bn32.c

vc环境下的pgp源码

	return 0;
}

int
bnMul_32(BigNum *dest, BigNum const *a, BigNum const *b)
{
	unsigned s, t;
	BNWORD32 *srcbuf;
	PGPBoolean	secure	= dest->isSecure || a->isSecure || b->isSecure;

	s = bniNorm_32((BNWORD32 *)a->ptr, a->size);
	t = bniNorm_32((BNWORD32 *)b->ptr, b->size);

	if (!s || !t) {
		dest->size = 0;
		return 0;
	}

	if (a == b)
		return bnSquare_32(dest, a);

	bnSizeCheck(dest, s+t);

	if (dest == a) {
		BNIALLOC( dest->mgr, secure, srcbuf, BNWORD32, s);
		if (!srcbuf)
			return -1;
		bniCopy_32(srcbuf, (BNWORD32 *)a->ptr, s);
		bniMul_32((BNWORD32 *)dest->ptr, srcbuf, s,
		                                 (BNWORD32 *)b->ptr, t);
		BNIFREE(srcbuf, s);
	} else if (dest == b) {
		BNIALLOC( dest->mgr, secure, srcbuf, BNWORD32, t);
		if (!srcbuf)
			return -1;
		bniCopy_32(srcbuf, (BNWORD32 *)b->ptr, t);
		bniMul_32((BNWORD32 *)dest->ptr, (BNWORD32 *)a->ptr, s,
		                                 srcbuf, t);
		BNIFREE(srcbuf, t);
	} else {
		bniMul_32((BNWORD32 *)dest->ptr, (BNWORD32 *)a->ptr, s,
		                                 (BNWORD32 *)b->ptr, t);
	}
	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, s+t);
	MALLOCDB;
	return 0;
}

int
bnMulQ_32(BigNum *dest, BigNum const *a, unsigned b)
{
	unsigned s;

	s = bniNorm_32((BNWORD32 *)a->ptr, a->size);
	if (!s || !b) {
		dest->size = 0;
		return 0;
	}
	if (b == 1)
		return bnCopy_32(dest, a);
	bnSizeCheck(dest, s+1);
	bniMulN1_32((BNWORD32 *)dest->ptr, (BNWORD32 *)a->ptr, s, b);
	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, s+1);
	MALLOCDB;
	return 0;
}

int
bnDivMod_32(BigNum *q, BigNum *r, BigNum const *n,
            BigNum const *d)
{
	unsigned dsize, nsize;
	BNWORD32 qhigh;

	dsize = bniNorm_32((BNWORD32 *)d->ptr, d->size);
	nsize = bniNorm_32((BNWORD32 *)n->ptr, n->size);

	if (nsize < dsize) {
		q->size = 0;	/* No quotient */
		r->size = nsize;
		return 0;	/* Success */
	}

	bnSizeCheck(q, nsize-dsize);

	if (r != n) {	/* You are allowed to reduce in place */
		bnSizeCheck(r, nsize);
		bniCopy_32((BNWORD32 *)r->ptr, (BNWORD32 *)n->ptr, nsize);
	}
		
	qhigh = bniDiv_32((BNWORD32 *)q->ptr, (BNWORD32 *)r->ptr, nsize,
	                  (BNWORD32 *)d->ptr, dsize);
	nsize -= dsize;
	if (qhigh) {
		bnSizeCheck(q, nsize+1);
		*((BNWORD32 *)q->ptr BIGLITTLE(-nsize-1,+nsize)) = qhigh;
		q->size = nsize+1;
	} else {
		q->size = bniNorm_32((BNWORD32 *)q->ptr, nsize);
	}
	r->size = bniNorm_32((BNWORD32 *)r->ptr, dsize);
	MALLOCDB;
	return 0;
}

int
bnMod_32(BigNum *dest, BigNum const *src, BigNum const *d)
{
	unsigned dsize, nsize;

	nsize = bniNorm_32((BNWORD32 *)src->ptr, src->size);
	dsize = bniNorm_32((BNWORD32 *)d->ptr, d->size);


	if (dest != src) {
		bnSizeCheck(dest, nsize);
		bniCopy_32((BNWORD32 *)dest->ptr, (BNWORD32 *)src->ptr, nsize);
	}

	if (nsize < dsize) {
		dest->size = nsize;	/* No quotient */
		return 0;
	}

	(void)bniDiv_32((BNWORD32 *)dest->ptr BIGLITTLE(-dsize,+dsize),
	                (BNWORD32 *)dest->ptr, nsize,
	                (BNWORD32 *)d->ptr, dsize);
	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, dsize);
	MALLOCDB;
	return 0;
}

unsigned
bnModQ_32(BigNum const *src, unsigned d)
{
	unsigned s;

	s = bniNorm_32((BNWORD32 *)src->ptr, src->size);
	if (!s)
		return 0;
	
	if (d & (d-1))	/* Not a power of 2 */
		d = bniModQ_32((BNWORD32 *)src->ptr, s, d);
	else
		d = (unsigned)((BNWORD32 *)src->ptr)[BIGLITTLE(-1,0)] & (d-1);
	return d;
}

int
bnExpMod_32(BigNum *dest, BigNum const *n,
	BigNum const *exp, BigNum const *mod)
{
	unsigned nsize, esize, msize;
	PGPBoolean		secure;
	
	secure	= dest->isSecure || n->isSecure ||
		exp->isSecure || mod->isSecure;

	nsize = bniNorm_32((BNWORD32 *)n->ptr, n->size);
	esize = bniNorm_32((BNWORD32 *)exp->ptr, exp->size);
	msize = bniNorm_32((BNWORD32 *)mod->ptr, mod->size);

	if (!msize || (((BNWORD32 *)mod->ptr)[BIGLITTLE(-1,0)] & 1) == 0)
		return -1;	/* Illegal modulus! */

	bnSizeCheck(dest, msize);

	/* Special-case base of 2 */
	if (nsize == 1 && ((BNWORD32 *)n->ptr)[BIGLITTLE(-1,0)] == 2) {
		if (bniTwoExpMod_32( dest->mgr, secure,
					(BNWORD32 *)dest->ptr,
				    (BNWORD32 *)exp->ptr, esize,
				    (BNWORD32 *)mod->ptr, msize) < 0)
			return -1;
	} else {
		if (bniExpMod_32( dest->mgr, secure,
						(BNWORD32 *)dest->ptr,
		                 (BNWORD32 *)n->ptr, nsize,
				 (BNWORD32 *)exp->ptr, esize,
				 (BNWORD32 *)mod->ptr, msize) < 0)
		return -1;
	}

	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, msize);
	MALLOCDB;
	return 0;
}

int
bnDoubleExpMod_32(BigNum *dest,
	BigNum const *n1, BigNum const *e1,
	BigNum const *n2, BigNum const *e2,
	BigNum const *mod)
{
	unsigned n1size, e1size, n2size, e2size, msize;
	PGPBoolean		secure;
	
	secure	= dest->isSecure || n1->isSecure || e1->isSecure ||
				n2->isSecure || e2->isSecure || mod->isSecure;

	n1size = bniNorm_32((BNWORD32 *)n1->ptr, n1->size);
	e1size = bniNorm_32((BNWORD32 *)e1->ptr, e1->size);
	n2size = bniNorm_32((BNWORD32 *)n2->ptr, n2->size);
	e2size = bniNorm_32((BNWORD32 *)e2->ptr, e2->size);
	msize = bniNorm_32((BNWORD32 *)mod->ptr, mod->size);

	if (!msize || (((BNWORD32 *)mod->ptr)[BIGLITTLE(-1,0)] & 1) == 0)
		return -1;	/* Illegal modulus! */

	bnSizeCheck(dest, msize);

	if (bniDoubleExpMod_32(
		dest->mgr, secure,
		(BNWORD32 *)dest->ptr,
		(BNWORD32 *)n1->ptr, n1size, (BNWORD32 *)e1->ptr, e1size,
		(BNWORD32 *)n2->ptr, n2size, (BNWORD32 *)e2->ptr, e2size,
		(BNWORD32 *)mod->ptr, msize) < 0)
		return -1;

	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, msize);
	MALLOCDB;
	return 0;
}

int
bnTwoExpMod_32(BigNum *n, BigNum const *exp,
	BigNum const *mod)
{
	unsigned esize, msize;
	PGPBoolean	secure	= n->isSecure || exp->isSecure || mod->isSecure;

	esize = bniNorm_32((BNWORD32 *)exp->ptr, exp->size);
	msize = bniNorm_32((BNWORD32 *)mod->ptr, mod->size);

	if (!msize || (((BNWORD32 *)mod->ptr)[BIGLITTLE(-1,0)] & 1) == 0)
		return -1;	/* Illegal modulus! */

	bnSizeCheck(n, msize);

	if (bniTwoExpMod_32( n->mgr, secure,
				(BNWORD32 *)n->ptr, (BNWORD32 *)exp->ptr, esize,
	            (BNWORD32 *)mod->ptr, msize) < 0)
		return -1;

	n->size = bniNorm_32((BNWORD32 *)n->ptr, msize);
	MALLOCDB;
	return 0;
}

int
bnGcd_32(BigNum *dest, BigNum const *a, BigNum const *b)
{
	BNWORD32 *tmp;
	unsigned asize, bsize;
	int i;
	PGPBoolean	secure	= dest->isSecure || a->isSecure || b->isSecure;

	/* Kind of silly, but we might as well permit it... */
	if (a == b)
		return dest == a ? 0 : bnCopy(dest, a);

	/* Ensure a is not the same as "dest" */
	if (a == dest) {
		a = b;
		b = dest;
	}

	asize = bniNorm_32((BNWORD32 *)a->ptr, a->size);
	bsize = bniNorm_32((BNWORD32 *)b->ptr, b->size);

	bnSizeCheck(dest, bsize+1);

	/* Copy a to tmp */
	BNIALLOC( dest->mgr, secure, tmp, BNWORD32, asize+1);
	if (!tmp)
		return -1;
	bniCopy_32(tmp, (BNWORD32 *)a->ptr, asize);

	/* Copy b to dest, if necessary */
	if (dest != b)
		bniCopy_32((BNWORD32 *)dest->ptr,
			   (BNWORD32 *)b->ptr, bsize);
	if (bsize > asize || (bsize == asize &&
	        bniCmp_32((BNWORD32 *)b->ptr, (BNWORD32 *)a->ptr, asize) > 0))
	{
		i = bniGcd_32((BNWORD32 *)dest->ptr, bsize, tmp, asize,
			&dest->size);
		if (i > 0)	/* Result in tmp, not dest */
			bniCopy_32((BNWORD32 *)dest->ptr, tmp, dest->size);
	} else {
		i = bniGcd_32(tmp, asize, (BNWORD32 *)dest->ptr, bsize,
			&dest->size);
		if (i == 0)	/* Result in tmp, not dest */
			bniCopy_32((BNWORD32 *)dest->ptr, tmp, dest->size);
	}
	BNIFREE(tmp, asize+1);
	MALLOCDB;
	return (i < 0) ? i : 0;
}

int
bnInv_32(BigNum *dest, BigNum const *src,
         BigNum const *mod)
{
	unsigned s, m;
	int i;
	PGPBoolean	secure;
	
	secure	= dest->isSecure || src->isSecure || mod->isSecure;

	s = bniNorm_32((BNWORD32 *)src->ptr, src->size);
	m = bniNorm_32((BNWORD32 *)mod->ptr, mod->size);

	/* bniInv_32 requires that the input be less than the modulus */
	if (m < s ||
	    (m==s && bniCmp_32((BNWORD32 *)src->ptr, (BNWORD32 *)mod->ptr, s)))
	{
		bnSizeCheck(dest, s + (m==s));
		if (dest != src)
			bniCopy_32((BNWORD32 *)dest->ptr,
			           (BNWORD32 *)src->ptr, s);
		/* Pre-reduce modulo the modulus */
		(void)bniDiv_32((BNWORD32 *)dest->ptr BIGLITTLE(-m,+m),
			        (BNWORD32 *)dest->ptr, s,
		                (BNWORD32 *)mod->ptr, m);
		s = bniNorm_32((BNWORD32 *)dest->ptr, m);
		MALLOCDB;
	} else {
		bnSizeCheck(dest, m+1);
		if (dest != src)
			bniCopy_32((BNWORD32 *)dest->ptr,
			           (BNWORD32 *)src->ptr, s);
	}

	i = bniInv_32(  dest->mgr, secure,
			(BNWORD32 *)dest->ptr, s, (BNWORD32 *)mod->ptr, m);
	if (i == 0)
		dest->size = bniNorm_32((BNWORD32 *)dest->ptr, m);

	MALLOCDB;
	return i;
}

/*
 * Shift a bignum left the appropriate number of bits,
 * multiplying by 2^amt.
 */
int 
bnLShift_32(BigNum *dest, unsigned amt)
{
	unsigned s = dest->size;
	BNWORD32 carry;

	if (amt % 32) {
		carry = bniLshift_32((BNWORD32 *)dest->ptr, s, amt % 32);
		if (carry) {
			s++;
			bnSizeCheck(dest, s);
			((BNWORD32 *)dest->ptr)[BIGLITTLE(-s,s-1)] = carry;
		}
	}

	amt /= 32;
	if (amt) {
		bnSizeCheck(dest, s+amt);
		memmove((BNWORD32 *)dest->ptr BIGLITTLE(-s-amt, +amt),
		        (BNWORD32 *)dest->ptr BIG(-s),
			s * sizeof(BNWORD32));
		bniZero_32((BNWORD32 *)dest->ptr, amt);
		s += amt;
	}
	dest->size = s;
	MALLOCDB;
	return 0;
}

/*
 * Shift a bignum right the appropriate number of bits,
 * dividing by 2^amt.
 */
void bnRShift_32(BigNum *dest, unsigned amt)
{
	unsigned s = dest->size;

	if (amt >= 32) {
		memmove(
		        (BNWORD32 *)dest->ptr BIG(-s+amt/32),
			(BNWORD32 *)dest->ptr BIGLITTLE(-s, +amt/32),
			(s-amt/32) * sizeof(BNWORD32));
		s -= amt/32;
		amt %= 32;
	}

	if (amt)
		(void)bniRshift_32((BNWORD32 *)dest->ptr, s, amt);

	dest->size = bniNorm_32((BNWORD32 *)dest->ptr, s);
	MALLOCDB;
}

/*
 * Shift a bignum right until it is odd, and return the number of
 * bits shifted.  n = d * 2^s.  Replaces n with d and returns s.
 * Returns 0 when given 0.  (Another valid answer is infinity.)
 */
unsigned
bnMakeOdd_32(BigNum *n)
{
	unsigned size;
	unsigned s;	/* shift amount */
	BNWORD32 *p;
	BNWORD32 t;

	p = (BNWORD32 *)n->ptr;
	size = bniNorm_32(p, n->size);
	if (!size)
		return 0;

	t = BIGLITTLE(p[-1],p[0]);
	s = 0;

	/* See how many words we have to shift */
	if (!t) {
		/* Shift by words */
		do {
			
			s++;
			BIGLITTLE(--p,p++);
		} while ((t = BIGLITTLE(p[-1],p[0])) == 0);
		size -= s;
		s *= 32;
		memmove((BNWORD32 *)n->ptr BIG(-size), p BIG(-size),
			size * sizeof(BNWORD32));
		p = (BNWORD32 *)n->ptr;
		MALLOCDB;
	}

	pgpAssert(t);

	/* Now count the bits */
	while ((t & 1) == 0) {
		t >>= 1;
		s++;
	}

	/* Shift the bits */
	if (s & (32-1)) {
		bniRshift_32(p, size, s & (32-1));
		/* Renormalize */
		if (BIGLITTLE(*(p-size),*(p+(size-1))) == 0)
			--size;
	}
	n->size = size;

	MALLOCDB;
	return s;
}