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<?php
if (class_exists('ParagonIE_Sodium_Core32_X25519', false)) {
return;
}
abstract class ParagonIE_Sodium_Core32_X25519 extends ParagonIE_Sodium_Core32_Curve25519 {
public static function fe_cswap(ParagonIE_Sodium_Core32_Curve25519_Fe $f, ParagonIE_Sodium_Core32_Curve25519_Fe $g, $b = 0) {
$f0 = (int) $f[0]
->toInt();
$f1 = (int) $f[1]
->toInt();
$f2 = (int) $f[2]
->toInt();
$f3 = (int) $f[3]
->toInt();
$f4 = (int) $f[4]
->toInt();
$f5 = (int) $f[5]
->toInt();
$f6 = (int) $f[6]
->toInt();
$f7 = (int) $f[7]
->toInt();
$f8 = (int) $f[8]
->toInt();
$f9 = (int) $f[9]
->toInt();
$g0 = (int) $g[0]
->toInt();
$g1 = (int) $g[1]
->toInt();
$g2 = (int) $g[2]
->toInt();
$g3 = (int) $g[3]
->toInt();
$g4 = (int) $g[4]
->toInt();
$g5 = (int) $g[5]
->toInt();
$g6 = (int) $g[6]
->toInt();
$g7 = (int) $g[7]
->toInt();
$g8 = (int) $g[8]
->toInt();
$g9 = (int) $g[9]
->toInt();
$b = -$b;
$x0 = ($f0 ^ $g0) & $b;
$x1 = ($f1 ^ $g1) & $b;
$x2 = ($f2 ^ $g2) & $b;
$x3 = ($f3 ^ $g3) & $b;
$x4 = ($f4 ^ $g4) & $b;
$x5 = ($f5 ^ $g5) & $b;
$x6 = ($f6 ^ $g6) & $b;
$x7 = ($f7 ^ $g7) & $b;
$x8 = ($f8 ^ $g8) & $b;
$x9 = ($f9 ^ $g9) & $b;
$f[0] = ParagonIE_Sodium_Core32_Int32::fromInt($f0 ^ $x0);
$f[1] = ParagonIE_Sodium_Core32_Int32::fromInt($f1 ^ $x1);
$f[2] = ParagonIE_Sodium_Core32_Int32::fromInt($f2 ^ $x2);
$f[3] = ParagonIE_Sodium_Core32_Int32::fromInt($f3 ^ $x3);
$f[4] = ParagonIE_Sodium_Core32_Int32::fromInt($f4 ^ $x4);
$f[5] = ParagonIE_Sodium_Core32_Int32::fromInt($f5 ^ $x5);
$f[6] = ParagonIE_Sodium_Core32_Int32::fromInt($f6 ^ $x6);
$f[7] = ParagonIE_Sodium_Core32_Int32::fromInt($f7 ^ $x7);
$f[8] = ParagonIE_Sodium_Core32_Int32::fromInt($f8 ^ $x8);
$f[9] = ParagonIE_Sodium_Core32_Int32::fromInt($f9 ^ $x9);
$g[0] = ParagonIE_Sodium_Core32_Int32::fromInt($g0 ^ $x0);
$g[1] = ParagonIE_Sodium_Core32_Int32::fromInt($g1 ^ $x1);
$g[2] = ParagonIE_Sodium_Core32_Int32::fromInt($g2 ^ $x2);
$g[3] = ParagonIE_Sodium_Core32_Int32::fromInt($g3 ^ $x3);
$g[4] = ParagonIE_Sodium_Core32_Int32::fromInt($g4 ^ $x4);
$g[5] = ParagonIE_Sodium_Core32_Int32::fromInt($g5 ^ $x5);
$g[6] = ParagonIE_Sodium_Core32_Int32::fromInt($g6 ^ $x6);
$g[7] = ParagonIE_Sodium_Core32_Int32::fromInt($g7 ^ $x7);
$g[8] = ParagonIE_Sodium_Core32_Int32::fromInt($g8 ^ $x8);
$g[9] = ParagonIE_Sodium_Core32_Int32::fromInt($g9 ^ $x9);
}
public static function fe_mul121666(ParagonIE_Sodium_Core32_Curve25519_Fe $f) {
$h = array();
for ($i = 0; $i < 10; ++$i) {
$h[$i] = $f[$i]
->toInt64()
->mulInt(121666, 17);
}
$carry9 = $h[9]
->addInt(1 << 24)
->shiftRight(25);
$h[0] = $h[0]
->addInt64($carry9
->mulInt(19, 5));
$h[9] = $h[9]
->subInt64($carry9
->shiftLeft(25));
$carry1 = $h[1]
->addInt(1 << 24)
->shiftRight(25);
$h[2] = $h[2]
->addInt64($carry1);
$h[1] = $h[1]
->subInt64($carry1
->shiftLeft(25));
$carry3 = $h[3]
->addInt(1 << 24)
->shiftRight(25);
$h[4] = $h[4]
->addInt64($carry3);
$h[3] = $h[3]
->subInt64($carry3
->shiftLeft(25));
$carry5 = $h[5]
->addInt(1 << 24)
->shiftRight(25);
$h[6] = $h[6]
->addInt64($carry5);
$h[5] = $h[5]
->subInt64($carry5
->shiftLeft(25));
$carry7 = $h[7]
->addInt(1 << 24)
->shiftRight(25);
$h[8] = $h[8]
->addInt64($carry7);
$h[7] = $h[7]
->subInt64($carry7
->shiftLeft(25));
$carry0 = $h[0]
->addInt(1 << 25)
->shiftRight(26);
$h[1] = $h[1]
->addInt64($carry0);
$h[0] = $h[0]
->subInt64($carry0
->shiftLeft(26));
$carry2 = $h[2]
->addInt(1 << 25)
->shiftRight(26);
$h[3] = $h[3]
->addInt64($carry2);
$h[2] = $h[2]
->subInt64($carry2
->shiftLeft(26));
$carry4 = $h[4]
->addInt(1 << 25)
->shiftRight(26);
$h[5] = $h[5]
->addInt64($carry4);
$h[4] = $h[4]
->subInt64($carry4
->shiftLeft(26));
$carry6 = $h[6]
->addInt(1 << 25)
->shiftRight(26);
$h[7] = $h[7]
->addInt64($carry6);
$h[6] = $h[6]
->subInt64($carry6
->shiftLeft(26));
$carry8 = $h[8]
->addInt(1 << 25)
->shiftRight(26);
$h[9] = $h[9]
->addInt64($carry8);
$h[8] = $h[8]
->subInt64($carry8
->shiftLeft(26));
for ($i = 0; $i < 10; ++$i) {
$h[$i] = $h[$i]
->toInt32();
}
$h2 = $h;
return ParagonIE_Sodium_Core32_Curve25519_Fe::fromArray($h2);
}
public static function crypto_scalarmult_curve25519_ref10($n, $p) {
$e = '' . $n;
$e[0] = self::intToChr(self::chrToInt($e[0]) & 248);
$e[31] = self::intToChr(self::chrToInt($e[31]) & 127 | 64);
$x1 = self::fe_frombytes($p);
$x2 = self::fe_1();
$z2 = self::fe_0();
$x3 = self::fe_copy($x1);
$z3 = self::fe_1();
$swap = 0;
for ($pos = 254; $pos >= 0; --$pos) {
$b = self::chrToInt($e[(int) floor($pos / 8)]) >> ($pos & 7);
$b &= 1;
$swap ^= $b;
self::fe_cswap($x2, $x3, $swap);
self::fe_cswap($z2, $z3, $swap);
$swap = $b;
$tmp0 = self::fe_sub($x3, $z3);
$tmp1 = self::fe_sub($x2, $z2);
$x2 = self::fe_add($x2, $z2);
$z2 = self::fe_add($x3, $z3);
$z3 = self::fe_mul($tmp0, $x2);
$z2 = self::fe_mul($z2, $tmp1);
$tmp0 = self::fe_sq($tmp1);
$tmp1 = self::fe_sq($x2);
$x3 = self::fe_add($z3, $z2);
$z2 = self::fe_sub($z3, $z2);
$x2 = self::fe_mul($tmp1, $tmp0);
$tmp1 = self::fe_sub($tmp1, $tmp0);
$z2 = self::fe_sq($z2);
$z3 = self::fe_mul121666($tmp1);
$x3 = self::fe_sq($x3);
$tmp0 = self::fe_add($tmp0, $z3);
$z3 = self::fe_mul($x1, $z2);
$z2 = self::fe_mul($tmp1, $tmp0);
}
self::fe_cswap($x2, $x3, $swap);
self::fe_cswap($z2, $z3, $swap);
$z2 = self::fe_invert($z2);
$x2 = self::fe_mul($x2, $z2);
return (string) self::fe_tobytes($x2);
}
public static function edwards_to_montgomery(ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsY, ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsZ) {
$tempX = self::fe_add($edwardsZ, $edwardsY);
$tempZ = self::fe_sub($edwardsZ, $edwardsY);
$tempZ = self::fe_invert($tempZ);
return self::fe_mul($tempX, $tempZ);
}
public static function crypto_scalarmult_curve25519_ref10_base($n) {
$e = '' . $n;
$e[0] = self::intToChr(self::chrToInt($e[0]) & 248);
$e[31] = self::intToChr(self::chrToInt($e[31]) & 127 | 64);
$A = self::ge_scalarmult_base($e);
if (!$A->Y instanceof ParagonIE_Sodium_Core32_Curve25519_Fe || !$A->Z instanceof ParagonIE_Sodium_Core32_Curve25519_Fe) {
throw new TypeError('Null points encountered');
}
$pk = self::edwards_to_montgomery($A->Y, $A->Z);
return self::fe_tobytes($pk);
}
}