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/*
This file is adapted from ref10/scalarmult.c:
The code for Mongomery ladder is replace by the ladder assembly function;
Inversion is done in the same way as amd64-51/.
(fe is first converted into fe51 after Mongomery ladder)
*/
#include <stddef.h>
#ifdef HAVE_AVX_ASM
#include "utils.h"
#include "curve25519_sandy2x.h"
#include "../scalarmult_curve25519.h"
#include "fe.h"
#include "fe51.h"
#include "ladder.h"
#include "ladder_base.h"
#define x1 var[0]
#define x2 var[1]
#define z2 var[2]
static int
crypto_scalarmult_curve25519_sandy2x(unsigned char *q, const unsigned char *n,
const unsigned char *p)
{
unsigned char *t = q;
fe var[3];
fe51 x_51;
fe51 z_51;
unsigned int i;
for (i = 0; i < 32; i++) {
t[i] = n[i];
}
t[0] &= 248;
t[31] &= 127;
t[31] |= 64;
fe_frombytes(x1, p);
ladder(var, t);
z_51.v[0] = (z2[1] << 26) + z2[0];
z_51.v[1] = (z2[3] << 26) + z2[2];
z_51.v[2] = (z2[5] << 26) + z2[4];
z_51.v[3] = (z2[7] << 26) + z2[6];
z_51.v[4] = (z2[9] << 26) + z2[8];
x_51.v[0] = (x2[1] << 26) + x2[0];
x_51.v[1] = (x2[3] << 26) + x2[2];
x_51.v[2] = (x2[5] << 26) + x2[4];
x_51.v[3] = (x2[7] << 26) + x2[6];
x_51.v[4] = (x2[9] << 26) + x2[8];
fe51_invert(&z_51, &z_51);
fe51_mul(&x_51, &x_51, &z_51);
fe51_pack(q, &x_51);
return 0;
}
#undef x2
#undef z2
#define x2 var[0]
#define z2 var[1]
static int
crypto_scalarmult_curve25519_sandy2x_base(unsigned char *q,
const unsigned char *n)
{
unsigned char *t = q;
fe var[3];
fe51 x_51;
fe51 z_51;
unsigned int i;
for (i = 0;i < 32; i++) {
t[i] = n[i];
}
t[0] &= 248;
t[31] &= 127;
t[31] |= 64;
ladder_base(var, t);
z_51.v[0] = (z2[1] << 26) + z2[0];
z_51.v[1] = (z2[3] << 26) + z2[2];
z_51.v[2] = (z2[5] << 26) + z2[4];
z_51.v[3] = (z2[7] << 26) + z2[6];
z_51.v[4] = (z2[9] << 26) + z2[8];
x_51.v[0] = (x2[1] << 26) + x2[0];
x_51.v[1] = (x2[3] << 26) + x2[2];
x_51.v[2] = (x2[5] << 26) + x2[4];
x_51.v[3] = (x2[7] << 26) + x2[6];
x_51.v[4] = (x2[9] << 26) + x2[8];
fe51_invert(&z_51, &z_51);
fe51_mul(&x_51, &x_51, &z_51);
fe51_pack(q, &x_51);
return 0;
}
struct crypto_scalarmult_curve25519_implementation
crypto_scalarmult_curve25519_sandy2x_implementation = {
SODIUM_C99(.mult = ) crypto_scalarmult_curve25519_sandy2x,
SODIUM_C99(.mult_base = ) crypto_scalarmult_curve25519_sandy2x_base
};
#endif
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