[FIX] auth_saml: do not force using vulnerable cryptography module

auth_saml/__manifest__.py

@@ -12,14 +12,7 @@
  "license": "AGPL-3",
  "depends": ["base_setup", "web"],
  "external_dependencies": {
- # Place an upper bound on cryptography version to be compatible with
- # pyopenssl 19 mentioned in Odoo 15's requirements.txt. If we don't do
- # this, installing this module will try to upgrade cryptography to the latest
- # version because the minimum required version in pysaml2 (>=3.1) is greater than
- # version 2.6 (from Odoo's requirement.txt). Since cryptography/pyopenssl don't
- # declare minimum supported versions, this lead to inconsistencies.
- # https://github.com/OCA/server-auth/issues/424
- "python": ["pysaml2", "cryptography<37"],
+ "python": ["pysaml2"],
  "bin": ["xmlsec1"],
  # special definition used by OCA to install packages
  "deb": ["xmlsec1"],

auth_saml/readme/INSTALL.rst

@@ -1,3 +1,8 @@
 This addon requires the python module ``pysaml2``.
 
 ``pysaml2`` requires the binary ``xmlsec1`` (on Debian or Ubuntu you can install it with ``apt-get install xmlsec1``)
+
+When following the requirements.txt from odoo, the cryptography module must not be the latest version, otherwise it is incompatible with pyopenssl 19.
+This is necessary because old cryptography/pyopenssl don't declare minimum supported versions.
+It is possible to use newer version of those libraries, eventually patching the Odoo core to stay compatible.
+As this issue is not related to this module, nothing is enforced at the module level.

test-requirements.txt

@@ -1 +1,3 @@
 responses
+# necessary to avoid incompatibilities with pyopenssl
+cryptography<37