Add conversion filters for serial numbers (#713)

* Refactoring.

* Add parse_filter and to_filter plugins.

* Mention filters when serial numbers are accepted or returned.

plugins/filter/openssl_csr_info.py

@@ -26,6 +26,8 @@ extends_documentation_fragment:
     - community.crypto.name_encoding
 seealso:
     - module: community.crypto.openssl_csr_info
+    - plugin: community.crypto.to_serial
+      plugin_type: filter
 '''
 
 EXAMPLES = '''
@@ -268,6 +270,8 @@ _value:
             description:
                 - The CSR's authority cert serial number.
                 - Is V(none) if the C(AuthorityKeyIdentifier) extension is not present.
+                - This return value is an B(integer). If you need the serial numbers as a colon-separated hex string,
+                  such as C(11:22:33), you need to convert it to that form with P(community.crypto.to_serial#filter).
             returned: success
             type: int
             sample: 12345

plugins/filter/parse_serial.py

@@ -0,0 +1,66 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2024, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+DOCUMENTATION = """
+name: parse_serial
+short_description: Convert a serial number as a colon-separated list of hex numbers to an integer
+author: Felix Fontein (@felixfontein)
+version_added: 2.18.0
+description:
+  - "Parses a colon-separated list of hex numbers of the form C(00:11:22:33) and returns the corresponding integer."
+options:
+  _input:
+    description:
+      - A serial number represented as a colon-separated list of hex numbers between 0 and 255.
+      - These numbers are interpreted as the byte presentation of an unsigned integer in network byte order.
+        That is, C(01:00) is interpreted as the integer 256.
+    type: string
+    required: true
+seealso:
+  - plugin: community.crypto.to_serial
+    plugin_type: filter
+"""
+
+EXAMPLES = """
+- name: Parse serial number
+  ansible.builtin.debug:
+    msg: "{{ '11:22:33' | community.crypto.parse_serial }}"
+"""
+
+RETURN = """
+  _value:
+    description:
+      - The serial number as an integer.
+    type: int
+"""
+
+from ansible.errors import AnsibleFilterError
+from ansible.module_utils.common.text.converters import to_native
+from ansible.module_utils.six import string_types
+
+from ansible_collections.community.crypto.plugins.module_utils.serial import parse_serial
+
+
+def parse_serial_filter(input):
+    if not isinstance(input, string_types):
+        raise AnsibleFilterError(
+            'The input for the community.crypto.parse_serial filter must be a string; got {type} instead'.format(type=type(input))
+        )
+    try:
+        return parse_serial(to_native(input))
+    except ValueError as exc:
+        raise AnsibleFilterError(to_native(exc))
+
+
+class FilterModule(object):
+    '''Ansible jinja2 filters'''
+
+    def filters(self):
+        return {
+            'parse_serial': parse_serial_filter,
+        }

plugins/filter/to_serial.py

@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2024, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+DOCUMENTATION = """
+name: to_serial
+short_description: Convert an integer to a colon-separated list of hex numbers
+author: Felix Fontein (@felixfontein)
+version_added: 2.18.0
+description:
+  - "Converts an integer to a colon-separated list of hex numbers of the form C(00:11:22:33)."
+options:
+  _input:
+    description:
+      - The non-negative integer to convert.
+    type: int
+    required: true
+seealso:
+  - plugin: community.crypto.to_serial
+    plugin_type: filter
+"""
+
+EXAMPLES = """
+- name: Convert integer to serial number
+  ansible.builtin.debug:
+    msg: "{{ 1234567 | community.crypto.to_serial }}"
+"""
+
+RETURN = """
+  _value:
+    description:
+      - A colon-separated list of hexadecimal numbers.
+      - Letters are upper-case, and all numbers have exactly two digits.
+      - The string is never empty. The representation of C(0) is C("00").
+    type: string
+"""
+
+from ansible.errors import AnsibleFilterError
+from ansible.module_utils.common.text.converters import to_native
+from ansible.module_utils.six import integer_types
+
+from ansible_collections.community.crypto.plugins.module_utils.serial import to_serial
+
+
+def to_serial_filter(input):
+    if not isinstance(input, integer_types):
+        raise AnsibleFilterError(
+            'The input for the community.crypto.to_serial filter must be an integer; got {type} instead'.format(type=type(input))
+        )
+    if input < 0:
+        raise AnsibleFilterError('The input for the community.crypto.to_serial filter must not be negative')
+    try:
+        return to_serial(input)
+    except ValueError as exc:
+        raise AnsibleFilterError(to_native(exc))
+
+
+class FilterModule(object):
+    '''Ansible jinja2 filters'''
+
+    def filters(self):
+        return {
+            'to_serial': to_serial_filter,
+        }

plugins/filter/x509_certificate_info.py

@@ -26,6 +26,8 @@ extends_documentation_fragment:
     - community.crypto.name_encoding
 seealso:
     - module: community.crypto.x509_certificate_info
+    - plugin: community.crypto.to_serial
+      plugin_type: filter
 '''
 
 EXAMPLES = '''
@@ -253,7 +255,10 @@ _value:
             type: str
             sample: sha256WithRSAEncryption
         serial_number:
-            description: The certificate's serial number.
+            description:
+                - The certificate's serial number.
+                - This return value is an B(integer). If you need the serial numbers as a colon-separated hex string,
+                  such as C(11:22:33), you need to convert it to that form with P(community.crypto.to_serial#filter).
             returned: success
             type: int
             sample: 1234
@@ -291,6 +296,8 @@ _value:
             description:
                 - The certificate's authority cert serial number.
                 - Is V(none) if the C(AuthorityKeyIdentifier) extension is not present.
+                - This return value is an B(integer). If you need the serial numbers as a colon-separated hex string,
+                  such as C(11:22:33), you need to convert it to that form with P(community.crypto.to_serial#filter).
             returned: success
             type: int
             sample: 12345

plugins/filter/x509_crl_info.py

@@ -35,6 +35,8 @@ extends_documentation_fragment:
     - community.crypto.name_encoding
 seealso:
     - module: community.crypto.x509_crl_info
+    - plugin: community.crypto.to_serial
+      plugin_type: filter
 '''
 
 EXAMPLES = '''
@@ -100,7 +102,10 @@ _value:
             elements: dict
             contains:
                 serial_number:
-                    description: Serial number of the certificate.
+                    description:
+                        - Serial number of the certificate.
+                        - This return value is an B(integer). If you need the serial numbers as a colon-separated hex string,
+                          such as C(11:22:33), you need to convert it to that form with P(community.crypto.to_serial#filter).
                     type: int
                     sample: 1234
                 revocation_date: