C++ (Cpp) fe25519_pack Examples

Example #1

File: ge25519.c Project: piyushpandey013/bailingwire

void ge25519_pack(unsigned char r[32], const ge25519_p3 *p)
{
  fe25519 tx, ty, zi;
  fe25519_invert(&zi, &p->z); 
  fe25519_mul(&tx, &p->x, &zi);
  fe25519_mul(&ty, &p->y, &zi);
  fe25519_pack(r, &ty);
  r[31] ^= fe25519_getparity(&tx) << 7;
}

Example #2

File: x25519-x86_64.c Project: AxiomaAbsurdo/time_web_app

void x25519_x86_64(uint8_t out[32], const uint8_t scalar[32],
                  const uint8_t point[32]) {
  uint8_t e[32];
  OPENSSL_memcpy(e, scalar, sizeof(e));

  e[0] &= 248;
  e[31] &= 127;
  e[31] |= 64;

  fe25519 t;
  fe25519 z;
  fe25519_unpack(&t, point);
  mladder(&t, &z, e);
  fe25519_invert(&z, &z);
  x25519_x86_64_mul(&t, &t, &z);
  fe25519_pack(out, &t);
}

Example #3

File: edmont_conv.c Project: fun-alex-alex2006hw/CryptoPill

int edmont_conv(unsigned char r[crypto_scalarmult_curve25519_BYTES],
                const unsigned char p[ED25519_PUBLICKEYBYTES]) {
  fe25519 u, y, num, den, inv, one;

  fe25519_unpack(&y, p);

  // u = (1 + y) / (1 -y)

  fe25519_setone(&one);
  fe25519_add(&num, &one, &y);

  fe25519_sub(&den, &one, &y);
  fe25519_invert(&inv, &den);

  fe25519_mul(&u, &num, &inv);

  fe25519_pack(r, &u);
  return 0;
}