crypto/modes/ccm128.c - platform/external/openssl - Git at Google

 /* ====================================================================
  * 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
  *    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.
  * ====================================================================
  */

 #include <openssl/crypto.h>
 #include "modes_lcl.h"
 #include <string.h>

 #ifndef MODES_DEBUG
 # ifndef NDEBUG
 #  define NDEBUG
 # endif
 #endif
 #include <assert.h>

 /* First you setup M and L parameters and pass the key schedule.
  * This is called once per session setup... */
 void CRYPTO_ccm128_init(CCM128_CONTEXT *ctx,
 	unsigned int M,unsigned int L,void *key,block128_f block)
 {
 	memset(ctx->nonce.c,0,sizeof(ctx->nonce.c));
 	ctx->nonce.c[0] = ((u8)(L-1)&7) | (u8)(((M-2)/2)&7)<<3;
 	ctx->blocks = 0;
 	ctx->block = block;
 	ctx->key = key;
 }

 /* !!! Following interfaces are to be called *once* per packet !!! */

 /* Then you setup per-message nonce and pass the length of the message */
 int CRYPTO_ccm128_setiv(CCM128_CONTEXT *ctx,
 	const unsigned char *nonce,size_t nlen,size_t mlen)
 {
 	unsigned int L = ctx->nonce.c[0]&7;	/* the L parameter */

 	if (nlen<(14-L)) return -1;		/* nonce is too short */

 	if (sizeof(mlen)==8 && L>=3) {
 		ctx->nonce.c[8]  = (u8)(mlen>>(56%(sizeof(mlen)*8)));
 		ctx->nonce.c[9]  = (u8)(mlen>>(48%(sizeof(mlen)*8)));
 		ctx->nonce.c[10] = (u8)(mlen>>(40%(sizeof(mlen)*8)));
 		ctx->nonce.c[11] = (u8)(mlen>>(32%(sizeof(mlen)*8)));
 	}
 	else
 		*(u32*)(&ctx->nonce.c[8]) = 0;

 	ctx->nonce.c[12] = (u8)(mlen>>24);
 	ctx->nonce.c[13] = (u8)(mlen>>16);
 	ctx->nonce.c[14] = (u8)(mlen>>8);
 	ctx->nonce.c[15] = (u8)mlen;

 	ctx->nonce.c[0] &= ~0x40;	/* clear Adata flag */
 	memcpy(&ctx->nonce.c[1],nonce,14-L);

 	return 0;
 }

 /* Then you pass additional authentication data, this is optional */
 void CRYPTO_ccm128_aad(CCM128_CONTEXT *ctx,
 	const unsigned char *aad,size_t alen)
 {	unsigned int i;
 	block128_f block = ctx->block;

 	if (alen==0) return;

 	ctx->nonce.c[0] |= 0x40;	/* set Adata flag */
 	(*block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
 	ctx->blocks++;

 	if (alen<(0x10000-0x100)) {
 		ctx->cmac.c[0] ^= (u8)(alen>>8);
 		ctx->cmac.c[1] ^= (u8)alen;
 		i=2;
 	}
 	else if (sizeof(alen)==8 && alen>=(size_t)1<<(32%(sizeof(alen)*8))) {
 		ctx->cmac.c[0] ^= 0xFF;
 		ctx->cmac.c[1] ^= 0xFF;
 		ctx->cmac.c[2] ^= (u8)(alen>>(56%(sizeof(alen)*8)));
 		ctx->cmac.c[3] ^= (u8)(alen>>(48%(sizeof(alen)*8)));
 		ctx->cmac.c[4] ^= (u8)(alen>>(40%(sizeof(alen)*8)));
 		ctx->cmac.c[5] ^= (u8)(alen>>(32%(sizeof(alen)*8)));
 		ctx->cmac.c[6] ^= (u8)(alen>>24);
 		ctx->cmac.c[7] ^= (u8)(alen>>16);
 		ctx->cmac.c[8] ^= (u8)(alen>>8);
 		ctx->cmac.c[9] ^= (u8)alen;
 		i=10;
 	}
 	else {
 		ctx->cmac.c[0] ^= 0xFF;
 		ctx->cmac.c[1] ^= 0xFE;
 		ctx->cmac.c[2] ^= (u8)(alen>>24);
 		ctx->cmac.c[3] ^= (u8)(alen>>16);
 		ctx->cmac.c[4] ^= (u8)(alen>>8);
 		ctx->cmac.c[5] ^= (u8)alen;
 		i=6;
 	}

 	do {
 		for(;i<16 && alen;++i,++aad,--alen)
 			ctx->cmac.c[i] ^= *aad;
 		(*block)(ctx->cmac.c,ctx->cmac.c,ctx->key),
 		ctx->blocks++;
 		i=0;
 	} while (alen);
 }

 /* Finally you encrypt or decrypt the message */

 /* counter part of nonce may not be larger than L*8 bits,
  * L is not larger than 8, therefore 64-bit counter... */
 static void ctr64_inc(unsigned char *counter) {
 	unsigned int n=8;
 	u8  c;

 	counter += 8;
 	do {
 		--n;
 		c = counter[n];
 		++c;
 		counter[n] = c;
 		if (c) return;
 	} while (n);
 }

 int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
 	const unsigned char *inp, unsigned char *out,
 	size_t len)
 {
 	size_t		n;
 	unsigned int	i,L;
 	unsigned char	flags0	= ctx->nonce.c[0];
 	block128_f	block	= ctx->block;
 	void *		key	= ctx->key;
 	union { u64 u[2]; u8 c[16]; } scratch;

 	if (!(flags0&0x40))
 		(*block)(ctx->nonce.c,ctx->cmac.c,key),
 		ctx->blocks++;

 	ctx->nonce.c[0] = L = flags0&7;
 	for (n=0,i=15-L;i<15;++i) {
 		n |= ctx->nonce.c[i];
 		ctx->nonce.c[i]=0;
 		n <<= 8;
 	}
 	n |= ctx->nonce.c[15];	/* reconstructed length */
 	ctx->nonce.c[15]=1;

 	if (n!=len) return -1;	/* length mismatch */

 	ctx->blocks += ((len+15)>>3)|1;
 	if (ctx->blocks > (U64(1)<<61))	return -2; /* too much data */

 	while (len>=16) {
 #if defined(STRICT_ALIGNMENT)
 		union { u64 u[2]; u8 c[16]; } temp;

 		memcpy (temp.c,inp,16);
 		ctx->cmac.u[0] ^= temp.u[0];
 		ctx->cmac.u[1] ^= temp.u[1];
 #else
 		ctx->cmac.u[0] ^= ((u64*)inp)[0];
 		ctx->cmac.u[1] ^= ((u64*)inp)[1];
 #endif
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);
 		(*block)(ctx->nonce.c,scratch.c,key);
 		ctr64_inc(ctx->nonce.c);
 #if defined(STRICT_ALIGNMENT)
 		temp.u[0] ^= scratch.u[0];
 		temp.u[1] ^= scratch.u[1];
 		memcpy(out,temp.c,16);
 #else
 		((u64*)out)[0] = scratch.u[0]^((u64*)inp)[0];
 		((u64*)out)[1] = scratch.u[1]^((u64*)inp)[1];
 #endif
 		inp += 16;
 		out += 16;
 		len -= 16;
 	}

 	if (len) {
 		for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);
 		(*block)(ctx->nonce.c,scratch.c,key);
 		for (i=0; i<len; ++i) out[i] = scratch.c[i]^inp[i];
 	}

 	for (i=15-L;i<16;++i)
 		ctx->nonce.c[i]=0;

 	(*block)(ctx->nonce.c,scratch.c,key);
 	ctx->cmac.u[0] ^= scratch.u[0];
 	ctx->cmac.u[1] ^= scratch.u[1];

 	ctx->nonce.c[0] = flags0;

 	return 0;
 }

 int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
 	const unsigned char *inp, unsigned char *out,
 	size_t len)
 {
 	size_t		n;
 	unsigned int	i,L;
 	unsigned char	flags0	= ctx->nonce.c[0];
 	block128_f	block	= ctx->block;
 	void *		key	= ctx->key;
 	union { u64 u[2]; u8 c[16]; } scratch;

 	if (!(flags0&0x40))
 		(*block)(ctx->nonce.c,ctx->cmac.c,key);

 	ctx->nonce.c[0] = L = flags0&7;
 	for (n=0,i=15-L;i<15;++i) {
 		n |= ctx->nonce.c[i];
 		ctx->nonce.c[i]=0;
 		n <<= 8;
 	}
 	n |= ctx->nonce.c[15];	/* reconstructed length */
 	ctx->nonce.c[15]=1;

 	if (n!=len) return -1;

 	while (len>=16) {
 #if defined(STRICT_ALIGNMENT)
 		union { u64 u[2]; u8 c[16]; } temp;
 #endif
 		(*block)(ctx->nonce.c,scratch.c,key);
 		ctr64_inc(ctx->nonce.c);
 #if defined(STRICT_ALIGNMENT)
 		memcpy (temp.c,inp,16);
 		ctx->cmac.u[0] ^= (scratch.u[0] ^= temp.u[0]);
 		ctx->cmac.u[1] ^= (scratch.u[1] ^= temp.u[1]);
 		memcpy (out,scratch.c,16);
 #else
 		ctx->cmac.u[0] ^= (((u64*)out)[0] = scratch.u[0]^((u64*)inp)[0]);
 		ctx->cmac.u[1] ^= (((u64*)out)[1] = scratch.u[1]^((u64*)inp)[1]);
 #endif
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);

 		inp += 16;
 		out += 16;
 		len -= 16;
 	}

 	if (len) {
 		(*block)(ctx->nonce.c,scratch.c,key);
 		for (i=0; i<len; ++i)
 			ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);
 	}

 	for (i=15-L;i<16;++i)
 		ctx->nonce.c[i]=0;

 	(*block)(ctx->nonce.c,scratch.c,key);
 	ctx->cmac.u[0] ^= scratch.u[0];
 	ctx->cmac.u[1] ^= scratch.u[1];

 	ctx->nonce.c[0] = flags0;

 	return 0;
 }

 static void ctr64_add (unsigned char *counter,size_t inc)
 {	size_t n=8, val=0;

 	counter += 8;
 	do {
 		--n;
 		val += counter[n] + (inc&0xff);
 		counter[n] = (unsigned char)val;
 		val >>= 8;	/* carry bit */
 		inc >>= 8;
 	} while(n && (inc || val));
 }

 int CRYPTO_ccm128_encrypt_ccm64(CCM128_CONTEXT *ctx,
 	const unsigned char *inp, unsigned char *out,
 	size_t len,ccm128_f stream)
 {
 	size_t		n;
 	unsigned int	i,L;
 	unsigned char	flags0	= ctx->nonce.c[0];
 	block128_f	block	= ctx->block;
 	void *		key	= ctx->key;
 	union { u64 u[2]; u8 c[16]; } scratch;

 	if (!(flags0&0x40))
 		(*block)(ctx->nonce.c,ctx->cmac.c,key),
 		ctx->blocks++;

 	ctx->nonce.c[0] = L = flags0&7;
 	for (n=0,i=15-L;i<15;++i) {
 		n |= ctx->nonce.c[i];
 		ctx->nonce.c[i]=0;
 		n <<= 8;
 	}
 	n |= ctx->nonce.c[15];	/* reconstructed length */
 	ctx->nonce.c[15]=1;

 	if (n!=len) return -1;	/* length mismatch */

 	ctx->blocks += ((len+15)>>3)|1;
 	if (ctx->blocks > (U64(1)<<61))	return -2; /* too much data */

 	if ((n=len/16)) {
 		(*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
 		n   *= 16;
 		inp += n;
 		out += n;
 		len -= n;
 		if (len) ctr64_add(ctx->nonce.c,n/16);
 	}

 	if (len) {
 		for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);
 		(*block)(ctx->nonce.c,scratch.c,key);
 		for (i=0; i<len; ++i) out[i] = scratch.c[i]^inp[i];
 	}

 	for (i=15-L;i<16;++i)
 		ctx->nonce.c[i]=0;

 	(*block)(ctx->nonce.c,scratch.c,key);
 	ctx->cmac.u[0] ^= scratch.u[0];
 	ctx->cmac.u[1] ^= scratch.u[1];

 	ctx->nonce.c[0] = flags0;

 	return 0;
 }

 int CRYPTO_ccm128_decrypt_ccm64(CCM128_CONTEXT *ctx,
 	const unsigned char *inp, unsigned char *out,
 	size_t len,ccm128_f stream)
 {
 	size_t		n;
 	unsigned int	i,L;
 	unsigned char	flags0	= ctx->nonce.c[0];
 	block128_f	block	= ctx->block;
 	void *		key	= ctx->key;
 	union { u64 u[2]; u8 c[16]; } scratch;

 	if (!(flags0&0x40))
 		(*block)(ctx->nonce.c,ctx->cmac.c,key);

 	ctx->nonce.c[0] = L = flags0&7;
 	for (n=0,i=15-L;i<15;++i) {
 		n |= ctx->nonce.c[i];
 		ctx->nonce.c[i]=0;
 		n <<= 8;
 	}
 	n |= ctx->nonce.c[15];	/* reconstructed length */
 	ctx->nonce.c[15]=1;

 	if (n!=len) return -1;

 	if ((n=len/16)) {
 		(*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
 		n   *= 16;
 		inp += n;
 		out += n;
 		len -= n;
 		if (len) ctr64_add(ctx->nonce.c,n/16);
 	}

 	if (len) {
 		(*block)(ctx->nonce.c,scratch.c,key);
 		for (i=0; i<len; ++i)
 			ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
 		(*block)(ctx->cmac.c,ctx->cmac.c,key);
 	}

 	for (i=15-L;i<16;++i)
 		ctx->nonce.c[i]=0;

 	(*block)(ctx->nonce.c,scratch.c,key);
 	ctx->cmac.u[0] ^= scratch.u[0];
 	ctx->cmac.u[1] ^= scratch.u[1];

 	ctx->nonce.c[0] = flags0;

 	return 0;
 }

 size_t CRYPTO_ccm128_tag(CCM128_CONTEXT *ctx,unsigned char *tag,size_t len)
 {	unsigned int M = (ctx->nonce.c[0]>>3)&7;	/* the M parameter */

 	M *= 2; M += 2;
 	if (len<M)	return 0;
 	memcpy(tag,ctx->cmac.c,M);
 	return M;
 }
	/* ====================================================================
	* 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
	* 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.
	* ====================================================================
	*/

	#include <openssl/crypto.h>
	#include "modes_lcl.h"
	#include <string.h>

	#ifndef MODES_DEBUG
	# ifndef NDEBUG
	# define NDEBUG
	# endif
	#endif
	#include <assert.h>

	/* First you setup M and L parameters and pass the key schedule.
	* This is called once per session setup... */
	void CRYPTO_ccm128_init(CCM128_CONTEXT *ctx,
	unsigned int M,unsigned int L,void *key,block128_f block)
	{
	memset(ctx->nonce.c,0,sizeof(ctx->nonce.c));
	ctx->nonce.c[0] = ((u8)(L-1)&7) \| (u8)(((M-2)/2)&7)<<3;
	ctx->blocks = 0;
	ctx->block = block;
	ctx->key = key;
	}

	/* !!! Following interfaces are to be called once per packet !!! */

	/* Then you setup per-message nonce and pass the length of the message */
	int CRYPTO_ccm128_setiv(CCM128_CONTEXT *ctx,
	const unsigned char *nonce,size_t nlen,size_t mlen)
	{
	unsigned int L = ctx->nonce.c[0]&7; /* the L parameter */

	if (nlen<(14-L)) return -1; /* nonce is too short */

	if (sizeof(mlen)==8 && L>=3) {
	ctx->nonce.c[8] = (u8)(mlen>>(56%(sizeof(mlen)*8)));
	ctx->nonce.c[9] = (u8)(mlen>>(48%(sizeof(mlen)*8)));
	ctx->nonce.c[10] = (u8)(mlen>>(40%(sizeof(mlen)*8)));
	ctx->nonce.c[11] = (u8)(mlen>>(32%(sizeof(mlen)*8)));
	}
	else
	(u32)(&ctx->nonce.c[8]) = 0;

	ctx->nonce.c[12] = (u8)(mlen>>24);
	ctx->nonce.c[13] = (u8)(mlen>>16);
	ctx->nonce.c[14] = (u8)(mlen>>8);
	ctx->nonce.c[15] = (u8)mlen;

	ctx->nonce.c[0] &= ~0x40; /* clear Adata flag */
	memcpy(&ctx->nonce.c[1],nonce,14-L);

	return 0;
	}

	/* Then you pass additional authentication data, this is optional */
	void CRYPTO_ccm128_aad(CCM128_CONTEXT *ctx,
	const unsigned char *aad,size_t alen)
	{ unsigned int i;
	block128_f block = ctx->block;

	if (alen==0) return;

	ctx->nonce.c[0] \|= 0x40; /* set Adata flag */
	(*block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
	ctx->blocks++;

	if (alen<(0x10000-0x100)) {
	ctx->cmac.c[0] ^= (u8)(alen>>8);
	ctx->cmac.c[1] ^= (u8)alen;
	i=2;
	}
	else if (sizeof(alen)==8 && alen>=(size_t)1<<(32%(sizeof(alen)*8))) {
	ctx->cmac.c[0] ^= 0xFF;
	ctx->cmac.c[1] ^= 0xFF;
	ctx->cmac.c[2] ^= (u8)(alen>>(56%(sizeof(alen)*8)));
	ctx->cmac.c[3] ^= (u8)(alen>>(48%(sizeof(alen)*8)));
	ctx->cmac.c[4] ^= (u8)(alen>>(40%(sizeof(alen)*8)));
	ctx->cmac.c[5] ^= (u8)(alen>>(32%(sizeof(alen)*8)));
	ctx->cmac.c[6] ^= (u8)(alen>>24);
	ctx->cmac.c[7] ^= (u8)(alen>>16);
	ctx->cmac.c[8] ^= (u8)(alen>>8);
	ctx->cmac.c[9] ^= (u8)alen;
	i=10;
	}
	else {
	ctx->cmac.c[0] ^= 0xFF;
	ctx->cmac.c[1] ^= 0xFE;
	ctx->cmac.c[2] ^= (u8)(alen>>24);
	ctx->cmac.c[3] ^= (u8)(alen>>16);
	ctx->cmac.c[4] ^= (u8)(alen>>8);
	ctx->cmac.c[5] ^= (u8)alen;
	i=6;
	}

	do {
	for(;i<16 && alen;++i,++aad,--alen)
	ctx->cmac.c[i] ^= *aad;
	(*block)(ctx->cmac.c,ctx->cmac.c,ctx->key),
	ctx->blocks++;
	i=0;
	} while (alen);
	}

	/* Finally you encrypt or decrypt the message */

	/* counter part of nonce may not be larger than L*8 bits,
	* L is not larger than 8, therefore 64-bit counter... */
	static void ctr64_inc(unsigned char *counter) {
	unsigned int n=8;
	u8 c;

	counter += 8;
	do {
	--n;
	c = counter[n];
	++c;
	counter[n] = c;
	if (c) return;
	} while (n);
	}

	int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
	const unsigned char inp, unsigned char out,
	size_t len)
	{
	size_t n;
	unsigned int i,L;
	unsigned char flags0 = ctx->nonce.c[0];
	block128_f block = ctx->block;
	void * key = ctx->key;
	union { u64 u[2]; u8 c[16]; } scratch;

	if (!(flags0&0x40))
	(*block)(ctx->nonce.c,ctx->cmac.c,key),
	ctx->blocks++;

	ctx->nonce.c[0] = L = flags0&7;
	for (n=0,i=15-L;i<15;++i) {
	n \|= ctx->nonce.c[i];
	ctx->nonce.c[i]=0;
	n <<= 8;
	}
	n \|= ctx->nonce.c[15]; /* reconstructed length */
	ctx->nonce.c[15]=1;

	if (n!=len) return -1; /* length mismatch */

	ctx->blocks += ((len+15)>>3)\|1;
	if (ctx->blocks > (U64(1)<<61)) return -2; /* too much data */

	while (len>=16) {
	#if defined(STRICT_ALIGNMENT)
	union { u64 u[2]; u8 c[16]; } temp;

	memcpy (temp.c,inp,16);
	ctx->cmac.u[0] ^= temp.u[0];
	ctx->cmac.u[1] ^= temp.u[1];
	#else
	ctx->cmac.u[0] ^= ((u64*)inp)[0];
	ctx->cmac.u[1] ^= ((u64*)inp)[1];
	#endif
	(*block)(ctx->cmac.c,ctx->cmac.c,key);
	(*block)(ctx->nonce.c,scratch.c,key);
	ctr64_inc(ctx->nonce.c);
	#if defined(STRICT_ALIGNMENT)
	temp.u[0] ^= scratch.u[0];
	temp.u[1] ^= scratch.u[1];
	memcpy(out,temp.c,16);
	#else
	((u64)out)[0] = scratch.u[0]^((u64)inp)[0];
	((u64)out)[1] = scratch.u[1]^((u64)inp)[1];
	#endif
	inp += 16;
	out += 16;
	len -= 16;
	}

	if (len) {
	for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
	(*block)(ctx->cmac.c,ctx->cmac.c,key);
	(*block)(ctx->nonce.c,scratch.c,key);
	for (i=0; i<len; ++i) out[i] = scratch.c[i]^inp[i];
	}

	for (i=15-L;i<16;++i)
	ctx->nonce.c[i]=0;

	(*block)(ctx->nonce.c,scratch.c,key);
	ctx->cmac.u[0] ^= scratch.u[0];
	ctx->cmac.u[1] ^= scratch.u[1];

	ctx->nonce.c[0] = flags0;

	return 0;
	}

	int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
	const unsigned char inp, unsigned char out,
	size_t len)
	{
	size_t n;
	unsigned int i,L;
	unsigned char flags0 = ctx->nonce.c[0];
	block128_f block = ctx->block;
	void * key = ctx->key;
	union { u64 u[2]; u8 c[16]; } scratch;

	if (!(flags0&0x40))
	(*block)(ctx->nonce.c,ctx->cmac.c,key);

	ctx->nonce.c[0] = L = flags0&7;
	for (n=0,i=15-L;i<15;++i) {
	n \|= ctx->nonce.c[i];
	ctx->nonce.c[i]=0;
	n <<= 8;
	}
	n \|= ctx->nonce.c[15]; /* reconstructed length */
	ctx->nonce.c[15]=1;

	if (n!=len) return -1;

	while (len>=16) {
	#if defined(STRICT_ALIGNMENT)
	union { u64 u[2]; u8 c[16]; } temp;
	#endif
	(*block)(ctx->nonce.c,scratch.c,key);
	ctr64_inc(ctx->nonce.c);
	#if defined(STRICT_ALIGNMENT)
	memcpy (temp.c,inp,16);
	ctx->cmac.u[0] ^= (scratch.u[0] ^= temp.u[0]);
	ctx->cmac.u[1] ^= (scratch.u[1] ^= temp.u[1]);
	memcpy (out,scratch.c,16);
	#else
	ctx->cmac.u[0] ^= (((u64)out)[0] = scratch.u[0]^((u64)inp)[0]);
	ctx->cmac.u[1] ^= (((u64)out)[1] = scratch.u[1]^((u64)inp)[1]);
	#endif
	(*block)(ctx->cmac.c,ctx->cmac.c,key);

	inp += 16;
	out += 16;
	len -= 16;
	}

	if (len) {
	(*block)(ctx->nonce.c,scratch.c,key);
	for (i=0; i<len; ++i)
	ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
	(*block)(ctx->cmac.c,ctx->cmac.c,key);
	}

	for (i=15-L;i<16;++i)
	ctx->nonce.c[i]=0;

	(*block)(ctx->nonce.c,scratch.c,key);
	ctx->cmac.u[0] ^= scratch.u[0];
	ctx->cmac.u[1] ^= scratch.u[1];

	ctx->nonce.c[0] = flags0;

	return 0;
	}

	static void ctr64_add (unsigned char *counter,size_t inc)
	{ size_t n=8, val=0;

	counter += 8;
	do {
	--n;
	val += counter[n] + (inc&0xff);
	counter[n] = (unsigned char)val;
	val >>= 8; /* carry bit */
	inc >>= 8;
	} while(n && (inc \|\| val));
	}

	int CRYPTO_ccm128_encrypt_ccm64(CCM128_CONTEXT *ctx,
	const unsigned char inp, unsigned char out,
	size_t len,ccm128_f stream)
	{
	size_t n;
	unsigned int i,L;
	unsigned char flags0 = ctx->nonce.c[0];
	block128_f block = ctx->block;
	void * key = ctx->key;
	union { u64 u[2]; u8 c[16]; } scratch;

	if (!(flags0&0x40))
	(*block)(ctx->nonce.c,ctx->cmac.c,key),
	ctx->blocks++;

	ctx->nonce.c[0] = L = flags0&7;
	for (n=0,i=15-L;i<15;++i) {
	n \|= ctx->nonce.c[i];
	ctx->nonce.c[i]=0;
	n <<= 8;
	}
	n \|= ctx->nonce.c[15]; /* reconstructed length */
	ctx->nonce.c[15]=1;

	if (n!=len) return -1; /* length mismatch */

	ctx->blocks += ((len+15)>>3)\|1;
	if (ctx->blocks > (U64(1)<<61)) return -2; /* too much data */

	if ((n=len/16)) {
	(*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
	n *= 16;
	inp += n;
	out += n;
	len -= n;
	if (len) ctr64_add(ctx->nonce.c,n/16);
	}

	if (len) {
	for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
	(*block)(ctx->cmac.c,ctx->cmac.c,key);
	(*block)(ctx->nonce.c,scratch.c,key);
	for (i=0; i<len; ++i) out[i] = scratch.c[i]^inp[i];
	}

	for (i=15-L;i<16;++i)
	ctx->nonce.c[i]=0;

	(*block)(ctx->nonce.c,scratch.c,key);
	ctx->cmac.u[0] ^= scratch.u[0];
	ctx->cmac.u[1] ^= scratch.u[1];

	ctx->nonce.c[0] = flags0;

	return 0;
	}

	int CRYPTO_ccm128_decrypt_ccm64(CCM128_CONTEXT *ctx,
	const unsigned char inp, unsigned char out,
	size_t len,ccm128_f stream)
	{
	size_t n;
	unsigned int i,L;
	unsigned char flags0 = ctx->nonce.c[0];
	block128_f block = ctx->block;
	void * key = ctx->key;
	union { u64 u[2]; u8 c[16]; } scratch;

	if (!(flags0&0x40))
	(*block)(ctx->nonce.c,ctx->cmac.c,key);

	ctx->nonce.c[0] = L = flags0&7;
	for (n=0,i=15-L;i<15;++i) {
	n \|= ctx->nonce.c[i];
	ctx->nonce.c[i]=0;
	n <<= 8;
	}
	n \|= ctx->nonce.c[15]; /* reconstructed length */
	ctx->nonce.c[15]=1;

	if (n!=len) return -1;

	if ((n=len/16)) {
	(*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
	n *= 16;
	inp += n;
	out += n;
	len -= n;
	if (len) ctr64_add(ctx->nonce.c,n/16);
	}

	if (len) {
	(*block)(ctx->nonce.c,scratch.c,key);
	for (i=0; i<len; ++i)
	ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
	(*block)(ctx->cmac.c,ctx->cmac.c,key);
	}

	for (i=15-L;i<16;++i)
	ctx->nonce.c[i]=0;

	(*block)(ctx->nonce.c,scratch.c,key);
	ctx->cmac.u[0] ^= scratch.u[0];
	ctx->cmac.u[1] ^= scratch.u[1];

	ctx->nonce.c[0] = flags0;

	return 0;
	}

	size_t CRYPTO_ccm128_tag(CCM128_CONTEXT ctx,unsigned char tag,size_t len)
	{ unsigned int M = (ctx->nonce.c[0]>>3)&7; /* the M parameter */

	M *= 2; M += 2;
	if (len<M) return 0;
	memcpy(tag,ctx->cmac.c,M);
	return M;
	}