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--- /dev/null
+++ xnu/xnu-792.17.14/bsd/dev/random/randomdev.c
@@ -0,0 +1,442 @@
+/*
+ * Copyright (c)1999-2004 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_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 <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 /* let the kernel pick the device number */
+
+d_ioctl_t random_ioctl;
+
+/*
+ * 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 */
+ random_ioctl, /* ioctl */
+ (stop_fcn_t *)nulldev, /* stop */
+ (reset_fcn_t *)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 */
+
+
+enum {kBSizeInBits = 160}; // MUST be a multiple of 32!!!
+enum {kBSizeInBytes = kBSizeInBits / 8};
+typedef u_int32_t BlockWord;
+enum {kWordSizeInBits = 32};
+enum {kBSize = 5};
+typedef BlockWord Block[kBSize];
+
+/* define prototypes to keep the compiler happy... */
+
+void add_blocks(Block a, Block b, BlockWord carry);
+void fips_initialize(void);
+void random_block(Block b);
+
+/*
+ * Get 120 bits from yarrow
+ */
+
+/*
+ * add block b to block a
+ */
+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;
+
+/*
+ * Setup for fips compliance
+ */
+
+/*
+ * get a random block of data per fips 186-2
+ */
+void
+random_block(Block b)
+{
+ // do one iteration
+ Block xSeed;
+ prngOutput (gPrngRef, (BYTE*) &xSeed, sizeof (xSeed));
+
+ // add the seed to the previous value of g_xkey
+ add_blocks (g_xkey, xSeed, 0);
+
+ // compute "G"
+ SHA1Update (&g_sha1_ctx, (const u_int8_t *) &g_xkey, sizeof (g_xkey));
+
+ // add zeros to fill the internal SHA-1 buffer
+ SHA1Update (&g_sha1_ctx, (const u_int8_t *)zeros, sizeof (zeros));
+
+ // write the resulting block
+ memmove(b, g_sha1_ctx.h.b8, sizeof (Block));
+
+ // fix up the next value of g_xkey
+ add_blocks (g_xkey, b, 1);
+}
+
+/*
+ *Initialize ONLY the Yarrow generator.
+ */
+void
+PreliminarySetup(void)
+{
+ 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);
+
+ fips_initialize ();
+}
+
+void
+fips_initialize(void)
+{
+ /* Read the initial value of g_xkey from yarrow */
+ prngOutput (gPrngRef, (BYTE*) &g_xkey, sizeof (g_xkey));
+
+ /* initialize our SHA1 generator */
+ SHA1Init (&g_sha1_ctx);
+
+ /* other initializations */
+ memset (zeros, 0, sizeof (zeros));
+ g_bytes_used = 0;
+ random_block(g_random_data);
+}
+
+/*
+ * Called to initialize our device,
+ * and to register ourselves with devfs
+ */
+void
+random_init(void)
+{
+ 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, 0666, "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, 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);
+}
+
+/*
+ * Open the device. Make sure init happened, and make sure the caller is
+ * authorized.
+ */
+
+int
+random_open(__unused dev_t dev, int flags, __unused int devtype, __unused 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);
+#ifndef __APPLE__
+ if ((securelevel >= 1) && proc_suser(p))
+ return (EPERM);
+#endif /* !__APPLE__ */
+ }
+
+ return (0);
+}
+
+
+/*
+ * close the device.
+ */
+
+int
+random_close(__unused dev_t dev, __unused int flags, __unused int mode, __unused struct proc *p)
+{
+ return (0);
+}
+
+
+/*
+ * Get entropic data from the Security Server, and use it to reseed the
+ * prng.
+ */
+int
+random_write (__unused dev_t dev, struct uio *uio, __unused 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_resid(uio) > 0 && retCode == 0) {
+ /* get the user's data */
+ // LP64todo - fix this! uio_resid may be 64-bit value
+ int bytesToInput = min(uio_resid(uio), sizeof (rdBuffer));
+ retCode = uiomove(rdBuffer, bytesToInput, uio);
+ if (retCode != 0)
+ goto /*ugh*/ error_exit;
+
+ /* put it in Yarrow */
+ if (prngInput(gPrngRef, (BYTE*)rdBuffer,
+ bytesToInput, SYSTEM_SOURCE,
+ bytesToInput * 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(__unused dev_t dev, struct uio *uio, __unused int ioflag)
+{
+ int retCode = 0;
+
+ if (gRandomError != 0)
+ return (ENOTSUP);
+
+ /* lock down the mutex */
+ mutex_lock(gYarrowMutex);
+
+ int bytes_remaining = uio_resid(uio);
+ while (bytes_remaining > 0 && retCode == 0) {
+ /* get the user's data */
+ 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;
+}
+
+/* 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);
+
+ 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);
+}
+
+/*
+ * Return an unsigned long pseudo-random number.
+ */
+u_long
+RandomULong(void)
+{
+ u_long buf;
+ read_random(&buf, sizeof (buf));
+ return (buf);
+}
+