Support cryptography 35.0.0 for all modules except openssl_pkcs12 (#294)

* Add some workarounds for cryptography 35.0.0.

* Make fix work with very old cryptography versions as well (which supported multiple backends).

* [TEMP] Disable openssl_pkcs12 tests to see whether everything else works.

* Revert "[TEMP] Disable openssl_pkcs12 tests to see whether everything else works."

This reverts commit 3f905bc795.

* Add changelog fragment.

* Remove unnecessary assignment.

* Simplify code change.

* [TEMP] Disable openssl_pkcs12 tests to see whether everything else works.

* Revert "[TEMP] Disable openssl_pkcs12 tests to see whether everything else works."

This reverts commit fdb210528e.

changelogs/fragments/294-cryptography-35.0.0.yml

@@ -0,0 +1,4 @@
+bugfixes:
+  - "get_certificate - fix compatibility with the cryptography 35.0.0 release (https://github.com/ansible-collections/community.crypto/pull/294)."
+  - "openssl_csr_info - fix compatibility with the cryptography 35.0.0 release (https://github.com/ansible-collections/community.crypto/pull/294)."
+  - "x509_certificate_info - fix compatibility with the cryptography 35.0.0 release (https://github.com/ansible-collections/community.crypto/pull/294)."

plugins/module_utils/crypto/_obj2txt.py

@@ -20,6 +20,10 @@ from __future__ import absolute_import, division, print_function
 __metaclass__ = type
 
 
+# WARNING: this function no longer works with cryptography 35.0.0 and newer!
+#          It must **ONLY** be used in compatibility code for older
+#          cryptography versions!
+
 def obj2txt(openssl_lib, openssl_ffi, obj):
     # Set to 80 on the recommendation of
     # https://www.openssl.org/docs/crypto/OBJ_nid2ln.html#return_values

plugins/module_utils/crypto/cryptography_support.py

@@ -30,6 +30,7 @@ from ._asn1 import serialize_asn1_string_as_der
 try:
     import cryptography
     from cryptography import x509
+    from cryptography.hazmat.backends import default_backend
     from cryptography.hazmat.primitives import serialization
     import ipaddress
 except ImportError:
@@ -68,9 +69,19 @@ def cryptography_get_extensions_from_cert(cert):
     # Since cryptography won't give us the DER value for an extension
     # (that is only stored for unrecognized extensions), we have to re-do
     # the extension parsing outselves.
+    backend = default_backend()
+    try:
+        # For certain old versions of cryptography, backend is a MultiBackend object,
+        # which has no _lib attribute. In that case, revert to the old approach.
+        backend._lib
+    except AttributeError:
+        backend = cert._backend
+
     result = dict()
-    backend = cert._backend
     x509_obj = cert._x509
+    # With cryptography 35.0.0, we can no longer use obj2txt. Unfortunately it still does
+    # not allow to get the raw value of an extension, so we have to use this ugly hack:
+    exts = list(cert.extensions)
 
     for i in range(backend._lib.X509_get_ext_count(x509_obj)):
         ext = backend._lib.X509_get_ext(x509_obj, i)
@@ -84,8 +95,12 @@ def cryptography_get_extensions_from_cert(cert):
             critical=(crit == 1),
             value=base64.b64encode(der),
         )
-        oid = obj2txt(backend._lib, backend._ffi, backend._lib.X509_EXTENSION_get_object(ext))
+        try:
+            oid = obj2txt(backend._lib, backend._ffi, backend._lib.X509_EXTENSION_get_object(ext))
+        except AttributeError:
+            oid = exts[i].oid.dotted_string
         result[oid] = entry
+
     return result
 
 
@@ -94,7 +109,13 @@ def cryptography_get_extensions_from_csr(csr):
     # (that is only stored for unrecognized extensions), we have to re-do
     # the extension parsing outselves.
     result = dict()
-    backend = csr._backend
+    backend = default_backend()
+    try:
+        # For certain old versions of cryptography, backend is a MultiBackend object,
+        # which has no _lib attribute. In that case, revert to the old approach.
+        backend._lib
+    except AttributeError:
+        backend = csr._backend
 
     extensions = backend._lib.X509_REQ_get_extensions(csr._x509_req)
     extensions = backend._ffi.gc(
@@ -105,6 +126,10 @@ def cryptography_get_extensions_from_csr(csr):
         )
     )
 
+    # With cryptography 35.0.0, we can no longer use obj2txt. Unfortunately it still does
+    # not allow to get the raw value of an extension, so we have to use this ugly hack:
+    exts = list(csr.extensions)
+
     for i in range(backend._lib.sk_X509_EXTENSION_num(extensions)):
         ext = backend._lib.sk_X509_EXTENSION_value(extensions, i)
         if ext == backend._ffi.NULL:
@@ -117,8 +142,12 @@ def cryptography_get_extensions_from_csr(csr):
             critical=(crit == 1),
             value=base64.b64encode(der),
         )
-        oid = obj2txt(backend._lib, backend._ffi, backend._lib.X509_EXTENSION_get_object(ext))
+        try:
+            oid = obj2txt(backend._lib, backend._ffi, backend._lib.X509_EXTENSION_get_object(ext))
+        except AttributeError:
+            oid = exts[i].oid.dotted_string
         result[oid] = entry
+
     return result
 
 
@@ -489,9 +518,15 @@ def parse_pkcs12(pkcs12_bytes, passphrase=None):
     friendly_name = None
     if certificate:
         # See https://github.com/pyca/cryptography/issues/5760#issuecomment-842687238
-        maybe_name = certificate._backend._lib.X509_alias_get0(
-            certificate._x509, certificate._backend._ffi.NULL)
-        if maybe_name != certificate._backend._ffi.NULL:
-            friendly_name = certificate._backend._ffi.string(maybe_name)
+        backend = default_backend()
+        try:
+            # For certain old versions of cryptography, backend is a MultiBackend object,
+            # which has no _lib attribute. In that case, revert to the old approach.
+            backend._lib
+        except AttributeError:
+            backend = certificate._backend
+        maybe_name = backend._lib.X509_alias_get0(certificate._x509, backend._ffi.NULL)
+        if maybe_name != backend._ffi.NULL:
+            friendly_name = backend._ffi.string(maybe_name)
 
     return private_key, certificate, additional_certificates, friendly_name