ef9461ba0e
generator, found on IvyBridge and supposedly later CPUs, accessible with RDRAND instruction. From the Intel whitepapers and articles about Bull Mountain, it seems that we do not need to perform post-processing of RDRAND results, like AES-encryption of the data with random IV and keys, which was done for Padlock. Intel claims that sanitization is performed in hardware. Make both Padlock and Bull Mountain random generators support code covered by kernel config options, for the benefit of people who prefer minimal kernels. Also add the tunables to disable hardware generator even if detected. Reviewed by: markm, secteam (simon) Tested by: bapt, Michael Moll <kvedulv@kvedulv.de> MFC after: 3 weeks
118 lines
3.0 KiB
C
118 lines
3.0 KiB
C
/*-
|
|
* 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 "opt_cpu.h"
|
|
|
|
#ifdef IVY_RNG
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/time.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/selinfo.h>
|
|
#include <sys/systm.h>
|
|
#include <dev/random/randomdev.h>
|
|
|
|
#define RETRY_COUNT 10
|
|
|
|
static void random_ivy_init(void);
|
|
static void random_ivy_deinit(void);
|
|
static int random_ivy_read(void *, int);
|
|
|
|
struct random_systat random_ivy = {
|
|
.ident = "Hardware, Intel IvyBridge+ RNG",
|
|
.init = random_ivy_init,
|
|
.deinit = random_ivy_deinit,
|
|
.read = random_ivy_read,
|
|
.write = (random_write_func_t *)random_null_func,
|
|
.reseed = (random_reseed_func_t *)random_null_func,
|
|
.seeded = 1,
|
|
};
|
|
|
|
static inline int
|
|
ivy_rng_store(long *tmp)
|
|
{
|
|
#ifdef __GNUCLIKE_ASM
|
|
uint32_t count;
|
|
|
|
__asm __volatile(
|
|
#ifdef __amd64__
|
|
".byte\t0x48,0x0f,0xc7,0xf0\n\t" /* rdrand %rax */
|
|
"jnc\t1f\n\t"
|
|
"movq\t%%rax,%1\n\t"
|
|
"movl\t$8,%%eax\n"
|
|
#else /* i386 */
|
|
".byte\t0x0f,0xc7,0xf0\n\t" /* rdrand %eax */
|
|
"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 void
|
|
random_ivy_init(void)
|
|
{
|
|
}
|
|
|
|
void
|
|
random_ivy_deinit(void)
|
|
{
|
|
}
|
|
|
|
static int
|
|
random_ivy_read(void *buf, int c)
|
|
{
|
|
char *b;
|
|
long tmp;
|
|
int count, res, retry;
|
|
|
|
for (count = c, b = buf; count > 0; count -= res, b += res) {
|
|
for (retry = 0; retry < RETRY_COUNT; retry++) {
|
|
res = ivy_rng_store(&tmp);
|
|
if (res != 0)
|
|
break;
|
|
}
|
|
if (res == 0)
|
|
break;
|
|
if (res > count)
|
|
res = count;
|
|
memcpy(b, &tmp, res);
|
|
}
|
|
return (c - count);
|
|
}
|
|
|
|
#endif
|