Writing a cert file to a directory without permission system may fail

[herquan-docusign]

Describe the bug

In this line, after writing a certificate to file, the extension will set the mode. However if that file is located in a directory where the permission is not available, like a memory file system, function set_mode may either crash or raise an exception. There should be an option to disable setting the mode or ignore the failure with a warning message.

Related command

az ssh cert --public-key-file id_rsa.pub --file x:\memoryfs

Errors

...
  File "C:\Users\heran.quan\.azure\cliextensions\ssh\azext_ssh\custom.py", line 242, in _get_and_write_certificate
    _write_cert_file(certificate, cert_file)
  File "C:\Users\heran.quan\.azure\cliextensions\ssh\azext_ssh\custom.py", line 347, in _write_cert_file
    oschmod.set_mode(cert_file, 0o644)
  File "C:\Users\heran.quan\.azure\cliextensions\ssh\oschmod\__init__.py", line 186, in set_mode
    return win_set_permissions(path, new_mode)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\heran.quan\.azure\cliextensions\ssh\oschmod\__init__.py", line 403, in win_set_permissions
    _win_set_permissions(path, mode, get_object_type(path))
  File "C:\Users\heran.quan\.azure\cliextensions\ssh\oschmod\__init__.py", line 421, in _win_set_permissions
    for _ in range(0, dacl.GetAceCount()):
                      ^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'GetAceCount'

Issue script & Debug output

import win32security # According to "https://pypi.org/project/Win32Security", "This project has been archived."
# x:\ is a memory file system and the ACL may not be available
sec_des = win32security.GetNamedSecurityInfo("x:\\", win32security.SE_FILE_OBJECT,win32security.DACL_SECURITY_INFORMATION)
dacl = sec_des.GetSecurityDescriptorDacl()
print(dacl)

Expected behavior

Raise an exception and give us an option to not set mode
Or print an warning

Environment Summary

{
  "azure-cli": "2.75.0",
  "azure-cli-core": "2.75.0",
  "azure-cli-telemetry": "1.1.0",
  "extensions": {
    "ssh": "2.0.6"
  }
}

Additional context

No response

[yonzhan]

Thank you for opening this issue, we will look into it.