#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <string.h>
#include <miscfs/devfs/devfs.h>
#include <kern/lock.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <sys/uio_internal.h>
#include <dev/random/randomdev.h>
#include <dev/random/YarrowCoreLib/include/yarrow.h>
#include <crypto/sha1.h>
#define RANDOM_MAJOR -1
d_ioctl_t random_ioctl;
static struct cdevsw random_cdevsw =
{
random_open,
random_close,
random_read,
random_write,
random_ioctl,
(stop_fcn_t *)nulldev,
(reset_fcn_t *)nulldev,
NULL,
eno_select,
eno_mmap,
eno_strat,
eno_getc,
eno_putc,
0
};
static int gRandomInstalled = 0;
static PrngRef gPrngRef;
static int gRandomError = 1;
static mutex_t *gYarrowMutex = 0;
#define RESEED_TICKS 50
enum {kBSizeInBits = 160}; enum {kBSizeInBytes = kBSizeInBits / 8};
typedef u_int32_t BlockWord;
enum {kWordSizeInBits = 32};
enum {kBSize = 5};
typedef BlockWord Block[kBSize];
void add_blocks(Block a, Block b, BlockWord carry);
void fips_initialize(void);
void random_block(Block b);
void
add_blocks(Block a, Block b, BlockWord carry)
{
int i = kBSize;
while (--i >= 0)
{
u_int64_t c = (u_int64_t)carry +
(u_int64_t)a[i] +
(u_int64_t)b[i];
a[i] = c & ((1LL << kWordSizeInBits) - 1);
carry = c >> kWordSizeInBits;
}
}
struct sha1_ctxt g_sha1_ctx;
char zeros[(512 - kBSizeInBits) / 8];
Block g_xkey;
Block g_random_data;
int g_bytes_used;
void
random_block(Block b)
{
Block xSeed;
prngOutput (gPrngRef, (BYTE*) &xSeed, sizeof (xSeed));
add_blocks (g_xkey, xSeed, 0);
SHA1Update (&g_sha1_ctx, (const u_int8_t *) &g_xkey, sizeof (g_xkey));
SHA1Update (&g_sha1_ctx, (const u_int8_t *)zeros, sizeof (zeros));
memmove(b, g_sha1_ctx.h.b8, sizeof (Block));
add_blocks (g_xkey, b, 1);
}
void
PreliminarySetup(void)
{
prng_error_status perr;
struct timeval tt;
char buffer [16];
perr = prngInitialize(&gPrngRef);
if (perr != 0) {
printf ("Couldn't initialize Yarrow, /dev/random will not work.\n");
return;
}
gRandomError = 0;
microtime(&tt);
perr = prngInput(gPrngRef, (BYTE*) &tt, sizeof (tt), SYSTEM_SOURCE, 8);
if (perr != 0) {
printf ("Couldn't seed Yarrow.\n");
return;
}
perr = prngOutput(gPrngRef, (BYTE*)buffer, sizeof (buffer));
perr = prngForceReseed(gPrngRef, RESEED_TICKS);
gYarrowMutex = mutex_alloc(0);
fips_initialize ();
}
void
fips_initialize(void)
{
prngOutput (gPrngRef, (BYTE*) &g_xkey, sizeof (g_xkey));
SHA1Init (&g_sha1_ctx);
memset (zeros, 0, sizeof (zeros));
g_bytes_used = 0;
random_block(g_random_data);
}
void
random_init(void)
{
int ret;
if (gRandomInstalled)
return;
gRandomInstalled = 1;
PreliminarySetup();
ret = cdevsw_add(RANDOM_MAJOR, &random_cdevsw);
if (ret < 0) {
printf("random_init: failed to allocate a major number!\n");
gRandomInstalled = 0;
return;
}
devfs_make_node(makedev (ret, 0), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0666, "random", 0);
devfs_make_node(makedev (ret, 1), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0666, "urandom", 0);
}
int
random_ioctl( __unused dev_t dev, u_long cmd, __unused caddr_t data,
__unused int flag, __unused struct proc *p )
{
switch (cmd) {
case FIONBIO:
case FIOASYNC:
break;
default:
return ENODEV;
}
return (0);
}
int
random_open(__unused dev_t dev, int flags, __unused int devtype, __unused struct proc *p)
{
if (gRandomError != 0) {
return (ENOTSUP);
}
if (flags & FWRITE) {
if (securelevel >= 2)
return (EPERM);
#ifndef __APPLE__
if ((securelevel >= 1) && proc_suser(p))
return (EPERM);
#endif
}
return (0);
}
int
random_close(__unused dev_t dev, __unused int flags, __unused int mode, __unused struct proc *p)
{
return (0);
}
int
random_write (__unused dev_t dev, struct uio *uio, __unused int ioflag)
{
int retCode = 0;
char rdBuffer[256];
if (gRandomError != 0) {
return (ENOTSUP);
}
mutex_lock(gYarrowMutex);
while (uio_resid(uio) > 0 && retCode == 0) {
int bytesToInput = min(uio_resid(uio), sizeof (rdBuffer));
retCode = uiomove(rdBuffer, bytesToInput, uio);
if (retCode != 0)
goto error_exit;
if (prngInput(gPrngRef, (BYTE*)rdBuffer,
bytesToInput, SYSTEM_SOURCE,
bytesToInput * 8) != 0) {
retCode = EIO;
goto error_exit;
}
}
if (prngForceReseed(gPrngRef, RESEED_TICKS) != 0) {
retCode = EIO;
goto error_exit;
}
error_exit:
mutex_unlock(gYarrowMutex);
return (retCode);
}
int random_read(__unused dev_t dev, struct uio *uio, __unused int ioflag)
{
int retCode = 0;
if (gRandomError != 0)
return (ENOTSUP);
mutex_lock(gYarrowMutex);
int bytes_remaining = uio_resid(uio);
while (bytes_remaining > 0 && retCode == 0) {
int bytes_to_read = 0;
int bytes_available = kBSizeInBytes - g_bytes_used;
if (bytes_available == 0)
{
random_block(g_random_data);
g_bytes_used = 0;
bytes_available = kBSizeInBytes;
}
bytes_to_read = min (bytes_remaining, bytes_available);
retCode = uiomove(((u_int8_t*)g_random_data)+ g_bytes_used, bytes_to_read, uio);
g_bytes_used += bytes_to_read;
if (retCode != 0)
goto error_exit;
bytes_remaining = uio_resid(uio);
}
retCode = 0;
error_exit:
mutex_unlock(gYarrowMutex);
return retCode;
}
void
read_random(void* buffer, u_int numbytes)
{
if (gYarrowMutex == 0) {
PreliminarySetup ();
}
mutex_lock(gYarrowMutex);
int bytes_remaining = numbytes;
while (bytes_remaining > 0) {
int bytes_to_read = min(bytes_remaining, kBSizeInBytes - g_bytes_used);
if (bytes_to_read == 0)
{
random_block(g_random_data);
g_bytes_used = 0;
bytes_to_read = min(bytes_remaining, kBSizeInBytes);
}
memmove (buffer, ((u_int8_t*)g_random_data)+ g_bytes_used, bytes_to_read);
g_bytes_used += bytes_to_read;
bytes_remaining -= bytes_to_read;
}
mutex_unlock(gYarrowMutex);
}
u_long
RandomULong(void)
{
u_long buf;
read_random(&buf, sizeof (buf));
return (buf);
}