Change memory managment from a fixed size array to a list.
  This is needed to avoid running into out of buffer situations
  where we cannot alloc a new buffer because we hit the array size
  limit (ZBUF).
  Use a combined allocation for the struct and the actual data buffer
  to not increase the number of malloc calls. [1]

  Defer initialization of zbuf until we actually need it.

  Make sure the output buffer will be large enough in all cases.

  Details discussed with: kib [1]
  Reviewed by:            kib [1]

a consistent interface to h/w and s/w crypto algorithms for use by the
kernel and (for h/w at least) by user-mode apps.  Access for user-level
code is through a /dev/crypto device that'll eventually be used by openssl
to (potentially) accelerate many applications.  Coming soon is an IPsec
that makes use of this service to accelerate ESP, AH, and IPCOMP protocols.

Included here is the "core" crypto support, /dev/crypto driver, various
crypto algorithms that are not already present in the KAME crypto area,
and support routines used by crypto device drivers.

Obtained from:	openbsd