fips/rand/fips_drbg_lib.c - third_party/openssl - Git at Google

 /* 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/fips_rand.h>
 #include "fips_rand_lcl.h"

 /* Support framework for SP800-90 DRBGs */

 int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
 	{
 	int rv;
 	memset(dctx, 0, sizeof(DRBG_CTX));
 	dctx->status = DRBG_STATUS_UNINITIALISED;
 	dctx->xflags = flags;
 	dctx->type = type;

 	dctx->iflags = 0;
 	dctx->entropy_blocklen = 0;
 	dctx->health_check_cnt = 0;
 	dctx->health_check_interval = DRBG_HEALTH_INTERVAL;

 	rv = fips_drbg_hash_init(dctx);

 	if (rv == -2)
 		rv = fips_drbg_ctr_init(dctx);
 	if (rv == -2)
 		rv = fips_drbg_hmac_init(dctx);
 	if (rv == -2)
 		rv = fips_drbg_ec_init(dctx);

 	if (rv <= 0)
 		{
 		if (rv == -2)
 			FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
 		else
 			FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
 		}

 	/* If not in test mode run selftests on DRBG of the same type */

 	if (!(dctx->xflags & DRBG_FLAG_TEST))
 		{
 		if (!FIPS_drbg_health_check(dctx))
 			{
 			FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
 			return 0;
 			}
 		}

 	return rv;
 	}

 DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
 	{
 	DRBG_CTX *dctx;
 	dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
 	if (!dctx)
 		{
 		FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
 		return NULL;
 		}

 	if (type == 0)
 		{
 		memset(dctx, 0, sizeof(DRBG_CTX));
 		dctx->type = 0;
 		dctx->status = DRBG_STATUS_UNINITIALISED;
 		return dctx;
 		}

 	if (FIPS_drbg_init(dctx, type, flags) <= 0)
 		{
 		OPENSSL_free(dctx);
 		return NULL;
 		}

 	return dctx;
 	}

 void FIPS_drbg_free(DRBG_CTX *dctx)
 	{
 	if (dctx->uninstantiate)
 		dctx->uninstantiate(dctx);
 	/* Don't free up default DRBG */
 	if (dctx == FIPS_get_default_drbg())
 		{
 		memset(dctx, 0, sizeof(DRBG_CTX));
 		dctx->type = 0;
 		dctx->status = DRBG_STATUS_UNINITIALISED;
 		}
 	else
 		{
 		OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
 		OPENSSL_free(dctx);
 		}
 	}

 static size_t fips_get_entropy(DRBG_CTX *dctx, unsigned char **pout,
 				int entropy, size_t min_len, size_t max_len)
 	{
 	unsigned char *tout, *p;
 	size_t bl = dctx->entropy_blocklen, rv;
 	if (!dctx->get_entropy)
 		return 0;
 	if (dctx->xflags & DRBG_FLAG_TEST || !bl)
 		return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
 	rv = dctx->get_entropy(dctx, &tout, entropy + bl,
 				min_len + bl, max_len + bl);
 	*pout = tout + bl;
 	if (rv < (min_len + bl) || (rv % bl))
 		return 0;
 	/* Compare consecutive blocks for continuous PRNG test */
 	for (p = tout; p < tout + rv - bl; p += bl)
 		{
 		if (!memcmp(p, p + bl, bl))
 			{
 			FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
 			return 0;
 			}
 		}
 	rv -= bl;
 	if (rv > max_len)
 		return max_len;
 	return rv;
 	}

 static void fips_cleanup_entropy(DRBG_CTX *dctx,
 					unsigned char *out, size_t olen)
 	{
 	size_t bl;
 	if (dctx->xflags & DRBG_FLAG_TEST)
 		bl = 0;
 	else
 		bl = dctx->entropy_blocklen;
 	/* Call cleanup with original arguments */
 	dctx->cleanup_entropy(dctx, out - bl, olen + bl);
 	}


 int FIPS_drbg_instantiate(DRBG_CTX *dctx,
 				const unsigned char *pers, size_t perslen)
 	{
 	size_t entlen = 0, noncelen = 0;
 	unsigned char *nonce = NULL, *entropy = NULL;

 #if 0
 	/* Put here so error script picks them up */
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
 				FIPS_R_PERSONALISATION_STRING_TOO_LONG);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
 	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_DRBG_NOT_INITIALISED);
 #endif

 	int r = 0;

 	if (perslen > dctx->max_pers)
 		{
 		r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
 		goto end;
 		}

 	if (!dctx->instantiate)
 		{
 		r = FIPS_R_DRBG_NOT_INITIALISED;
 		goto end;
 		}

 	if (dctx->status != DRBG_STATUS_UNINITIALISED)
 		{
 		if (dctx->status == DRBG_STATUS_ERROR)
 			r = FIPS_R_IN_ERROR_STATE;
 		else
 			r = FIPS_R_ALREADY_INSTANTIATED;
 		goto end;
 		}

 	dctx->status = DRBG_STATUS_ERROR;

 	entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 				dctx->min_entropy, dctx->max_entropy);

 	if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 		{
 		r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 		goto end;
 		}

 	if (dctx->max_nonce > 0 && dctx->get_nonce)
 		{
 		noncelen = dctx->get_nonce(dctx, &nonce,
 					dctx->strength / 2,
 					dctx->min_nonce, dctx->max_nonce);

 		if (noncelen < dctx->min_nonce || noncelen > dctx->max_nonce)
 			{
 			r = FIPS_R_ERROR_RETRIEVING_NONCE;
 			goto end;
 			}

 		}

 	if (!dctx->instantiate(dctx,
 				entropy, entlen,
 				nonce, noncelen,
 				pers, perslen))
 		{
 		r = FIPS_R_ERROR_INSTANTIATING_DRBG;
 		goto end;
 		}


 	dctx->status = DRBG_STATUS_READY;
 	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 		dctx->reseed_counter = 1;

 	end:

 	if (entropy && dctx->cleanup_entropy)
 		fips_cleanup_entropy(dctx, entropy, entlen);

 	if (nonce && dctx->cleanup_nonce)
 		dctx->cleanup_nonce(dctx, nonce, noncelen);

 	if (dctx->status == DRBG_STATUS_READY)
 		return 1;

 	if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
 		FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);

 	return 0;

 	}

 static int drbg_reseed(DRBG_CTX *dctx,
 			const unsigned char *adin, size_t adinlen, int hcheck)
 	{
 	unsigned char *entropy = NULL;
 	size_t entlen = 0;
 	int r = 0;

 #if 0
 	FIPSerr(FIPS_F_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
 	FIPSerr(FIPS_F_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
 #endif
 	if (dctx->status != DRBG_STATUS_READY
 		&& dctx->status != DRBG_STATUS_RESEED)
 		{
 		if (dctx->status == DRBG_STATUS_ERROR)
 			r = FIPS_R_IN_ERROR_STATE;
 		else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 			r = FIPS_R_NOT_INSTANTIATED;
 		goto end;
 		}

 	if (!adin)
 		adinlen = 0;
 	else if (adinlen > dctx->max_adin)
 		{
 		r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 		goto end;
 		}

 	dctx->status = DRBG_STATUS_ERROR;
 	/* Peform health check on all reseed operations if not a prediction
 	 * resistance request and not in test mode.
 	 */
 	if (hcheck && !(dctx->xflags & DRBG_FLAG_TEST))
 		{
 		if (!FIPS_drbg_health_check(dctx))
 			{
 			r = FIPS_R_SELFTEST_FAILURE;
 			goto end;
 			}
 		}

 	entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
 				dctx->min_entropy, dctx->max_entropy);

 	if (entlen < dctx->min_entropy || entlen > dctx->max_entropy)
 		{
 		r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
 		goto end;
 		}

 	if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
 		goto end;

 	dctx->status = DRBG_STATUS_READY;
 	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 		dctx->reseed_counter = 1;
 	end:

 	if (entropy && dctx->cleanup_entropy)
 		fips_cleanup_entropy(dctx, entropy, entlen);

 	if (dctx->status == DRBG_STATUS_READY)
 		return 1;

 	if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
 		FIPSerr(FIPS_F_DRBG_RESEED, r);

 	return 0;
 	}

 int FIPS_drbg_reseed(DRBG_CTX *dctx,
 			const unsigned char *adin, size_t adinlen)
 	{
 	return drbg_reseed(dctx, adin, adinlen, 1);
 	}

 static int fips_drbg_check(DRBG_CTX *dctx)
 	{
 	if (dctx->xflags & DRBG_FLAG_TEST)
 		return 1;
 	dctx->health_check_cnt++;
 	if (dctx->health_check_cnt >= dctx->health_check_interval)
 		{
 		if (!FIPS_drbg_health_check(dctx))
 			{
 			FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
 			return 0;
 			}
 		}
 	return 1;
 	}

 int FIPS_drbg_generate(DRBG_CTX *dctx, unsigned char *out, size_t outlen,
 			int prediction_resistance,
 			const unsigned char *adin, size_t adinlen)
 	{
 	int r = 0;

 	if (FIPS_selftest_failed())
 		{
 		FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_SELFTEST_FAILED);
 		return 0;
 		}

 	if (!fips_drbg_check(dctx))
 		return 0;

 	if (dctx->status != DRBG_STATUS_READY
 		&& dctx->status != DRBG_STATUS_RESEED)
 		{
 		if (dctx->status == DRBG_STATUS_ERROR)
 			r = FIPS_R_IN_ERROR_STATE;
 		else if(dctx->status == DRBG_STATUS_UNINITIALISED)
 			r = FIPS_R_NOT_INSTANTIATED;
 		goto end;
 		}

 	if (outlen > dctx->max_request)
 		{
 		r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
 		return 0;
 		}

 	if (adinlen > dctx->max_adin)
 		{
 		r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
 		goto end;
 		}

 	if (dctx->iflags & DRBG_CUSTOM_RESEED)
 		dctx->generate(dctx, NULL, outlen, NULL, 0);
 	else if (dctx->reseed_counter >= dctx->reseed_interval)
 		dctx->status = DRBG_STATUS_RESEED;

 	if (dctx->status == DRBG_STATUS_RESEED || prediction_resistance)
 		{
 		/* If prediction resistance request don't do health check */
 		int hcheck = prediction_resistance ? 0 : 1;

 		if (!drbg_reseed(dctx, adin, adinlen, hcheck))
 			{
 			r = FIPS_R_RESEED_ERROR;
 			goto end;
 			}
 		adin = NULL;
 		adinlen = 0;
 		}

 	if (!dctx->generate(dctx, out, outlen, adin, adinlen))
 		{
 		r = FIPS_R_GENERATE_ERROR;
 		dctx->status = DRBG_STATUS_ERROR;
 		goto end;
 		}
 	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
 		{
 		if (dctx->reseed_counter >= dctx->reseed_interval)
 			dctx->status = DRBG_STATUS_RESEED;
 		else
 			dctx->reseed_counter++;
 		}

 	end:
 	if (r)
 		{
 		if (!(dctx->iflags & DRBG_FLAG_NOERR))
 			FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
 		return 0;
 		}

 	return 1;
 	}

 int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
 	{
 	int rv;
 	if (!dctx->uninstantiate)
 		rv = 1;
 	else
 		rv = dctx->uninstantiate(dctx);
 	/* Although we'd like to cleanse here we can't because we have to
 	 * test the uninstantiate really zeroes the data.
 	 */
 	memset(&dctx->d, 0, sizeof(dctx->d));
 	dctx->status = DRBG_STATUS_UNINITIALISED;
 	/* If method has problems uninstantiating, return error */
 	return rv;
 	}

 int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
 	size_t (*get_entropy)(DRBG_CTX *ctx, unsigned char **pout,
 				int entropy, size_t min_len, size_t max_len),
 	void (*cleanup_entropy)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 	size_t entropy_blocklen,
 	size_t (*get_nonce)(DRBG_CTX *ctx, unsigned char **pout,
 				int entropy, size_t min_len, size_t max_len),
 	void (*cleanup_nonce)(DRBG_CTX *ctx, unsigned char *out, size_t olen))
 	{
 	if (dctx->status != DRBG_STATUS_UNINITIALISED)
 		return 0;
 	dctx->entropy_blocklen = entropy_blocklen;
 	dctx->get_entropy = get_entropy;
 	dctx->cleanup_entropy = cleanup_entropy;
 	dctx->get_nonce = get_nonce;
 	dctx->cleanup_nonce = cleanup_nonce;
 	return 1;
 	}

 int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
 	size_t (*get_adin)(DRBG_CTX *ctx, unsigned char **pout),
 	void (*cleanup_adin)(DRBG_CTX *ctx, unsigned char *out, size_t olen),
 	int (*rand_seed_cb)(DRBG_CTX *ctx, const void *buf, int num),
 	int (*rand_add_cb)(DRBG_CTX *ctx,
 				const void *buf, int num, double entropy))
 	{
 	if (dctx->status != DRBG_STATUS_UNINITIALISED)
 		return 0;
 	dctx->get_adin = get_adin;
 	dctx->cleanup_adin = cleanup_adin;
 	dctx->rand_seed_cb = rand_seed_cb;
 	dctx->rand_add_cb = rand_add_cb;
 	return 1;
 	}

 void *FIPS_drbg_get_app_data(DRBG_CTX *dctx)
 	{
 	return dctx->app_data;
 	}

 void FIPS_drbg_set_app_data(DRBG_CTX *dctx, void *app_data)
 	{
 	dctx->app_data = app_data;
 	}

 size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
 	{
 	return dctx->blocklength;
 	}

 int FIPS_drbg_get_strength(DRBG_CTX *dctx)
 	{
 	return dctx->strength;
 	}

 void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
 	{
 	dctx->health_check_interval = interval;
 	}

 void FIPS_drbg_set_reseed_interval(DRBG_CTX *dctx, int interval)
 	{
 	dctx->reseed_interval = interval;
 	}

 static int drbg_stick = 0;

 void FIPS_drbg_stick(int onoff)
 	{
 	drbg_stick = onoff;
 	}

 /* Continuous DRBG utility function */
 int fips_drbg_cprng_test(DRBG_CTX *dctx, const unsigned char *out)
 	{
 	/* No CPRNG in test mode */
 	if (dctx->xflags & DRBG_FLAG_TEST)
 		return 1;
 	/* Check block is valid: should never happen */
 	if (dctx->lb_valid == 0)
 		{
 		FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
 		fips_set_selftest_fail();
 		return 0;
 		}
 	if (drbg_stick)
 		memcpy(dctx->lb, out, dctx->blocklength);
 	/* Check against last block: fail if match */
 	if (!memcmp(dctx->lb, out, dctx->blocklength))
 		{
 		FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
 		fips_set_selftest_fail();
 		return 0;
 		}
 	/* Save last block for next comparison */
 	memcpy(dctx->lb, out, dctx->blocklength);
 	return 1;
 	}
	/* 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/fips_rand.h>
	#include "fips_rand_lcl.h"

	/* Support framework for SP800-90 DRBGs */

	int FIPS_drbg_init(DRBG_CTX *dctx, int type, unsigned int flags)
	{
	int rv;
	memset(dctx, 0, sizeof(DRBG_CTX));
	dctx->status = DRBG_STATUS_UNINITIALISED;
	dctx->xflags = flags;
	dctx->type = type;

	dctx->iflags = 0;
	dctx->entropy_blocklen = 0;
	dctx->health_check_cnt = 0;
	dctx->health_check_interval = DRBG_HEALTH_INTERVAL;

	rv = fips_drbg_hash_init(dctx);

	if (rv == -2)
	rv = fips_drbg_ctr_init(dctx);
	if (rv == -2)
	rv = fips_drbg_hmac_init(dctx);
	if (rv == -2)
	rv = fips_drbg_ec_init(dctx);

	if (rv <= 0)
	{
	if (rv == -2)
	FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_UNSUPPORTED_DRBG_TYPE);
	else
	FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_ERROR_INITIALISING_DRBG);
	}

	/* If not in test mode run selftests on DRBG of the same type */

	if (!(dctx->xflags & DRBG_FLAG_TEST))
	{
	if (!FIPS_drbg_health_check(dctx))
	{
	FIPSerr(FIPS_F_FIPS_DRBG_INIT, FIPS_R_SELFTEST_FAILURE);
	return 0;
	}
	}

	return rv;
	}

	DRBG_CTX *FIPS_drbg_new(int type, unsigned int flags)
	{
	DRBG_CTX *dctx;
	dctx = OPENSSL_malloc(sizeof(DRBG_CTX));
	if (!dctx)
	{
	FIPSerr(FIPS_F_FIPS_DRBG_NEW, ERR_R_MALLOC_FAILURE);
	return NULL;
	}

	if (type == 0)
	{
	memset(dctx, 0, sizeof(DRBG_CTX));
	dctx->type = 0;
	dctx->status = DRBG_STATUS_UNINITIALISED;
	return dctx;
	}

	if (FIPS_drbg_init(dctx, type, flags) <= 0)
	{
	OPENSSL_free(dctx);
	return NULL;
	}

	return dctx;
	}

	void FIPS_drbg_free(DRBG_CTX *dctx)
	{
	if (dctx->uninstantiate)
	dctx->uninstantiate(dctx);
	/* Don't free up default DRBG */
	if (dctx == FIPS_get_default_drbg())
	{
	memset(dctx, 0, sizeof(DRBG_CTX));
	dctx->type = 0;
	dctx->status = DRBG_STATUS_UNINITIALISED;
	}
	else
	{
	OPENSSL_cleanse(&dctx->d, sizeof(dctx->d));
	OPENSSL_free(dctx);
	}
	}

	static size_t fips_get_entropy(DRBG_CTX dctx, unsigned char *pout,
	int entropy, size_t min_len, size_t max_len)
	{
	unsigned char tout, p;
	size_t bl = dctx->entropy_blocklen, rv;
	if (!dctx->get_entropy)
	return 0;
	if (dctx->xflags & DRBG_FLAG_TEST \|\| !bl)
	return dctx->get_entropy(dctx, pout, entropy, min_len, max_len);
	rv = dctx->get_entropy(dctx, &tout, entropy + bl,
	min_len + bl, max_len + bl);
	*pout = tout + bl;
	if (rv < (min_len + bl) \|\| (rv % bl))
	return 0;
	/* Compare consecutive blocks for continuous PRNG test */
	for (p = tout; p < tout + rv - bl; p += bl)
	{
	if (!memcmp(p, p + bl, bl))
	{
	FIPSerr(FIPS_F_FIPS_GET_ENTROPY, FIPS_R_ENTROPY_SOURCE_STUCK);
	return 0;
	}
	}
	rv -= bl;
	if (rv > max_len)
	return max_len;
	return rv;
	}

	static void fips_cleanup_entropy(DRBG_CTX *dctx,
	unsigned char *out, size_t olen)
	{
	size_t bl;
	if (dctx->xflags & DRBG_FLAG_TEST)
	bl = 0;
	else
	bl = dctx->entropy_blocklen;
	/* Call cleanup with original arguments */
	dctx->cleanup_entropy(dctx, out - bl, olen + bl);
	}


	int FIPS_drbg_instantiate(DRBG_CTX *dctx,
	const unsigned char *pers, size_t perslen)
	{
	size_t entlen = 0, noncelen = 0;
	unsigned char nonce = NULL, entropy = NULL;

	#if 0
	/* Put here so error script picks them up */
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE,
	FIPS_R_PERSONALISATION_STRING_TOO_LONG);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_IN_ERROR_STATE);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ALREADY_INSTANTIATED);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_ENTROPY);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_ERROR_RETRIEVING_NONCE);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_INSTANTIATE_ERROR);
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, FIPS_R_DRBG_NOT_INITIALISED);
	#endif

	int r = 0;

	if (perslen > dctx->max_pers)
	{
	r = FIPS_R_PERSONALISATION_STRING_TOO_LONG;
	goto end;
	}

	if (!dctx->instantiate)
	{
	r = FIPS_R_DRBG_NOT_INITIALISED;
	goto end;
	}

	if (dctx->status != DRBG_STATUS_UNINITIALISED)
	{
	if (dctx->status == DRBG_STATUS_ERROR)
	r = FIPS_R_IN_ERROR_STATE;
	else
	r = FIPS_R_ALREADY_INSTANTIATED;
	goto end;
	}

	dctx->status = DRBG_STATUS_ERROR;

	entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
	dctx->min_entropy, dctx->max_entropy);

	if (entlen < dctx->min_entropy \|\| entlen > dctx->max_entropy)
	{
	r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
	goto end;
	}

	if (dctx->max_nonce > 0 && dctx->get_nonce)
	{
	noncelen = dctx->get_nonce(dctx, &nonce,
	dctx->strength / 2,
	dctx->min_nonce, dctx->max_nonce);

	if (noncelen < dctx->min_nonce \|\| noncelen > dctx->max_nonce)
	{
	r = FIPS_R_ERROR_RETRIEVING_NONCE;
	goto end;
	}

	}

	if (!dctx->instantiate(dctx,
	entropy, entlen,
	nonce, noncelen,
	pers, perslen))
	{
	r = FIPS_R_ERROR_INSTANTIATING_DRBG;
	goto end;
	}


	dctx->status = DRBG_STATUS_READY;
	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
	dctx->reseed_counter = 1;

	end:

	if (entropy && dctx->cleanup_entropy)
	fips_cleanup_entropy(dctx, entropy, entlen);

	if (nonce && dctx->cleanup_nonce)
	dctx->cleanup_nonce(dctx, nonce, noncelen);

	if (dctx->status == DRBG_STATUS_READY)
	return 1;

	if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
	FIPSerr(FIPS_F_FIPS_DRBG_INSTANTIATE, r);

	return 0;

	}

	static int drbg_reseed(DRBG_CTX *dctx,
	const unsigned char *adin, size_t adinlen, int hcheck)
	{
	unsigned char *entropy = NULL;
	size_t entlen = 0;
	int r = 0;

	#if 0
	FIPSerr(FIPS_F_DRBG_RESEED, FIPS_R_NOT_INSTANTIATED);
	FIPSerr(FIPS_F_DRBG_RESEED, FIPS_R_ADDITIONAL_INPUT_TOO_LONG);
	#endif
	if (dctx->status != DRBG_STATUS_READY
	&& dctx->status != DRBG_STATUS_RESEED)
	{
	if (dctx->status == DRBG_STATUS_ERROR)
	r = FIPS_R_IN_ERROR_STATE;
	else if(dctx->status == DRBG_STATUS_UNINITIALISED)
	r = FIPS_R_NOT_INSTANTIATED;
	goto end;
	}

	if (!adin)
	adinlen = 0;
	else if (adinlen > dctx->max_adin)
	{
	r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
	goto end;
	}

	dctx->status = DRBG_STATUS_ERROR;
	/* Peform health check on all reseed operations if not a prediction
	* resistance request and not in test mode.
	*/
	if (hcheck && !(dctx->xflags & DRBG_FLAG_TEST))
	{
	if (!FIPS_drbg_health_check(dctx))
	{
	r = FIPS_R_SELFTEST_FAILURE;
	goto end;
	}
	}

	entlen = fips_get_entropy(dctx, &entropy, dctx->strength,
	dctx->min_entropy, dctx->max_entropy);

	if (entlen < dctx->min_entropy \|\| entlen > dctx->max_entropy)
	{
	r = FIPS_R_ERROR_RETRIEVING_ENTROPY;
	goto end;
	}

	if (!dctx->reseed(dctx, entropy, entlen, adin, adinlen))
	goto end;

	dctx->status = DRBG_STATUS_READY;
	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
	dctx->reseed_counter = 1;
	end:

	if (entropy && dctx->cleanup_entropy)
	fips_cleanup_entropy(dctx, entropy, entlen);

	if (dctx->status == DRBG_STATUS_READY)
	return 1;

	if (r && !(dctx->iflags & DRBG_FLAG_NOERR))
	FIPSerr(FIPS_F_DRBG_RESEED, r);

	return 0;
	}

	int FIPS_drbg_reseed(DRBG_CTX *dctx,
	const unsigned char *adin, size_t adinlen)
	{
	return drbg_reseed(dctx, adin, adinlen, 1);
	}

	static int fips_drbg_check(DRBG_CTX *dctx)
	{
	if (dctx->xflags & DRBG_FLAG_TEST)
	return 1;
	dctx->health_check_cnt++;
	if (dctx->health_check_cnt >= dctx->health_check_interval)
	{
	if (!FIPS_drbg_health_check(dctx))
	{
	FIPSerr(FIPS_F_FIPS_DRBG_CHECK, FIPS_R_SELFTEST_FAILURE);
	return 0;
	}
	}
	return 1;
	}

	int FIPS_drbg_generate(DRBG_CTX dctx, unsigned char out, size_t outlen,
	int prediction_resistance,
	const unsigned char *adin, size_t adinlen)
	{
	int r = 0;

	if (FIPS_selftest_failed())
	{
	FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_SELFTEST_FAILED);
	return 0;
	}

	if (!fips_drbg_check(dctx))
	return 0;

	if (dctx->status != DRBG_STATUS_READY
	&& dctx->status != DRBG_STATUS_RESEED)
	{
	if (dctx->status == DRBG_STATUS_ERROR)
	r = FIPS_R_IN_ERROR_STATE;
	else if(dctx->status == DRBG_STATUS_UNINITIALISED)
	r = FIPS_R_NOT_INSTANTIATED;
	goto end;
	}

	if (outlen > dctx->max_request)
	{
	r = FIPS_R_REQUEST_TOO_LARGE_FOR_DRBG;
	return 0;
	}

	if (adinlen > dctx->max_adin)
	{
	r = FIPS_R_ADDITIONAL_INPUT_TOO_LONG;
	goto end;
	}

	if (dctx->iflags & DRBG_CUSTOM_RESEED)
	dctx->generate(dctx, NULL, outlen, NULL, 0);
	else if (dctx->reseed_counter >= dctx->reseed_interval)
	dctx->status = DRBG_STATUS_RESEED;

	if (dctx->status == DRBG_STATUS_RESEED \|\| prediction_resistance)
	{
	/* If prediction resistance request don't do health check */
	int hcheck = prediction_resistance ? 0 : 1;

	if (!drbg_reseed(dctx, adin, adinlen, hcheck))
	{
	r = FIPS_R_RESEED_ERROR;
	goto end;
	}
	adin = NULL;
	adinlen = 0;
	}

	if (!dctx->generate(dctx, out, outlen, adin, adinlen))
	{
	r = FIPS_R_GENERATE_ERROR;
	dctx->status = DRBG_STATUS_ERROR;
	goto end;
	}
	if (!(dctx->iflags & DRBG_CUSTOM_RESEED))
	{
	if (dctx->reseed_counter >= dctx->reseed_interval)
	dctx->status = DRBG_STATUS_RESEED;
	else
	dctx->reseed_counter++;
	}

	end:
	if (r)
	{
	if (!(dctx->iflags & DRBG_FLAG_NOERR))
	FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, r);
	return 0;
	}

	return 1;
	}

	int FIPS_drbg_uninstantiate(DRBG_CTX *dctx)
	{
	int rv;
	if (!dctx->uninstantiate)
	rv = 1;
	else
	rv = dctx->uninstantiate(dctx);
	/* Although we'd like to cleanse here we can't because we have to
	* test the uninstantiate really zeroes the data.
	*/
	memset(&dctx->d, 0, sizeof(dctx->d));
	dctx->status = DRBG_STATUS_UNINITIALISED;
	/* If method has problems uninstantiating, return error */
	return rv;
	}

	int FIPS_drbg_set_callbacks(DRBG_CTX *dctx,
	size_t (get_entropy)(DRBG_CTX ctx, unsigned char **pout,
	int entropy, size_t min_len, size_t max_len),
	void (cleanup_entropy)(DRBG_CTX ctx, unsigned char *out, size_t olen),
	size_t entropy_blocklen,
	size_t (get_nonce)(DRBG_CTX ctx, unsigned char **pout,
	int entropy, size_t min_len, size_t max_len),
	void (cleanup_nonce)(DRBG_CTX ctx, unsigned char *out, size_t olen))
	{
	if (dctx->status != DRBG_STATUS_UNINITIALISED)
	return 0;
	dctx->entropy_blocklen = entropy_blocklen;
	dctx->get_entropy = get_entropy;
	dctx->cleanup_entropy = cleanup_entropy;
	dctx->get_nonce = get_nonce;
	dctx->cleanup_nonce = cleanup_nonce;
	return 1;
	}

	int FIPS_drbg_set_rand_callbacks(DRBG_CTX *dctx,
	size_t (get_adin)(DRBG_CTX ctx, unsigned char **pout),
	void (cleanup_adin)(DRBG_CTX ctx, unsigned char *out, size_t olen),
	int (rand_seed_cb)(DRBG_CTX ctx, const void *buf, int num),
	int (rand_add_cb)(DRBG_CTX ctx,
	const void *buf, int num, double entropy))
	{
	if (dctx->status != DRBG_STATUS_UNINITIALISED)
	return 0;
	dctx->get_adin = get_adin;
	dctx->cleanup_adin = cleanup_adin;
	dctx->rand_seed_cb = rand_seed_cb;
	dctx->rand_add_cb = rand_add_cb;
	return 1;
	}

	void FIPS_drbg_get_app_data(DRBG_CTX dctx)
	{
	return dctx->app_data;
	}

	void FIPS_drbg_set_app_data(DRBG_CTX dctx, void app_data)
	{
	dctx->app_data = app_data;
	}

	size_t FIPS_drbg_get_blocklength(DRBG_CTX *dctx)
	{
	return dctx->blocklength;
	}

	int FIPS_drbg_get_strength(DRBG_CTX *dctx)
	{
	return dctx->strength;
	}

	void FIPS_drbg_set_check_interval(DRBG_CTX *dctx, int interval)
	{
	dctx->health_check_interval = interval;
	}

	void FIPS_drbg_set_reseed_interval(DRBG_CTX *dctx, int interval)
	{
	dctx->reseed_interval = interval;
	}

	static int drbg_stick = 0;

	void FIPS_drbg_stick(int onoff)
	{
	drbg_stick = onoff;
	}

	/* Continuous DRBG utility function */
	int fips_drbg_cprng_test(DRBG_CTX dctx, const unsigned char out)
	{
	/* No CPRNG in test mode */
	if (dctx->xflags & DRBG_FLAG_TEST)
	return 1;
	/* Check block is valid: should never happen */
	if (dctx->lb_valid == 0)
	{
	FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_INTERNAL_ERROR);
	fips_set_selftest_fail();
	return 0;
	}
	if (drbg_stick)
	memcpy(dctx->lb, out, dctx->blocklength);
	/* Check against last block: fail if match */
	if (!memcmp(dctx->lb, out, dctx->blocklength))
	{
	FIPSerr(FIPS_F_FIPS_DRBG_CPRNG_TEST, FIPS_R_DRBG_STUCK);
	fips_set_selftest_fail();
	return 0;
	}
	/* Save last block for next comparison */
	memcpy(dctx->lb, out, dctx->blocklength);
	return 1;
	}