Removing oscrypto lib direct dependency

[mpgn]

Description

Removing the oscrypto lib that depend on a fork and use cryptography lib (thanks @azoxlpf for the idea)

Helped with claude max to avoid any regression

Type of change

Insert an "x" inside the brackets for relevant items (do not delete options)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Deprecation of feature or functionality
• This change requires a documentation update
• This requires a third party update (such as Impacket, Dploot, lsassy, etc)
• This PR was created with the assistance of AI (list what type of assistance, tool(s)/model(s) in the description)

Setup guide for the review

Tested against GOAD lab

Screenshots (if appropriate):

Checklist:

Insert an "x" inside the brackets for completed and relevant items (do not delete options)

• I have ran Ruff against my changes (poetry: poetry run ruff check ., use --fix to automatically fix what it can)
• I have added or updated the tests/e2e_commands.txt file if necessary (new modules or features are required to be added to the e2e tests)
• If reliant on changes of third party dependencies, such as Impacket, dploot, lsassy, etc, I have linked the relevant PRs in those projects
• I have linked relevant sources that describes the added technique (blog posts, documentation, etc)
• I have performed a self-review of my own code (not an AI review)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (PR here: https://github.com/Pennyw0rth/NetExec-Wiki)

[azoxlpf]

Note: this pr overlaps with #1277: pfx_to_pem_files() there does the same PFX/PEM loading with cryptography (pkcs12.load_key_and_certificates + load_pem_x509_certificate + load_pem_private_key). Once both land we'll have two independent loaders in the same file that can drift, could we expose a single helper here (something like load_cert_and_key(pfx_data=..., pfx_pass=..., pem_cert=..., pem_key=...) returning the cryptography objects) and have both from_pfx_data/from_pem and pfx_to_pem_files build on it?

[mpgn]

Note: this pr overlaps with #1277: pfx_to_pem_files() there does the same PFX/PEM loading with cryptography (pkcs12.load_key_and_certificates + load_pem_x509_certificate + load_pem_private_key). Once both land we'll have two independent loaders in the same file that can drift, could we expose a single helper here (something like load_cert_and_key(pfx_data=..., pfx_pass=..., pem_cert=..., pem_key=...) returning the cryptography objects) and have both from_pfx_data/from_pem and pfx_to_pem_files build on it?

not an issue, this pr will be merged first :)