community.crypto.openssh_keypair module – Generate OpenSSH private and public keys

Note

This module is part of the community.crypto collection (version 2.14.0).

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.openssh_keypair.

Synopsis

  • This module allows one to (re)generate OpenSSH private and public keys. It uses ssh-keygen to generate keys. One can generate rsa, dsa, rsa1, ed25519 or ecdsa private keys.

Requirements

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

  • ssh-keygen (if backend=openssh)

  • cryptography >= 2.6 (if backend=cryptography and OpenSSH < 7.8 is installed)

  • cryptography >= 3.0 (if backend=cryptography and OpenSSH >= 7.8 is installed)

Parameters

Parameter

Comments

attributes

aliases: attr

string

added in Ansible 2.3

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.

backend

string

added in community.crypto 1.7.0

Selects between the cryptography library or the OpenSSH binary opensshbin.

auto will default to opensshbin unless the OpenSSH binary is not installed or when using passphrase.

Choices:

  • "auto" ← (default)

  • "cryptography"

  • "opensshbin"

comment

string

Provides a new comment to the public key.

force

boolean

Should the key be regenerated even if 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 either add a leading zero so that Ansible’s YAML parser knows it is an octal number (like 0644 or 01777) or quote it (like '644' or '1777') so Ansible receives a string and can do its own conversion from string into number.

Giving Ansible a number without following one 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.

passphrase

string

added in community.crypto 1.7.0

Passphrase used to decrypt an existing private key or encrypt a newly generated private key.

Passphrases are not supported for type=rsa1.

Can only be used when backend=cryptography, or when backend=auto and a required cryptography version is installed.

path

path / required

Name of the files containing the public and private key. The file containing the public key will have the extension .pub.

private_key_format

string

added in community.crypto 1.7.0

Used when backend=cryptography to select a format for the private key at the provided path.

When set to auto this module will match the key format of the installed OpenSSH version.

For OpenSSH < 7.8 private keys will be in PKCS1 format except ed25519 keys which will be in OpenSSH format.

For OpenSSH >= 7.8 all private key types will be in the OpenSSH format.

Using this option when regenerate=partial_idempotence or regenerate=full_idempotence will cause a new keypair to be generated if the private key’s format does not match the value of private_key_format. This module will not however convert existing private keys between formats.

Choices:

  • "auto" ← (default)

  • "pkcs1"

  • "pkcs8"

  • "ssh"

regenerate

string

added in community.crypto 1.0.0

Allows to configure in which situations the module is allowed to regenerate private keys. The module will always generate a new key if the destination file does not exist.

By default, the key will be regenerated when it does not match the module’s options, except when the key cannot be read or the passphrase does not match. Please note that this changed for Ansible 2.10. For Ansible 2.9, the behavior was as if full_idempotence is specified.

If set to never, the module will fail if the key cannot be read or the passphrase is not matching, and will never regenerate an existing key.

If set to fail, the module will fail if the key does not correspond to the module’s options.

If set to partial_idempotence, the key will be regenerated if it does not conform to the module’s options. The key is not regenerated if it cannot be read (broken file), the key is protected by an unknown passphrase, or when they key is not protected by a passphrase, but a passphrase is specified.

If set to full_idempotence, the key will be regenerated if it does not conform to the module’s options. This is also the case if the key cannot be read (broken file), the key is protected by an unknown passphrase, or when they key is not protected by a passphrase, but a passphrase is specified. Make sure you have a backup when using this option!

If set to always, the module will always regenerate the key. This is equivalent to setting force to true.

Note that adjusting the comment and the permissions can be changed without regeneration. Therefore, even for never, the task can result in changed.

Choices:

  • "never"

  • "fail"

  • "partial_idempotence" ← (default)

  • "full_idempotence"

  • "always"

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

Specifies the number of bits in the private key to create. For RSA keys, the minimum size is 1024 bits and the default is 4096 bits. Generally, 2048 bits is considered sufficient. DSA keys must be exactly 1024 bits as specified by FIPS 186-2. For ECDSA keys, size determines the key length by selecting from one of three elliptic curve sizes: 256, 384 or 521 bits. Attempting to use bit lengths other than these three values for ECDSA keys will cause this module to fail. Ed25519 keys have a fixed length and the size will be ignored.

state

string

Whether the private and public keys should exist or not, taking action if the state is different from what is stated.

Choices:

  • "present" ← (default)

  • "absent"

type

string

The algorithm used to generate the SSH private key. rsa1 is for protocol version 1. rsa1 is deprecated and may not be supported by every version of ssh-keygen.

Choices:

  • "rsa" ← (default)

  • "dsa"

  • "rsa1"

  • "ecdsa"

  • "ed25519"

unsafe_writes

boolean

added in Ansible 2.2

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: full

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.

Notes

Note

  • In case the ssh key is broken or password protected, the module will fail. Set the force option to true if you want to regenerate the keypair.

  • In the case a custom mode, group, owner, or other file attribute is provided it will be applied to both key files.

Examples

- name: Generate an OpenSSH keypair with the default values (4096 bits, rsa)
  community.crypto.openssh_keypair:
    path: /tmp/id_ssh_rsa

- name: Generate an OpenSSH keypair with the default values (4096 bits, rsa) and encrypted private key
  community.crypto.openssh_keypair:
    path: /tmp/id_ssh_rsa
    passphrase: super_secret_password

- name: Generate an OpenSSH rsa keypair with a different size (2048 bits)
  community.crypto.openssh_keypair:
    path: /tmp/id_ssh_rsa
    size: 2048

- name: Force regenerate an OpenSSH keypair if it already exists
  community.crypto.openssh_keypair:
    path: /tmp/id_ssh_rsa
    force: true

- name: Generate an OpenSSH keypair with a different algorithm (dsa)
  community.crypto.openssh_keypair:
    path: /tmp/id_ssh_dsa
    type: dsa

Return Values

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

Key

Description

comment

string

The comment of the generated key.

Returned: changed or success

Sample: "test@comment"

filename

string

Path to the generated SSH private key file.

Returned: changed or success

Sample: "/tmp/id_ssh_rsa"

fingerprint

string

The fingerprint of the key.

Returned: changed or success

Sample: "SHA256:r4YCZxihVjedH2OlfjVGI6Y5xAYtdCwk8VxKyzVyYfM"

public_key

string

The public key of the generated SSH private key.

Returned: changed or success

Sample: "ssh-rsa AAAAB3Nza(...omitted...)veL4E3Xcw=="

size

integer

Size (in bits) of the SSH private key.

Returned: changed or success

Sample: 4096

type

string

Algorithm used to generate the SSH private key.

Returned: changed or success

Sample: "rsa"

Authors

  • David Kainz (@lolcube)