community.crypto.openssl_dhparam module – Generate OpenSSL Diffie-Hellman Parameters

Note

This module is part of the community.crypto collection (version 2.16.1).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install community.crypto. You need further requirements to be able to use this module, see Requirements for details.

To use it in a playbook, specify: community.crypto.openssl_dhparam.

Synopsis

  • This module allows one to (re)generate OpenSSL DH-params.

  • This module uses file common arguments to specify generated file permissions.

  • Please note that the module regenerates existing DH params if they do not match the module’s options. If you are concerned that this could overwrite your existing DH params, consider using the backup option.

  • The module can use the cryptography Python library, or the openssl executable. By default, it tries to detect which one is available. This can be overridden with the select_crypto_backend option.

Requirements

The below requirements are needed on the host that executes this module.

  • Either cryptography >= 2.0

  • Or OpenSSL binary openssl

Parameters

Parameter

Comments

attributes

aliases: attr

string

The attributes the resulting filesystem object should have.

To get supported flags look at the man page for chattr on the target system.

This string should contain the attributes in the same order as the one displayed by lsattr.

The = operator is assumed as default, otherwise + or - operators need to be included in the string.

backup

boolean

Create a backup file including a timestamp so you can get the original DH params back if you overwrote them with new ones by accident.

Choices:

  • false ← (default)

  • true

force

boolean

Should the parameters be regenerated even it it already exists.

Choices:

  • false ← (default)

  • true

group

string

Name of the group that should own the filesystem object, as would be fed to chown.

When left unspecified, it uses the current group of the current user unless you are root, in which case it can preserve the previous ownership.

mode

any

The permissions the resulting filesystem object should have.

For those used to /usr/bin/chmod remember that modes are actually octal numbers. You must give Ansible enough information to parse them correctly. For consistent results, quote octal numbers (for example, '644' or '1777') so Ansible receives a string and can do its own conversion from string into number. Adding a leading zero (for example, 0755) works sometimes, but can fail in loops and some other circumstances.

Giving Ansible a number without following either of these rules will end up with a decimal number which will have unexpected results.

As of Ansible 1.8, the mode may be specified as a symbolic mode (for example, u+rwx or u=rw,g=r,o=r).

If mode is not specified and the destination filesystem object does not exist, the default umask on the system will be used when setting the mode for the newly created filesystem object.

If mode is not specified and the destination filesystem object does exist, the mode of the existing filesystem object will be used.

Specifying mode is the best way to ensure filesystem objects are created with the correct permissions. See CVE-2020-1736 for further details.

owner

string

Name of the user that should own the filesystem object, as would be fed to chown.

When left unspecified, it uses the current user unless you are root, in which case it can preserve the previous ownership.

Specifying a numeric username will be assumed to be a user ID and not a username. Avoid numeric usernames to avoid this confusion.

path

path / required

Name of the file in which the generated parameters will be saved.

return_content

boolean

added in community.crypto 1.0.0

If set to true, will return the (current or generated) DH parameter’s content as dhparams.

Choices:

  • false ← (default)

  • true

select_crypto_backend

string

added in community.crypto 1.0.0

Determines which crypto backend to use.

The default choice is auto, which tries to use cryptography if available, and falls back to openssl.

If set to openssl, will try to use the OpenSSL openssl executable.

If set to cryptography, will try to use the cryptography library.

Choices:

  • "auto" ← (default)

  • "cryptography"

  • "openssl"

selevel

string

The level part of the SELinux filesystem object context.

This is the MLS/MCS attribute, sometimes known as the range.

When set to _default, it will use the level portion of the policy if available.

serole

string

The role part of the SELinux filesystem object context.

When set to _default, it will use the role portion of the policy if available.

setype

string

The type part of the SELinux filesystem object context.

When set to _default, it will use the type portion of the policy if available.

seuser

string

The user part of the SELinux filesystem object context.

By default it uses the system policy, where applicable.

When set to _default, it will use the user portion of the policy if available.

size

integer

Size (in bits) of the generated DH-params.

Default: 4096

state

string

Whether the parameters should exist or not, taking action if the state is different from what is stated.

Choices:

  • "absent"

  • "present" ← (default)

unsafe_writes

boolean

Influence when to use atomic operation to prevent data corruption or inconsistent reads from the target filesystem object.

By default this module uses atomic operations to prevent data corruption or inconsistent reads from the target filesystem objects, but sometimes systems are configured or just broken in ways that prevent this. One example is docker mounted filesystem objects, which cannot be updated atomically from inside the container and can only be written in an unsafe manner.

This option allows Ansible to fall back to unsafe methods of updating filesystem objects when atomic operations fail (however, it doesn’t force Ansible to perform unsafe writes).

IMPORTANT! Unsafe writes are subject to race conditions and can lead to data corruption.

Choices:

  • false ← (default)

  • true

Attributes

Attribute

Support

Description

check_mode

Support: full

Can run in check_mode and return changed status prediction without modifying target.

diff_mode

Support: none

Will return details on what has changed (or possibly needs changing in check_mode), when in diff mode.

safe_file_operations

Support: full

Uses Ansible’s strict file operation functions to ensure proper permissions and avoid data corruption.

See Also

See also

community.crypto.x509_certificate

Generate and/or check OpenSSL certificates.

community.crypto.openssl_csr

Generate OpenSSL Certificate Signing Request (CSR).

community.crypto.openssl_pkcs12

Generate OpenSSL PKCS#12 archive.

community.crypto.openssl_privatekey

Generate OpenSSL private keys.

community.crypto.openssl_publickey

Generate an OpenSSL public key from its private key.

Examples

- name: Generate Diffie-Hellman parameters with the default size (4096 bits)
  community.crypto.openssl_dhparam:
    path: /etc/ssl/dhparams.pem

- name: Generate DH Parameters with a different size (2048 bits)
  community.crypto.openssl_dhparam:
    path: /etc/ssl/dhparams.pem
    size: 2048

- name: Force regenerate an DH parameters if they already exist
  community.crypto.openssl_dhparam:
    path: /etc/ssl/dhparams.pem
    force: true

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key

Description

backup_file

string

Name of backup file created.

Returned: changed and if backup is true

Sample: "/path/to/dhparams.pem.2019-03-09@11:22~"

dhparams

string

added in community.crypto 1.0.0

The (current or generated) DH params’ content.

Returned: if state is present and return_content is true

filename

string

Path to the generated Diffie-Hellman parameters.

Returned: changed or success

Sample: "/etc/ssl/dhparams.pem"

size

integer

Size (in bits) of the Diffie-Hellman parameters.

Returned: changed or success

Sample: 4096

Authors

  • Thom Wiggers (@thomwiggers)