X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8f6c56a50524aa785f7e596d52dddfb331e18961..eb6b6ca394357805f2bdba989abae309f718b4d8:/bsd/dev/random/randomdev.c diff --git a/bsd/dev/random/randomdev.c b/bsd/dev/random/randomdev.c index d98b1e29c..7e5e10e3e 100644 --- a/bsd/dev/random/randomdev.c +++ b/bsd/dev/random/randomdev.c @@ -1,8 +1,8 @@ /* - * Copyright (c)1999-2004 Apple Computer, Inc. All rights reserved. + * 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 @@ -11,10 +11,10 @@ * 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, @@ -22,10 +22,11 @@ * 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 #include #include @@ -35,16 +36,23 @@ #include #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; @@ -54,166 +62,22 @@ 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 */ + 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, @@ -224,36 +88,25 @@ 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, - 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: @@ -263,47 +116,44 @@ random_ioctl( __unused dev_t dev, u_long cmd, __unused caddr_t data, 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; } @@ -312,131 +162,87 @@ 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); - - /* 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); + 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 +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; + 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(((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 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; - read_random(&buf, sizeof (buf)); - return (buf); + u_int32_t 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); +}