static int
testsimpel(void)
{
const char str42[] = "2a";
MINT *t2;
char *s;
mp_madd(c42, c1, t0);
testmcmp(c43, t0, "madd0");
mp_madd(t0, c1, t0);
testmcmp(c44, t0, "madd1");
mp_msub(t0, c1, t0);
testmcmp(c43, t0, "msub0");
mp_msub(t0, c1, t0);
testmcmp(c42, t0, "msub1");
mp_move(c42, t0);
testmcmp(c42, t0, "move0");
t2 = mp_xtom(str42);
testmcmp(c42, t2, "xtom");
s = mp_mtox(t2);
if (strcmp(str42, s) == 0)
printf("ok %d - %s\n", ++tnr, "mtox0");
else
printf("not ok %d - %s\n", ++tnr, "mtox0");
mp_mfree(t2);
}
void
mp_invert(MINT *x1, MINT *x0, MINT *c)
{
MINT u2, u3;
MINT v2, v3;
MINT zero;
MINT q, r;
MINT t;
MINT x0_prime;
static MINT *one = NULL;
/*
* Minimize calls to allocators. Don't use pointers for local
* variables, for the one "initialized" multiple precision
* variable, do it just once.
*/
if (one == NULL)
one = mp_itom(1);
zero.len = q.len = r.len = t.len = 0;
x0_prime.len = u2.len = u3.len = 0;
_mp_move(x0, &u3);
_mp_move(x0, &x0_prime);
v2.len = v3.len = 0;
_mp_move(one, &v2);
_mp_move(x1, &v3);
while (mp_mcmp(&v3, &zero) != 0) {
/* invariant: x0*u1 + x1*u2 = u3 */
/* invariant: x0*v1 + x2*v2 = v3 */
/* invariant: x(n+1) = x(n-1) % x(n) */
mp_mdiv(&u3, &v3, &q, &r);
_mp_move(&v3, &u3);
_mp_move(&r, &v3);
mp_mult(&q, &v2, &t);
mp_msub(&u2, &t, &t);
_mp_move(&v2, &u2);
_mp_move(&t, &v2);
}
/* now x0*u1 + x1*u2 == 1, therefore, (u2*x1) % x0 == 1 */
_mp_move(&u2, c);
if (mp_mcmp(c, &zero) < 0) {
mp_madd(&x0_prime, c, c);
}
_mp_xfree(&zero);
_mp_xfree(&v2);
_mp_xfree(&v3);
_mp_xfree(&u2);
_mp_xfree(&u3);
_mp_xfree(&q);
_mp_xfree(&r);
_mp_xfree(&t);
}
static void
m_sub(MINT *a, MINT *b, MINT *c)
{
int x, i;
int borrow;
short one;
MINT mone;
one = 1;
mone.len = 1;
mone.val = &one;
c->val = _mp_xalloc(a->len, "m_sub");
borrow = 0;
for (i = 0; i < b->len; i++) {
x = borrow + a->val[i] - b->val[i];
if (x & 0100000) {
borrow = -1;
c->val[i] = (short)(x & 077777);
} else {
borrow = 0;
c->val[i] = (short)x;
}
}
for (; i < a->len; i++) {
x = borrow + a->val[i];
if (x & 0100000) {
c->val[i] = (short)(x & 077777);
} else {
borrow = 0;
c->val[i] = (short)x;
}
}
if (borrow < 0) {
for (i = 0; i < a->len; i++) {
c->val[i] ^= 077777;
}
c->len = a->len;
mp_madd(c, &mone, c);
}
for (i = a->len-1; i >= 0; --i) {
if (c->val[i] > 0) {
if (borrow == 0) {
c->len = i + 1;
} else {
c->len = -i - 1;
}
return;
}
}
free(c->val);
}
void
mp_msub(MINT *a, MINT *b, MINT *c)
{
MINT x, y;
int sign;
x.len = y.len = 0;
_mp_move(a, &x);
_mp_move(b, &y);
_mp_xfree(c);
sign = 1;
if (x.len >= 0) {
if (y.len >= 0) {
if (x.len >= y.len) {
m_sub(&x, &y, c);
} else {
sign = -1;
mp_msub(&y, &x, c);
}
} else {
y.len = -y.len;
mp_madd(&x, &y, c);
}
} else {
if (y.len <= 0) {
x.len = -x.len;
y.len = -y.len;
mp_msub(&y, &x, c);
} else {
x.len = -x.len;
mp_madd(&x, &y, c);
sign = -1;
}
}
c->len = sign * c->len;
_mp_xfree(&x);
_mp_xfree(&y);
}
static int
m_in(MINT *a, short b, FILE *f)
{
MINT x, y, ten;
int sign, c;
short qten, qy;
_mp_xfree(a);
sign = 1;
ten.len = 1;
ten.val = &qten;
qten = b;
x.len = 0;
y.len = 1;
y.val = &qy;
while ((c = getc(f)) != EOF)
switch (c) {
case '\\':
(void) getc(f);
continue;
case '\t':
case '\n':
a->len *= sign;
_mp_xfree(&x);
return (0);
case ' ':
continue;
case '-':
sign = -sign;
continue;
default:
if (c >= '0' && c <= '9') {
qy = c - '0';
mp_mult(&x, &ten, a);
mp_madd(a, &y, a);
_mp_move(a, &x);
continue;
} else {
(void) ungetc(c, stdin);
a->len *= sign;
return (0);
}
}
return (EOF);
}
/*
* Choose middle 64 bits of the common key to use as our des key, possibly
* overwriting the lower order bits by setting parity.
*/
static void
extractdeskey(MINT *ck, DesData *deskey)
{
MINT *a;
MINT *z;
short r;
int i;
short base = (1 << 8);
char *k;
z = mp_itom(0);
a = mp_itom(0);
mp_madd(ck, z, a);
for (i = 0; i < ((KEYSIZE - 64) / 2) / 8; i++) {
mp_sdiv(a, base, a, &r);
}
k = (char *)deskey;
for (i = 0; i < 8; i++) {
mp_sdiv(a, base, a, &r);
*k++ = r;
}
mp_mfree(z);
mp_mfree(a);
}
/*
* Choose top 128 bits of the common key to use as our idea key.
*/
static void
extractideakey(MINT *ck, IdeaData *ideakey)
{
MINT *a;
MINT *z;
short r;
int i;
short base = (1 << 8);
char *k;
z = mp_itom(0);
a = mp_itom(0);
mp_madd(ck, z, a);
for (i = 0; i < ((KEYSIZE - 128) / 8); i++) {
mp_sdiv(a, base, a, &r);
}
k = (char *)ideakey;
for (i = 0; i < 16; i++) {
mp_sdiv(a, base, a, &r);
*k++ = r;
}
mp_mfree(z);
mp_mfree(a);
}
void madd(MINT *a, MINT *b, MINT *c) { mp_madd(a, b, c); }