openssh_cert – Generate OpenSSH host or user certificates

From Get docs
Ansible/docs/2.8/modules/openssh cert module


openssh_cert – Generate OpenSSH host or user certificates

New in version 2.8.


Synopsis

  • Generate and regenerate OpenSSH host or user certificates.

Requirements

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

  • ssh-keygen

Parameters

Parameter Choices/Defaults Comments

attributes

string

added in 2.3

The attributes the resulting file or directory 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.


aliases: attr

force

boolean

  • no

  • yes

Should the certificate be regenerated even if it already exists and is valid.

group

string

Name of the group that should own the file/directory, as would be fed to chown.

identifier

string

Specify the key identity when signing a public key. The identifier that is logged by the server when the certificate is used for authentication.

mode

string

The permissions the resulting file or directory 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).

options

list

Specify certificate options when signing a key. The option that are valid for user certificates are:

clear: Clear all enabled permissions. This is useful for clearing the default set of permissions so permissions may be added individually.

force-command=command: Forces the execution of command instead of any shell or command specified by the user when the certificate is used for authentication.

no-agent-forwarding: Disable ssh-agent forwarding (permitted by default).

no-port-forwarding: Disable port forwarding (permitted by default).

no-pty Disable: PTY allocation (permitted by default).

no-user-rc: Disable execution of ~/.ssh/rc by sshd (permitted by default).

no-x11-forwarding: Disable X11 forwarding (permitted by default)

permit-agent-forwarding: Allows ssh-agent forwarding.

permit-port-forwarding: Allows port forwarding.

permit-pty: Allows PTY allocation.

permit-user-rc: Allows execution of ~/.ssh/rc by sshd.

permit-x11-forwarding: Allows X11 forwarding.

source-address=address_list: Restrict the source addresses from which the certificate is considered valid. The address_list is a comma-separated list of one or more address/netmask pairs in CIDR format.

At present, no options are valid for host keys.

owner

string

Name of the user that should own the file/directory, as would be fed to chown.

path

path / required

Path of the file containing the certificate.

principals

list

Certificates may be limited to be valid for a set of principal (user/host) names. By default, generated certificates are valid for all users or hosts.

public_key

path / required

The path to the public key that will be signed with the signing key in order to generate the certificate.

selevel

string

Default:

"s0"

The level part of the SELinux file 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.

serial_number

integer

Specify the certificate serial number. The serial number is logged by the server when the certificate is used for authentication. The certificate serial number may be used in a KeyRevocationList. The serial number may be omitted for checks, but must be specified again for a new certificate. Note: The default value set by ssh-keygen is 0.

serole

string

The role part of the SELinux file context.

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

setype

string

The type part of the SELinux file context.

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

seuser

string

The user part of the SELinux file 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.

signing_key

path / required

The path to the private openssh key that is used for signing the public key in order to generate the certificate.

state

string

  • present

  • absent

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

type

string / required

  • host
  • user

Whether the module should generate a host or a user certificate.

unsafe_writes

boolean

added in 2.2

  • no

  • yes

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

By default this module uses atomic operations to prevent data corruption or inconsistent reads from the target files, but sometimes systems are configured or just broken in ways that prevent this. One example is docker mounted files, 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 files 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.

valid_at

string

Check if the certificate is valid at a certain point in time. If it is not the certificate will be regenerated. Time will always be interpreted as UTC. Mainly to be used with relative timespec for valid_from and / or valid_to. Note that if using relative time this module is NOT idempotent.

valid_from

string / required

The point in time the certificate is valid from. Time can be specified either as relative time or as absolute timestamp. Time will always be interpreted as UTC. Valid formats are: [+-]timespec | YYYY-MM-DD | YYYY-MM-DDTHH:MM:SS | YYYY-MM-DD HH:MM:SS | always where timespec can be an integer + [w | d | h | m | s] (e.g. +32w1d2h. Note that if using relative time this module is NOT idempotent.

valid_to

string / required

The point in time the certificate is valid to. Time can be specified either as relative time or as absolute timestamp. Time will always be interpreted as UTC. Valid formats are: [+-]timespec | YYYY-MM-DD | YYYY-MM-DDTHH:MM:SS | YYYY-MM-DD HH:MM:SS | forever where timespec can be an integer + [w | d | h | m | s] (e.g. +32w1d2h. Note that if using relative time this module is NOT idempotent.



Examples

# Generate an OpenSSH user certificate that is valid forever and for all users
- openssh_cert:
    type: user
    signing_key: /path/to/private_key
    public_key: /path/to/public_key.pub
    path: /path/to/certificate
    valid_from: always
    valid_to: forever

# Generate an OpenSSH host certificate that is valid for 32 weeks from now and will be regenerated
# if it is valid for less than 2 weeks from the time the module is being run
- openssh_cert:
    type: host
    signing_key: /path/to/private_key
    public_key: /path/to/public_key.pub
    path: /path/to/certificate
    valid_from: +0s
    valid_to: +32w
    valid_at: +2w

# Generate an OpenSSH host certificate that is valid forever and only for example.com and examplehost
- openssh_cert:
    type: host
    signing_key: /path/to/private_key
    public_key: /path/to/public_key.pub
    path: /path/to/certificate
    valid_from: always
    valid_to: forever
    principals:
        - example.com
        - examplehost

# Generate an OpenSSH host Certificate that is valid from 21.1.2001 to 21.1.2019
- openssh_cert:
    type: host
    signing_key: /path/to/private_key
    public_key: /path/to/public_key.pub
    path: /path/to/certificate
    valid_from: "2001-01-21"
    valid_to: "2019-01-21"

# Generate an OpenSSH user Certificate with clear and force-command option:
- openssh_cert:
    type: user
    signing_key: /path/to/private_key
    public_key: /path/to/public_key.pub
    path: /path/to/certificate
    valid_from: always
    valid_to: forever
    options:
        - "clear"
        - "force-command=/tmp/bla/foo"

Return Values

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

Key Returned Description

filename

string

changed or success

path to the certificate


Sample:

/tmp/certificate-cert.pub

info

list

change or success

Information about the certificate. Output of ssh-keygen -L -f.


type

string

changed or success

type of the certificate (host or user)


Sample:

host




Status

Authors

  • David Kainz (@lolcube)

Hint

If you notice any issues in this documentation you can edit this document to improve it.


© 2012–2018 Michael DeHaan
© 2018–2019 Red Hat, Inc.
Licensed under the GNU General Public License version 3.
https://docs.ansible.com/ansible/2.8/modules/openssh_cert_module.html