Sha256: f7aca8c9b2f06109e8891e7aa328065525b7bbc50e54aa139f34a82439e76bfc
Contents?: true
Size: 760 Bytes
Versions: 13
Compression:
Stored size: 760 Bytes
Contents
#include "fe.h"
#include "x25519_ref10.h"
int x25519_ref10_scalarmult(uint8_t *q, const uint8_t *n, const uint8_t *p)
{
uint8_t e[32];
unsigned int i;
fe x1;
fe x2;
fe z2;
fe x3;
fe z3;
fe tmp0;
fe tmp1;
int pos;
unsigned int swap;
unsigned int b;
for (i = 0;i < 32;++i) e[i] = n[i];
e[0] &= 248;
e[31] &= 127;
e[31] |= 64;
fe_frombytes(x1,p);
fe_1(x2);
fe_0(z2);
fe_copy(x3,x1);
fe_1(z3);
swap = 0;
for (pos = 254;pos >= 0;--pos) {
b = e[pos / 8] >> (pos & 7);
b &= 1;
swap ^= b;
fe_cswap(x2,x3,swap);
fe_cswap(z2,z3,swap);
swap = b;
#include "montgomery.h"
}
fe_cswap(x2,x3,swap);
fe_cswap(z2,z3,swap);
fe_invert(z2,z2);
fe_mul(x2,x2,z2);
fe_tobytes(q,x2);
return 0;
}
Version data entries
13 entries across 13 versions & 2 rubygems