openssl/fips/rand/fips_drbg_rand.c
Dr. Stephen Henson de2132de93 Delete strength parameter from FIPS_drbg_generate. It isn't very useful
(strength can be queried using FIPS_drbg_get_strength ) and adds a
substantial extra overhead to health check (need to check every combination
of parameters).
2011-09-12 13:20:57 +00:00

175 lines
4.9 KiB
C

/* fips/rand/fips_drbg_rand.c */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
* project.
*/
/* ====================================================================
* Copyright (c) 2011 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
* licensing@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
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/fips_rand.h>
#include "fips_rand_lcl.h"
/* Mapping of SP800-90 DRBGs to OpenSSL RAND_METHOD */
/* Since we only have one global PRNG used at any time in OpenSSL use a global
* variable to store context.
*/
static DRBG_CTX ossl_dctx;
DRBG_CTX *FIPS_get_default_drbg(void)
{
return &ossl_dctx;
}
static int fips_drbg_bytes(unsigned char *out, int count)
{
DRBG_CTX *dctx = &ossl_dctx;
int rv = 0;
unsigned char *adin = NULL;
size_t adinlen = 0;
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
do
{
size_t rcnt;
if (count > (int)dctx->max_request)
rcnt = dctx->max_request;
else
rcnt = count;
if (dctx->get_adin)
{
adinlen = dctx->get_adin(dctx, &adin);
if (adinlen && !adin)
{
FIPSerr(FIPS_F_FIPS_DRBG_BYTES, FIPS_R_ERROR_RETRIEVING_ADDITIONAL_INPUT);
goto err;
}
}
rv = FIPS_drbg_generate(dctx, out, rcnt, 0, adin, adinlen);
if (adin)
{
if (dctx->cleanup_adin)
dctx->cleanup_adin(dctx, adin, adinlen);
adin = NULL;
}
if (!rv)
goto err;
out += rcnt;
count -= rcnt;
}
while (count);
rv = 1;
err:
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
return rv;
}
static int fips_drbg_pseudo(unsigned char *out, int count)
{
if (fips_drbg_bytes(out, count) <= 0)
return -1;
return 1;
}
static int fips_drbg_status(void)
{
DRBG_CTX *dctx = &ossl_dctx;
int rv;
CRYPTO_r_lock(CRYPTO_LOCK_RAND);
rv = dctx->status == DRBG_STATUS_READY ? 1 : 0;
CRYPTO_r_unlock(CRYPTO_LOCK_RAND);
return rv;
}
static void fips_drbg_cleanup(void)
{
DRBG_CTX *dctx = &ossl_dctx;
CRYPTO_w_lock(CRYPTO_LOCK_RAND);
FIPS_drbg_uninstantiate(dctx);
CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
}
static int fips_drbg_seed(const void *seed, int seedlen)
{
DRBG_CTX *dctx = &ossl_dctx;
if (dctx->rand_seed_cb)
return dctx->rand_seed_cb(dctx, seed, seedlen);
return 1;
}
static int fips_drbg_add(const void *seed, int seedlen,
double add_entropy)
{
DRBG_CTX *dctx = &ossl_dctx;
if (dctx->rand_add_cb)
return dctx->rand_add_cb(dctx, seed, seedlen, add_entropy);
return 1;
}
static const RAND_METHOD rand_drbg_meth =
{
fips_drbg_seed,
fips_drbg_bytes,
fips_drbg_cleanup,
fips_drbg_add,
fips_drbg_pseudo,
fips_drbg_status
};
const RAND_METHOD *FIPS_drbg_method(void)
{
return &rand_drbg_meth;
}