<?php
if (class_exists('ParagonIE_Sodium_Core32_X25519', false)) {
return;
}
/**
* Class ParagonIE_Sodium_Core32_X25519
*/
abstract class ParagonIE_Sodium_Core32_X25519 extends ParagonIE_Sodium_Core32_Curve25519
{
/**
* Alters the objects passed to this method in place.
*
* @internal You should not use this directly from another application
*
* @param ParagonIE_Sodium_Core32_Curve25519_Fe $f
* @param ParagonIE_Sodium_Core32_Curve25519_Fe $g
* @param int $b
* @return void
* @throws SodiumException
* @throws TypeError
* @psalm-suppress MixedMethodCall
*/
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;
/** @var int $x0 */
$x0 = ($f0 ^ $g0) & $b;
/** @var int $x1 */
$x1 = ($f1 ^ $g1) & $b;
/** @var int $x2 */
$x2 = ($f2 ^ $g2) & $b;
/** @var int $x3 */
$x3 = ($f3 ^ $g3) & $b;
/** @var int $x4 */
$x4 = ($f4 ^ $g4) & $b;
/** @var int $x5 */
$x5 = ($f5 ^ $g5) & $b;
/** @var int $x6 */
$x6 = ($f6 ^ $g6) & $b;
/** @var int $x7 */
$x7 = ($f7 ^ $g7) & $b;
/** @var int $x8 */
$x8 = ($f8 ^ $g8) & $b;
/** @var int $x9 */
$x9 = ($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);
}
/**
* @internal You should not use this directly from another application
*
* @param ParagonIE_Sodium_Core32_Curve25519_Fe $f
* @return ParagonIE_Sodium_Core32_Curve25519_Fe
* @throws SodiumException
* @throws TypeError
* @psalm-suppress MixedAssignment
* @psalm-suppress MixedMethodCall
*/
public static function fe_mul121666(ParagonIE_Sodium_Core32_Curve25519_Fe $f)
{
/** @var array<int, ParagonIE_Sodium_Core32_Int64> $h */
$h = array();
for ($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();
}
/** @var array<int, ParagonIE_Sodium_Core32_Int32> $h2 */
$h2 = $h;
return ParagonIE_Sodium_Core32_Curve25519_Fe::fromArray($h2);
}
/**
* @internal You should not use this directly from another application
*
* Inline comments preceded by # are from libsodium's ref10 code.
*
* @param string $n
* @param string $p
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function crypto_scalarmult_curve25519_ref10($n, $p)
{
# for (i = 0;i < 32;++i) e[i] = n[i];
$e = '' . $n;
# e[0] &= 248;
$e[0] = self::intToChr(
self::chrToInt($e[0]) & 248
);
# e[31] &= 127;
# e[31] |= 64;
$e[31] = self::intToChr(
(self::chrToInt($e[31]) & 127) | 64
);
# fe_frombytes(x1,p);
$x1 = self::fe_frombytes($p);
# fe_1(x2);
$x2 = self::fe_1();
# fe_0(z2);
$z2 = self::fe_0();
# fe_copy(x3,x1);
$x3 = self::fe_copy($x1);
# fe_1(z3);
$z3 = self::fe_1();
# swap = 0;
/** @var int $swap */
$swap = 0;
# for (pos = 254;pos >= 0;--pos) {
for ($pos = 254; $pos >= 0; --$pos) {
# b = e[pos / 8] >> (pos & 7);
/** @var int $b */
$b = self::chrToInt(
$e[(int) floor($pos / 8)]
) >> ($pos & 7);
# b &= 1;
$b &= 1;
# swap ^= b;
$swap ^= $b;
# fe_cswap(x2,x3,swap);
self::fe_cswap($x2, $x3, $swap);
# fe_cswap(z2,z3,swap);
self::fe_cswap($z2, $z3, $swap);
# swap = b;
/** @var int $swap */
$swap = $b;
# fe_sub(tmp0,x3,z3);
$tmp0 = self::fe_sub($x3, $z3);
# fe_sub(tmp1,x2,z2);
$tmp1 = self::fe_sub($x2, $z2);
# fe_add(x2,x2,z2);
$x2 = self::fe_add($x2, $z2);
# fe_add(z2,x3,z3);
$z2 = self::fe_add($x3, $z3);
# fe_mul(z3,tmp0,x2);
$z3 = self::fe_mul($tmp0, $x2);
# fe_mul(z2,z2,tmp1);
$z2 = self::fe_mul($z2, $tmp1);
# fe_sq(tmp0,tmp1);
$tmp0 = self::fe_sq($tmp1);
# fe_sq(tmp1,x2);
$tmp1 = self::fe_sq($x2);
# fe_add(x3,z3,z2);
$x3 = self::fe_add($z3, $z2);
# fe_sub(z2,z3,z2);
$z2 = self::fe_sub($z3, $z2);
# fe_mul(x2,tmp1,tmp0);
$x2 = self::fe_mul($tmp1, $tmp0);
# fe_sub(tmp1,tmp1,tmp0);
$tmp1 = self::fe_sub($tmp1, $tmp0);
# fe_sq(z2,z2);
$z2 = self::fe_sq($z2);
# fe_mul121666(z3,tmp1);
$z3 = self::fe_mul121666($tmp1);
# fe_sq(x3,x3);
$x3 = self::fe_sq($x3);
# fe_add(tmp0,tmp0,z3);
$tmp0 = self::fe_add($tmp0, $z3);
# fe_mul(z3,x1,z2);
$z3 = self::fe_mul($x1, $z2);
# fe_mul(z2,tmp1,tmp0);
$z2 = self::fe_mul($tmp1, $tmp0);
}
# fe_cswap(x2,x3,swap);
self::fe_cswap($x2, $x3, $swap);
# fe_cswap(z2,z3,swap);
self::fe_cswap($z2, $z3, $swap);
# fe_invert(z2,z2);
$z2 = self::fe_invert($z2);
# fe_mul(x2,x2,z2);
$x2 = self::fe_mul($x2, $z2);
# fe_tobytes(q,x2);
return (string) self::fe_tobytes($x2);
}
/**
* @internal You should not use this directly from another application
*
* @param ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsY
* @param ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsZ
* @return ParagonIE_Sodium_Core32_Curve25519_Fe
* @throws SodiumException
* @throws TypeError
*/
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);
}
/**
* @internal You should not use this directly from another application
*
* @param string $n
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function crypto_scalarmult_curve25519_ref10_base($n)
{
# for (i = 0;i < 32;++i) e[i] = n[i];
$e = '' . $n;
# e[0] &= 248;
$e[0] = self::intToChr(
self::chrToInt($e[0]) & 248
);
# e[31] &= 127;
# e[31] |= 64;
$e[31] = self::intToChr(
(self::chrToInt($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);
}
}