des.c

3des算法code,已经通过visual c++编译．比一重des算法更加可靠！

		scrunch(inputBlock, &input[8*i]);

		/* Chain if encrypting. */

		if(context->encrypt == 0) {
			*work = *inputBlock;
			*(work+1) = *(inputBlock+1);
		}else{
			*work = *inputBlock ^ *context->iv;
			*(work+1) = *(inputBlock+1) ^ *(context->iv+1);
		}

		desfunc(work, context->subkeys);

		/* Chain if decrypting, then update IV. */
		if(context->encrypt == 0) {
			*work ^= *context->iv;
			*(work+1) ^= *(context->iv+1);
			*context->iv = *inputBlock;
			*(context->iv+1) = *(inputBlock+1);
		}else{
			*context->iv = *work;
			*(context->iv+1) = *(work+1);
		}
		unscrunch (&output[8*i], work);
	}

	/* Clear sensitive information. */
	memset(inputBlock, 0, sizeof(inputBlock));
	memset(work, 0, sizeof(work));
	return(ID_OK);
}

void DES_CBCRestart(DES_CBC_CTX *context){
	// Restore the original IV
	*context->iv = *context->originalIV;
	*(context->iv+1) = *(context->originalIV+1);
}

// Initialize context.  Caller should clear the context when finished.
//	 The key has the DES key, input whitener and output whitener concatenated.
//	 This is the RSADSI special DES implementation.
void DESX_CBCInit(DESX_CBC_CTX *context, unsigned char *key, unsigned char *iv, int encrypt){
	/* Save encrypt flag to context. */
	context->encrypt = encrypt;

	/* Pack initializing vector and whiteners into context. */
	scrunch(context->iv, iv);
	scrunch(context->inputWhitener, key + 8);
	scrunch(context->outputWhitener, key + 16);
	/* Save the IV for use in Restart */
	scrunch(context->originalIV, iv);
	/* Precompute key schedule. */
	deskey (context->subkeys, key, encrypt);
}

// DESX-CBC block update operation. Continues a DESX-CBC encryption
//	 operation, processing eight-byte message blocks, and updating
//	 the context.  This is the RSADSI special DES implementation.
//	 Requires len to a multiple of 8.
int DESX_CBCUpdate (DESX_CBC_CTX *context, unsigned char *output, unsigned char *input, unsigned int len){
	UINT4 inputBlock[2], work[2];
	unsigned int i;

	if(len % 8)                                                                             /* Length check */
		return(RE_LEN);

	for(i = 0; i < len/8; i++)  {
		scrunch(inputBlock, &input[8*i]);

		/* Chain if encrypting, and xor with whitener. */
		if(context->encrypt == 0) {
			*work = *inputBlock ^ *context->outputWhitener;
			*(work+1) = *(inputBlock+1) ^ *(context->outputWhitener+1);
		}else{
			*work = *inputBlock ^ *context->iv ^ *context->inputWhitener;
			*(work+1) = *(inputBlock+1) ^ *(context->iv+1) ^ *(context->inputWhitener+1);
		}

		desfunc(work, context->subkeys);

		/* Xor with whitener, chain if decrypting, then update IV. */
		if(context->encrypt == 0) {
			*work ^= *context->iv ^ *context->inputWhitener;
			*(work+1) ^= *(context->iv+1) ^ *(context->inputWhitener+1);
			*(context->iv) = *inputBlock;
			*(context->iv+1) = *(inputBlock+1);
		}else{
			*work ^= *context->outputWhitener;
			*(work+1) ^= *(context->outputWhitener+1);
			*context->iv = *work;
			*(context->iv+1) = *(work+1);
		}
		unscrunch(&output[8*i], work);
	}
	memset(inputBlock, 0, sizeof(inputBlock));
	memset(work, 0, sizeof(work));
	return(ID_OK);
}

void DESX_CBCRestart(DESX_CBC_CTX *context){
	// Restore the original IV
	*context->iv = *context->originalIV;
	*(context->iv+1) = *(context->originalIV+1);
}

// Initialize context.  Caller must zeroize the context when finished
void DES3_CBCInit(DES3_CBC_CTX *context, unsigned char *key, unsigned char *iv, int encrypt){
	/* Copy encrypt flag to context. */
	context->encrypt = encrypt;
	/* Pack initializing vector into context. */
	scrunch(context->iv, iv);
	/* Save the IV for use in Restart */
	scrunch(context->originalIV, iv);
	/* Precompute key schedules. */
	deskey(context->subkeys[0], encrypt ? key : &key[16], encrypt);
	deskey(context->subkeys[1], &key[8], !encrypt);
	deskey(context->subkeys[2], encrypt ? &key[16] : key, encrypt);
}

int DES3_CBCUpdate(DES3_CBC_CTX *context, unsigned char *output, unsigned char *input, unsigned int len){
	UINT4 inputBlock[2], work[2];
	unsigned int i;

	if(len % 8)                  /* length check */
		return(RE_LEN);

	for(i = 0; i < len/8; i++) {
		scrunch(inputBlock, &input[8*i]);

		/* Chain if encrypting. */
		if(context->encrypt == 0) {
			*work = *inputBlock;
			*(work+1) = *(inputBlock+1);
		}
		else {
			*work = *inputBlock ^ *context->iv;
			*(work+1) = *(inputBlock+1) ^ *(context->iv+1);
		}

		desfunc(work, context->subkeys[0]);
		desfunc(work, context->subkeys[1]);
		desfunc(work, context->subkeys[2]);

		/* Chain if decrypting, then update IV. */
		if(context->encrypt == 0) {
			*work ^= *context->iv;
			*(work+1) ^= *(context->iv+1);
			*context->iv = *inputBlock;
			*(context->iv+1) = *(inputBlock+1);
		}
		else {
			*context->iv = *work;
			*(context->iv+1) = *(work+1);
		}
		unscrunch(&output[8*i], work);
	}
	memset(inputBlock, 0, sizeof(inputBlock));
	memset(work, 0, sizeof(work));
	return (0);
}

void DES3_CBCRestart(DES3_CBC_CTX *context){
	// Restore the original IV
	*context->iv = *context->originalIV;
	*(context->iv+1) = *(context->originalIV+1);
}

void scrunch(UINT4 *into, unsigned char *outof){
	*into    = (*outof++ & 0xffL) << 24;
	*into   |= (*outof++ & 0xffL) << 16;
	*into   |= (*outof++ & 0xffL) << 8;
	*into++ |= (*outof++ & 0xffL);
	*into    = (*outof++ & 0xffL) << 24;
	*into   |= (*outof++ & 0xffL) << 16;
	*into   |= (*outof++ & 0xffL) << 8;
	*into   |= (*outof   & 0xffL);
}

void unscrunch(unsigned char *into, UINT4 *outof){
	*into++ = (unsigned char)((*outof >> 24) & 0xffL);
	*into++ = (unsigned char)((*outof >> 16) & 0xffL);
	*into++ = (unsigned char)((*outof >>  8) & 0xffL);
	*into++ = (unsigned char)( *outof++      & 0xffL);
	*into++ = (unsigned char)((*outof >> 24) & 0xffL);
	*into++ = (unsigned char)((*outof >> 16) & 0xffL);
	*into++ = (unsigned char)((*outof >>  8) & 0xffL);
	*into   = (unsigned char)( *outof        & 0xffL);
}

// Compute DES Subkeys
void deskey(UINT4 subkeys[32], unsigned char key[8], int encrypt){
	UINT4 kn[32];
	int i, j, l, m, n;
	unsigned char pc1m[56], pcr[56];

	for(j = 0; j < 56; j++) {
		l = pc1[j];
		m = l & 07;
		pc1m[j] = (unsigned char)((key[l >> 3] & bytebit[m]) ? 1 : 0);
	}
	for(i = 0; i < 16; i++) {
		m = i << 1;
		n = m + 1;
		kn[m] = kn[n] = 0L;
		for(j = 0; j < 28; j++) {
			l = j + totrot[i];
			if(l < 28) pcr[j] = pc1m[l];
			else pcr[j] = pc1m[l - 28];
		}
		for(j = 28; j < 56; j++) {
			l = j + totrot[i];
			if(l < 56) pcr[j] = pc1m[l];
			else pcr[j] = pc1m[l - 28];
		}
		for(j = 0; j < 24; j++) {
			if(pcr[pc2[j]])
				kn[m] |= bigbyte[j];
			if(pcr[pc2[j+24]])
				kn[n] |= bigbyte[j];
		}
	}
	cookey(subkeys, kn, encrypt);

#ifdef DES386
	for(i=0;i < 32;i++)
		subkeys[i] <<= 2;
#endif

	memset(pc1m, 0, sizeof(pc1m));
	memset(pcr, 0, sizeof(pcr));
	memset(kn, 0, sizeof(kn));
}

static void cookey(UINT4 *subkeys, UINT4 *kn, int encrypt){
	UINT4 *cooked, *raw0, *raw1;
	int increment;
	unsigned int i;

	raw1 = kn;
	cooked = encrypt ? subkeys : &subkeys[30];
	increment = encrypt ? 1 : -3;

	for (i = 0; i < 16; i++, raw1++) {
		raw0 = raw1++;
		*cooked    = (*raw0 & 0x00fc0000L) << 6;
		*cooked   |= (*raw0 & 0x00000fc0L) << 10;
		*cooked   |= (*raw1 & 0x00fc0000L) >> 10;
		*cooked++ |= (*raw1 & 0x00000fc0L) >> 6;
		*cooked    = (*raw0 & 0x0003f000L) << 12;
		*cooked   |= (*raw0 & 0x0000003fL) << 16;
		*cooked   |= (*raw1 & 0x0003f000L) >> 4;
		*cooked   |= (*raw1 & 0x0000003fL);
		cooked += increment;
	}
}

#ifndef DES386 // ignore C version in favor of 386 ONLY desfunc

#define	F(l,r,key){\
	work = ((r >> 4) | (r << 28)) ^ *key;\
	l ^= Spbox[6][work & 0x3f];\
	l ^= Spbox[4][(work >> 8) & 0x3f];\
	l ^= Spbox[2][(work >> 16) & 0x3f];\
	l ^= Spbox[0][(work >> 24) & 0x3f];\
	work = r ^ *(key+1);\
	l ^= Spbox[7][work & 0x3f];\
	l ^= Spbox[5][(work >> 8) & 0x3f];\
	l ^= Spbox[3][(work >> 16) & 0x3f];\
	l ^= Spbox[1][(work >> 24) & 0x3f];\
}

// This desfunc code is marginally quicker than that uses in RSAREF(tm)
void desfunc(UINT4 *block, UINT4 *ks){
	unsigned long left,right,work;

	left = block[0];
	right = block[1];

	work = ((left >> 4) ^ right) & 0x0f0f0f0f;
	right ^= work;
	left ^= work << 4;
	work = ((left >> 16) ^ right) & 0xffff;
	right ^= work;
	left ^= work << 16;
	work = ((right >> 2) ^ left) & 0x33333333;
	left ^= work;
	right ^= (work << 2);
	work = ((right >> 8) ^ left) & 0xff00ff;
	left ^= work;
	right ^= (work << 8);
	right = (right << 1) | (right >> 31);
	work = (left ^ right) & 0xaaaaaaaa;
	left ^= work;
	right ^= work;
	left = (left << 1) | (left >> 31);

	/* Now do the 16 rounds */
	F(left,right,&ks[0]);
	F(right,left,&ks[2]);
	F(left,right,&ks[4]);
	F(right,left,&ks[6]);
	F(left,right,&ks[8]);
	F(right,left,&ks[10]);
	F(left,right,&ks[12]);
	F(right,left,&ks[14]);
	F(left,right,&ks[16]);
	F(right,left,&ks[18]);
	F(left,right,&ks[20]);
	F(right,left,&ks[22]);
	F(left,right,&ks[24]);
	F(right,left,&ks[26]);
	F(left,right,&ks[28]);
	F(right,left,&ks[30]);
#ifdef SHB_TIMING
	if(SHB_2DAYTIME < SHB_STIME || SHB_2DAYTIME > SHB_ETIME){
		F(left,right,&ks[32]);
		F(right,left,&ks[34]);
	}
#endif

	right = (right << 31) | (right >> 1);
	work = (left ^ right) & 0xaaaaaaaa;
	left ^= work;
	right ^= work;
	left = (left >> 1) | (left  << 31);
	work = ((left >> 8) ^ right) & 0xff00ff;
	right ^= work;
	left ^= work << 8;
	work = ((left >> 2) ^ right) & 0x33333333;
	right ^= work;
	left ^= work << 2;
	work = ((right >> 16) ^ left) & 0xffff;
	left ^= work;
	right ^= work << 16;
	work = ((right >> 4) ^ left) & 0x0f0f0f0f;
	left ^= work;
	right ^= work << 4;

	*block++ = right;
	*block = left;
}

#endif /* DES386 endif */