GETENTROPY(2) | System Calls Manual | GETENTROPY(2) |
getentropy
— get
entropy
#include
<unistd.h>
int
getentropy
(void
*buf, size_t
buflen);
getentropy
()
fills a buffer with high-quality entropy, which can be used as input for
process-context pseudorandom generators like
arc4random(3).
The maximum buffer size permitted is 256 bytes.
getentropy
()
is not intended for regular code; please use the
arc4random(3) family of
functions instead.
The high-quality entropy data is provided by the random(4) subsystem.
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
getentropy
() will succeed unless:
The getentropy
() function appeared in
OpenBSD 5.6.
September 28, 2019 | OpenBSD-6.7 |