[Q&A] AttributeError: module 'cryptography.hazmat.primitives.serialization' has no attribute 'pkcs12'

[hwpang]

Python version (python3 -V)

3.10.14

NVFlare version (python3 -m pip list | grep "nvflare")

2.4.1

NVFlare branch (if running examples, please use the branch that corresponds to the NVFlare version, git branch)

2.4

Operating system

Ubuntu 20.04

Have you successfully run any of the following examples?

• hello-numpy-sag with simulator
• hello-pt with simulator
• hello-numpy-sag with POC
• hello-pt with POC

Please describe your question

I'm a new user of NVFlare and am currently going through the tutorials. I am able to run FL in the simulation mode, but I'm not able to get POC mode to work.

When I run nvflare poc prepare -n 2, I had the following error:

prepare poc at /tmp/nvflare/poc for 2 clients
This will delete poc workspace directory: '/tmp/nvflare/poc' and create a new one. Is it OK to proceed? (y/N) y
provision at /tmp/nvflare/poc for 2 clients with /tmp/nvflare/poc/project.yml
Exception raised during provision.  Incomplete prod_n folder removed.
Traceback (most recent call last):
  File "/anaconda/envs/nvflare-env/lib/python3.10/site-packages/nvflare/lighter/spec.py", line 174, in provision
    b.build(project, ctx)
  File "/anaconda/envs/nvflare-env/lib/python3.10/site-packages/nvflare/lighter/impl/cert.py", line 137, in build
    self._build_write_cert_pair(server, "server", ctx)
  File "/anaconda/envs/nvflare-env/lib/python3.10/site-packages/nvflare/lighter/impl/cert.py", line 119, in _build_write_cert_pair
    pkcs12 = serialization.pkcs12.serialize_key_and_certificates(
AttributeError: module 'cryptography.hazmat.primitives.serialization' has no attribute 'pkcs12'

However, if I open up a Python REPL, I can import pkcs12 from cryptography.hazmat.primitives.serialization:

Python 3.10.14 (main, May  6 2024, 19:42:50) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from cryptography.hazmat.primitives.serialization import pkcs12
>>> 

[YuanTingHsieh]

@hwpang thanks for reporting.

@IsaacYangSLA do we need to also apply this #2721 to 2.4?

[YuanTingHsieh]

Should be fixed by #2746

[hwpang]

Thanks! It is fixed! I got the expected output after #2746.

nvflare poc prepare -n 2
prepare poc at /tmp/nvflare/poc for 2 clients
This will delete poc workspace directory: '/tmp/nvflare/poc' and create a new one. Is it OK to proceed? (y/N) y
provision at /tmp/nvflare/poc for 2 clients with /tmp/nvflare/poc/project.yml
Generated results can be found under /tmp/nvflare/poc/example_project/prod_00.