iPXE
Functions
random_nz.c File Reference

Random non-zero bytes. More...

#include <stddef.h>
#include <stdint.h>
#include <ipxe/rbg.h>
#include <ipxe/random_nz.h>

Go to the source code of this file.

Functions

 FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
 
int get_random_nz (void *data, size_t len)
 Get random non-zero bytes. More...
 

Detailed Description

Random non-zero bytes.

The RSA algorithm requires the generation of random non-zero bytes, i.e. bytes in the range [0x01,0xff].

This algorithm is designed to comply with ANS X9.82 Part 1-2006 Section 9.2.1. This standard is not freely available, but most of the text appears to be shared with NIST SP 800-90, which can be downloaded from

http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf

Where possible, references are given to both documents. In the case of any disagreement, ANS X9.82 takes priority over NIST SP 800-90. (In particular, note that some algorithms that are Approved by NIST SP 800-90 are not Approved by ANS X9.82.)

Definition in file random_nz.c.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL  )

◆ get_random_nz()

int get_random_nz ( void *  data,
size_t  len 
)

Get random non-zero bytes.

Parameters
dataOutput buffer
lenLength of output buffer
Return values
rcReturn status code

This algorithm is designed to be isomorphic to the Simple Discard Method described in ANS X9.82 Part 1-2006 Section 9.2.1 (NIST SP 800-90 Section B.5.1.1).

Definition at line 62 of file random_nz.c.

62  {
63  uint8_t *bytes = data;
64  int rc;
65 
66  while ( len ) {
67 
68  /* Generate random byte */
69  if ( ( rc = rbg_generate ( NULL, 0, 0, bytes, 1 ) ) != 0 )
70  return rc;
71 
72  /* Move to next byte if this byte is acceptable */
73  if ( *bytes != 0 ) {
74  bytes++;
75  len--;
76  }
77  }
78 
79  return 0;
80 }
struct arbelprm_rc_send_wqe rc
Definition: arbel.h:14
static int rbg_generate(const void *additional, size_t additional_len, int prediction_resist, void *data, size_t len)
Generate bits using RBG.
Definition: rbg.h:36
unsigned char uint8_t
Definition: stdint.h:10
uint32_t len
Length.
Definition: ena.h:14
struct arbelprm_port_state_change_st data
Message.
Definition: arbel.h:12
uint8_t bytes[64]
Definition: ib_mad.h:16
#define NULL
NULL pointer (VOID *)
Definition: Base.h:362

References bytes, data, len, NULL, rbg_generate(), and rc.

Referenced by rsa_encrypt().