ParagonIE_Sodium_Core32_Curve25519::ge_frombytes_negate_vartime() public WP 1.0
{} It's a method of the class: ParagonIE_Sodium_Core32_Curve25519{}
No Hooks.
Return
ParagonIE_Sodium_Core32_Curve25519_Ge_P3
. Null. Nothing.
Usage
$result = ParagonIE_Sodium_Core32_Curve25519::ge_frombytes_negate_vartime( $s );
- $s(string) (required)
- -
Code of ParagonIE_Sodium_Core32_Curve25519::ge_frombytes_negate_vartime() ParagonIE Sodium Core32 Curve25519::ge frombytes negate vartime WP 5.7
public static function ge_frombytes_negate_vartime($s)
{
static $d = null;
if (!$d) {
/** @var ParagonIE_Sodium_Core32_Curve25519_Fe $d */
$d = ParagonIE_Sodium_Core32_Curve25519_Fe::fromArray(
array(
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[0]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[1]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[2]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[3]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[4]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[5]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[6]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[7]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[8]),
ParagonIE_Sodium_Core32_Int32::fromInt(self::$d[9])
)
);
}
# fe_frombytes(h->Y,s);
# fe_1(h->Z);
$h = new ParagonIE_Sodium_Core32_Curve25519_Ge_P3(
self::fe_0(),
self::fe_frombytes($s),
self::fe_1()
);
# fe_sq(u,h->Y);
# fe_mul(v,u,d);
# fe_sub(u,u,h->Z); /* u = y^2-1 */
# fe_add(v,v,h->Z); /* v = dy^2+1 */
$u = self::fe_sq($h->Y);
/** @var ParagonIE_Sodium_Core32_Curve25519_Fe $d */
$v = self::fe_mul($u, $d);
$u = self::fe_sub($u, $h->Z); /* u = y^2 - 1 */
$v = self::fe_add($v, $h->Z); /* v = dy^2 + 1 */
# fe_sq(v3,v);
# fe_mul(v3,v3,v); /* v3 = v^3 */
# fe_sq(h->X,v3);
# fe_mul(h->X,h->X,v);
# fe_mul(h->X,h->X,u); /* x = uv^7 */
$v3 = self::fe_sq($v);
$v3 = self::fe_mul($v3, $v); /* v3 = v^3 */
$h->X = self::fe_sq($v3);
$h->X = self::fe_mul($h->X, $v);
$h->X = self::fe_mul($h->X, $u); /* x = uv^7 */
# fe_pow22523(h->X,h->X); /* x = (uv^7)^((q-5)/8) */
# fe_mul(h->X,h->X,v3);
# fe_mul(h->X,h->X,u); /* x = uv^3(uv^7)^((q-5)/8) */
$h->X = self::fe_pow22523($h->X); /* x = (uv^7)^((q-5)/8) */
$h->X = self::fe_mul($h->X, $v3);
$h->X = self::fe_mul($h->X, $u); /* x = uv^3(uv^7)^((q-5)/8) */
# fe_sq(vxx,h->X);
# fe_mul(vxx,vxx,v);
# fe_sub(check,vxx,u); /* vx^2-u */
$vxx = self::fe_sq($h->X);
$vxx = self::fe_mul($vxx, $v);
$check = self::fe_sub($vxx, $u); /* vx^2 - u */
# if (fe_isnonzero(check)) {
# fe_add(check,vxx,u); /* vx^2+u */
# if (fe_isnonzero(check)) {
# return -1;
# }
# fe_mul(h->X,h->X,sqrtm1);
# }
if (self::fe_isnonzero($check)) {
$check = self::fe_add($vxx, $u); /* vx^2 + u */
if (self::fe_isnonzero($check)) {
throw new RangeException('Internal check failed.');
}
$h->X = self::fe_mul(
$h->X,
ParagonIE_Sodium_Core32_Curve25519_Fe::fromIntArray(self::$sqrtm1)
);
}
# if (fe_isnegative(h->X) == (s[31] >> 7)) {
# fe_neg(h->X,h->X);
# }
$i = self::chrToInt($s[31]);
if (self::fe_isnegative($h->X) === ($i >> 7)) {
$h->X = self::fe_neg($h->X);
}
# fe_mul(h->T,h->X,h->Y);
$h->T = self::fe_mul($h->X, $h->Y);
return $h;
}