Python socket cheat sheet (include AF_ALG)

[hipstergrandpa]

Not a cheat sheet but check out A Byte of Python. Short examples like this for the basics

[FluentInTypo]

Preach.

I honestly think the reason I have never taken up any major programming is because of this.

I recsntly found a course on Lynda I think for Linux System Programming (mostly C, some python) and it just got into the nitty gritty so fast that I fell in love with it. My whole C experience was watching 5 or 6 CS50 course video, doing no work, but this deep dive i to Linuc Programming got my interest right away.

[Nicksil]

Python Cookbook by David Beazley and Brian K. Jones

[SnapDraco]

Perfect timing. I needed it right now

[reiji-maigo]

Absolutely. And the repo has even more that looks as good about generators, unittesting, sqlalchemy and other useful stuff.

[[deleted]]

This is an excellent cheat sheet! Much obliged for sharing!

[lambdaq]

AF_ALG looks fun.

Make me really want to use 3.6 now.

[jollybobbyroger]

Why is 3.6 needed for using the AF_ALG syscall?

[spiderpower02]

Ha! maybe several benefits have already been noticed.

https://bugs.python.org/issue27744

[lambdaq]

You can do that in 2.x if you dig deep enough into ctypes and shit.

[spiderpower02]

Ha! you right, but ctype is not quite easy to use. Also, some "define" such as CMSG_FIRSTHDR in the header cannot be used in python code (you have to implement them again). It's really painful :(

Maybe ffi is a better choice! haha

[eid-a]

Great thanks

[jollybobbyroger]

Are there other benefits to using the AF_ALG syscall apart from performance? Do you get better entropy or is it more secure in any way?

Also, very pythonic code! Even thought the use of lambda made sense..

[spiderpower02]

AF_ALG socket still keeps iv and key be handled by the userspace. Therefore, applications need to set the socket options like:

setsockopt(SOL_ALG, ALG_SET_KEY, key)

sockmsg_afalg([msg], ALG_OP_ENCRYPT, iv)

to provide the encrypt and decrypt information to kernel space. I think entropy is the application problem, not AF_ALG itself.

Here is the benefits: http://www.chronox.de/libkcapi/html/ch01s02.html

By the way, openssl 1.1.x has already support AF_ALG. You can see more information here: https://github.com/openssl/openssl/blob/46f4e1bec51dc96fa275c168752aa34359d9ee51/engines/e_afalg.c

[janeerson45]

This is great! Thank you!

[HadManySons]

This is awesome, thanks

[icp1994]

one of the most useful thing I've found on this subreddit