#include <string.h>
#include <kern/cpu_number.h>
#include <kern/cpu_data.h>
#include <kern/misc_protos.h>
#include <kern/thread.h>
#include <sys/random.h>
#include <corecrypto/ccdrbg.h>
#include <prng/YarrowCoreLib/include/yarrow.h>
#include <libkern/OSByteOrder.h>
#include <libkern/OSAtomic.h>
#include <mach/mach_time.h>
#include <prng/random.h>
#include "fips_sha1.h"
#define RESEED_TICKS 50
typedef u_int8_t BlockWord;
enum {kBSize = 20};
typedef BlockWord Block[kBSize];
enum {kBlockSize = sizeof(Block)};
struct YarrowContext {
PrngRef PrngRef;
Block xkey;
Block random_data;
int bytes_used;
unsigned char SelfTestInitialized;
u_int32_t LastBlockChecksum;
uint64_t bytes_since_reseed;
};
typedef struct YarrowContext *YarrowContextp;
void add_blocks(Block a, Block b, BlockWord carry);
void fips_initialize(YarrowContextp yp);
void random_block(YarrowContextp yp, Block b, int addOptional);
u_int32_t CalculateCRC(u_int8_t* buffer, size_t length);
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 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,
};
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;
}
void
random_block(YarrowContextp pp, Block b, int addOptional)
{
SHA1_CTX sha1_ctx;
int repeatCount = 0;
do
{
if (addOptional)
{
Block xSeed;
prngOutput (pp->PrngRef, (BYTE*) &xSeed, sizeof (xSeed));
add_blocks (pp->xkey, xSeed, 0);
}
FIPS_SHA1Init(&sha1_ctx);
FIPS_SHA1Update(&sha1_ctx, pp->xkey, kBlockSize);
FIPS_SHA1Update (&sha1_ctx, (const u_int8_t *)zeros, sizeof (zeros));
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]);
}
u_int32_t new_crc = CalculateCRC(sha1_ctx.h.b8, sizeof (Block));
int cmp = new_crc == pp->LastBlockChecksum;
pp->LastBlockChecksum = new_crc;
if (!pp->SelfTestInitialized)
{
pp->SelfTestInitialized = 1;
return;
}
else if (!cmp)
{
return;
}
repeatCount += 1;
add_blocks (pp->xkey, b, 1);
} while (repeatCount < 2);
panic("FIPS random self-test failed.");
}
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(YarrowContextp yp)
{
memset(&yp->xkey, 0, sizeof(yp->xkey));
memset (zeros, 0, sizeof (zeros));
yp->bytes_used = 0;
random_block(yp, yp->random_data, FALSE);
if (memcmp(kKnownAnswer, yp->random_data, kBlockSize) != 0)
{
panic("FIPS random self test failed");
}
random_block(yp, yp->random_data, TRUE);
}
static int
yarrow_init(
const struct ccdrbg_info *info,
struct ccdrbg_state *drbg,
unsigned long entropyLength, const void* entropy,
unsigned long nonceLength, const void* nonce,
unsigned long psLength, const void* ps)
{
#pragma unused(info)
#pragma unused(nonceLength)
#pragma unused(nonce)
#pragma unused(psLength)
#pragma unused(ps)
YarrowContextp yp = (YarrowContextp) drbg;
prng_error_status perr;
char buffer[16];
yp->SelfTestInitialized = 0;
perr = prngInitialize(&yp->PrngRef);
if (perr != 0) {
panic("Couldn't initialize Yarrow, /dev/random will not work.");
}
perr = prngInput(yp->PrngRef, __DECONST(BYTE*, entropy), (UINT) entropyLength,
SYSTEM_SOURCE, (UINT) entropyLength * 8);
if (perr != 0) {
panic("Couldn't seed Yarrow.\n");
}
perr = prngOutput(yp->PrngRef, (BYTE*) buffer, (UINT) sizeof(buffer));
perr = prngForceReseed(yp->PrngRef, RESEED_TICKS);
fips_initialize(yp);
yp->bytes_since_reseed = 0;
return perr;
}
static int
yarrow_generate(
struct ccdrbg_state *prng,
unsigned long outlen, void *out,
unsigned long inlen, const void *in)
{
#pragma unused(inlen)
#pragma unused(in)
YarrowContextp yp = (YarrowContextp) prng;
int bytes_read = 0;
int bytes_remaining = (int) outlen;
yp->bytes_since_reseed += outlen;
if (yp->bytes_since_reseed != outlen &&
yp->bytes_since_reseed > RESEED_BYTES)
return CCDRBG_STATUS_NEED_RESEED;
while (bytes_remaining > 0) {
int bytes_to_read = MIN(bytes_remaining,
kBlockSize - yp->bytes_used);
if (bytes_to_read == 0) {
random_block(yp, yp->random_data, TRUE);
yp->bytes_used = 0;
bytes_to_read = MIN(bytes_remaining, kBlockSize);
}
memmove((u_int8_t*) out + bytes_read,
((u_int8_t*)yp->random_data) + yp->bytes_used,
bytes_to_read);
yp->bytes_used += bytes_to_read;
bytes_read += bytes_to_read;
bytes_remaining -= bytes_to_read;
}
return CCDRBG_STATUS_OK;
}
static int
yarrow_reseed(
struct ccdrbg_state *prng,
unsigned long entropylen, const void *entropy,
unsigned long inlen, const void *in)
{
#pragma unused(inlen)
#pragma unused(in)
YarrowContextp yp = (YarrowContextp) prng;
(void) prngInput(yp->PrngRef, __DECONST(BYTE*, entropy), (UINT) entropylen,
SYSTEM_SOURCE, (UINT) entropylen * 8);
(void) prngForceReseed(yp->PrngRef, RESEED_TICKS);
yp->bytes_since_reseed = 0;
return CCDRBG_STATUS_OK;
}
static void
yarrow_destroy(
struct ccdrbg_state *prng)
{
#pragma unused(prng)
}
void
ccdrbg_factory_yarrow(
struct ccdrbg_info *info,
const void *custom)
{
info->size = sizeof(struct YarrowContext);
info->init = yarrow_init;
info->generate = yarrow_generate;
info->reseed = yarrow_reseed;
info->done = yarrow_destroy;
info->custom = custom;
}