* Copyright (c) 1999-2009 Apple, 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
* 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,
* 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@
*/
-/*
- WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!
-
- THIS FILE IS NEEDED TO PASS FIPS ACCEPTANCE FOR THE RANDOM NUMBER GENERATOR.
- IF YOU ALTER IT IN ANY WAY, WE WILL NEED TO GO THOUGH FIPS ACCEPTANCE AGAIN,
- AN OPERATION THAT IS VERY EXPENSIVE AND TIME CONSUMING. IN OTHER WORDS,
- DON'T MESS WITH THIS FILE.
-
- WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!
-*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fcntl.h>
#include <string.h>
#include <miscfs/devfs/devfs.h>
-#include <kern/lock.h>
+#include <kern/locks.h>
#include <kern/clock.h>
#include <sys/time.h>
#include <sys/malloc.h>
+#include <sys/sysproto.h>
#include <sys/uio_internal.h>
#include <dev/random/randomdev.h>
-#include <dev/random/YarrowCoreLib/include/yarrow.h>
#include <libkern/OSByteOrder.h>
+#include <libkern/OSAtomic.h>
#include <mach/mach_time.h>
-#include <machine/machine_routines.h>
-
-#include "fips_sha1.h"
#define RANDOM_MAJOR -1 /* let the kernel pick the device number */
+#define RANDOM_MINOR 0
+#define URANDOM_MINOR 1
d_ioctl_t random_ioctl;
*/
static struct cdevsw random_cdevsw =
{
- random_open, /* open */
- random_close, /* close */
- random_read, /* read */
- random_write, /* write */
- random_ioctl, /* ioctl */
+ 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 lck_grp_t *gYarrowGrp;
-static lck_attr_t *gYarrowAttr;
-static lck_grp_attr_t *gYarrowGrpAttr;
-static lck_mtx_t *gYarrowMutex = 0;
-
-#define RESEED_TICKS 50 /* how long a reseed operation can take */
-
-
-typedef u_int8_t BlockWord;
-enum {kBSize = 20};
-typedef BlockWord Block[kBSize];
-enum {kBlockSize = sizeof(Block)};
-
-/* 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, int addOptional);
-u_int32_t CalculateCRC(u_int8_t* buffer, size_t length);
-
-/*
- * Get 120 bits from yarrow
- */
-
-/*
- * add block b to block a
- */
-void
-add_blocks(Block a, Block b, BlockWord carry)
-{
- int i = kBlockSize - 1;
- while (i >= 0)
- {
- u_int32_t c = (u_int32_t)carry +
- (u_int32_t)a[i] +
- (u_int32_t)b[i];
- a[i] = c & 0xff;
- carry = c >> 8;
- i -= 1;
- }
-}
-
-
-
-static char zeros[(512 - kBSize * 8) / 8];
-static Block g_xkey;
-static Block g_random_data;
-static int g_bytes_used;
-static unsigned char g_SelfTestInitialized = 0;
-static u_int32_t gLastBlockChecksum;
-
-static const u_int32_t g_crc_table[] =
-{
- 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
- 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
- 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
- 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
- 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
- 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
- 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
- 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
- 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
- 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
- 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
- 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
- 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
- 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
- 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
- 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
- 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
- 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
- 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
- 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
- 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
- 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
- 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
- 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
- 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
- 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
- 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
- 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
- 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
- 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
- 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
- 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D,
+ NULL, /* tty's */
+ eno_select, /* select */
+ eno_mmap, /* mmap */
+ eno_strat, /* strategy */
+ eno_getc, /* getc */
+ eno_putc, /* putc */
+ 0 /* type */
};
-/*
- * Setup for fips compliance
- */
-
-/*
- * calculate a crc-32 checksum
- */
-u_int32_t CalculateCRC(u_int8_t* buffer, size_t length)
-{
- u_int32_t crc = 0;
-
- size_t i;
- for (i = 0; i < length; ++i)
- {
- u_int32_t temp = (crc ^ ((u_int32_t) buffer[i])) & 0xFF;
- crc = (crc >> 8) ^ g_crc_table[temp];
- }
-
- return crc;
-}
-
-/*
- * get a random block of data per fips 186-2
- */
-void
-random_block(Block b, int addOptional)
-{
- SHA1_CTX sha1_ctx;
-
- int repeatCount = 0;
- do
- {
- // do one iteration
-
- if (addOptional)
- {
- // create an xSeed to add.
- Block xSeed;
- prngOutput (gPrngRef, (BYTE*) &xSeed, sizeof (xSeed));
-
- // add the seed to the previous value of g_xkey
- add_blocks (g_xkey, xSeed, 0);
- }
-
- // initialize the value of H
- FIPS_SHA1Init(&sha1_ctx);
-
- // to stay compatible with the FIPS specification, we need to flip the bytes in
- // g_xkey to little endian byte order. In our case, this makes exactly no difference
- // (random is random), but we need to do it anyway to keep FIPS happy
-
- // compute "G"
- FIPS_SHA1Update(&sha1_ctx, g_xkey, kBlockSize);
-
- // add zeros to fill the internal SHA-1 buffer
- FIPS_SHA1Update (&sha1_ctx, (const u_int8_t *)zeros, sizeof (zeros));
-
- // we have to do a byte order correction here because the sha1 math is being done internally
- // as u_int32_t, not a stream of bytes. Since we maintain our data as a byte stream, we need
- // to convert
-
- u_int32_t* finger = (u_int32_t*) b;
-
- unsigned j;
- for (j = 0; j < kBlockSize / sizeof (u_int32_t); ++j)
- {
- *finger++ = OSSwapHostToBigInt32(sha1_ctx.h.b32[j]);
- }
-
- // calculate the CRC-32 of the block
- u_int32_t new_crc = CalculateCRC(sha1_ctx.h.b8, sizeof (Block));
-
- // make sure we don't repeat
- int cmp = new_crc == gLastBlockChecksum;
- gLastBlockChecksum = new_crc;
- if (!g_SelfTestInitialized)
- {
- g_SelfTestInitialized = 1;
- return;
- }
- else if (!cmp)
- {
- return;
- }
-
- repeatCount += 1;
-
- // fix up the next value of g_xkey
- add_blocks (g_xkey, b, 1);
- } while (repeatCount < 2);
-
- /*
- * If we got here, three sucessive checksums of the random number
- * generator have been the same. Since the odds of this happening are
- * 1 in 18,446,744,073,709,551,616, (1 in 18 quintillion) one of the following has
- * most likely happened:
- *
- * 1: There is a significant bug in this code.
- * 2: There has been a massive system failure.
- * 3: The universe has ceased to exist.
- *
- * There is no good way to recover from any of these cases. We
- * therefore panic.
- */
-
- panic("FIPS random self-test failed.");
-}
-
-/*
- *Initialize ONLY the Yarrow generator.
- */
-void
-PreliminarySetup(void)
-{
- prng_error_status perr;
-
- /* 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;
-
- struct timeval tt;
- char buffer [16];
-
- /* 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 */
- gYarrowGrpAttr = lck_grp_attr_alloc_init();
- gYarrowGrp = lck_grp_alloc_init("random", gYarrowGrpAttr);
- gYarrowAttr = lck_attr_alloc_init();
- gYarrowMutex = lck_mtx_alloc_init(gYarrowGrp, gYarrowAttr);
-
- fips_initialize ();
-}
-
-const Block kKnownAnswer = {0x92, 0xb4, 0x04, 0xe5, 0x56, 0x58, 0x8c, 0xed, 0x6c, 0x1a, 0xcd, 0x4e, 0xbf, 0x05, 0x3f, 0x68, 0x09, 0xf7, 0x3a, 0x93};
-
-void
-fips_initialize(void)
-{
- /* So that we can do the self test, set the seed to zero */
- memset(&g_xkey, 0, sizeof(g_xkey));
-
- /* other initializations */
- memset (zeros, 0, sizeof (zeros));
- g_bytes_used = 0;
- random_block(g_random_data, FALSE);
-
- // check here to see if we got the initial data we were expecting
- if (memcmp(kKnownAnswer, g_random_data, kBlockSize) != 0)
- {
- panic("FIPS random self test failed");
- }
-
- // now do the random block again to make sure that userland doesn't get predicatable data
- random_block(g_random_data, TRUE);
-}
/*
* Called to initialize our device,
{
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;
+ panic("random_init: failed to allocate a major number!");
}
- devfs_make_node(makedev (ret, 0), DEVFS_CHAR,
- UID_ROOT, GID_WHEEL, 0666, "random", 0);
+ devfs_make_node(makedev(ret, RANDOM_MINOR), DEVFS_CHAR,
+ UID_ROOT, GID_WHEEL, 0666, "random", 0);
/*
- * also make urandom
+ * 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);
+ devfs_make_node(makedev(ret, URANDOM_MINOR), 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 )
+random_ioctl( __unused dev_t dev, u_long cmd, __unused caddr_t data,
+ __unused int flag, __unused struct proc *p )
{
switch (cmd) {
case FIONBIO:
return ENODEV;
}
- return (0);
+ 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);
+ if (securelevel >= 2) {
+ return EPERM;
+ }
#ifndef __APPLE__
- if ((securelevel >= 1) && proc_suser(p))
- return (EPERM);
-#endif /* !__APPLE__ */
+ if ((securelevel >= 1) && proc_suser(p)) {
+ return EPERM;
+ }
+#endif /* !__APPLE__ */
}
- return (0);
+ return 0;
}
/*
* close the device.
*/
-
+
int
random_close(__unused dev_t dev, __unused int flags, __unused int mode, __unused struct proc *p)
{
- return (0);
+ return 0;
}
* prng.
*/
int
-random_write (__unused dev_t dev, struct uio *uio, __unused int ioflag)
+random_write(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 */
- lck_mtx_lock(gYarrowMutex);
-
- /* Security server is sending us entropy */
-
- while (uio_resid(uio) > 0 && retCode == 0) {
- /* get the user's data */
- 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. */
- lck_mtx_unlock(gYarrowMutex);
- return (retCode);
+ int retCode = 0;
+ char rdBuffer[256];
+
+ if (minor(dev) != RANDOM_MINOR) {
+ return EPERM;
+ }
+
+ /* Security server is sending us entropy */
+
+ while (uio_resid(uio) > 0 && retCode == 0) {
+ /* get the user's data */
+ int bytesToInput = MIN(uio_resid(uio),
+ (user_ssize_t) sizeof(rdBuffer));
+ retCode = uiomove(rdBuffer, bytesToInput, uio);
+ if (retCode != 0) {
+ break;
+ }
+ retCode = write_random(rdBuffer, bytesToInput);
+ if (retCode != 0) {
+ break;
+ }
+ }
+
+ 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 */
- lck_mtx_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 = kBlockSize - g_bytes_used;
- if (bytes_available == 0)
- {
- random_block(g_random_data, TRUE);
- g_bytes_used = 0;
- bytes_available = kBlockSize;
+ int retCode = 0;
+ char buffer[512];
+
+ user_ssize_t bytes_remaining = uio_resid(uio);
+ while (bytes_remaining > 0 && retCode == 0) {
+ int bytesToRead = MIN(bytes_remaining,
+ (user_ssize_t) sizeof(buffer));
+ read_random(buffer, bytesToRead);
+
+ retCode = uiomove(buffer, bytesToRead, uio);
+ if (retCode != 0) {
+ break;
}
-
- bytes_to_read = min (bytes_remaining, bytes_available);
-
- retCode = uiomove(((caddr_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:
- lck_mtx_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 ();
- }
-
- lck_mtx_lock(gYarrowMutex);
-
- int bytes_read = 0;
-
- int bytes_remaining = numbytes;
- while (bytes_remaining > 0) {
- int bytes_to_read = min(bytes_remaining, kBlockSize - g_bytes_used);
- if (bytes_to_read == 0)
- {
- random_block(g_random_data, TRUE);
- g_bytes_used = 0;
- bytes_to_read = min(bytes_remaining, kBlockSize);
- }
-
- memmove ((u_int8_t*) buffer + bytes_read, ((u_int8_t*)g_random_data)+ g_bytes_used, bytes_to_read);
- g_bytes_used += bytes_to_read;
- bytes_read += bytes_to_read;
- bytes_remaining -= bytes_to_read;
- }
-
- lck_mtx_unlock(gYarrowMutex);
+ return retCode;
}
/*
RandomULong(void)
{
u_int32_t buf;
- read_random(&buf, sizeof (buf));
- return (buf);
+ read_random(&buf, sizeof(buf));
+ return buf;
+}
+
+
+int
+getentropy(__unused struct proc * p, struct getentropy_args *gap, __unused int * ret)
+{
+ user_addr_t user_addr;
+ uint32_t user_size;
+ char buffer[256];
+
+ user_addr = (vm_map_offset_t)gap->buffer;
+ user_size = gap->size;
+ /* Can't request more than 256 random bytes
+ * at once. Complying with openbsd getentropy()
+ */
+ if (user_size > sizeof(buffer)) {
+ return EINVAL;
+ }
+ read_random(buffer, user_size);
+ return copyout(buffer, user_addr, user_size);
}
projects / apple / xnu.git / blobdiff