X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/91447636331957f3d9b5ca5b508f07c526b0074d..0c530ab8987f0ae6a1a3d9284f40182b88852816:/bsd/dev/random/randomdev.c diff --git a/bsd/dev/random/randomdev.c b/bsd/dev/random/randomdev.c index 747656750..04e1883a4 100644 --- a/bsd/dev/random/randomdev.c +++ b/bsd/dev/random/randomdev.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 1999-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c)1999-2004 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -35,6 +36,7 @@ #include #include +#include #define RANDOM_MAJOR -1 /* let the kernel pick the device number */ @@ -71,10 +73,180 @@ 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, 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 = 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; +unsigned char g_SelfTestInitialized = 0; +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 + */ + +/* + * 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) +{ + int repeatCount = 0; + do + { + if (addOptional) + { + // 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)); + + // calculate the CRC-32 of the block + u_int32_t new_crc = CalculateCRC(g_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 ) +void +PreliminarySetup(void) { prng_error_status perr; struct timeval tt; @@ -108,13 +280,45 @@ void PreliminarySetup( void ) } /* 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); + + fips_initialize (); +} + +const Block kKnownAnswer = {0x92b404e5, 0x56588ced, 0x6c1acd4e, 0xbf053f68, 0x9f73a93}; + +void +fips_initialize(void) +{ + /* So that we can do the self test, set the seed to zero */ + memset(&g_xkey, 0, 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, FALSE); + + // check here to see if we got the initial data we were expecting + int i; + for (i = 0; i < kBSize; ++i) + { + if (kKnownAnswer[i] != g_random_data[i]) + { + panic("FIPS random self test failed"); + } + } + + // now do the random block again to make sure that userland doesn't get predictable data + random_block(g_random_data, TRUE); } /* @@ -122,7 +326,7 @@ void PreliminarySetup( void ) * and to register ourselves with devfs */ void -random_init( void ) +random_init(void) { int ret; @@ -237,9 +441,9 @@ random_write (__unused dev_t dev, struct uio *uio, __unused int ioflag) goto /*ugh*/ error_exit; /* put it in Yarrow */ - if (prngInput(gPrngRef, (BYTE*) rdBuffer, - sizeof (rdBuffer), SYSTEM_SOURCE, - sizeof (rdBuffer) * 8) != 0) { + if (prngInput(gPrngRef, (BYTE*)rdBuffer, + bytesToInput, SYSTEM_SOURCE, + bytesToInput * 8) != 0) { retCode = EIO; goto error_exit; } @@ -261,36 +465,38 @@ error_exit: /* do this to make sure the mutex unlocks. */ /* * 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; - char wrBuffer[512]; - + if (gRandomError != 0) return (ENOTSUP); /* lock down the mutex */ mutex_lock(gYarrowMutex); - while (uio_resid(uio) > 0 && retCode == 0) { + int bytes_remaining = uio_resid(uio); + while (bytes_remaining > 0 && retCode == 0) { /* get the user's data */ - // LP64todo - fix this! uio_resid may be 64-bit value - int bytesToRead = min(uio_resid(uio), sizeof (wrBuffer)); - - /* get the data from Yarrow */ - if (prngOutput(gPrngRef, (BYTE *) wrBuffer, sizeof (wrBuffer)) != 0) { - printf ("Couldn't read data from Yarrow.\n"); - - /* something's really weird */ - retCode = EIO; - goto error_exit; - } - - retCode = uiomove(wrBuffer, bytesToRead, uio); - + int bytes_to_read = 0; + + int bytes_available = kBSizeInBytes - g_bytes_used; + if (bytes_available == 0) + { + random_block(g_random_data, TRUE); + 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; @@ -309,7 +515,25 @@ read_random(void* buffer, u_int numbytes) } mutex_lock(gYarrowMutex); - prngOutput(gPrngRef, (BYTE *) buffer, numbytes); + + int bytes_read = 0; + + 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, TRUE); + g_bytes_used = 0; + bytes_to_read = min(bytes_remaining, kBSizeInBytes); + } + + memmove (buffer, ((u_int8_t*)g_random_data)+ bytes_read, bytes_to_read); + g_bytes_used += bytes_to_read; + bytes_read += bytes_to_read; + bytes_remaining -= bytes_to_read; + } + mutex_unlock(gYarrowMutex); } @@ -317,7 +541,7 @@ read_random(void* buffer, u_int numbytes) * Return an unsigned long pseudo-random number. */ u_long -RandomULong( void ) +RandomULong(void) { u_long buf; read_random(&buf, sizeof (buf));