ANS X9.82 specifies several Approved algorithms for use in a
Deterministic Random Bit Generator (DRBG). One such algorithm is
HMAC_DRBG, which can be implemented using the existing iPXE SHA-1 and
HMAC functionality. This algorithm provides a maximum security
strength of 128 bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>