/*
- * Copyright (c)1999-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2009 Apple, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* @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/proc.h>
#include <string.h>
#include <miscfs/devfs/devfs.h>
#include <kern/lock.h>
+#include <kern/clock.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>
+
+#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 */
0 /* type */
};
+
+/*
+ WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!
+
+ ANY CODE PROTECTED UNDER "#ifdef __arm__" IS SERIOUSLY SUPPOSED TO BE THERE!
+ IF YOU REMOVE ARM CODE, RANDOM WILL NOT MEAN ANYTHING FOR iPHONES ALL OVER.
+ PLEASE DON'T TOUCH __arm__ CODE IN THIS FILE!
+
+ WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING!
+*/
+
+
/* Used to detect whether we've already been initialized */
-static int gRandomInstalled = 0;
+static UInt8 gRandomInstalled = 0;
static PrngRef gPrngRef;
static int gRandomError = 1;
-static mutex_t *gYarrowMutex = 0;
+static lck_grp_t *gYarrowGrp;
+static lck_attr_t *gYarrowAttr;
+static lck_grp_attr_t *gYarrowGrpAttr;
+static lck_mtx_t *gYarrowMutex = 0;
+static UInt8 gYarrowInitializationLock = 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 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);
+void random_block(Block b, int addOptional);
+u_int32_t CalculateCRC(u_int8_t* buffer, size_t length);
/*
* Get 120 bits from yarrow
void
add_blocks(Block a, Block b, BlockWord carry)
{
- int i = kBSize;
- while (--i >= 0)
+ int i = kBlockSize - 1;
+ 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;
+ 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;
}
}
-struct sha1_ctxt g_sha1_ctx;
-char zeros[(512 - kBSizeInBits) / 8];
-Block g_xkey;
-Block g_random_data;
-int g_bytes_used;
+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,
+};
/*
* Setup for fips compliance
*/
/*
- * get a random block of data per fips 186-2
+ * calculate a crc-32 checksum
*/
-void
-random_block(Block b)
+u_int32_t CalculateCRC(u_int8_t* buffer, size_t length)
{
- // do one iteration
- Block xSeed;
- prngOutput (gPrngRef, (BYTE*) &xSeed, sizeof (xSeed));
+ u_int32_t crc = 0;
- // 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));
+ 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];
+ }
- // add zeros to fill the internal SHA-1 buffer
- SHA1Update (&g_sha1_ctx, (const u_int8_t *)zeros, sizeof (zeros));
+ return crc;
+}
+
+/*
+ * get a random block of data per fips 186-2
+ */
+void
+random_block(Block b, int addOptional)
+{
+ SHA1_CTX sha1_ctx;
- // write the resulting block
- memmove(b, g_sha1_ctx.h.b8, sizeof (Block));
+ 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);
- // fix up the next value of g_xkey
- add_blocks (g_xkey, b, 1);
+ /*
+ * 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.");
}
/*
PreliminarySetup(void)
{
prng_error_status perr;
- struct timeval tt;
- char buffer [16];
+
+ /* Multiple threads can enter this as a result of an earlier
+ * check of gYarrowMutex. We make sure that only one of them
+ * can enter at a time. If one of them enters and discovers
+ * that gYarrowMutex is no longer NULL, we know that another
+ * thread has initialized the Yarrow state and we can exit.
+ */
+
+ /* The first thread that enters this function will find
+ * gYarrowInitializationLock set to 0. It will atomically
+ * set the value to 1 and, seeing that it was zero, drop
+ * out of the loop. Other threads will see that the value is
+ * 1 and continue to loop until we are initialized.
+ */
+
+ while (OSTestAndSet(0, &gYarrowInitializationLock)); /* serialize access to this function */
+
+ if (gYarrowMutex) {
+ /* we've already been initialized, clear and get out */
+ goto function_exit;
+ }
/* create a Yarrow object */
perr = prngInitialize(&gPrngRef);
/* 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. */
+ /* On OSX, securityd will add much more entropy as soon as it */
+ /* comes up. On iOS, entropy is added with each system interrupt. */
microtime(&tt);
/*
if (perr != 0) {
/* an error, complain */
printf ("Couldn't seed Yarrow.\n");
- return;
+ goto function_exit;
}
/* turn the data around */
- perr = prngOutput(gPrngRef, (BYTE*)buffer, sizeof (buffer));
+ 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);
+ 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 ();
+
+function_exit:
+ /* allow other threads to figure out whether or not we have been initialized. */
+ gYarrowInitializationLock = 0;
}
+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)
{
- /* 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);
+ /* 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);
+ 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);
}
/*
{
int ret;
- if (gRandomInstalled)
+ if (OSTestAndSet(0, &gRandomInstalled)) {
+ /* do this atomically so that it works correctly with
+ multiple threads */
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) {
*/
devfs_make_node(makedev (ret, 1), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0666, "urandom", 0);
+
+ /* setup yarrow and the mutex if needed*/
+ PreliminarySetup();
}
int
}
/* get control of the Yarrow instance, Yarrow is NOT thread safe */
- mutex_lock(gYarrowMutex);
+ lck_mtx_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,
+ if (prngInput(gPrngRef, (BYTE*) rdBuffer,
bytesToInput, SYSTEM_SOURCE,
bytesToInput * 8) != 0) {
retCode = EIO;
/* retCode should be 0 at this point */
error_exit: /* do this to make sure the mutex unlocks. */
- mutex_unlock(gYarrowMutex);
+ lck_mtx_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
+random_read(__unused dev_t dev, struct uio *uio, __unused int ioflag)
{
int retCode = 0;
return (ENOTSUP);
/* lock down the mutex */
- mutex_lock(gYarrowMutex);
+ 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 = kBSizeInBytes - g_bytes_used;
+ int bytes_available = kBlockSize - g_bytes_used;
if (bytes_available == 0)
{
- random_block(g_random_data);
+ random_block(g_random_data, TRUE);
g_bytes_used = 0;
- bytes_available = kBSizeInBytes;
+ bytes_available = kBlockSize;
}
bytes_to_read = min (bytes_remaining, bytes_available);
- retCode = uiomove(((u_int8_t*)g_random_data)+ g_bytes_used, bytes_to_read, uio);
+ retCode = uiomove(((caddr_t)g_random_data)+ g_bytes_used, bytes_to_read, uio);
g_bytes_used += bytes_to_read;
if (retCode != 0)
retCode = 0;
error_exit:
- mutex_unlock(gYarrowMutex);
+ lck_mtx_unlock(gYarrowMutex);
return retCode;
}
PreliminarySetup ();
}
- mutex_lock(gYarrowMutex);
+ lck_mtx_lock(gYarrowMutex);
+ int bytes_read = 0;
int bytes_remaining = numbytes;
while (bytes_remaining > 0) {
- int bytes_to_read = min(bytes_remaining, kBSizeInBytes - g_bytes_used);
+ int bytes_to_read = min(bytes_remaining, kBlockSize - g_bytes_used);
if (bytes_to_read == 0)
{
- random_block(g_random_data);
+ random_block(g_random_data, TRUE);
g_bytes_used = 0;
- bytes_to_read = min(bytes_remaining, kBSizeInBytes);
+ bytes_to_read = min(bytes_remaining, kBlockSize);
}
- memmove (buffer, ((u_int8_t*)g_random_data)+ g_bytes_used, bytes_to_read);
+ 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;
}
- mutex_unlock(gYarrowMutex);
+ lck_mtx_unlock(gYarrowMutex);
}
/*
- * Return an unsigned long pseudo-random number.
+ * Return an u_int32_t pseudo-random number.
*/
-u_long
+u_int32_t
RandomULong(void)
{
- u_long buf;
+ u_int32_t buf;
read_random(&buf, sizeof (buf));
return (buf);
}
projects / apple / xnu.git / blobdiff