openssl/crypto/modes/ccm128.c

316 lines
8.6 KiB
C

/* ====================================================================
* 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>
typedef struct {
union { u64 u[2]; u8 c[16]; } nonce, cmac;
u64 blocks;
block128_f block;
void *key;
} CCM128_CONTEXT;
/* First you setup M and L parameters and pass the key schedule */
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) {
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 */
static void ctr128_inc(unsigned char *counter) {
unsigned int n=16;
u8 c;
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;
union { u64 u[2]; u8 c[16]; } scratch;
if (!(flags0&0x40))
(*block)(ctx->nonce.c,ctx->cmac.c,ctx->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,ctx->key);
(*block)(ctx->nonce.c,scratch.c,ctx->key);
ctr128_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,ctx->key);
(*block)(ctx->nonce.c,scratch.c,ctx->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,ctx->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;
union { u64 u[2]; u8 c[16]; } scratch;
if (!(flags0&0x40))
(*block)(ctx->nonce.c,ctx->cmac.c,ctx->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) {
(*block)(ctx->nonce.c,scratch.c,ctx->key);
ctr128_inc(ctx->nonce.c);
#if defined(STRICT_ALIGNMENT)
memcpy (ctx->inp.c,inp,16);
for (i=0; i<16/sizeof(size_t); ++i)
ctx->cmac.s[i] ^= (scratch.s[i] ^= ctx->inp.s[i]);
memcpy (out,scratch,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,ctx->key);
inp += 16;
out += 16;
len -= 16;
}
if (len) {
(*block)(ctx->nonce.c,scratch.c,ctx->key);
for (i=0; i<len; ++len)
ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
(*block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
}
for (i=15-L;i<16;++i)
ctx->nonce.c[i]=0;
(*block)(ctx->nonce.c,scratch.c,ctx->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;
}