f02e47dc1e
Contains: * Refactor the hardware RNG CPU instruction sources to feed into the software mixer. This is unfinished. The actual harvesting needs to be sorted out. Modified by me (see below). * Remove 'frac' parameter from random_harvest(). This was never used and adds extra code for no good reason. * Remove device write entropy harvesting. This provided a weak attack vector, was not very good at bootstrapping the device. To follow will be a replacement explicit reseed knob. * Separate out all the RANDOM_PURE sources into separate harvest entities. This adds some secuity in the case where more than one is present. * Review all the code and fix anything obviously messy or inconsistent. Address som review concerns while I'm here, like rename the pseudo-rng to 'dummy'. Submitted by: Arthur Mesh <arthurmesh@gmail.com> (the first item)
142 lines
3.5 KiB
C
142 lines
3.5 KiB
C
/*-
|
|
* Copyright (c) 2013 David E. O'Brien <obrien@NUXI.org>
|
|
* Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer
|
|
* in this position and unchanged.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/module.h>
|
|
#include <sys/random.h>
|
|
#include <sys/selinfo.h>
|
|
#include <sys/systm.h>
|
|
|
|
#include <machine/md_var.h>
|
|
#include <machine/specialreg.h>
|
|
|
|
#include <dev/random/live_entropy_sources.h>
|
|
#include <dev/random/random_adaptors.h>
|
|
#include <dev/random/randomdev.h>
|
|
|
|
#define RETRY_COUNT 10
|
|
|
|
static int random_ivy_read(void *, int);
|
|
|
|
struct random_hardware_source random_ivy = {
|
|
.ident = "Hardware, Intel IvyBridge+ RNG",
|
|
.source = RANDOM_PURE_RDRAND,
|
|
.read = random_ivy_read
|
|
};
|
|
|
|
static inline int
|
|
ivy_rng_store(uint64_t *tmp)
|
|
{
|
|
#ifdef __GNUCLIKE_ASM
|
|
uint32_t count;
|
|
|
|
__asm __volatile(
|
|
#ifdef __amd64__
|
|
"rdrand\t%%rax\n\t"
|
|
"jnc\t1f\n\t"
|
|
"movq\t%%rax,%1\n\t"
|
|
"movl\t$8,%%eax\n"
|
|
#else /* i386 */
|
|
"rdrand\t%%eax\n\t"
|
|
"jnc\t1f\n\t"
|
|
"movl\t%%eax,%1\n\t"
|
|
"movl\t$4,%%eax\n"
|
|
#endif
|
|
"1:\n" /* %eax is cleared by processor on failure */
|
|
: "=a" (count), "=g" (*tmp) : "a" (0) : "cc");
|
|
return (count);
|
|
#else /* __GNUCLIKE_ASM */
|
|
return (0);
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
random_ivy_read(void *buf, int c)
|
|
{
|
|
uint8_t *b;
|
|
int count, ret, retry;
|
|
uint64_t tmp;
|
|
|
|
b = buf;
|
|
for (count = c; count > 0; count -= ret) {
|
|
for (retry = 0; retry < RETRY_COUNT; retry++) {
|
|
ret = ivy_rng_store(&tmp);
|
|
if (ret != 0)
|
|
break;
|
|
}
|
|
if (ret == 0)
|
|
break;
|
|
if (ret > count)
|
|
ret = count;
|
|
memcpy(b, &tmp, ret);
|
|
b += ret;
|
|
}
|
|
return (c - count);
|
|
}
|
|
|
|
static int
|
|
rdrand_modevent(module_t mod, int type, void *unused)
|
|
{
|
|
int error = 0;
|
|
|
|
switch (type) {
|
|
case MOD_LOAD:
|
|
if (cpu_feature2 & CPUID2_RDRAND)
|
|
live_entropy_source_register(&random_ivy);
|
|
else
|
|
#ifndef KLD_MODULE
|
|
if (bootverbose)
|
|
#endif
|
|
printf("%s: RDRAND is not present\n",
|
|
random_ivy.ident);
|
|
break;
|
|
|
|
case MOD_UNLOAD:
|
|
if (cpu_feature2 & CPUID2_RDRAND)
|
|
live_entropy_source_deregister(&random_ivy);
|
|
break;
|
|
|
|
case MOD_SHUTDOWN:
|
|
break;
|
|
|
|
default:
|
|
error = EOPNOTSUPP;
|
|
break;
|
|
|
|
}
|
|
|
|
return (error);
|
|
}
|
|
|
|
LIVE_ENTROPY_SRC_MODULE(random_rdrand, rdrand_modevent, 1);
|