openssl_csr_info: move main code to module_utils to allow easier implementation of diff mode (#204)

* Move openssl_csr_info code to module_utils.

* Add changelog fragment.

* Apply suggestions from code review

Co-authored-by: Ajpantuso <ajpantuso@gmail.com>

Co-authored-by: Ajpantuso <ajpantuso@gmail.com>

changelogs/fragments/204-openssl_csr_info.yml

@@ -0,0 +1,2 @@
+minor_changes:
+- "openssl_csr_info - refactor module to allow code re-use for diff mode (https://github.com/ansible-collections/community.crypto/pull/204)."

plugins/module_utils/crypto/module_backends/csr_info.py

@@ -0,0 +1,461 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright: (c) 2016-2017, Yanis Guenane <yanis+ansible@guenane.org>
+# Copyright: (c) 2017, Markus Teufelberger <mteufelberger+ansible@mgit.at>
+# Copyright: (c) 2020, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+import abc
+import binascii
+import traceback
+
+from distutils.version import LooseVersion
+
+from ansible.module_utils import six
+from ansible.module_utils.basic import missing_required_lib
+from ansible.module_utils._text import to_native, to_text, to_bytes
+
+from ansible_collections.community.crypto.plugins.module_utils.crypto.support import (
+    load_certificate_request,
+    get_fingerprint_of_bytes,
+)
+
+from ansible_collections.community.crypto.plugins.module_utils.crypto.cryptography_support import (
+    cryptography_decode_name,
+    cryptography_get_extensions_from_csr,
+    cryptography_oid_to_name,
+)
+
+from ansible_collections.community.crypto.plugins.module_utils.crypto.pyopenssl_support import (
+    pyopenssl_get_extensions_from_csr,
+    pyopenssl_normalize_name,
+    pyopenssl_normalize_name_attribute,
+    pyopenssl_parse_name_constraints,
+)
+
+MINIMAL_CRYPTOGRAPHY_VERSION = '1.3'
+MINIMAL_PYOPENSSL_VERSION = '0.15'
+
+PYOPENSSL_IMP_ERR = None
+try:
+    import OpenSSL
+    from OpenSSL import crypto
+    PYOPENSSL_VERSION = LooseVersion(OpenSSL.__version__)
+    if OpenSSL.SSL.OPENSSL_VERSION_NUMBER >= 0x10100000:
+        # OpenSSL 1.1.0 or newer
+        OPENSSL_MUST_STAPLE_NAME = b"tlsfeature"
+        OPENSSL_MUST_STAPLE_VALUE = b"status_request"
+    else:
+        # OpenSSL 1.0.x or older
+        OPENSSL_MUST_STAPLE_NAME = b"1.3.6.1.5.5.7.1.24"
+        OPENSSL_MUST_STAPLE_VALUE = b"DER:30:03:02:01:05"
+except ImportError:
+    PYOPENSSL_IMP_ERR = traceback.format_exc()
+    PYOPENSSL_FOUND = False
+else:
+    PYOPENSSL_FOUND = True
+
+CRYPTOGRAPHY_IMP_ERR = None
+try:
+    import cryptography
+    from cryptography import x509
+    from cryptography.hazmat.primitives import serialization
+    CRYPTOGRAPHY_VERSION = LooseVersion(cryptography.__version__)
+except ImportError:
+    CRYPTOGRAPHY_IMP_ERR = traceback.format_exc()
+    CRYPTOGRAPHY_FOUND = False
+else:
+    CRYPTOGRAPHY_FOUND = True
+
+
+TIMESTAMP_FORMAT = "%Y%m%d%H%M%SZ"
+
+
+@six.add_metaclass(abc.ABCMeta)
+class CSRInfoRetrieval(object):
+    def __init__(self, module, backend, content, validate_signature):
+        # content must be a bytes string
+        self.module = module
+        self.backend = backend
+        self.content = content
+        self.validate_signature = validate_signature
+
+    @abc.abstractmethod
+    def _get_subject_ordered(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_key_usage(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_extended_key_usage(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_basic_constraints(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_ocsp_must_staple(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_subject_alt_name(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_name_constraints(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_public_key(self, binary):
+        pass
+
+    @abc.abstractmethod
+    def _get_subject_key_identifier(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_authority_key_identifier(self):
+        pass
+
+    @abc.abstractmethod
+    def _get_all_extensions(self):
+        pass
+
+    @abc.abstractmethod
+    def _is_signature_valid(self):
+        pass
+
+    def get_info(self):
+        result = dict()
+        self.csr = load_certificate_request(None, content=self.content, backend=self.backend)
+
+        subject = self._get_subject_ordered()
+        result['subject'] = dict()
+        for k, v in subject:
+            result['subject'][k] = v
+        result['subject_ordered'] = subject
+        result['key_usage'], result['key_usage_critical'] = self._get_key_usage()
+        result['extended_key_usage'], result['extended_key_usage_critical'] = self._get_extended_key_usage()
+        result['basic_constraints'], result['basic_constraints_critical'] = self._get_basic_constraints()
+        result['ocsp_must_staple'], result['ocsp_must_staple_critical'] = self._get_ocsp_must_staple()
+        result['subject_alt_name'], result['subject_alt_name_critical'] = self._get_subject_alt_name()
+        (
+            result['name_constraints_permitted'],
+            result['name_constraints_excluded'],
+            result['name_constraints_critical'],
+        ) = self._get_name_constraints()
+
+        result['public_key'] = self._get_public_key(binary=False)
+        pk = self._get_public_key(binary=True)
+        result['public_key_fingerprints'] = get_fingerprint_of_bytes(pk) if pk is not None else dict()
+
+        if self.backend != 'pyopenssl':
+            ski = self._get_subject_key_identifier()
+            if ski is not None:
+                ski = to_native(binascii.hexlify(ski))
+                ski = ':'.join([ski[i:i + 2] for i in range(0, len(ski), 2)])
+            result['subject_key_identifier'] = ski
+
+            aki, aci, acsn = self._get_authority_key_identifier()
+            if aki is not None:
+                aki = to_native(binascii.hexlify(aki))
+                aki = ':'.join([aki[i:i + 2] for i in range(0, len(aki), 2)])
+            result['authority_key_identifier'] = aki
+            result['authority_cert_issuer'] = aci
+            result['authority_cert_serial_number'] = acsn
+
+        result['extensions_by_oid'] = self._get_all_extensions()
+
+        result['signature_valid'] = self._is_signature_valid()
+        if self.validate_signature and not result['signature_valid']:
+            self.module.fail_json(
+                msg='CSR signature is invalid!',
+                **result
+            )
+        return result
+
+
+class CSRInfoRetrievalCryptography(CSRInfoRetrieval):
+    """Validate the supplied CSR, using the cryptography backend"""
+    def __init__(self, module, content, validate_signature):
+        super(CSRInfoRetrievalCryptography, self).__init__(module, 'cryptography', content, validate_signature)
+
+    def _get_subject_ordered(self):
+        result = []
+        for attribute in self.csr.subject:
+            result.append([cryptography_oid_to_name(attribute.oid), attribute.value])
+        return result
+
+    def _get_key_usage(self):
+        try:
+            current_key_ext = self.csr.extensions.get_extension_for_class(x509.KeyUsage)
+            current_key_usage = current_key_ext.value
+            key_usage = dict(
+                digital_signature=current_key_usage.digital_signature,
+                content_commitment=current_key_usage.content_commitment,
+                key_encipherment=current_key_usage.key_encipherment,
+                data_encipherment=current_key_usage.data_encipherment,
+                key_agreement=current_key_usage.key_agreement,
+                key_cert_sign=current_key_usage.key_cert_sign,
+                crl_sign=current_key_usage.crl_sign,
+                encipher_only=False,
+                decipher_only=False,
+            )
+            if key_usage['key_agreement']:
+                key_usage.update(dict(
+                    encipher_only=current_key_usage.encipher_only,
+                    decipher_only=current_key_usage.decipher_only
+                ))
+
+            key_usage_names = dict(
+                digital_signature='Digital Signature',
+                content_commitment='Non Repudiation',
+                key_encipherment='Key Encipherment',
+                data_encipherment='Data Encipherment',
+                key_agreement='Key Agreement',
+                key_cert_sign='Certificate Sign',
+                crl_sign='CRL Sign',
+                encipher_only='Encipher Only',
+                decipher_only='Decipher Only',
+            )
+            return sorted([
+                key_usage_names[name] for name, value in key_usage.items() if value
+            ]), current_key_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, False
+
+    def _get_extended_key_usage(self):
+        try:
+            ext_keyusage_ext = self.csr.extensions.get_extension_for_class(x509.ExtendedKeyUsage)
+            return sorted([
+                cryptography_oid_to_name(eku) for eku in ext_keyusage_ext.value
+            ]), ext_keyusage_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, False
+
+    def _get_basic_constraints(self):
+        try:
+            ext_keyusage_ext = self.csr.extensions.get_extension_for_class(x509.BasicConstraints)
+            result = ['CA:{0}'.format('TRUE' if ext_keyusage_ext.value.ca else 'FALSE')]
+            if ext_keyusage_ext.value.path_length is not None:
+                result.append('pathlen:{0}'.format(ext_keyusage_ext.value.path_length))
+            return sorted(result), ext_keyusage_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, False
+
+    def _get_ocsp_must_staple(self):
+        try:
+            try:
+                # This only works with cryptography >= 2.1
+                tlsfeature_ext = self.csr.extensions.get_extension_for_class(x509.TLSFeature)
+                value = cryptography.x509.TLSFeatureType.status_request in tlsfeature_ext.value
+            except AttributeError:
+                # Fallback for cryptography < 2.1
+                oid = x509.oid.ObjectIdentifier("1.3.6.1.5.5.7.1.24")
+                tlsfeature_ext = self.csr.extensions.get_extension_for_oid(oid)
+                value = tlsfeature_ext.value.value == b"\x30\x03\x02\x01\x05"
+            return value, tlsfeature_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, False
+
+    def _get_subject_alt_name(self):
+        try:
+            san_ext = self.csr.extensions.get_extension_for_class(x509.SubjectAlternativeName)
+            result = [cryptography_decode_name(san) for san in san_ext.value]
+            return result, san_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, False
+
+    def _get_name_constraints(self):
+        try:
+            nc_ext = self.csr.extensions.get_extension_for_class(x509.NameConstraints)
+            permitted = [cryptography_decode_name(san) for san in nc_ext.value.permitted_subtrees or []]
+            excluded = [cryptography_decode_name(san) for san in nc_ext.value.excluded_subtrees or []]
+            return permitted, excluded, nc_ext.critical
+        except cryptography.x509.ExtensionNotFound:
+            return None, None, False
+
+    def _get_public_key(self, binary):
+        return self.csr.public_key().public_bytes(
+            serialization.Encoding.DER if binary else serialization.Encoding.PEM,
+            serialization.PublicFormat.SubjectPublicKeyInfo
+        )
+
+    def _get_subject_key_identifier(self):
+        try:
+            ext = self.csr.extensions.get_extension_for_class(x509.SubjectKeyIdentifier)
+            return ext.value.digest
+        except cryptography.x509.ExtensionNotFound:
+            return None
+
+    def _get_authority_key_identifier(self):
+        try:
+            ext = self.csr.extensions.get_extension_for_class(x509.AuthorityKeyIdentifier)
+            issuer = None
+            if ext.value.authority_cert_issuer is not None:
+                issuer = [cryptography_decode_name(san) for san in ext.value.authority_cert_issuer]
+            return ext.value.key_identifier, issuer, ext.value.authority_cert_serial_number
+        except cryptography.x509.ExtensionNotFound:
+            return None, None, None
+
+    def _get_all_extensions(self):
+        return cryptography_get_extensions_from_csr(self.csr)
+
+    def _is_signature_valid(self):
+        return self.csr.is_signature_valid
+
+
+class CSRInfoRetrievalPyOpenSSL(CSRInfoRetrieval):
+    """validate the supplied CSR."""
+
+    def __init__(self, module, content, validate_signature):
+        super(CSRInfoRetrievalPyOpenSSL, self).__init__(module, 'pyopenssl', content, validate_signature)
+
+    def __get_name(self, name):
+        result = []
+        for sub in name.get_components():
+            result.append([pyopenssl_normalize_name(sub[0]), to_text(sub[1])])
+        return result
+
+    def _get_subject_ordered(self):
+        return self.__get_name(self.csr.get_subject())
+
+    def _get_extension(self, short_name):
+        for extension in self.csr.get_extensions():
+            if extension.get_short_name() == short_name:
+                result = [
+                    pyopenssl_normalize_name(usage.strip()) for usage in to_text(extension, errors='surrogate_or_strict').split(',')
+                ]
+                return sorted(result), bool(extension.get_critical())
+        return None, False
+
+    def _get_key_usage(self):
+        return self._get_extension(b'keyUsage')
+
+    def _get_extended_key_usage(self):
+        return self._get_extension(b'extendedKeyUsage')
+
+    def _get_basic_constraints(self):
+        return self._get_extension(b'basicConstraints')
+
+    def _get_ocsp_must_staple(self):
+        extensions = self.csr.get_extensions()
+        oms_ext = [
+            ext for ext in extensions
+            if to_bytes(ext.get_short_name()) == OPENSSL_MUST_STAPLE_NAME and to_bytes(ext) == OPENSSL_MUST_STAPLE_VALUE
+        ]
+        if OpenSSL.SSL.OPENSSL_VERSION_NUMBER < 0x10100000:
+            # Older versions of libssl don't know about OCSP Must Staple
+            oms_ext.extend([ext for ext in extensions if ext.get_short_name() == b'UNDEF' and ext.get_data() == b'\x30\x03\x02\x01\x05'])
+        if oms_ext:
+            return True, bool(oms_ext[0].get_critical())
+        else:
+            return None, False
+
+    def _get_subject_alt_name(self):
+        for extension in self.csr.get_extensions():
+            if extension.get_short_name() == b'subjectAltName':
+                result = [pyopenssl_normalize_name_attribute(altname.strip()) for altname in
+                          to_text(extension, errors='surrogate_or_strict').split(', ')]
+                return result, bool(extension.get_critical())
+        return None, False
+
+    def _get_name_constraints(self):
+        for extension in self.csr.get_extensions():
+            if extension.get_short_name() == b'nameConstraints':
+                permitted, excluded = pyopenssl_parse_name_constraints(extension)
+                return permitted, excluded, bool(extension.get_critical())
+        return None, None, False
+
+    def _get_public_key(self, binary):
+        try:
+            return crypto.dump_publickey(
+                crypto.FILETYPE_ASN1 if binary else crypto.FILETYPE_PEM,
+                self.csr.get_pubkey()
+            )
+        except AttributeError:
+            try:
+                bio = crypto._new_mem_buf()
+                if binary:
+                    rc = crypto._lib.i2d_PUBKEY_bio(bio, self.csr.get_pubkey()._pkey)
+                else:
+                    rc = crypto._lib.PEM_write_bio_PUBKEY(bio, self.csr.get_pubkey()._pkey)
+                if rc != 1:
+                    crypto._raise_current_error()
+                return crypto._bio_to_string(bio)
+            except AttributeError:
+                self.module.warn('Your pyOpenSSL version does not support dumping public keys. '
+                                 'Please upgrade to version 16.0 or newer, or use the cryptography backend.')
+
+    def _get_subject_key_identifier(self):
+        # Won't be implemented
+        return None
+
+    def _get_authority_key_identifier(self):
+        # Won't be implemented
+        return None, None, None
+
+    def _get_all_extensions(self):
+        return pyopenssl_get_extensions_from_csr(self.csr)
+
+    def _is_signature_valid(self):
+        try:
+            return bool(self.csr.verify(self.csr.get_pubkey()))
+        except crypto.Error:
+            # OpenSSL error means that key is not consistent
+            return False
+
+
+def get_csr_info(module, backend, content, validate_signature=True):
+    if backend == 'cryptography':
+        info = CSRInfoRetrievalCryptography(module, content, validate_signature=validate_signature)
+    elif backend == 'pyopenssl':
+        info = CSRInfoRetrievalPyOpenSSL(module, content, validate_signature=validate_signature)
+    return info.get_info()
+
+
+def select_backend(module, backend, content, validate_signature=True):
+    if backend == 'auto':
+        # Detection what is possible
+        can_use_cryptography = CRYPTOGRAPHY_FOUND and CRYPTOGRAPHY_VERSION >= LooseVersion(MINIMAL_CRYPTOGRAPHY_VERSION)
+        can_use_pyopenssl = PYOPENSSL_FOUND and PYOPENSSL_VERSION >= LooseVersion(MINIMAL_PYOPENSSL_VERSION)
+
+        # First try cryptography, then pyOpenSSL
+        if can_use_cryptography:
+            backend = 'cryptography'
+        elif can_use_pyopenssl:
+            backend = 'pyopenssl'
+
+        # Success?
+        if backend == 'auto':
+            module.fail_json(msg=("Can't detect any of the required Python libraries "
+                                  "cryptography (>= {0}) or PyOpenSSL (>= {1})").format(
+                                      MINIMAL_CRYPTOGRAPHY_VERSION,
+                                      MINIMAL_PYOPENSSL_VERSION))
+
+    if backend == 'pyopenssl':
+        if not PYOPENSSL_FOUND:
+            module.fail_json(msg=missing_required_lib('pyOpenSSL >= {0}'.format(MINIMAL_PYOPENSSL_VERSION)),
+                             exception=PYOPENSSL_IMP_ERR)
+        try:
+            getattr(crypto.X509Req, 'get_extensions')
+        except AttributeError:
+            module.fail_json(msg='You need to have PyOpenSSL>=0.15 to generate CSRs')
+
+        module.deprecate('The module is using the PyOpenSSL backend. This backend has been deprecated',
+                         version='2.0.0', collection_name='community.crypto')
+        return backend, CSRInfoRetrievalPyOpenSSL(module, content, validate_signature=validate_signature)
+    elif backend == 'cryptography':
+        if not CRYPTOGRAPHY_FOUND:
+            module.fail_json(msg=missing_required_lib('cryptography >= {0}'.format(MINIMAL_CRYPTOGRAPHY_VERSION)),
+                             exception=CRYPTOGRAPHY_IMP_ERR)
+        return backend, CSRInfoRetrievalCryptography(module, content, validate_signature=validate_signature)
+    else:
+        raise ValueError('Unsupported value for backend: {0}'.format(backend))

plugins/modules/openssl_csr_info.py

@@ -225,428 +225,17 @@ authority_cert_serial_number:
 '''
 
 
-import abc
-import binascii
-import os
-import traceback
-
-from distutils.version import LooseVersion
-
-from ansible.module_utils.basic import AnsibleModule, missing_required_lib
-from ansible.module_utils._text import to_native, to_text, to_bytes
+from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils._text import to_native
 
 from ansible_collections.community.crypto.plugins.module_utils.crypto.basic import (
     OpenSSLObjectError,
 )
 
-from ansible_collections.community.crypto.plugins.module_utils.crypto.support import (
-    OpenSSLObject,
-    load_certificate_request,
-    get_fingerprint_of_bytes,
+from ansible_collections.community.crypto.plugins.module_utils.crypto.module_backends.csr_info import (
+    select_backend,
 )
 
-from ansible_collections.community.crypto.plugins.module_utils.crypto.cryptography_support import (
-    cryptography_decode_name,
-    cryptography_get_extensions_from_csr,
-    cryptography_oid_to_name,
-)
-
-from ansible_collections.community.crypto.plugins.module_utils.crypto.pyopenssl_support import (
-    pyopenssl_get_extensions_from_csr,
-    pyopenssl_normalize_name,
-    pyopenssl_normalize_name_attribute,
-    pyopenssl_parse_name_constraints,
-)
-
-MINIMAL_CRYPTOGRAPHY_VERSION = '1.3'
-MINIMAL_PYOPENSSL_VERSION = '0.15'
-
-PYOPENSSL_IMP_ERR = None
-try:
-    import OpenSSL
-    from OpenSSL import crypto
-    PYOPENSSL_VERSION = LooseVersion(OpenSSL.__version__)
-    if OpenSSL.SSL.OPENSSL_VERSION_NUMBER >= 0x10100000:
-        # OpenSSL 1.1.0 or newer
-        OPENSSL_MUST_STAPLE_NAME = b"tlsfeature"
-        OPENSSL_MUST_STAPLE_VALUE = b"status_request"
-    else:
-        # OpenSSL 1.0.x or older
-        OPENSSL_MUST_STAPLE_NAME = b"1.3.6.1.5.5.7.1.24"
-        OPENSSL_MUST_STAPLE_VALUE = b"DER:30:03:02:01:05"
-except ImportError:
-    PYOPENSSL_IMP_ERR = traceback.format_exc()
-    PYOPENSSL_FOUND = False
-else:
-    PYOPENSSL_FOUND = True
-
-CRYPTOGRAPHY_IMP_ERR = None
-try:
-    import cryptography
-    from cryptography import x509
-    from cryptography.hazmat.primitives import serialization
-    CRYPTOGRAPHY_VERSION = LooseVersion(cryptography.__version__)
-except ImportError:
-    CRYPTOGRAPHY_IMP_ERR = traceback.format_exc()
-    CRYPTOGRAPHY_FOUND = False
-else:
-    CRYPTOGRAPHY_FOUND = True
-
-
-TIMESTAMP_FORMAT = "%Y%m%d%H%M%SZ"
-
-
-class CertificateSigningRequestInfo(OpenSSLObject):
-    def __init__(self, module, backend):
-        super(CertificateSigningRequestInfo, self).__init__(
-            module.params['path'] or '',
-            'present',
-            False,
-            module.check_mode,
-        )
-        self.backend = backend
-        self.module = module
-        self.content = module.params['content']
-        if self.content is not None:
-            self.content = self.content.encode('utf-8')
-
-    def generate(self):
-        # Empty method because OpenSSLObject wants this
-        pass
-
-    def dump(self):
-        # Empty method because OpenSSLObject wants this
-        pass
-
-    @abc.abstractmethod
-    def _get_subject_ordered(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_key_usage(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_extended_key_usage(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_basic_constraints(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_ocsp_must_staple(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_subject_alt_name(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_name_constraints(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_public_key(self, binary):
-        pass
-
-    @abc.abstractmethod
-    def _get_subject_key_identifier(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_authority_key_identifier(self):
-        pass
-
-    @abc.abstractmethod
-    def _get_all_extensions(self):
-        pass
-
-    @abc.abstractmethod
-    def _is_signature_valid(self):
-        pass
-
-    def get_info(self):
-        result = dict()
-        self.csr = load_certificate_request(self.path, content=self.content, backend=self.backend)
-
-        subject = self._get_subject_ordered()
-        result['subject'] = dict()
-        for k, v in subject:
-            result['subject'][k] = v
-        result['subject_ordered'] = subject
-        result['key_usage'], result['key_usage_critical'] = self._get_key_usage()
-        result['extended_key_usage'], result['extended_key_usage_critical'] = self._get_extended_key_usage()
-        result['basic_constraints'], result['basic_constraints_critical'] = self._get_basic_constraints()
-        result['ocsp_must_staple'], result['ocsp_must_staple_critical'] = self._get_ocsp_must_staple()
-        result['subject_alt_name'], result['subject_alt_name_critical'] = self._get_subject_alt_name()
-        (
-            result['name_constraints_permitted'],
-            result['name_constraints_excluded'],
-            result['name_constraints_critical'],
-        ) = self._get_name_constraints()
-
-        result['public_key'] = self._get_public_key(binary=False)
-        pk = self._get_public_key(binary=True)
-        result['public_key_fingerprints'] = get_fingerprint_of_bytes(pk) if pk is not None else dict()
-
-        if self.backend != 'pyopenssl':
-            ski = self._get_subject_key_identifier()
-            if ski is not None:
-                ski = to_native(binascii.hexlify(ski))
-                ski = ':'.join([ski[i:i + 2] for i in range(0, len(ski), 2)])
-            result['subject_key_identifier'] = ski
-
-            aki, aci, acsn = self._get_authority_key_identifier()
-            if aki is not None:
-                aki = to_native(binascii.hexlify(aki))
-                aki = ':'.join([aki[i:i + 2] for i in range(0, len(aki), 2)])
-            result['authority_key_identifier'] = aki
-            result['authority_cert_issuer'] = aci
-            result['authority_cert_serial_number'] = acsn
-
-        result['extensions_by_oid'] = self._get_all_extensions()
-
-        result['signature_valid'] = self._is_signature_valid()
-        if not result['signature_valid']:
-            self.module.fail_json(
-                msg='CSR signature is invalid!',
-                **result
-            )
-        return result
-
-
-class CertificateSigningRequestInfoCryptography(CertificateSigningRequestInfo):
-    """Validate the supplied CSR, using the cryptography backend"""
-    def __init__(self, module):
-        super(CertificateSigningRequestInfoCryptography, self).__init__(module, 'cryptography')
-
-    def _get_subject_ordered(self):
-        result = []
-        for attribute in self.csr.subject:
-            result.append([cryptography_oid_to_name(attribute.oid), attribute.value])
-        return result
-
-    def _get_key_usage(self):
-        try:
-            current_key_ext = self.csr.extensions.get_extension_for_class(x509.KeyUsage)
-            current_key_usage = current_key_ext.value
-            key_usage = dict(
-                digital_signature=current_key_usage.digital_signature,
-                content_commitment=current_key_usage.content_commitment,
-                key_encipherment=current_key_usage.key_encipherment,
-                data_encipherment=current_key_usage.data_encipherment,
-                key_agreement=current_key_usage.key_agreement,
-                key_cert_sign=current_key_usage.key_cert_sign,
-                crl_sign=current_key_usage.crl_sign,
-                encipher_only=False,
-                decipher_only=False,
-            )
-            if key_usage['key_agreement']:
-                key_usage.update(dict(
-                    encipher_only=current_key_usage.encipher_only,
-                    decipher_only=current_key_usage.decipher_only
-                ))
-
-            key_usage_names = dict(
-                digital_signature='Digital Signature',
-                content_commitment='Non Repudiation',
-                key_encipherment='Key Encipherment',
-                data_encipherment='Data Encipherment',
-                key_agreement='Key Agreement',
-                key_cert_sign='Certificate Sign',
-                crl_sign='CRL Sign',
-                encipher_only='Encipher Only',
-                decipher_only='Decipher Only',
-            )
-            return sorted([
-                key_usage_names[name] for name, value in key_usage.items() if value
-            ]), current_key_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, False
-
-    def _get_extended_key_usage(self):
-        try:
-            ext_keyusage_ext = self.csr.extensions.get_extension_for_class(x509.ExtendedKeyUsage)
-            return sorted([
-                cryptography_oid_to_name(eku) for eku in ext_keyusage_ext.value
-            ]), ext_keyusage_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, False
-
-    def _get_basic_constraints(self):
-        try:
-            ext_keyusage_ext = self.csr.extensions.get_extension_for_class(x509.BasicConstraints)
-            result = []
-            result.append('CA:{0}'.format('TRUE' if ext_keyusage_ext.value.ca else 'FALSE'))
-            if ext_keyusage_ext.value.path_length is not None:
-                result.append('pathlen:{0}'.format(ext_keyusage_ext.value.path_length))
-            return sorted(result), ext_keyusage_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, False
-
-    def _get_ocsp_must_staple(self):
-        try:
-            try:
-                # This only works with cryptography >= 2.1
-                tlsfeature_ext = self.csr.extensions.get_extension_for_class(x509.TLSFeature)
-                value = cryptography.x509.TLSFeatureType.status_request in tlsfeature_ext.value
-            except AttributeError as dummy:
-                # Fallback for cryptography < 2.1
-                oid = x509.oid.ObjectIdentifier("1.3.6.1.5.5.7.1.24")
-                tlsfeature_ext = self.csr.extensions.get_extension_for_oid(oid)
-                value = tlsfeature_ext.value.value == b"\x30\x03\x02\x01\x05"
-            return value, tlsfeature_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, False
-
-    def _get_subject_alt_name(self):
-        try:
-            san_ext = self.csr.extensions.get_extension_for_class(x509.SubjectAlternativeName)
-            result = [cryptography_decode_name(san) for san in san_ext.value]
-            return result, san_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, False
-
-    def _get_name_constraints(self):
-        try:
-            nc_ext = self.csr.extensions.get_extension_for_class(x509.NameConstraints)
-            permitted = [cryptography_decode_name(san) for san in nc_ext.value.permitted_subtrees or []]
-            excluded = [cryptography_decode_name(san) for san in nc_ext.value.excluded_subtrees or []]
-            return permitted, excluded, nc_ext.critical
-        except cryptography.x509.ExtensionNotFound:
-            return None, None, False
-
-    def _get_public_key(self, binary):
-        return self.csr.public_key().public_bytes(
-            serialization.Encoding.DER if binary else serialization.Encoding.PEM,
-            serialization.PublicFormat.SubjectPublicKeyInfo
-        )
-
-    def _get_subject_key_identifier(self):
-        try:
-            ext = self.csr.extensions.get_extension_for_class(x509.SubjectKeyIdentifier)
-            return ext.value.digest
-        except cryptography.x509.ExtensionNotFound:
-            return None
-
-    def _get_authority_key_identifier(self):
-        try:
-            ext = self.csr.extensions.get_extension_for_class(x509.AuthorityKeyIdentifier)
-            issuer = None
-            if ext.value.authority_cert_issuer is not None:
-                issuer = [cryptography_decode_name(san) for san in ext.value.authority_cert_issuer]
-            return ext.value.key_identifier, issuer, ext.value.authority_cert_serial_number
-        except cryptography.x509.ExtensionNotFound:
-            return None, None, None
-
-    def _get_all_extensions(self):
-        return cryptography_get_extensions_from_csr(self.csr)
-
-    def _is_signature_valid(self):
-        return self.csr.is_signature_valid
-
-
-class CertificateSigningRequestInfoPyOpenSSL(CertificateSigningRequestInfo):
-    """validate the supplied CSR."""
-
-    def __init__(self, module):
-        super(CertificateSigningRequestInfoPyOpenSSL, self).__init__(module, 'pyopenssl')
-
-    def __get_name(self, name):
-        result = []
-        for sub in name.get_components():
-            result.append([pyopenssl_normalize_name(sub[0]), to_text(sub[1])])
-        return result
-
-    def _get_subject_ordered(self):
-        return self.__get_name(self.csr.get_subject())
-
-    def _get_extension(self, short_name):
-        for extension in self.csr.get_extensions():
-            if extension.get_short_name() == short_name:
-                result = [
-                    pyopenssl_normalize_name(usage.strip()) for usage in to_text(extension, errors='surrogate_or_strict').split(',')
-                ]
-                return sorted(result), bool(extension.get_critical())
-        return None, False
-
-    def _get_key_usage(self):
-        return self._get_extension(b'keyUsage')
-
-    def _get_extended_key_usage(self):
-        return self._get_extension(b'extendedKeyUsage')
-
-    def _get_basic_constraints(self):
-        return self._get_extension(b'basicConstraints')
-
-    def _get_ocsp_must_staple(self):
-        extensions = self.csr.get_extensions()
-        oms_ext = [
-            ext for ext in extensions
-            if to_bytes(ext.get_short_name()) == OPENSSL_MUST_STAPLE_NAME and to_bytes(ext) == OPENSSL_MUST_STAPLE_VALUE
-        ]
-        if OpenSSL.SSL.OPENSSL_VERSION_NUMBER < 0x10100000:
-            # Older versions of libssl don't know about OCSP Must Staple
-            oms_ext.extend([ext for ext in extensions if ext.get_short_name() == b'UNDEF' and ext.get_data() == b'\x30\x03\x02\x01\x05'])
-        if oms_ext:
-            return True, bool(oms_ext[0].get_critical())
-        else:
-            return None, False
-
-    def _get_subject_alt_name(self):
-        for extension in self.csr.get_extensions():
-            if extension.get_short_name() == b'subjectAltName':
-                result = [pyopenssl_normalize_name_attribute(altname.strip()) for altname in
-                          to_text(extension, errors='surrogate_or_strict').split(', ')]
-                return result, bool(extension.get_critical())
-        return None, False
-
-    def _get_name_constraints(self):
-        for extension in self.csr.get_extensions():
-            if extension.get_short_name() == b'nameConstraints':
-                permitted, excluded = pyopenssl_parse_name_constraints(extension)
-                return permitted, excluded, bool(extension.get_critical())
-        return None, None, False
-
-    def _get_public_key(self, binary):
-        try:
-            return crypto.dump_publickey(
-                crypto.FILETYPE_ASN1 if binary else crypto.FILETYPE_PEM,
-                self.csr.get_pubkey()
-            )
-        except AttributeError:
-            try:
-                bio = crypto._new_mem_buf()
-                if binary:
-                    rc = crypto._lib.i2d_PUBKEY_bio(bio, self.csr.get_pubkey()._pkey)
-                else:
-                    rc = crypto._lib.PEM_write_bio_PUBKEY(bio, self.csr.get_pubkey()._pkey)
-                if rc != 1:
-                    crypto._raise_current_error()
-                return crypto._bio_to_string(bio)
-            except AttributeError:
-                self.module.warn('Your pyOpenSSL version does not support dumping public keys. '
-                                 'Please upgrade to version 16.0 or newer, or use the cryptography backend.')
-
-    def _get_subject_key_identifier(self):
-        # Won't be implemented
-        return None
-
-    def _get_authority_key_identifier(self):
-        # Won't be implemented
-        return None, None, None
-
-    def _get_all_extensions(self):
-        return pyopenssl_get_extensions_from_csr(self.csr)
-
-    def _is_signature_valid(self):
-        try:
-            return bool(self.csr.verify(self.csr.get_pubkey()))
-        except crypto.Error:
-            # OpenSSL error means that key is not consistent
-            return False
-
 
 def main():
     module = AnsibleModule(
@@ -664,53 +253,19 @@ def main():
         supports_check_mode=True,
     )
 
+    if module.params['content'] is not None:
+        data = module.params['content'].encode('utf-8')
+    else:
+        try:
+            with open(module.params['path'], 'rb') as f:
+                data = f.read()
+        except (IOError, OSError) as e:
+            module.fail_json(msg='Error while reading CSR file from disk: {0}'.format(e))
+
+    backend, module_backend = select_backend(module, module.params['select_crypto_backend'], data, validate_signature=True)
+
     try:
-        if module.params['path'] is not None:
-            base_dir = os.path.dirname(module.params['path']) or '.'
-            if not os.path.isdir(base_dir):
-                module.fail_json(
-                    name=base_dir,
-                    msg='The directory %s does not exist or the file is not a directory' % base_dir
-                )
-
-        backend = module.params['select_crypto_backend']
-        if backend == 'auto':
-            # Detect what backend we can use
-            can_use_cryptography = CRYPTOGRAPHY_FOUND and CRYPTOGRAPHY_VERSION >= LooseVersion(MINIMAL_CRYPTOGRAPHY_VERSION)
-            can_use_pyopenssl = PYOPENSSL_FOUND and PYOPENSSL_VERSION >= LooseVersion(MINIMAL_PYOPENSSL_VERSION)
-
-            # If cryptography is available we'll use it
-            if can_use_cryptography:
-                backend = 'cryptography'
-            elif can_use_pyopenssl:
-                backend = 'pyopenssl'
-
-            # Fail if no backend has been found
-            if backend == 'auto':
-                module.fail_json(msg=("Can't detect any of the required Python libraries "
-                                      "cryptography (>= {0}) or PyOpenSSL (>= {1})").format(
-                                          MINIMAL_CRYPTOGRAPHY_VERSION,
-                                          MINIMAL_PYOPENSSL_VERSION))
-
-        if backend == 'pyopenssl':
-            if not PYOPENSSL_FOUND:
-                module.fail_json(msg=missing_required_lib('pyOpenSSL >= {0}'.format(MINIMAL_PYOPENSSL_VERSION)),
-                                 exception=PYOPENSSL_IMP_ERR)
-            try:
-                getattr(crypto.X509Req, 'get_extensions')
-            except AttributeError:
-                module.fail_json(msg='You need to have PyOpenSSL>=0.15')
-
-            module.deprecate('The module is using the PyOpenSSL backend. This backend has been deprecated',
-                             version='2.0.0', collection_name='community.crypto')
-            certificate = CertificateSigningRequestInfoPyOpenSSL(module)
-        elif backend == 'cryptography':
-            if not CRYPTOGRAPHY_FOUND:
-                module.fail_json(msg=missing_required_lib('cryptography >= {0}'.format(MINIMAL_CRYPTOGRAPHY_VERSION)),
-                                 exception=CRYPTOGRAPHY_IMP_ERR)
-            certificate = CertificateSigningRequestInfoCryptography(module)
-
-        result = certificate.get_info()
+        result = module_backend.get_info()
         module.exit_json(**result)
     except OpenSSLObjectError as exc:
         module.fail_json(msg=to_native(exc))