Object* UnMarshaller::get_positive_varint() {
bool done;
unsigned long val = get_varint(&done);
bool is_fixnum = done;
mp_int mp_val;
// do we need to switch to bignum math?
if(!done) {
int shift = sizeof(long) * 7;
mp_int a;
mp_init_set_int(&mp_val, val);
mp_init(&a);
#if (__WORDSIZE == 64)
// mp_(init_)set_int can only deal with 32 bit values,
// so the above call only copied the lower 32 bits of _val_.
// Handle the upper 32 bits as well:
mp_set_int(&a, val >> 32);
mp_mul_2d(&a, 32, &a);
mp_add(&a, &mp_val, &mp_val);
#endif
while(!done) {
unsigned int byte = stream.get();
mp_set_int(&a, byte & ~128);
mp_mul_2d(&a, shift, &a);
mp_add(&a, &mp_val, &mp_val);
shift += 7;
done = byte < 128;
}
mp_clear(&a);
}
/* Store non-zero to ret if arg is square, and zero if not */
int mp_is_square(mp_int *arg,int *ret)
{
int res;
mp_digit c;
mp_int t;
unsigned long r;
/* Default to Non-square :) */
*ret = MP_NO;
if (arg->sign == MP_NEG) {
return MP_VAL;
}
/* digits used? (TSD) */
if (arg->used == 0) {
return MP_OKAY;
}
/* First check mod 128 (suppose that DIGIT_BIT is at least 7) */
if (rem_128[127 & DIGIT(arg,0)] == 1) {
return MP_OKAY;
}
/* Next check mod 105 (3*5*7) */
if ((res = mp_mod_d(arg,105,&c)) != MP_OKAY) {
return res;
}
if (rem_105[c] == 1) {
return MP_OKAY;
}
/* product of primes less than 2^31 */
if ((res = mp_init_set_int(&t,11L*13L*17L*19L*23L*29L*31L)) != MP_OKAY) {
return res;
}
if ((res = mp_mod(arg,&t,&t)) != MP_OKAY) {
goto ERR;
}
r = mp_get_int(&t);
/* Check for other prime modules, note it's not an ERROR but we must
* free "t" so the easiest way is to goto ERR. We know that res
* is already equal to MP_OKAY from the mp_mod call
*/
if ( (1L<<(r%11)) & 0x5C4L ) goto ERR;
if ( (1L<<(r%13)) & 0x9E4L ) goto ERR;
if ( (1L<<(r%17)) & 0x5CE8L ) goto ERR;
if ( (1L<<(r%19)) & 0x4F50CL ) goto ERR;
if ( (1L<<(r%23)) & 0x7ACCA0L ) goto ERR;
if ( (1L<<(r%29)) & 0xC2EDD0CL ) goto ERR;
if ( (1L<<(r%31)) & 0x6DE2B848L ) goto ERR;
/* Final check - is sqr(sqrt(arg)) == arg ? */
if ((res = mp_sqrt(arg,&t)) != MP_OKAY) {
goto ERR;
}
if ((res = mp_sqr(&t,&t)) != MP_OKAY) {
goto ERR;
}
*ret = (mp_cmp_mag(&t,arg) == MP_EQ) ? MP_YES : MP_NO;
ERR:mp_clear(&t);
return res;
}
/* two complement or */
int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
{
int res = MP_OKAY, bits;
int as = mp_isneg(a), bs = mp_isneg(b);
mp_int *mx = NULL, _mx, acpy, bcpy;
if ((as != MP_NO) || (bs != MP_NO)) {
bits = MAX(mp_count_bits(a), mp_count_bits(b));
res = mp_init_set_int(&_mx, 1uL);
if (res != MP_OKAY) {
goto end;
}
mx = &_mx;
res = mp_mul_2d(mx, bits + 1, mx);
if (res != MP_OKAY) {
goto end;
}
if (as != MP_NO) {
res = mp_init(&acpy);
if (res != MP_OKAY) {
goto end;
}
res = mp_add(mx, a, &acpy);
if (res != MP_OKAY) {
mp_clear(&acpy);
goto end;
}
a = &acpy;
}
if (bs != MP_NO) {
res = mp_init(&bcpy);
if (res != MP_OKAY) {
goto end;
}
res = mp_add(mx, b, &bcpy);
if (res != MP_OKAY) {
mp_clear(&bcpy);
goto end;
}
b = &bcpy;
}
}
res = mp_or(a, b, c);
if (((as != MP_NO) || (bs != MP_NO)) && (res == MP_OKAY)) {
res = mp_sub(c, mx, c);
}
end:
if (a == &acpy) {
mp_clear(&acpy);
}
if (b == &bcpy) {
mp_clear(&bcpy);
}
if (mx == &_mx) {
mp_clear(mx);
}
return res;
}
/*
Sets ret to nonzero value if arg is square, 0 if not
Sets t to the square root of arg if one is available, 0 if not
*/
static int mp_issquare(mp_int *arg, int *ret, mp_int *t)
{
int res;
mp_digit c;
mp_int tmp;
unsigned long r;
/* Default to Non-square :) */
*ret = MP_NO;
if (arg->sign == MP_NEG) {
return MP_VAL;
}
/* digits used? (TSD) */
if (arg->used == 0) {
return MP_OKAY;
}
/* First check mod 128 (suppose that DIGIT_BIT is at least 7) */
if (rem_128[127 & DIGIT(arg, 0)] == 1) {
mp_set_int(t, (mp_digit)(0));
return MP_OKAY;
}
/* Next check mod 105 (3*5*7) */
if ((res = mp_mod_d(arg, 105, &c)) != MP_OKAY) {
mp_set_int(t, (mp_digit)(0));
return res;
}
if (rem_105[c] == 1) {
mp_set_int(t, (mp_digit)(0));
return MP_OKAY;
}
if ((res =
mp_init_set_int(t,
11L * 13L * 17L * 19L * 23L * 29L * 31L)) != MP_OKAY) {
mp_set_int(t, (mp_digit)(0));
return res;
}
if ((res = mp_mod(arg, t, t)) != MP_OKAY) {
goto ERR;
}
r = mp_get_int(t);
/* Check for other prime modules. We know that res
* is already equal to MP_OKAY from the mp_mod call
*/
if ((1L << (r % 11)) & 0x5C4L)
goto ERR;
if ((1L << (r % 13)) & 0x9E4L)
goto ERR;
if ((1L << (r % 17)) & 0x5CE8L)
goto ERR;
if ((1L << (r % 19)) & 0x4F50CL)
goto ERR;
if ((1L << (r % 23)) & 0x7ACCA0L)
goto ERR;
if ((1L << (r % 29)) & 0xC2EDD0CL)
goto ERR;
if ((1L << (r % 31)) & 0x6DE2B848L)
goto ERR;
/* Final check - is sqr(sqrt(arg)) == arg ? */
if ((res = mp_sqrt(arg, t)) != MP_OKAY) {
goto ERR;
}
mp_init(&tmp);
if ((res = mp_sqr(t, &tmp)) != MP_OKAY) {
goto ERR;
}
*ret = (mp_cmp_mag(&tmp, arg) == MP_EQ) ? MP_YES : MP_NO;
mp_clear(&tmp);
return res;
ERR:
mp_set_int(t, (mp_digit)(0));
mp_clear(&tmp);
return res;
}
/* two complement and */
int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
{
int res = MP_OKAY, bits, abits, bbits;
int sa = a->sign, sb = b->sign;
mp_int *mx = NULL, _mx, acpy, bcpy;
if ((sa == MP_NEG) || (sb == MP_NEG)) {
abits = mp_count_bits(a);
bbits = mp_count_bits(b);
bits = MP_MAX(abits, bbits);
res = mp_init_set_int(&_mx, 1uL);
if (res != MP_OKAY) {
goto end;
}
mx = &_mx;
res = mp_mul_2d(mx, bits + 1, mx);
if (res != MP_OKAY) {
goto end;
}
if (sa == MP_NEG) {
res = mp_init(&acpy);
if (res != MP_OKAY) {
goto end;
}
res = mp_add(mx, a, &acpy);
if (res != MP_OKAY) {
mp_clear(&acpy);
goto end;
}
a = &acpy;
}
if (sb == MP_NEG) {
res = mp_init(&bcpy);
if (res != MP_OKAY) {
goto end;
}
res = mp_add(mx, b, &bcpy);
if (res != MP_OKAY) {
mp_clear(&bcpy);
goto end;
}
b = &bcpy;
}
}
res = mp_and(a, b, c);
if ((sa == MP_NEG) && (sb == MP_NEG) && (res == MP_OKAY)) {
res = mp_sub(c, mx, c);
}
end:
if (a == &acpy) {
mp_clear(&acpy);
}
if (b == &bcpy) {
mp_clear(&bcpy);
}
if (mx == &_mx) {
mp_clear(mx);
}
return res;
}
