md5.c

Calc Software Package for Number Calc

	HH( b, c, d, a, in[ 6], S34,   76029189UL); /* 44 */
	HH( a, b, c, d, in[ 9], S31, 3654602809UL); /* 45 */
	HH( d, a, b, c, in[12], S32, 3873151461UL); /* 46 */
	HH( c, d, a, b, in[15], S33,  530742520UL); /* 47 */
	HH( b, c, d, a, in[ 2], S34, 3299628645UL); /* 48 */

	/* Round 4 */
	II( a, b, c, d, in[ 0], S41, 4096336452UL); /* 49 */
	II( d, a, b, c, in[ 7], S42, 1126891415UL); /* 50 */
	II( c, d, a, b, in[14], S43, 2878612391UL); /* 51 */
	II( b, c, d, a, in[ 5], S44, 4237533241UL); /* 52 */
	II( a, b, c, d, in[12], S41, 1700485571UL); /* 53 */
	II( d, a, b, c, in[ 3], S42, 2399980690UL); /* 54 */
	II( c, d, a, b, in[10], S43, 4293915773UL); /* 55 */
	II( b, c, d, a, in[ 1], S44, 2240044497UL); /* 56 */
	II( a, b, c, d, in[ 8], S41, 1873313359UL); /* 57 */
	II( d, a, b, c, in[15], S42, 4264355552UL); /* 58 */
	II( c, d, a, b, in[ 6], S43, 2734768916UL); /* 59 */
	II( b, c, d, a, in[13], S44, 1309151649UL); /* 60 */
	II( a, b, c, d, in[ 4], S41, 4149444226UL); /* 61 */
	II( d, a, b, c, in[11], S42, 3174756917UL); /* 62 */
	II( c, d, a, b, in[ 2], S43,  718787259UL); /* 63 */
	II( b, c, d, a, in[ 9], S44, 3951481745UL); /* 64 */

	digest[0] += a;
	digest[1] += b;
	digest[2] += c;
	digest[3] += d;
}


/*
 * MD5_chkpt - checkpoint a MD5 state
 *
 * given:
 *	state	the state to checkpoint
 *
 * This function will ensure that the the hash chunk buffer is empty.
 * Any partially hashed data will be padded out with 0's and hashed.
 */
static void
MD5_chkpt(HASH *state)
{
	MD5_CTX *dig = &state->h_union.h_md5;	/* digest state */
#if CALC_BYTE_ORDER == BIG_ENDIAN
	int cnt;
#endif

	/*
	 * checkpoint if partial buffer exists
	 */
	if (dig->datalen > 0) {

		/* pad to the end of the chunk */
		memset((USB8 *)dig->data + dig->datalen, 0,
		       MD5_CHUNKSIZE-dig->datalen);
#if CALC_BYTE_ORDER == BIG_ENDIAN
		if (state->bytes) {
			/* byte swap data into little endian order */
			for (cnt=0; cnt < (int)MD5_CHUNKWORDS; ++cnt) {
				SWAP_B8_IN_B32(dig->data + cnt,
					dig->data + cnt);
			}
		}
#endif

		/* transform padded chunk */
		MD5Transform((USB32*)dig->digest, dig->data);
		MD5COUNT(dig, MD5_CHUNKSIZE-dig->datalen);

		/* empty buffer */
		dig->datalen = 0;
	}
}


/*
 * MD5_note - note a special value
 *
 * given:
 *	state		the state to hash
 *	special		a special value (MD5_HASH_XYZ) to note
 *
 * This function will note that a special value is about to be hashed.
 * Types include negative values, complex values, division, zero numeric
 * and array of HALFs.
 */
static void
MD5_note(int special, HASH *state)
{
	MD5_CTX *dig = &state->h_union.h_md5;	/* digest state */
	unsigned int i;

	/*
	 * change state to reflect a special value
	 */
	dig->digest[0] ^= special;
	for (i=1; i < MD5_DIGESTWORDS; ++i) {
		dig->digest[i] ^= (special + dig->digest[i-1] + i);
	}
	return;
}


/*
 * MD5_type - note a VALUE type
 *
 * given:
 *	state		the state to hash
 *	type		the VALUE type to note
 *
 * This function will note that a type of value is about to be hashed.
 * The type of a VALUE will be noted.  For purposes of hash comparison,
 * we will do nothing with V_NUM and V_COM so that the other functions
 * can hash to the same value regardless of if MD5_value() is called
 * or not.  We also do nothing with V_STR so that a hash of a string
 * will produce the same value as the standard hash function.
 */
static void
MD5_type(int type, HASH *state)
{
	MD5_CTX *dig = &state->h_union.h_md5;	/* digest state */
	unsigned int i;

	/*
	 * ignore NUMBER and COMPLEX
	 */
	if (type == V_NUM || type == V_COM || type == V_STR) {
		return;
	}

	/*
	 * change state to reflect a VALUE type
	 */
	dig->digest[0] += type;
	for (i=1; i < MD5_DIGESTWORDS; ++i) {
		dig->digest[i] += ((type+i) ^ dig->digest[i-1]);
	}
	return;
}


/*
 * MD5_init_state - initialize a hash state structure for this hash
 *
 * given:
 *	state	- pointer to the hfunction element to initialize
 */
void
MD5_init_state(HASH *state)
{
	/*
	 * initalize state
	 */
	state->hashtype = MD5_HASH_TYPE;
	state->bytes = TRUE;
	state->update = MD5Update;
	state->chkpt = MD5_chkpt;
	state->note = MD5_note;
	state->type = MD5_type;
	state->final = MD5_final_state;
	state->cmp = MD5_cmp;
	state->print = MD5_print;
	state->base = MD5_BASE;
	state->chunksize = MD5_CHUNKSIZE;
	state->unionsize = sizeof(MD5_CTX);

	/*
	 * perform the internal init function
	 */
	memset((void *)&(state->h_union.h_md5), 0, sizeof(MD5_CTX));
	MD5Init(state);
	return;
}


/*
 * MD5_final_state - complete hash state and return a ZVALUE
 *
 * given:
 *	state	the state to complete and convert
 *
 * returns:
 *	a ZVALUE representing the state
 */
static ZVALUE
MD5_final_state(HASH *state)
{
	MD5_CTX *dig = &state->h_union.h_md5;		/* digest state */
	ZVALUE ret;		/* return ZVALUE of completed hash state */
	unsigned int i;

	/*
	 * malloc and initialize if state is NULL
	 */
	if (state == NULL) {
		state = (HASH *)malloc(sizeof(HASH));
		if (state == NULL) {
			math_error("cannot malloc HASH");
			/*NOTREACHED*/
		}
		MD5_init_state(state);
	}

	/*
	 * complete the hash state
	 */
	MD5Final(state);

	/*
	 * allocate storage for ZVALUE
	 */
	ret.len = MD5_DIGESTSIZE/sizeof(HALF);
	ret.sign = 0;
	ret.v = alloc(ret.len);

	/*
	 * load ZVALUE
	 */
#if CALC_BYTE_ORDER == LITTLE_ENDIAN && BASEB == 16
	for (i = 0; i < MD5_DIGESTSIZE; i += 2) {
		SWAP_B8_IN_B16(((USB8 *)dig->digest) + i,
			((USB8 *) dig->digest) + i);
	}
#else
	for (i = 0; i < MD5_DIGESTWORDS; ++i) {
		SWAP_B8_IN_B32(dig->digest + i, dig->digest + i);
	}
#endif

	for (i=0; i < (unsigned int)ret.len; ++i) {
		ret.v[ret.len-i-1] = ((HALF*)dig->digest)[i];
	}

	ztrim(&ret);

	/*
	 * return ZVALUE
	 */
	return ret;
}


/*
 * MD5_cmp - compare two hash states
 *
 * given:
 *	a	first hash state
 *	b	second hash state
 *
 * returns:
 *	TRUE => hash states are different
 *	FALSE => hash states are the same
 */
static int
MD5_cmp(HASH *a, HASH *b)
{
	/*
	 * firewall and quick check
	 */
	if (a == b) {
		/* pointers to the same object */
		return FALSE;
	}
	if (a == NULL || b == NULL) {
		/* one is NULL, so they differ */
		return TRUE;
	}

	/*
	 * compare concat states
	 */
	if (a->bytes != b->bytes)
		return TRUE;

	/*
	 * compare bit counts
	 */
	if (a->h_union.h_md5.countLo != b->h_union.h_md5.countLo ||
	    a->h_union.h_md5.countHi != b->h_union.h_md5.countHi) {
		/* counts differ */
		return TRUE;
	}

	/*
	 * compare pending buffers
	 */
	if (a->h_union.h_md5.datalen != b->h_union.h_md5.datalen) {
		/* buffer lengths differ */
		return TRUE;
	}
	if (memcmp((char*)a->h_union.h_md5.data,
		   (char*)b->h_union.h_md5.data,
		   a->h_union.h_md5.datalen) != 0) {
		/* buffer contents differ */
		return TRUE;
	}

	/*
	 * compare digest
	 */
	return (memcmp((char*)(a->h_union.h_md5.digest),
		       (char*)(b->h_union.h_md5.digest),
		       MD5_DIGESTSIZE) != 0);
}


/*
 * MD5_print - print a hash state
 *
 * given:
 *	state	the hash state to print
 */
static void
MD5_print(HASH *state)
{
	/*
	 * form the hash value
	 */
	if (conf->calc_debug & CALCDBG_HASH_STATE) {
		char buf[DEBUG_SIZE+1]; /* hash value buffer */

		/*
		 * print numeric debug value
		 *
		 * NOTE: This value represents only the hash value as of
		 *	 the last full update or finalization.	Thus it
		 *	 may NOT be the actual hash value.
		 */
		sprintf(buf,
			"md5: 0x%08x%08x%08x%08x data: %d octets",
			(int)state->h_union.h_md5.digest[0],
			(int)state->h_union.h_md5.digest[1],
			(int)state->h_union.h_md5.digest[2],
			(int)state->h_union.h_md5.digest[3],
			(int)state->h_union.h_md5.datalen);
		math_str(buf);
	} else {
		math_str("md5 hash state");
	}
	return;
}