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

 /* fips/rand/fips_drbg_ctr.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.
  * ====================================================================
  */

 #include <stdlib.h>
 #include <string.h>
 #include <openssl/crypto.h>
 #include <openssl/fips.h>
 #include <openssl/fips_rand.h>
 #include "fips_rand_lcl.h"

 static void inc_128(DRBG_CTR_CTX *cctx)
 	{
 	int i;
 	unsigned char c;
 	unsigned char *p = cctx->V + 15;
 	for (i = 0; i < 16; i++)
 		{
 		c = *p;
 		c++;
 		*p = c;
 		if (c)
 			return;
 		p--;
 		}
 	}

 static void ctr_XOR(DRBG_CTR_CTX *cctx, const unsigned char *in, size_t inlen)
 	{
 	size_t i, n;
 	/* Any zero padding will have no effect on the result as we
 	 * are XORing. So just process however much input we have.
 	 */

 	if (!in || !inlen)
 		return;

 	if (inlen < cctx->keylen)
 		n = inlen;
 	else
 		n = cctx->keylen;

 	for (i = 0; i < n; i++)
 		cctx->K[i] ^= in[i];
 	if (inlen <= cctx->keylen)
 		return;

 	n = inlen - cctx->keylen;
 	/* Should never happen */
 	if (n > 16)
 		n = 16;
 	for (i = 0; i < 16; i++)
 		cctx->V[i] ^= in[i + cctx->keylen];
 	}

 /* Process a complete block using BCC algorithm of SPP 800-90 10.4.3 */

 static void ctr_BCC_block(DRBG_CTR_CTX *cctx, unsigned char *out,
 				const unsigned char *in)
 	{
 	int i;
 	for (i = 0; i < 16; i++)
 		out[i] ^= in[i];
 	AES_encrypt(out, out, &cctx->df_ks);
 #if 0
 fprintf(stderr, "BCC in+out\n");
 BIO_dump_fp(stderr, in, 16);
 BIO_dump_fp(stderr, out, 16);
 #endif
 	}

 /* Handle several BCC operations for as much data as we need for K and X */
 static void ctr_BCC_blocks(DRBG_CTR_CTX *cctx, const unsigned char *in)
 	{
 	ctr_BCC_block(cctx, cctx->KX, in);
 	ctr_BCC_block(cctx, cctx->KX + 16, in);
 	if (cctx->keylen != 16)
 		ctr_BCC_block(cctx, cctx->KX + 32, in);
 	}
 /* Initialise BCC blocks: these have the value 0,1,2 in leftmost positions:
  * see 10.4.2 stage 7.
  */
 static void ctr_BCC_init(DRBG_CTR_CTX *cctx)
 	{
 	memset(cctx->KX, 0, 48);
 	memset(cctx->bltmp, 0, 16);
 	ctr_BCC_block(cctx, cctx->KX, cctx->bltmp);
 	cctx->bltmp[3] = 1;
 	ctr_BCC_block(cctx, cctx->KX + 16, cctx->bltmp);
 	if (cctx->keylen != 16)
 		{
 		cctx->bltmp[3] = 2;
 		ctr_BCC_block(cctx, cctx->KX + 32, cctx->bltmp);
 		}
 	}

 /* Process several blocks into BCC algorithm, some possibly partial */
 static void ctr_BCC_update(DRBG_CTR_CTX *cctx,
 				const unsigned char *in, size_t inlen)
 	{
 	if (!in || !inlen)
 		return;
 	/* If we have partial block handle it first */
 	if (cctx->bltmp_pos)
 		{
 		size_t left = 16 - cctx->bltmp_pos;
 		/* If we now have a complete block process it */
 		if (inlen >= left)
 			{
 			memcpy(cctx->bltmp + cctx->bltmp_pos, in, left);
 			ctr_BCC_blocks(cctx, cctx->bltmp);
 			cctx->bltmp_pos = 0;
 			inlen -= left;
 			in += left;
 			}
 		}
 	/* Process zero or more complete blocks */
 	while (inlen >= 16)
 		{
 		ctr_BCC_blocks(cctx, in);
 		in += 16;
 		inlen -= 16;
 		}
 	/* Copy any remaining partial block to the temporary buffer */
 	if (inlen > 0)
 		{
 		memcpy(cctx->bltmp + cctx->bltmp_pos, in, inlen);
 		cctx->bltmp_pos += inlen;
 		}
 	}

 static void ctr_BCC_final(DRBG_CTR_CTX *cctx)
 	{
 	if (cctx->bltmp_pos)
 		{
 		memset(cctx->bltmp + cctx->bltmp_pos, 0, 16 - cctx->bltmp_pos);
 		ctr_BCC_blocks(cctx, cctx->bltmp);
 		}
 	}

 static void ctr_df(DRBG_CTR_CTX *cctx,
 			const unsigned char *in1, size_t in1len,
 			const unsigned char *in2, size_t in2len,
 			const unsigned char *in3, size_t in3len)
 	{
 	size_t inlen;
 	unsigned char *p = cctx->bltmp;
 	static unsigned char c80 = 0x80;

 	ctr_BCC_init(cctx);
 	if (!in1)
 		in1len = 0;
 	if (!in2)
 		in2len = 0;
 	if (!in3)
 		in3len = 0;
 	inlen = in1len + in2len + in3len;
 	/* Initialise L||N in temporary block */
 	*p++ = (inlen >> 24) & 0xff;
 	*p++ = (inlen >> 16) & 0xff;
 	*p++ = (inlen >> 8) & 0xff;
 	*p++ = inlen & 0xff;
 	/* NB keylen is at most 32 bytes */
 	*p++ = 0;
 	*p++ = 0;
 	*p++ = 0;
 	*p = (unsigned char)((cctx->keylen + 16) & 0xff);
 	cctx->bltmp_pos = 8;
 	ctr_BCC_update(cctx, in1, in1len);
 	ctr_BCC_update(cctx, in2, in2len);
 	ctr_BCC_update(cctx, in3, in3len);
 	ctr_BCC_update(cctx, &c80, 1);
 	ctr_BCC_final(cctx);
 	/* Set up key K */
 	AES_set_encrypt_key(cctx->KX, cctx->keylen * 8, &cctx->df_kxks);
 	/* X follows key K */
 	AES_encrypt(cctx->KX + cctx->keylen, cctx->KX, &cctx->df_kxks);
 	AES_encrypt(cctx->KX, cctx->KX + 16, &cctx->df_kxks);
 	if (cctx->keylen != 16)
 		AES_encrypt(cctx->KX + 16, cctx->KX + 32, &cctx->df_kxks);
 #if 0
 fprintf(stderr, "Output of ctr_df:\n");
 BIO_dump_fp(stderr, cctx->KX, cctx->keylen + 16);
 #endif
 	}

 /* NB the no-df  Update in SP800-90 specifies a constant input length
  * of seedlen, however other uses of this algorithm pad the input with
  * zeroes if necessary and have up to two parameters XORed together,
  * handle both cases in this function instead.
  */

 static void ctr_Update(DRBG_CTX *dctx,
 		const unsigned char *in1, size_t in1len,
 		const unsigned char *in2, size_t in2len,
 		const unsigned char *nonce, size_t noncelen)
 	{
 	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
 	/* ks is already setup for correct key */
 	inc_128(cctx);
 	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
 	/* If keylen longer than 128 bits need extra encrypt */
 	if (cctx->keylen != 16)
 		{
 		inc_128(cctx);
 		AES_encrypt(cctx->V, cctx->K + 16, &cctx->ks);
 		}
 	inc_128(cctx);
 	AES_encrypt(cctx->V, cctx->V, &cctx->ks);
 	/* If 192 bit key part of V is on end of K */
 	if (cctx->keylen == 24)
 		{
 		memcpy(cctx->V + 8, cctx->V, 8);
 		memcpy(cctx->V, cctx->K + 24, 8);
 		}

 	if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
 		{
 		/* If no input reuse existing derived value */
 		if (in1 || nonce || in2)
 			ctr_df(cctx, in1, in1len, nonce, noncelen, in2, in2len);
 		/* If this a reuse input in1len != 0 */
 		if (in1len)
 			ctr_XOR(cctx, cctx->KX, dctx->seedlen);
 		}
 	else
 		{
 		ctr_XOR(cctx, in1, in1len);
 		ctr_XOR(cctx, in2, in2len);
 		}

 	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
 #if 0
 fprintf(stderr, "K+V after update is:\n");
 BIO_dump_fp(stderr, cctx->K, cctx->keylen);
 BIO_dump_fp(stderr, cctx->V, 16);
 #endif
 	}

 static int drbg_ctr_instantiate(DRBG_CTX *dctx,
 			const unsigned char *ent, size_t entlen,
 			const unsigned char *nonce, size_t noncelen,
 			const unsigned char *pers, size_t perslen)
 	{
 	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
 	memset(cctx->K, 0, sizeof(cctx->K));
 	memset(cctx->V, 0, sizeof(cctx->V));
 	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
 	ctr_Update(dctx, ent, entlen, pers, perslen, nonce, noncelen);
 	return 1;
 	}

 static int drbg_ctr_reseed(DRBG_CTX *dctx,
 			const unsigned char *ent, size_t entlen,
 			const unsigned char *adin, size_t adinlen)
 	{
 	ctr_Update(dctx, ent, entlen, adin, adinlen, NULL, 0);
 	return 1;
 	}

 static int drbg_ctr_generate(DRBG_CTX *dctx,
 			unsigned char *out, size_t outlen,
 			const unsigned char *adin, size_t adinlen)
 	{
 	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
 	if (adin && adinlen)
 		{
 		ctr_Update(dctx, adin, adinlen, NULL, 0, NULL, 0);
 		/* This means we reuse derived value */
 		if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
 			{
 			adin = NULL;
 			adinlen = 1;
 			}
 		}
 	else
 		adinlen = 0;

 	for (;;)
 		{
 		inc_128(cctx);
 		if (!(dctx->xflags & DRBG_FLAG_TEST) && !dctx->lb_valid)
 			{
 			AES_encrypt(cctx->V, dctx->lb, &cctx->ks);
 			dctx->lb_valid = 1;
 			continue;
 			}
 		if (outlen < 16)
 			{
 			/* Use K as temp space as it will be updated */
 			AES_encrypt(cctx->V, cctx->K, &cctx->ks);
 			if (!fips_drbg_cprng_test(dctx, cctx->K))
 				return 0;
 			memcpy(out, cctx->K, outlen);
 			break;
 			}
 		AES_encrypt(cctx->V, out, &cctx->ks);
 		if (!fips_drbg_cprng_test(dctx, out))
 			return 0;
 		out += 16;
 		outlen -= 16;
 		if (outlen == 0)
 			break;
 		}

 	ctr_Update(dctx, adin, adinlen, NULL, 0, NULL, 0);

 	return 1;

 	}

 static int drbg_ctr_uninstantiate(DRBG_CTX *dctx)
 	{
 	memset(&dctx->d.ctr, 0, sizeof(DRBG_CTR_CTX));
 	return 1;
 	}

 int fips_drbg_ctr_init(DRBG_CTX *dctx)
 	{
 	DRBG_CTR_CTX *cctx = &dctx->d.ctr;

 	size_t keylen;

 	switch (dctx->type)
 		{
 		case NID_aes_128_ctr:
 		keylen = 16;
 		break;

 		case NID_aes_192_ctr:
 		keylen = 24;
 		break;

 		case NID_aes_256_ctr:
 		keylen = 32;
 		break;

 		default:
 		return -2;
 		}

 	dctx->instantiate = drbg_ctr_instantiate;
 	dctx->reseed = drbg_ctr_reseed;
 	dctx->generate = drbg_ctr_generate;
 	dctx->uninstantiate = drbg_ctr_uninstantiate;

 	cctx->keylen = keylen;
 	dctx->strength = keylen * 8;
 	dctx->blocklength = 16;
 	dctx->seedlen = keylen + 16;

 	if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
 		{
 		/* df initialisation */
 		static unsigned char df_key[32] =
 			{
 			0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
 			0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
 			0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
 			0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
 			};
 		/* Set key schedule for df_key */
 		AES_set_encrypt_key(df_key, dctx->strength, &cctx->df_ks);

 		dctx->min_entropy = cctx->keylen;
 		dctx->max_entropy = DRBG_MAX_LENGTH;
 		dctx->min_nonce = dctx->min_entropy / 2;
 		dctx->max_nonce = DRBG_MAX_LENGTH;
 		dctx->max_pers = DRBG_MAX_LENGTH;
 		dctx->max_adin = DRBG_MAX_LENGTH;
 		}
 	else
 		{
 		dctx->min_entropy = dctx->seedlen;
 		dctx->max_entropy = dctx->seedlen;
 		/* Nonce not used */
 		dctx->min_nonce = 0;
 		dctx->max_nonce = 0;
 		dctx->max_pers = dctx->seedlen;
 		dctx->max_adin = dctx->seedlen;
 		}

 	dctx->max_request = 1<<16;
 	dctx->reseed_interval = 1<<24;

 	return 1;
 	}
	/* fips/rand/fips_drbg_ctr.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.
	* ====================================================================
	*/

	#include <stdlib.h>
	#include <string.h>
	#include <openssl/crypto.h>
	#include <openssl/fips.h>
	#include <openssl/fips_rand.h>
	#include "fips_rand_lcl.h"

	static void inc_128(DRBG_CTR_CTX *cctx)
	{
	int i;
	unsigned char c;
	unsigned char *p = cctx->V + 15;
	for (i = 0; i < 16; i++)
	{
	c = *p;
	c++;
	*p = c;
	if (c)
	return;
	p--;
	}
	}

	static void ctr_XOR(DRBG_CTR_CTX cctx, const unsigned char in, size_t inlen)
	{
	size_t i, n;
	/* Any zero padding will have no effect on the result as we
	* are XORing. So just process however much input we have.
	*/

	if (!in \|\| !inlen)
	return;

	if (inlen < cctx->keylen)
	n = inlen;
	else
	n = cctx->keylen;

	for (i = 0; i < n; i++)
	cctx->K[i] ^= in[i];
	if (inlen <= cctx->keylen)
	return;

	n = inlen - cctx->keylen;
	/* Should never happen */
	if (n > 16)
	n = 16;
	for (i = 0; i < 16; i++)
	cctx->V[i] ^= in[i + cctx->keylen];
	}

	/* Process a complete block using BCC algorithm of SPP 800-90 10.4.3 */

	static void ctr_BCC_block(DRBG_CTR_CTX cctx, unsigned char out,
	const unsigned char *in)
	{
	int i;
	for (i = 0; i < 16; i++)
	out[i] ^= in[i];
	AES_encrypt(out, out, &cctx->df_ks);
	#if 0
	fprintf(stderr, "BCC in+out\n");
	BIO_dump_fp(stderr, in, 16);
	BIO_dump_fp(stderr, out, 16);
	#endif
	}

	/* Handle several BCC operations for as much data as we need for K and X */
	static void ctr_BCC_blocks(DRBG_CTR_CTX cctx, const unsigned char in)
	{
	ctr_BCC_block(cctx, cctx->KX, in);
	ctr_BCC_block(cctx, cctx->KX + 16, in);
	if (cctx->keylen != 16)
	ctr_BCC_block(cctx, cctx->KX + 32, in);
	}
	/* Initialise BCC blocks: these have the value 0,1,2 in leftmost positions:
	* see 10.4.2 stage 7.
	*/
	static void ctr_BCC_init(DRBG_CTR_CTX *cctx)
	{
	memset(cctx->KX, 0, 48);
	memset(cctx->bltmp, 0, 16);
	ctr_BCC_block(cctx, cctx->KX, cctx->bltmp);
	cctx->bltmp[3] = 1;
	ctr_BCC_block(cctx, cctx->KX + 16, cctx->bltmp);
	if (cctx->keylen != 16)
	{
	cctx->bltmp[3] = 2;
	ctr_BCC_block(cctx, cctx->KX + 32, cctx->bltmp);
	}
	}

	/* Process several blocks into BCC algorithm, some possibly partial */
	static void ctr_BCC_update(DRBG_CTR_CTX *cctx,
	const unsigned char *in, size_t inlen)
	{
	if (!in \|\| !inlen)
	return;
	/* If we have partial block handle it first */
	if (cctx->bltmp_pos)
	{
	size_t left = 16 - cctx->bltmp_pos;
	/* If we now have a complete block process it */
	if (inlen >= left)
	{
	memcpy(cctx->bltmp + cctx->bltmp_pos, in, left);
	ctr_BCC_blocks(cctx, cctx->bltmp);
	cctx->bltmp_pos = 0;
	inlen -= left;
	in += left;
	}
	}
	/* Process zero or more complete blocks */
	while (inlen >= 16)
	{
	ctr_BCC_blocks(cctx, in);
	in += 16;
	inlen -= 16;
	}
	/* Copy any remaining partial block to the temporary buffer */
	if (inlen > 0)
	{
	memcpy(cctx->bltmp + cctx->bltmp_pos, in, inlen);
	cctx->bltmp_pos += inlen;
	}
	}

	static void ctr_BCC_final(DRBG_CTR_CTX *cctx)
	{
	if (cctx->bltmp_pos)
	{
	memset(cctx->bltmp + cctx->bltmp_pos, 0, 16 - cctx->bltmp_pos);
	ctr_BCC_blocks(cctx, cctx->bltmp);
	}
	}

	static void ctr_df(DRBG_CTR_CTX *cctx,
	const unsigned char *in1, size_t in1len,
	const unsigned char *in2, size_t in2len,
	const unsigned char *in3, size_t in3len)
	{
	size_t inlen;
	unsigned char *p = cctx->bltmp;
	static unsigned char c80 = 0x80;

	ctr_BCC_init(cctx);
	if (!in1)
	in1len = 0;
	if (!in2)
	in2len = 0;
	if (!in3)
	in3len = 0;
	inlen = in1len + in2len + in3len;
	/* Initialise L\|\|N in temporary block */
	*p++ = (inlen >> 24) & 0xff;
	*p++ = (inlen >> 16) & 0xff;
	*p++ = (inlen >> 8) & 0xff;
	*p++ = inlen & 0xff;
	/* NB keylen is at most 32 bytes */
	*p++ = 0;
	*p++ = 0;
	*p++ = 0;
	*p = (unsigned char)((cctx->keylen + 16) & 0xff);
	cctx->bltmp_pos = 8;
	ctr_BCC_update(cctx, in1, in1len);
	ctr_BCC_update(cctx, in2, in2len);
	ctr_BCC_update(cctx, in3, in3len);
	ctr_BCC_update(cctx, &c80, 1);
	ctr_BCC_final(cctx);
	/* Set up key K */
	AES_set_encrypt_key(cctx->KX, cctx->keylen * 8, &cctx->df_kxks);
	/* X follows key K */
	AES_encrypt(cctx->KX + cctx->keylen, cctx->KX, &cctx->df_kxks);
	AES_encrypt(cctx->KX, cctx->KX + 16, &cctx->df_kxks);
	if (cctx->keylen != 16)
	AES_encrypt(cctx->KX + 16, cctx->KX + 32, &cctx->df_kxks);
	#if 0
	fprintf(stderr, "Output of ctr_df:\n");
	BIO_dump_fp(stderr, cctx->KX, cctx->keylen + 16);
	#endif
	}

	/* NB the no-df Update in SP800-90 specifies a constant input length
	* of seedlen, however other uses of this algorithm pad the input with
	* zeroes if necessary and have up to two parameters XORed together,
	* handle both cases in this function instead.
	*/

	static void ctr_Update(DRBG_CTX *dctx,
	const unsigned char *in1, size_t in1len,
	const unsigned char *in2, size_t in2len,
	const unsigned char *nonce, size_t noncelen)
	{
	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
	/* ks is already setup for correct key */
	inc_128(cctx);
	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
	/* If keylen longer than 128 bits need extra encrypt */
	if (cctx->keylen != 16)
	{
	inc_128(cctx);
	AES_encrypt(cctx->V, cctx->K + 16, &cctx->ks);
	}
	inc_128(cctx);
	AES_encrypt(cctx->V, cctx->V, &cctx->ks);
	/* If 192 bit key part of V is on end of K */
	if (cctx->keylen == 24)
	{
	memcpy(cctx->V + 8, cctx->V, 8);
	memcpy(cctx->V, cctx->K + 24, 8);
	}

	if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
	{
	/* If no input reuse existing derived value */
	if (in1 \|\| nonce \|\| in2)
	ctr_df(cctx, in1, in1len, nonce, noncelen, in2, in2len);
	/* If this a reuse input in1len != 0 */
	if (in1len)
	ctr_XOR(cctx, cctx->KX, dctx->seedlen);
	}
	else
	{
	ctr_XOR(cctx, in1, in1len);
	ctr_XOR(cctx, in2, in2len);
	}

	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
	#if 0
	fprintf(stderr, "K+V after update is:\n");
	BIO_dump_fp(stderr, cctx->K, cctx->keylen);
	BIO_dump_fp(stderr, cctx->V, 16);
	#endif
	}

	static int drbg_ctr_instantiate(DRBG_CTX *dctx,
	const unsigned char *ent, size_t entlen,
	const unsigned char *nonce, size_t noncelen,
	const unsigned char *pers, size_t perslen)
	{
	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
	memset(cctx->K, 0, sizeof(cctx->K));
	memset(cctx->V, 0, sizeof(cctx->V));
	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
	ctr_Update(dctx, ent, entlen, pers, perslen, nonce, noncelen);
	return 1;
	}

	static int drbg_ctr_reseed(DRBG_CTX *dctx,
	const unsigned char *ent, size_t entlen,
	const unsigned char *adin, size_t adinlen)
	{
	ctr_Update(dctx, ent, entlen, adin, adinlen, NULL, 0);
	return 1;
	}

	static int drbg_ctr_generate(DRBG_CTX *dctx,
	unsigned char *out, size_t outlen,
	const unsigned char *adin, size_t adinlen)
	{
	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
	if (adin && adinlen)
	{
	ctr_Update(dctx, adin, adinlen, NULL, 0, NULL, 0);
	/* This means we reuse derived value */
	if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
	{
	adin = NULL;
	adinlen = 1;
	}
	}
	else
	adinlen = 0;

	for (;;)
	{
	inc_128(cctx);
	if (!(dctx->xflags & DRBG_FLAG_TEST) && !dctx->lb_valid)
	{
	AES_encrypt(cctx->V, dctx->lb, &cctx->ks);
	dctx->lb_valid = 1;
	continue;
	}
	if (outlen < 16)
	{
	/* Use K as temp space as it will be updated */
	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
	if (!fips_drbg_cprng_test(dctx, cctx->K))
	return 0;
	memcpy(out, cctx->K, outlen);
	break;
	}
	AES_encrypt(cctx->V, out, &cctx->ks);
	if (!fips_drbg_cprng_test(dctx, out))
	return 0;
	out += 16;
	outlen -= 16;
	if (outlen == 0)
	break;
	}

	ctr_Update(dctx, adin, adinlen, NULL, 0, NULL, 0);

	return 1;

	}

	static int drbg_ctr_uninstantiate(DRBG_CTX *dctx)
	{
	memset(&dctx->d.ctr, 0, sizeof(DRBG_CTR_CTX));
	return 1;
	}

	int fips_drbg_ctr_init(DRBG_CTX *dctx)
	{
	DRBG_CTR_CTX *cctx = &dctx->d.ctr;

	size_t keylen;

	switch (dctx->type)
	{
	case NID_aes_128_ctr:
	keylen = 16;
	break;

	case NID_aes_192_ctr:
	keylen = 24;
	break;

	case NID_aes_256_ctr:
	keylen = 32;
	break;

	default:
	return -2;
	}

	dctx->instantiate = drbg_ctr_instantiate;
	dctx->reseed = drbg_ctr_reseed;
	dctx->generate = drbg_ctr_generate;
	dctx->uninstantiate = drbg_ctr_uninstantiate;

	cctx->keylen = keylen;
	dctx->strength = keylen * 8;
	dctx->blocklength = 16;
	dctx->seedlen = keylen + 16;

	if (dctx->xflags & DRBG_FLAG_CTR_USE_DF)
	{
	/* df initialisation */
	static unsigned char df_key[32] =
	{
	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
	0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
	0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
	0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f
	};
	/* Set key schedule for df_key */
	AES_set_encrypt_key(df_key, dctx->strength, &cctx->df_ks);

	dctx->min_entropy = cctx->keylen;
	dctx->max_entropy = DRBG_MAX_LENGTH;
	dctx->min_nonce = dctx->min_entropy / 2;
	dctx->max_nonce = DRBG_MAX_LENGTH;
	dctx->max_pers = DRBG_MAX_LENGTH;
	dctx->max_adin = DRBG_MAX_LENGTH;
	}
	else
	{
	dctx->min_entropy = dctx->seedlen;
	dctx->max_entropy = dctx->seedlen;
	/* Nonce not used */
	dctx->min_nonce = 0;
	dctx->max_nonce = 0;
	dctx->max_pers = dctx->seedlen;
	dctx->max_adin = dctx->seedlen;
	}

	dctx->max_request = 1<<16;
	dctx->reseed_interval = 1<<24;

	return 1;
	}