openssl/fips/rand/fips_rand.c
2011-11-05 18:14:42 +00:00

432 lines
11 KiB
C

/* ====================================================================
* Copyright (c) 2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#define OPENSSL_FIPSAPI
/*
* This is a FIPS approved AES PRNG based on ANSI X9.31 A.2.4.
*/
#include <openssl/crypto.h>
#include "e_os.h"
/* If we don't define _XOPEN_SOURCE_EXTENDED, struct timeval won't
be defined and gettimeofday() won't be declared with strict compilers
like DEC C in ANSI C mode. */
#ifndef _XOPEN_SOURCE_EXTENDED
#define _XOPEN_SOURCE_EXTENDED 1
#endif
#include <openssl/rand.h>
#include <openssl/aes.h>
#include <openssl/err.h>
#include <openssl/fips_rand.h>
#if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS))
# include <sys/time.h>
#endif
#if defined(OPENSSL_SYS_VXWORKS)
# include <time.h>
#endif
#include <assert.h>
#ifndef OPENSSL_SYS_WIN32
# ifdef OPENSSL_UNISTD
# include OPENSSL_UNISTD
# else
# include <unistd.h>
# endif
#endif
#include <string.h>
#include <openssl/fips.h>
#include "fips_locl.h"
#ifdef OPENSSL_FIPS
void *OPENSSL_stderr(void);
#define AES_BLOCK_LENGTH 16
/* AES FIPS PRNG implementation */
typedef struct
{
int seeded;
int keyed;
int test_mode;
int second;
int error;
unsigned long counter;
AES_KEY ks;
int vpos;
/* Temporary storage for key if it equals seed length */
unsigned char tmp_key[AES_BLOCK_LENGTH];
unsigned char V[AES_BLOCK_LENGTH];
unsigned char DT[AES_BLOCK_LENGTH];
unsigned char last[AES_BLOCK_LENGTH];
} FIPS_PRNG_CTX;
static FIPS_PRNG_CTX sctx;
static int fips_prng_fail = 0;
void FIPS_x931_stick(int onoff)
{
fips_prng_fail = onoff;
}
static void fips_rand_prng_reset(FIPS_PRNG_CTX *ctx)
{
ctx->seeded = 0;
ctx->keyed = 0;
ctx->test_mode = 0;
ctx->counter = 0;
ctx->second = 0;
ctx->error = 0;
ctx->vpos = 0;
OPENSSL_cleanse(ctx->V, AES_BLOCK_LENGTH);
OPENSSL_cleanse(&ctx->ks, sizeof(AES_KEY));
}
static int fips_set_prng_key(FIPS_PRNG_CTX *ctx,
const unsigned char *key, unsigned int keylen)
{
if (FIPS_selftest_failed())
{
FIPSerr(FIPS_F_FIPS_SET_PRNG_KEY, FIPS_R_SELFTEST_FAILED);
return 0;
}
if (keylen != 16 && keylen != 24 && keylen != 32)
{
/* error: invalid key size */
return 0;
}
AES_set_encrypt_key(key, keylen << 3, &ctx->ks);
if (keylen == 16)
{
memcpy(ctx->tmp_key, key, 16);
ctx->keyed = 2;
}
else
ctx->keyed = 1;
ctx->seeded = 0;
ctx->second = 0;
return 1;
}
static int fips_set_prng_seed(FIPS_PRNG_CTX *ctx,
const unsigned char *seed, unsigned int seedlen)
{
unsigned int i;
if (!ctx->keyed)
return 0;
/* In test mode seed is just supplied data */
if (ctx->test_mode)
{
if (seedlen != AES_BLOCK_LENGTH)
return 0;
memcpy(ctx->V, seed, AES_BLOCK_LENGTH);
ctx->seeded = 1;
return 1;
}
/* Outside test mode XOR supplied data with existing seed */
for (i = 0; i < seedlen; i++)
{
ctx->V[ctx->vpos++] ^= seed[i];
if (ctx->vpos == AES_BLOCK_LENGTH)
{
ctx->vpos = 0;
/* Special case if first seed and key length equals
* block size check key and seed do not match.
*/
if (ctx->keyed == 2)
{
if (!memcmp(ctx->tmp_key, ctx->V, 16))
{
RANDerr(RAND_F_FIPS_SET_PRNG_SEED,
RAND_R_PRNG_SEED_MUST_NOT_MATCH_KEY);
return 0;
}
OPENSSL_cleanse(ctx->tmp_key, 16);
ctx->keyed = 1;
}
ctx->seeded = 1;
}
}
return 1;
}
static int fips_set_test_mode(FIPS_PRNG_CTX *ctx)
{
if (ctx->keyed)
{
RANDerr(RAND_F_FIPS_SET_TEST_MODE,RAND_R_PRNG_KEYED);
return 0;
}
ctx->test_mode = 1;
return 1;
}
int FIPS_x931_test_mode(void)
{
return fips_set_test_mode(&sctx);
}
int FIPS_x931_set_dt(unsigned char *dt)
{
if (!sctx.test_mode)
{
RANDerr(RAND_F_FIPS_X931_SET_DT,RAND_R_NOT_IN_TEST_MODE);
return 0;
}
memcpy(sctx.DT, dt, AES_BLOCK_LENGTH);
return 1;
}
void FIPS_get_timevec(unsigned char *buf, unsigned long *pctr)
{
#ifdef OPENSSL_SYS_WIN32
FILETIME ft;
#elif defined(OPENSSL_SYS_VXWORKS)
struct timespec ts;
#else
struct timeval tv;
#endif
#ifndef GETPID_IS_MEANINGLESS
unsigned long pid;
#endif
#ifdef OPENSSL_SYS_WIN32
GetSystemTimeAsFileTime(&ft);
buf[0] = (unsigned char) (ft.dwHighDateTime & 0xff);
buf[1] = (unsigned char) ((ft.dwHighDateTime >> 8) & 0xff);
buf[2] = (unsigned char) ((ft.dwHighDateTime >> 16) & 0xff);
buf[3] = (unsigned char) ((ft.dwHighDateTime >> 24) & 0xff);
buf[4] = (unsigned char) (ft.dwLowDateTime & 0xff);
buf[5] = (unsigned char) ((ft.dwLowDateTime >> 8) & 0xff);
buf[6] = (unsigned char) ((ft.dwLowDateTime >> 16) & 0xff);
buf[7] = (unsigned char) ((ft.dwLowDateTime >> 24) & 0xff);
#elif defined(OPENSSL_SYS_VXWORKS)
clock_gettime(CLOCK_REALTIME, &ts);
buf[0] = (unsigned char) (ts.tv_sec & 0xff);
buf[1] = (unsigned char) ((ts.tv_sec >> 8) & 0xff);
buf[2] = (unsigned char) ((ts.tv_sec >> 16) & 0xff);
buf[3] = (unsigned char) ((ts.tv_sec >> 24) & 0xff);
buf[4] = (unsigned char) (ts.tv_nsec & 0xff);
buf[5] = (unsigned char) ((ts.tv_nsec >> 8) & 0xff);
buf[6] = (unsigned char) ((ts.tv_nsec >> 16) & 0xff);
buf[7] = (unsigned char) ((ts.tv_nsec >> 24) & 0xff);
#else
gettimeofday(&tv,NULL);
buf[0] = (unsigned char) (tv.tv_sec & 0xff);
buf[1] = (unsigned char) ((tv.tv_sec >> 8) & 0xff);
buf[2] = (unsigned char) ((tv.tv_sec >> 16) & 0xff);
buf[3] = (unsigned char) ((tv.tv_sec >> 24) & 0xff);
buf[4] = (unsigned char) (tv.tv_usec & 0xff);
buf[5] = (unsigned char) ((tv.tv_usec >> 8) & 0xff);
buf[6] = (unsigned char) ((tv.tv_usec >> 16) & 0xff);
buf[7] = (unsigned char) ((tv.tv_usec >> 24) & 0xff);
#endif
buf[8] = (unsigned char) (*pctr & 0xff);
buf[9] = (unsigned char) ((*pctr >> 8) & 0xff);
buf[10] = (unsigned char) ((*pctr >> 16) & 0xff);
buf[11] = (unsigned char) ((*pctr >> 24) & 0xff);
(*pctr)++;
#ifndef GETPID_IS_MEANINGLESS
pid=(unsigned long)getpid();
buf[12] = (unsigned char) (pid & 0xff);
buf[13] = (unsigned char) ((pid >> 8) & 0xff);
buf[14] = (unsigned char) ((pid >> 16) & 0xff);
buf[15] = (unsigned char) ((pid >> 24) & 0xff);
#endif
}
static int fips_rand(FIPS_PRNG_CTX *ctx,
unsigned char *out, unsigned int outlen)
{
unsigned char R[AES_BLOCK_LENGTH], I[AES_BLOCK_LENGTH];
unsigned char tmp[AES_BLOCK_LENGTH];
int i;
if (ctx->error)
{
RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_ERROR);
return 0;
}
if (!ctx->keyed)
{
RANDerr(RAND_F_FIPS_RAND,RAND_R_NO_KEY_SET);
return 0;
}
if (!ctx->seeded)
{
RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_NOT_SEEDED);
return 0;
}
for (;;)
{
if (!ctx->test_mode)
FIPS_get_timevec(ctx->DT, &ctx->counter);
AES_encrypt(ctx->DT, I, &ctx->ks);
for (i = 0; i < AES_BLOCK_LENGTH; i++)
tmp[i] = I[i] ^ ctx->V[i];
AES_encrypt(tmp, R, &ctx->ks);
for (i = 0; i < AES_BLOCK_LENGTH; i++)
tmp[i] = R[i] ^ I[i];
AES_encrypt(tmp, ctx->V, &ctx->ks);
/* Continuous PRNG test */
if (ctx->second)
{
if (fips_prng_fail)
memcpy(ctx->last, R, AES_BLOCK_LENGTH);
if (!memcmp(R, ctx->last, AES_BLOCK_LENGTH))
{
RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_STUCK);
ctx->error = 1;
fips_set_selftest_fail();
return 0;
}
}
memcpy(ctx->last, R, AES_BLOCK_LENGTH);
if (!ctx->second)
{
ctx->second = 1;
if (!ctx->test_mode)
continue;
}
if (outlen <= AES_BLOCK_LENGTH)
{
memcpy(out, R, outlen);
break;
}
memcpy(out, R, AES_BLOCK_LENGTH);
out += AES_BLOCK_LENGTH;
outlen -= AES_BLOCK_LENGTH;
}
return 1;
}
int FIPS_x931_set_key(const unsigned char *key, int keylen)
{
int ret;
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
ret = fips_set_prng_key(&sctx, key, keylen);
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
return ret;
}
int FIPS_x931_seed(const void *seed, int seedlen)
{
int ret;
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
ret = fips_set_prng_seed(&sctx, seed, seedlen);
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
return ret;
}
int FIPS_x931_bytes(unsigned char *out, int count)
{
int ret;
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
ret = fips_rand(&sctx, out, count);
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
return ret;
}
int FIPS_x931_status(void)
{
int ret;
CRYPTO_r_lock(CRYPTO_LOCK_RAND);
ret = sctx.seeded;
CRYPTO_r_unlock(CRYPTO_LOCK_RAND);
return ret;
}
void FIPS_x931_reset(void)
{
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
fips_rand_prng_reset(&sctx);
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
}
static int fips_do_rand_seed(const void *seed, int seedlen)
{
FIPS_x931_seed(seed, seedlen);
return 1;
}
static int fips_do_rand_add(const void *seed, int seedlen,
double add_entropy)
{
FIPS_x931_seed(seed, seedlen);
return 1;
}
static const RAND_METHOD rand_x931_meth=
{
fips_do_rand_seed,
FIPS_x931_bytes,
FIPS_x931_reset,
fips_do_rand_add,
FIPS_x931_bytes,
FIPS_x931_status
};
const RAND_METHOD *FIPS_x931_method(void)
{
return &rand_x931_meth;
}
#endif