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--- /dev/null
+++ xnu/xnu-344.12.2/bsd/dev/random/randomdev.c
@@ -0,0 +1,303 @@
+/*
+ * Copyright (c) 1999, 2000-2002 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License"). You may not use this file except in compliance with the
+ * License. Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ *
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#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 <miscfs/devfs/devfs.h>
+#include <kern/lock.h>
+#include <sys/time.h>
+#include <sys/malloc.h>
+
+#include <dev/random/randomdev.h>
+#include <dev/random/YarrowCoreLib/include/yarrow.h>
+
+#define RANDOM_MAJOR -1 /* let the kernel pick the device number */
+
+/*
+ * A struct describing which functions will get invoked for certain
+ * actions.
+ */
+static struct cdevsw random_cdevsw =
+{
+ random_open, /* open */
+ random_close, /* close */
+ random_read, /* read */
+ random_write, /* write */
+ eno_ioctl, /* ioctl */
+ nulldev, /* stop */
+ nulldev, /* reset */
+ NULL, /* tty's */
+ eno_select, /* select */
+ eno_mmap, /* mmap */
+ eno_strat, /* strategy */
+ eno_getc, /* getc */
+ eno_putc, /* putc */
+ 0 /* type */
+};
+
+/* Used to detect whether we've already been initialized */
+static int gRandomInstalled = 0;
+static PrngRef gPrngRef;
+static int gRandomError = 1;
+static mutex_t *gYarrowMutex = 0;
+
+#define RESEED_TICKS 50 /* how long a reseed operation can take */
+
+/*
+ *Initialize ONLY the Yarrow generator.
+ */
+void PreliminarySetup ()
+{
+ prng_error_status perr;
+ struct timeval tt;
+ char buffer [16];
+
+ /* create a Yarrow object */
+ perr = prngInitialize(&gPrngRef);
+ if (perr != 0) {
+ printf ("Couldn't initialize Yarrow, /dev/random will not work.\n");
+ return;
+ }
+
+ /* clear the error flag, reads and write should then work */
+ gRandomError = 0;
+
+ /* get a little non-deterministic data as an initial seed. */
+ microtime(&tt);
+
+ /*
+ * So how much of the system clock is entropic?
+ * It's hard to say, but assume that at least the
+ * least significant byte of a 64 bit structure
+ * is entropic. It's probably more, how can you figure
+ * the exact time the user turned the computer on, for example.
+ */
+ perr = prngInput(gPrngRef, (BYTE*) &tt, sizeof (tt), SYSTEM_SOURCE, 8);
+ if (perr != 0) {
+ /* an error, complain */
+ printf ("Couldn't seed Yarrow.\n");
+ return;
+ }
+
+ /* turn the data around */
+ perr = prngOutput(gPrngRef, (BYTE*) buffer, sizeof (buffer));
+
+ /* and scramble it some more */
+ perr = prngForceReseed(gPrngRef, RESEED_TICKS);
+
+ /* make a mutex to control access */
+ gYarrowMutex = mutex_alloc(0);
+}
+
+/*
+ * Called to initialize our device,
+ * and to register ourselves with devfs
+ */
+void
+random_init()
+{
+ int ret;
+
+ if (gRandomInstalled)
+ return;
+
+ /* install us in the file system */
+ gRandomInstalled = 1;
+
+ /* setup yarrow and the mutex */
+ 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, 0644, "random", 0);
+
+ /*
+ * also make urandom
+ * (which is exactly the same thing in our context)
+ */
+ devfs_make_node(makedev (ret, 1), DEVFS_CHAR,
+ UID_ROOT, GID_WHEEL, 0644, "urandom", 0);
+}
+
+/*
+ * Open the device. Make sure init happened, and make sure the caller is
+ * authorized.
+ */
+
+int
+random_open(dev_t dev, int flags, int devtype, struct proc *p)
+{
+ if (gRandomError != 0) {
+ /* forget it, yarrow didn't come up */
+ return (ENOTSUP);
+ }
+
+ /*
+ * if we are being opened for write,
+ * make sure that we have privledges do so
+ */
+ if (flags & FWRITE) {
+ if (securelevel >= 2)
+ return (EPERM);
+ if ((securelevel >= 1) && suser(p->p_ucred, &p->p_acflag))
+ return (EPERM);
+ }
+
+ return (0);
+}
+
+
+/*
+ * close the device.
+ */
+
+int
+random_close(dev_t dev, int flags, int mode, struct proc *p)
+{
+ return (0);
+}
+
+
+/*
+ * Get entropic data from the Security Server, and use it to reseed the
+ * prng.
+ */
+int
+random_write (dev_t dev, struct uio *uio, int ioflag)
+{
+ int retCode = 0;
+ char rdBuffer[256];
+
+ if (gRandomError != 0) {
+ return (ENOTSUP);
+ }
+
+ /* get control of the Yarrow instance, Yarrow is NOT thread safe */
+ mutex_lock(gYarrowMutex);
+
+ /* Security server is sending us entropy */
+
+ while (uio->uio_resid > 0 && retCode == 0) {
+ /* get the user's data */
+ int bytesToInput = min(uio->uio_resid, sizeof (rdBuffer));
+ retCode = uiomove(rdBuffer, bytesToInput, uio);
+ if (retCode != 0)
+ goto /*ugh*/ error_exit;
+
+ /* put it in Yarrow */
+ if (prngInput(gPrngRef, (BYTE*) rdBuffer,
+ sizeof (rdBuffer), SYSTEM_SOURCE,
+ sizeof (rdBuffer) * 8) != 0) {
+ retCode = EIO;
+ goto error_exit;
+ }
+ }
+
+ /* force a reseed */
+ if (prngForceReseed(gPrngRef, RESEED_TICKS) != 0) {
+ retCode = EIO;
+ goto error_exit;
+ }
+
+ /* retCode should be 0 at this point */
+
+error_exit: /* do this to make sure the mutex unlocks. */
+ mutex_unlock(gYarrowMutex);
+ return (retCode);
+}
+
+/*
+ * return data to the caller. Results unpredictable.
+ */
+int
+random_read(dev_t dev, struct uio *uio, int ioflag)
+{
+ int retCode = 0;
+ char wrBuffer[512];
+
+ if (gRandomError != 0)
+ return (ENOTSUP);
+
+ /* lock down the mutex */
+ mutex_lock(gYarrowMutex);
+
+ while (uio->uio_resid > 0 && retCode == 0) {
+ /* get the user's data */
+ int bytesToRead = min(uio->uio_resid, sizeof (wrBuffer));
+
+ /* get the data from Yarrow */
+ if (prngOutput(gPrngRef, (BYTE *) wrBuffer, sizeof (wrBuffer)) != 0) {
+ printf ("Couldn't read data from Yarrow.\n");
+
+ /* something's really weird */
+ retCode = EIO;
+ goto error_exit;
+ }
+
+ retCode = uiomove(wrBuffer, bytesToRead, uio);
+
+ if (retCode != 0)
+ goto error_exit;
+ }
+
+ retCode = 0;
+
+error_exit:
+ mutex_unlock(gYarrowMutex);
+ return retCode;
+}
+
+/* export good random numbers to the rest of the kernel */
+void
+read_random(void* buffer, u_int numbytes)
+{
+ if (gYarrowMutex == 0) { /* are we initialized? */
+ PreliminarySetup ();
+ }
+
+ mutex_lock(gYarrowMutex);
+ prngOutput(gPrngRef, (BYTE *) buffer, numbytes);
+ mutex_unlock(gYarrowMutex);
+}
+
+/*
+ * Return an unsigned long pseudo-random number.
+ */
+u_long
+RandomULong()
+{
+ u_long buf;
+ read_random(&buf, sizeof (buf));
+ return (buf);
+}
+