Added support for certificates in DER format for `x509_certificate_info` module (#622)

* Added support for DER format

* Updated description

* Adjusted description

The content of the certificate cannot be in DER format due to an input encoding problem in the Ansible module, but it works fine when reading the certificate from a file

* Update support.py

* Added der_support_enabled flag for DER-format support

* Added changelog fragment for #603

* Fixed typo

* Fixed missing import

* Resolved issues found by static code analysis

* Update plugins/module_utils/crypto/support.py

Committed suggested change

Co-authored-by: Felix Fontein <felix@fontein.de>

* Apply suggestions from code review

Co-authored-by: Felix Fontein <felix@fontein.de>

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/622-der-format-support.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - "x509_certificate_info - added support for certificates in DER format when using ``path`` parameter (https://github.com/ansible-collections/community.crypto/issues/603)."

plugins/module_utils/crypto/module_backends/certificate_info.py

@@ -143,9 +143,9 @@ class CertificateInfoRetrieval(object):
     def _get_issuer_uri(self):
         pass
 
-    def get_info(self, prefer_one_fingerprint=False):
+    def get_info(self, prefer_one_fingerprint=False, der_support_enabled=False):
         result = dict()
-        self.cert = load_certificate(None, content=self.content, backend=self.backend)
+        self.cert = load_certificate(None, content=self.content, backend=self.backend, der_support_enabled=der_support_enabled)
 
         result['signature_algorithm'] = self._get_signature_algorithm()
         subject = self._get_subject_ordered()

plugins/module_utils/crypto/support.py

@@ -18,6 +18,10 @@ import re
 from ansible.module_utils import six
 from ansible.module_utils.common.text.converters import to_native, to_bytes
 
+from ansible_collections.community.crypto.plugins.module_utils.crypto.pem import (
+    identify_pem_format,
+)
+
 try:
     from OpenSSL import crypto
     HAS_PYOPENSSL = True
@@ -189,7 +193,7 @@ def load_publickey(path=None, content=None, backend=None):
             raise OpenSSLObjectError('Error while deserializing key: {0}'.format(e))
 
 
-def load_certificate(path, content=None, backend='cryptography'):
+def load_certificate(path, content=None, backend='cryptography', der_support_enabled=False):
     """Load the specified certificate."""
 
     try:
@@ -201,12 +205,21 @@ def load_certificate(path, content=None, backend='cryptography'):
     except (IOError, OSError) as exc:
         raise OpenSSLObjectError(exc)
     if backend == 'pyopenssl':
+        if der_support_enabled is False or identify_pem_format(cert_content):
             return crypto.load_certificate(crypto.FILETYPE_PEM, cert_content)
+        elif der_support_enabled:
+            raise OpenSSLObjectError('Certificate in DER format is not supported by the pyopenssl backend.')
     elif backend == 'cryptography':
+        if der_support_enabled is False or identify_pem_format(cert_content):
             try:
                 return x509.load_pem_x509_certificate(cert_content, cryptography_backend())
             except ValueError as exc:
                 raise OpenSSLObjectError(exc)
+        elif der_support_enabled:
+            try:
+                return x509.load_der_x509_certificate(cert_content, cryptography_backend())
+            except ValueError as exc:
+                raise OpenSSLObjectError('Cannot parse DER certificate: {0}'.format(exc))
 
 
 def load_certificate_request(path, content=None, backend='cryptography'):

plugins/modules/x509_certificate_info.py

@@ -40,6 +40,7 @@ options:
         description:
             - Remote absolute path where the certificate file is loaded from.
             - Either I(path) or I(content) must be specified, but not both.
+            - PEM and DER formats are supported.
         type: path
     content:
         description:
@@ -447,7 +448,7 @@ def main():
             valid_at[k] = get_relative_time_option(v, 'valid_at.{0}'.format(k))
 
     try:
-        result = module_backend.get_info()
+        result = module_backend.get_info(der_support_enabled=module.params['content'] is None)
 
         not_before = module_backend.get_not_before()
         not_after = module_backend.get_not_after()