lokinet/crypto/curve25519/scalarmult_curve25519.c

#include <sodium/crypto_scalarmult_curve25519.h>
#include <sodium/private/implementations.h>
#include "scalarmult_curve25519.h"
#include <sodium/runtime.h>

#include "sandy2x/curve25519_sandy2x.h"
#include "ref10/x25519_ref10.h"
static const crypto_scalarmult_curve25519_implementation *implementation =
    &crypto_scalarmult_curve25519_ref10_implementation;

int
crypto_scalarmult_curve25519(unsigned char *q, const unsigned char *n,
                             const unsigned char *p)
{
  size_t i;
  volatile unsigned char d = 0;

  if(implementation->mult(q, n, p) != 0)
  {
    return -1; /* LCOV_EXCL_LINE */
  }
  for(i = 0; i < crypto_scalarmult_curve25519_BYTES; i++)
  {
    d |= q[i];
  }
  return -(1 & ((d - 1) >> 8));
}

int
crypto_scalarmult_curve25519_base(unsigned char *q, const unsigned char *n)
{
  return implementation->mult_base(q, n);
}

size_t
crypto_scalarmult_curve25519_bytes(void)
{
  return crypto_scalarmult_curve25519_BYTES;
}

size_t
crypto_scalarmult_curve25519_scalarbytes(void)
{
  return crypto_scalarmult_curve25519_SCALARBYTES;
}

int
_crypto_scalarmult_curve25519_pick_best_implementation(void)
{
  implementation = &crypto_scalarmult_curve25519_ref10_implementation;

#ifdef HAVE_AVX_ASM
  if(sodium_runtime_has_avx())
  {
    implementation = &crypto_scalarmult_curve25519_sandy2x_implementation;
  }
#endif
  return 0;
}