Module Name: src
Committed By: nia
Date: Wed May 6 16:17:37 UTC 2020
Modified Files:
src/distrib/sets/lists/comp: mi
src/include: unistd.h
src/lib/libc/gen: Makefile.inc
src/lib/libc/include: namespace.h
Added Files:
src/lib/libc/gen: getentropy.3 getentropy.c
Log Message:
Add getentropy() to libc - a simple wrapper to access the kernel CSPRNG.
Posted to tech-userlevel@ a week ago and reviewed by riastradh@.
GETENTROPY(3) Library Functions Manual GETENTROPY(3)
NAME
getentropy - fill a buffer with high quality random data
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
getentropy(void *buf, size_t buflen);
DESCRIPTION
The getentropy() function fills a buffer with high quality random data,
suitable for seeding cryptographically secure psuedorandom number
generators.
getentropy() is only intended for seeding random number generators and is
not intended for use by regular code which simply needs secure random
data. For this purpose, please use arc4random(3).
The maximum value for buflen is 256 bytes.
IMPLEMENTATION NOTES
getentropy() reads from the sysctl(7) variable kern.arandom.
RETURN VALUES
The getentropy() function returns 0 on success, and -1 if an error
occurred.
ERRORS
getentropy() will succeed unless:
[EFAULT] The buf argument points to an invalid memory address.
[EIO] Too many bytes were requested.
SEE ALSO
arc4random(3), rnd(4)
STANDARDS
The getentropy() function is non-standard.
HISTORY
The getentropy() function first appeared in OpenBSD 5.6, then in
FreeBSD 12.0, and NetBSD 10.
To generate a diff of this commit:
cvs rdiff -u -r1.2324 -r1.2325 src/distrib/sets/lists/comp/mi
cvs rdiff -u -r1.156 -r1.157 src/include/unistd.h
cvs rdiff -u -r1.201 -r1.202 src/lib/libc/gen/Makefile.inc
cvs rdiff -u -r0 -r1.1 src/lib/libc/gen/getentropy.3 \
src/lib/libc/gen/getentropy.c
cvs rdiff -u -r1.198 -r1.199 src/lib/libc/include/namespace.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
