[issue27266] Always use getrandom() in os.random() on Linux and add block=False parameter to os.urandom()

Theodore Tso added the comment: Larry, at least on FreeBSD, it sounds like the implementation could just the kern.random.sys.seeded sysctl, and return . (Note: what is the proposed behaviour if the PRNG is not seeded? Return Null?) As far as OpenBSD is concerned, it's true that

[issue26839] Python 3.5 running on Linux kernel 3.17+ can block at startup or on importing the random module on getrandom()

Theodore Tso added the comment: Oh --- and about people wondering whether os.random is being used for cryptographic purposes or not "most of the time" or not --- again, welcome to my world. I get complaints all the time from people who try to do "dd if=/dev/urandom of=/dev

[issue26839] Python 3.5 running on Linux kernel 3.17+ can block at startup or on importing the random module on getrandom()

Theodore Tso added the comment: One of the reasons why trying to deal with randomness is hard is because a lot of it is about trust. Did Intel backdoor RDRAND to help out the NSA? You might have one answer if you work for the NSA, and perhaps if you are willing to assume the worst about

[issue26839] Python 3.5 running on Linux kernel 3.17+ can block at startup or on importing the random module on getrandom()

Theodore Tso added the comment: I ran the experiment Colm asked me to run --- and yes, if you boot a system with Python 3.5.1 with the boot options "init=/usr/bin/python3", you're going to have a bad time. The problem is that in a KVM environment where things are very quiet

[issue26839] Python 3.5 running on Linux kernel 3.17+ can block at startup or on importing the random module on getrandom()

Theodore Tso added the comment: Hi. Colm alerted me to this bug, so I thought I would chime in as the author of Linux's getrandom(2) function. First of all, if you are OK with reading from /dev/urandom, then you might as well use getrandom's GRND_NONBLOCK flag. They are