog_tcp:
# Only one option among "syslog_socket", "syslog_udp", "syslog_tcp" can be configured at the same time

# You can configure the syslog facility ( "kern", "user", "mail", "daemon", "auth", "syslog", "lpr", "news", "uucp", "cron", "authpriv", "ftp", "local0", "local1", "local2", "local3", "local4", "local5", "local6" or "local7"):
syslog_facility: "user"
# You can set the hostname (for use only with syslog_udp or syslog_tcp)
# syslog_hostname: "localhsm-pkcs11"
# You can set the process name (defaults to the process name obtained from the OS)
# syslog_process: "NetHSM Pkcs11"
# You can set the pid used in logs (defaults to the process id obtained from the OS)
# syslog_pid: 0
# You can also configure a custom file, or "-" for stderr.
# log_file: /tmp/p11nethsm.log

# Each "slot" represents a HSM cluster of server that share the same user and keys.
  - label: LocalHSM                        # Name your NetHSM however you want
    description: Local HSM (docker)        # Optional description

    # Users connecting to the NetHSM server
      username: "operator"
      # If the password starts with `env:`, it will obtain the password from an environment variable:
      # password: "env:LOCALHSMPASS"
      password: "localpass"
      username: "admin"

    # List the NetHSM instances
      - url: "https://keyfender:8443/api/v1"   # URL to reach the server
        # To avoid having to re-open connections on each requests, the module keeps a connection pool to each instance. If the module is used by a multithreaded application, multiple connections can be opened at the same time.
        # This configures the maximum number of connections in the pool at the same time.
        # Note that this does not limit the total number of open connections.
        # Having a degree of parrallelism that is higher than the max number of idle connection can lead overhead as those connections will be closed an re-opened frenquently
        max_idle_connections: 10
        # By default, the certificate of the HSM will be validated using the system's root certificate authority.
        # When the NetHSM uses a self-signed certificate, it can be verified against an allowed list of sha256 fingerprint of the NetHSM's certificate:
          - "31:92:8E:A4:5E:16:5C:A7:33:44:E8:E9:8E:64:C4:AE:7B:2A:57:E5:77:43:49:F3:69:C9:8F:C4:2F:3A:3B:6E"
        # Alternatively certificate checks can be skipped entirely with danger_insecure_cert option.
        # This should be avoided if possible and certainly not used with a productive NetHSM.
        # danger_insecure_cert: true
    # Configure the network retry mechanism. If absent, no retries are attempted on a network error
      # The number of retries after a network error
      count: 3
      # The delay between retries, in integer seconds
      delay_seconds: 1
    # Configurable timeout for network operations. If a network operation takes more than, `timeout_seconds`, consider it failed. If `retries` is configured, it will be retried.
    # Defaults to infinite
    timeout_seconds: 10


If multiple NetHSM instances are listed in the same slot, these instances must be configured in a cluster. The credentials of the users and the keys must be the same on all instances.

The module will use the instances in a round-robin fashion, trying another instance if one fails.


The operator and administrator users are both optional but the module won’t start if no user is configured. This is so you can configure the module with only an administrator user, only an operator user or both at the same time.

When the two users are set the module will use the operator by default and only use the administrator user when the action needs it.

The regular PKCS11 user is mapped to the NetHSM operator and the PKCS11 SO is mapped to the NetHSM administrator.


The password can be provided by multiple means:

  • In plain text in the configuration password: "mypassword"

  • In an environment variable read by the module with the env: prefix: env:ENV_STORING_THE_PASSWORD

  • Via the login function of pkcs11, example for pcks11-tool: pkcs11-tool --module -p opPassphrase To provide the the admin password you need to use --so-pin instead: pkcs11-tool --module --login --login-type so --so-pin Administrator

If the password of an user is not set in the configuration file a login will be required to provide the password (3rd method).

A NetHSM that is not operational is considered as a slot with the token not present.