X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/5d5c5d0d5b79ade9a973d55186ffda2638ba2b6e..04b8595b18b1b41ac7a206e4b3d51a635f8413d7:/bsd/dev/random/randomdev.c diff --git a/bsd/dev/random/randomdev.c b/bsd/dev/random/randomdev.c index 87624e22d..1b96f774c 100644 --- a/bsd/dev/random/randomdev.c +++ b/bsd/dev/random/randomdev.c @@ -1,33 +1,32 @@ /* - * Copyright (c)1999-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 1999-2009 Apple, Inc. All rights reserved. * - * @APPLE_LICENSE_OSREFERENCE_HEADER_START@ + * @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 + * 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_LICENSE_OSREFERENCE_HEADER_END@ + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ + #include #include #include @@ -37,16 +36,22 @@ #include #include #include -#include +#include +#include #include #include #include #include -#include -#include + +#include +#include + +#include #define RANDOM_MAJOR -1 /* let the kernel pick the device number */ +#define RANDOM_MINOR 0 +#define URANDOM_MINOR 1 d_ioctl_t random_ioctl; @@ -72,150 +77,6 @@ static struct cdevsw random_cdevsw = 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, @@ -226,31 +87,21 @@ 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; + panic("random_init: failed to allocate a major number!"); } - devfs_make_node(makedev (ret, 0), DEVFS_CHAR, + devfs_make_node(makedev (ret, RANDOM_MINOR), 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, + devfs_make_node(makedev (ret, URANDOM_MINOR), DEVFS_CHAR, UID_ROOT, GID_WHEEL, 0666, "urandom", 0); + } int @@ -276,11 +127,6 @@ random_ioctl( __unused dev_t dev, u_long cmd, __unused caddr_t data, 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 @@ -314,130 +160,63 @@ random_close(__unused dev_t dev, __unused int flags, __unused int mode, __unused * 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 */ - mutex_lock(gYarrowMutex); - + 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 */ - // LP64todo - fix this! uio_resid may be 64-bit value - int bytesToInput = min(uio_resid(uio), sizeof (rdBuffer)); + int bytesToInput = MIN(uio_resid(uio), + (user_ssize_t) 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; + break; + retCode = write_random(rdBuffer, bytesToInput); + if (retCode != 0) + break; } - - /* retCode should be 0 at this point */ - -error_exit: /* do this to make sure the mutex unlocks. */ - mutex_unlock(gYarrowMutex); - return (retCode); + + 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; - - 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; + 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_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 retCode; } /* - * 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); }