angelovcom.net

X25519.php (11042B)

---

 <?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);
     }
 }