IDGEN32(9) OpenBSD Kernel Manual IDGEN32(9)NAME
idgen32 - non-repeating ID generation
SYNOPSIS
#include <crypto/idgen.h>
void
idgen32_init(struct idgen32_ctx *ctx);
uint32_t
idgen32(struct idgen32_ctx *ctx);
DESCRIPTION
The idgen32() functions provide a facility to generate a stream of 32-bit
numbers that are strongly unpredictable and have a repetition cycle close
to 2^32. Such numbers are useful as protocol identifiers where there are
negative consequences to reusing an ID within a short time period, as may
happen if they are simply assigned at random.
The idgen32_init() function prepares a context structure for use.
The idgen32() function returns a new ID in host byte order. Note that
this function will never return 0 as it often has a special meaning in
network protocols.
SEE ALSOarc4random(9)HISTORY
The idgen32 functions were added in OpenBSD 4.4.
OpenBSD 4.9 January 9, 2011 OpenBSD 4.9