ccm128.c: initial draft.
This commit is contained in:
Andy Polyakov
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f4bfe97fc9
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303
crypto/modes/ccm128.c
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303
crypto/modes/ccm128.c
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/* ====================================================================
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* Copyright (c) 2011 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. All advertising materials mentioning features or use of this
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* software must display the following acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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*
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* endorse or promote products derived from this software without
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* prior written permission. For written permission, please contact
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* openssl-core@openssl.org.
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*
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* 5. Products derived from this software may not be called "OpenSSL"
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* nor may "OpenSSL" appear in their names without prior written
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* permission of the OpenSSL Project.
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*
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* 6. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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*
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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* ====================================================================
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*/
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#include <openssl/crypto.h>
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#include "modes_lcl.h"
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#include <string.h>
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#ifndef MODES_DEBUG
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# ifndef NDEBUG
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# define NDEBUG
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# endif
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#endif
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#include <assert.h>
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typedef struct {
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union { u8 c[16]; size_t s[16/sizeof(size_t)]; } nonce, cmac,
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scratch, inp;
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u64 blocks;
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block128_f block;
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void *key;
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} CCM128_CONTEXT;
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/* First you setup M and L parameters and pass the key schedule */
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void CRYPTO_ccm128_init(CCM128_CONTEXT *ctx,
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unsigned int M,unsigned int L,void *key)
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{
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memset(ctx->nonce.c,0,sizeof(ctx->nonce.c));
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ctx->nonce.c[0] = ((u8)(L-1)&7) | (u8)(((M-2)/2)&7)<<3;
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ctx->blocks = 0;
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ctx->key = key;
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}
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/* !!! Following interfaces are to be called *once* per packet !!! */
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/* Then you setup per-message nonce and pass the length of the message */
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int CRYPTO_ccm128_setiv(CCM128_CONTEXT *ctx,
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const unsigned char *nonce,size_t nlen,size_t mlen)
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{
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unsigned int L = ctx->nonce.c[0]&7; /* the L parameter */
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if (nlen<(14-L)) return -1; /* nonce is too short */
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if (sizeof(mlen)==8 && L>=3) {
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ctx->nonce.c[8] = (u8)(mlen>>(56%(sizeof(mlen)*8)));
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ctx->nonce.c[9] = (u8)(mlen>>(48%(sizeof(mlen)*8)));
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ctx->nonce.c[10] = (u8)(mlen>>(40%(sizeof(mlen)*8)));
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ctx->nonce.c[11] = (u8)(mlen>>(32%(sizeof(mlen)*8)));
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}
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else
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*((size_t *)&ctx->nonce.s[8]) = 0;
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ctx->nonce.c[12] = (u8)(mlen>>24);
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ctx->nonce.c[13] = (u8)(mlen>>16);
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ctx->nonce.c[14] = (u8)(mlen>>8);
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ctx->nonce.c[15] = (u8)mlen;
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ctx->nonce.c[0] &= ~0x40; /* clear Adata flag */
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memcpy(&ctx->nonce.c[1],nonce,14-L);
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return 0;
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}
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/* Then you pass additional authentication data, this is optional */
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void CRYPTO_ccm128_aad(CCM128_CONTEXT *ctx,
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const unsigned char *aad,size_t alen)
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{ unsigned int i;
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if (alen==0) return;
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ctx->nonce.c[0] |= 0x40; /* set Adata flag */
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(*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
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ctx->blocks++;
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if (alen<(0x10000-0x100)) {
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ctx->cmac.c[0] ^= (u8)(alen>>8);
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ctx->cmac.c[1] ^= (u8)alen;
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i=2;
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}
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else if (sizeof(alen)==8 && alen>=(size_t)1<<32) {
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ctx->cmac.c[0] ^= 0xFF;
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ctx->cmac.c[1] ^= 0xFF;
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ctx->cmac.c[2] ^= (u8)(alen>>(56%(sizeof(alen)*8)));
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ctx->cmac.c[3] ^= (u8)(alen>>(48%(sizeof(alen)*8)));
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ctx->cmac.c[4] ^= (u8)(alen>>(40%(sizeof(alen)*8)));
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ctx->cmac.c[5] ^= (u8)(alen>>(32%(sizeof(alen)*8)));
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ctx->cmac.c[6] ^= (u8)(alen>>24);
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ctx->cmac.c[7] ^= (u8)(alen>>16);
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ctx->cmac.c[8] ^= (u8)(alen>>8);
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ctx->cmac.c[9] ^= (u8)alen;
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i=10;
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}
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else {
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ctx->cmac.c[0] ^= 0xFF;
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ctx->cmac.c[1] ^= 0xFE;
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ctx->cmac.c[2] ^= (u8)(alen>>24);
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ctx->cmac.c[3] ^= (u8)(alen>>16);
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ctx->cmac.c[4] ^= (u8)(alen>>8);
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ctx->cmac.c[5] ^= (u8)alen;
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i=6;
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}
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do {
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for(;i<16 && alen;++i,++aad,--alen)
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ctx->cmac.c[i] ^= *aad;
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(*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key),
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ctx->blocks++;
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i=0;
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} while (alen);
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}
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/* Finally you encrypt or decrypt the message */
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static void ctr128_inc(unsigned char *counter) {
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unsigned int n=16;
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u8 c;
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do {
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--n;
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c = counter[n];
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++c;
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counter[n] = c;
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if (c) return;
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} while (n);
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}
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int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
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const unsigned char *inp, unsigned char *out,
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size_t len)
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{
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size_t n;
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unsigned int i;
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unsigned char flags = ctx->nonce.c[0];
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if (!(flags&0x40))
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(*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key),
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ctx->blocks++;
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flags &= 7; /* extract the L parameter */
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for (n=0,i=15-flags;i<15;++i) {
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n |= ctx->nonce.c[i]; ctx->nonce.c[i]=0;
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n <<= 8;
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}
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n |= ctx->nonce.c[15]; /* reconstructed length */
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ctx->nonce.c[15]=1;
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if (n!=len) return -1; /* length mismatch */
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ctx->blocks += ((len+15)>>3)|1;
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if (ctx->blocks > (U64(1)<<61)) return -2; /* too much data */
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while (len>=16) {
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#if defined(STRICT_ALIGNMENT)
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memcpy (ctx->inp.c,inp,16);
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= ctx->inp.s[i];
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#else
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= ((size_t*)inp)[i];
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#endif
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(*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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ctr128_inc(ctx->nonce.c);
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#if defined(STRICT_ALIGNMENT)
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->inp.s[i] ^= ctx->scratch.s[i];
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memcpy(out,ctx->inp.c,16);
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#else
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for (i=0; i<16/sizeof(size_t); ++i)
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((size_t*)out)[i] = ctx->scratch.s[i]^((size_t*)inp)[i];
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#endif
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inp += 16;
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out += 16;
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len -= 16;
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}
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if (len) {
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for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
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(*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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for (i=0; i<len; ++i) out[i] = ctx->scratch.c[i]^inp[i];
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}
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for (i=15-flags;i<16;++i)
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ctx->nonce.c[i]=0;
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= ctx->scratch.s[i];
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return 0;
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}
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int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
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const unsigned char *inp, unsigned char *out,
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size_t len)
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{
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size_t n;
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unsigned int i;
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unsigned char flags = ctx->nonce.c[0];
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if (!(flags&0x40))
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(*ctx->block)(ctx->nonce.c,ctx->cmac.c,ctx->key);
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flags &= 7; /* extract the L parameter */
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for (n=0,i=15-flags;i<15;++i) {
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n |= ctx->nonce.c[i]; ctx->nonce.c[i]=0;
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n <<= 8;
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}
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n |= ctx->nonce.c[15]; /* reconstructed length */
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ctx->nonce.c[15]=1;
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if (n!=len) return -1;
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while (len>=16) {
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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ctr128_inc(ctx->nonce.c);
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#if defined(STRICT_ALIGNMENT)
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memcpy (ctx->inp.c,inp,16);
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= (ctx->scratch.s[i] ^= ctx->inp.s[i]);
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memcpy (out,ctx->scratch,16);
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#else
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= ((size_t*)out)[i] = ctx->scratch.s[i]^((size_t*)inp)[i];
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#endif
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(*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
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inp += 16;
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out += 16;
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len -= 16;
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}
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if (len) {
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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for (i=0; i<len; ++len)
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ctx->cmac.c[i] ^= (out[i] = ctx->scratch.c[i]^inp[i]);
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(*ctx->block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
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}
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for (i=15-flags;i<16;++i)
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ctx->nonce.c[i]=0;
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(*ctx->block)(ctx->nonce.c,ctx->scratch.c,ctx->key);
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for (i=0; i<16/sizeof(size_t); ++i)
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ctx->cmac.s[i] ^= ctx->scratch.s[i];
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return 0;
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}
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size_t CRYPTO_ccm128_tag(CCM128_CONTEXT *ctx,unsigned char *tag,size_t len)
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{ unsigned int M = (ctx->nonce.c[0]>>3)&7; /* the M parameter */
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M *= 2; M += 2;
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if (len<M) return 0;
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memcpy(tag,ctx->cmac.c,M);
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return M;
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}
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