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A comment on Myths about /dev/urandom (2014). Parent comment

Re:Myths about /dev/urandom (2014) by eddieh on Thursday January 05, 2017 @08:49PM (#13333262)
arc4random and arc4random_buf are probably better still.
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Re:Myths about /dev/urandom (2014) by nshepperd on Thursday January 05, 2017 @09:17PM (#13333390)
Please don't use arc4random* for cryptographic purposes. RC4 is broken -- there are practical attacks against it. It's fine for non-secure purposes though (eg. monte carlo simulation).
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Re:Myths about /dev/urandom (2014) by eddieh on Thursday January 05, 2017 @10:11PM (#13333609)
The 'arc4' no longer refers to RC4 on macOS/iOS and OpenBSD. On those systems 'arc4random' is playfully a bacronym for "A Replacement Call for Random". The new arc4random* implementation will now be replaced as cryptographic techniques advance.

It appears the Apple and OpenBSD implementations use the getentropy syscall and then add additional entropy mixing.

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Re:Myths about /dev/urandom (2014) by gbrown_ on Friday January 06, 2017 @04:53AM (#13335104)
Yup, OpenBSD have even changed calls to other entropy sources to returning strong random by default from arc4random.

http://marc.info/?l=openbsd-cvs&m=141807513728073&w=2

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Re:Myths about /dev/urandom (2014) by arthur2e5 on Friday January 06, 2017 @10:10AM (#13336809)
libbsd is also using getentropy: https://cgit.freedesktop.org/libbsd/tree/src/arc4random.c
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Re:Myths about /dev/urandom (2014) by tossedaway334 on Thursday January 05, 2017 @09:37PM (#13333469)
arc4random uses chacha20 on openBSD now, has for several years, OSX and FreeBSD are yet to update...
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Re:Myths about /dev/urandom (2014) by eddieh on Thursday January 05, 2017 @09:44PM (#13333504)
The macOS Sierra man page says it uses the NIST-approved AES cipher and will be replaced as the techniques advance.
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