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new update from Michael Fromberger

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git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@20854 ec53bebd-3082-4978-b11e-865c3cabbd6b
This commit is contained in:
Love Hörnquist Åstrand
2007-06-03 18:04:10 +00:00
parent 8dd610121e
commit 5339b67f33
1 changed files with 25 additions and 20 deletions
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45
lib/hcrypto/imath/imath.c
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@@ -725,10 +725,11 @@ mp_result mp_int_mul(mp_int a, mp_int b, mp_int c)
/* Output is positive if inputs have same sign, otherwise negative */ /* Output is positive if inputs have same sign, otherwise negative */
osign = (MP_SIGN(a) == MP_SIGN(b)) ? MP_ZPOS : MP_NEG; osign = (MP_SIGN(a) == MP_SIGN(b)) ? MP_ZPOS : MP_NEG;
/* If the output is not equal to any of the inputs, we'll write the /* If the output is not identical to any of the inputs, we'll write
results there directly; otherwise, allocate a temporary space. */ the results directly; otherwise, allocate a temporary space. */
ua = MP_USED(a); ub = MP_USED(b); ua = MP_USED(a); ub = MP_USED(b);
osize = ua + ub; osize = MAX(ua, ub);
osize = 4 * ((osize + 1) / 2);
if(c == a || c == b) { if(c == a || c == b) {
p = ROUND_PREC(osize); p = ROUND_PREC(osize);
@@ -809,7 +810,7 @@ mp_result mp_int_sqr(mp_int a, mp_int c)
CHECK(a != NULL && c != NULL); CHECK(a != NULL && c != NULL);
/* Get a temporary buffer big enough to hold the result */ /* Get a temporary buffer big enough to hold the result */
osize = (mp_size) 2 * MP_USED(a); osize = (mp_size) 4 * ((MP_USED(a) + 1) / 2);
if(a == c) { if(a == c) {
p = ROUND_PREC(osize); p = ROUND_PREC(osize);
p = MAX(p, default_precision); p = MAX(p, default_precision);
@@ -2308,26 +2309,26 @@ static int s_kmul(mp_digit *da, mp_digit *db, mp_digit *dc,
product; twice the space is plenty. product; twice the space is plenty.
*/ */
if((t1 = s_alloc(4 * buf_size)) == NULL) return 0; if((t1 = s_alloc(4 * buf_size)) == NULL) return 0;
t2 = t1 + buf_size; t2 = t1 + buf_size;
t3 = t2 + buf_size; t3 = t2 + buf_size;
ZERO(t1, 4 * buf_size); ZERO(t1, 4 * buf_size);
/* t1 and t2 are initially used as temporaries to compute the inner product /* t1 and t2 are initially used as temporaries to compute the inner product
(a1 + a0)(b1 + b0) = a1b1 + a1b0 + a0b1 + a0b0 (a1 + a0)(b1 + b0) = a1b1 + a1b0 + a0b1 + a0b0
*/ */
carry = s_uadd(da, a_top, t1, bot_size, at_size); /* t1 = a1 + a0 */ carry = s_uadd(da, a_top, t1, bot_size, at_size); /* t1 = a1 + a0 */
t1[bot_size] = carry; t1[bot_size] = carry;
carry = s_uadd(db, b_top, t2, bot_size, bt_size); /* t2 = b1 + b0 */ carry = s_uadd(db, b_top, t2, bot_size, bt_size); /* t2 = b1 + b0 */
t2[bot_size] = carry; t2[bot_size] = carry;
(void) s_kmul(t1, t2, t3, bot_size + 1, bot_size + 1); /* t3 = t1 * t2 */ (void) s_kmul(t1, t2, t3, bot_size + 1, bot_size + 1); /* t3 = t1 * t2 */
/* Now we'll get t1 = a0b0 and t2 = a1b1, and subtract them out so that /* Now we'll get t1 = a0b0 and t2 = a1b1, and subtract them out so that
we're left with only the pieces we want: t3 = a1b0 + a0b1 we're left with only the pieces we want: t3 = a1b0 + a0b1
*/ */
ZERO(t1, bot_size + 1); ZERO(t1, buf_size);
ZERO(t2, bot_size + 1); ZERO(t2, buf_size);
(void) s_kmul(da, db, t1, bot_size, bot_size); /* t1 = a0 * b0 */ (void) s_kmul(da, db, t1, bot_size, bot_size); /* t1 = a0 * b0 */
(void) s_kmul(a_top, b_top, t2, at_size, bt_size); /* t2 = a1 * b1 */ (void) s_kmul(a_top, b_top, t2, at_size, bt_size); /* t2 = a1 * b1 */
@@ -2337,11 +2338,13 @@ static int s_kmul(mp_digit *da, mp_digit *db, mp_digit *dc,
/* Assemble the output value */ /* Assemble the output value */
COPY(t1, dc, buf_size); COPY(t1, dc, buf_size);
(void) s_uadd(t3, dc + bot_size, dc + bot_size, carry = s_uadd(t3, dc + bot_size, dc + bot_size,
buf_size + 1, buf_size + 1); buf_size + 1, buf_size);
assert(carry == 0);
(void) s_uadd(t2, dc + 2*bot_size, dc + 2*bot_size, carry = s_uadd(t2, dc + 2*bot_size, dc + 2*bot_size,
buf_size, buf_size); buf_size, buf_size);
assert(carry == 0);
s_free(t1); /* note t2 and t3 are just internal pointers to t1 */ s_free(t1); /* note t2 and t3 are just internal pointers to t1 */
} }
@@ -2390,7 +2393,7 @@ static int s_ksqr(mp_digit *da, mp_digit *dc, mp_size size_a)
if(multiply_threshold && size_a > multiply_threshold) { if(multiply_threshold && size_a > multiply_threshold) {
mp_size bot_size = (size_a + 1) / 2; mp_size bot_size = (size_a + 1) / 2;
mp_digit *a_top = da + bot_size; mp_digit *a_top = da + bot_size;
mp_digit *t1, *t2, *t3; mp_digit *t1, *t2, *t3, carry;
mp_size at_size = size_a - bot_size; mp_size at_size = size_a - bot_size;
mp_size buf_size = 2 * bot_size; mp_size buf_size = 2 * bot_size;
@@ -2420,11 +2423,13 @@ static int s_ksqr(mp_digit *da, mp_digit *dc, mp_size size_a)
/* Assemble the output value */ /* Assemble the output value */
COPY(t1, dc, 2 * bot_size); COPY(t1, dc, 2 * bot_size);
(void) s_uadd(t3, dc + bot_size, dc + bot_size, carry = s_uadd(t3, dc + bot_size, dc + bot_size,
buf_size + 1, buf_size + 1); buf_size + 1, buf_size);
assert(carry == 0);
(void) s_uadd(t2, dc + 2*bot_size, dc + 2*bot_size,
buf_size, buf_size); carry = s_uadd(t2, dc + 2*bot_size, dc + 2*bot_size,
buf_size, buf_size);
assert(carry == 0);
s_free(t1); /* note that t2 and t2 are internal pointers only */ s_free(t1); /* note that t2 and t2 are internal pointers only */