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   1  <?php
   2  
   3  /**
   4   * Class ParagonIE_Sodium_Core32_Int64
   5   *
   6   * Encapsulates a 64-bit integer.
   7   *
   8   * These are immutable. It always returns a new instance.
   9   */
  10  class ParagonIE_Sodium_Core32_Int64
  11  {
  12      /**
  13       * @var array<int, int> - four 16-bit integers
  14       */
  15      public $limbs = array(0, 0, 0, 0);
  16  
  17      /**
  18       * @var int
  19       */
  20      public $overflow = 0;
  21  
  22      /**
  23       * @var bool
  24       */
  25      public $unsignedInt = false;
  26  
  27      /**
  28       * ParagonIE_Sodium_Core32_Int64 constructor.
  29       * @param array $array
  30       * @param bool $unsignedInt
  31       */
  32      public function __construct($array = array(0, 0, 0, 0), $unsignedInt = false)
  33      {
  34          $this->limbs = array(
  35              (int) $array[0],
  36              (int) $array[1],
  37              (int) $array[2],
  38              (int) $array[3]
  39          );
  40          $this->overflow = 0;
  41          $this->unsignedInt = $unsignedInt;
  42      }
  43  
  44      /**
  45       * Adds two int64 objects
  46       *
  47       * @param ParagonIE_Sodium_Core32_Int64 $addend
  48       * @return ParagonIE_Sodium_Core32_Int64
  49       */
  50      public function addInt64(ParagonIE_Sodium_Core32_Int64 $addend)
  51      {
  52          $i0 = $this->limbs[0];
  53          $i1 = $this->limbs[1];
  54          $i2 = $this->limbs[2];
  55          $i3 = $this->limbs[3];
  56          $j0 = $addend->limbs[0];
  57          $j1 = $addend->limbs[1];
  58          $j2 = $addend->limbs[2];
  59          $j3 = $addend->limbs[3];
  60  
  61          $r3 = $i3 + ($j3 & 0xffff);
  62          $carry = $r3 >> 16;
  63  
  64          $r2 = $i2 + ($j2 & 0xffff) + $carry;
  65          $carry = $r2 >> 16;
  66  
  67          $r1 = $i1 + ($j1 & 0xffff) + $carry;
  68          $carry = $r1 >> 16;
  69  
  70          $r0 = $i0 + ($j0 & 0xffff) + $carry;
  71          $carry = $r0 >> 16;
  72  
  73          $r0 &= 0xffff;
  74          $r1 &= 0xffff;
  75          $r2 &= 0xffff;
  76          $r3 &= 0xffff;
  77  
  78          $return = new ParagonIE_Sodium_Core32_Int64(
  79              array($r0, $r1, $r2, $r3)
  80          );
  81          $return->overflow = $carry;
  82          $return->unsignedInt = $this->unsignedInt;
  83          return $return;
  84      }
  85  
  86      /**
  87       * Adds a normal integer to an int64 object
  88       *
  89       * @param int $int
  90       * @return ParagonIE_Sodium_Core32_Int64
  91       * @throws SodiumException
  92       * @throws TypeError
  93       */
  94      public function addInt($int)
  95      {
  96          ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
  97          /** @var int $int */
  98          $int = (int) $int;
  99  
 100          $i0 = $this->limbs[0];
 101          $i1 = $this->limbs[1];
 102          $i2 = $this->limbs[2];
 103          $i3 = $this->limbs[3];
 104  
 105          $r3 = $i3 + ($int & 0xffff);
 106          $carry = $r3 >> 16;
 107  
 108          $r2 = $i2 + (($int >> 16) & 0xffff) + $carry;
 109          $carry = $r2 >> 16;
 110  
 111          $r1 = $i1 + $carry;
 112          $carry = $r1 >> 16;
 113  
 114          $r0 = $i0 + $carry;
 115          $carry = $r0 >> 16;
 116  
 117          $r0 &= 0xffff;
 118          $r1 &= 0xffff;
 119          $r2 &= 0xffff;
 120          $r3 &= 0xffff;
 121          $return = new ParagonIE_Sodium_Core32_Int64(
 122              array($r0, $r1, $r2, $r3)
 123          );
 124          $return->overflow = $carry;
 125          $return->unsignedInt = $this->unsignedInt;
 126          return $return;
 127      }
 128  
 129      /**
 130       * @param int $b
 131       * @return int
 132       */
 133      public function compareInt($b = 0)
 134      {
 135          $gt = 0;
 136          $eq = 1;
 137  
 138          $i = 4;
 139          $j = 0;
 140          while ($i > 0) {
 141              --$i;
 142              /** @var int $x1 */
 143              $x1 = $this->limbs[$i];
 144              /** @var int $x2 */
 145              $x2 = ($b >> ($j << 4)) & 0xffff;
 146              /** int */
 147              $gt |= (($x2 - $x1) >> 8) & $eq;
 148              /** int */
 149              $eq &= (($x2 ^ $x1) - 1) >> 8;
 150          }
 151          return ($gt + $gt - $eq) + 1;
 152      }
 153  
 154      /**
 155       * @param int $b
 156       * @return bool
 157       */
 158      public function isGreaterThan($b = 0)
 159      {
 160          return $this->compareInt($b) > 0;
 161      }
 162  
 163      /**
 164       * @param int $b
 165       * @return bool
 166       */
 167      public function isLessThanInt($b = 0)
 168      {
 169          return $this->compareInt($b) < 0;
 170      }
 171  
 172      /**
 173       * @param int $hi
 174       * @param int $lo
 175       * @return ParagonIE_Sodium_Core32_Int64
 176       */
 177      public function mask64($hi = 0, $lo = 0)
 178      {
 179          /** @var int $a */
 180          $a = ($hi >> 16) & 0xffff;
 181          /** @var int $b */
 182          $b = ($hi) & 0xffff;
 183          /** @var int $c */
 184          $c = ($lo >> 16) & 0xffff;
 185          /** @var int $d */
 186          $d = ($lo & 0xffff);
 187          return new ParagonIE_Sodium_Core32_Int64(
 188              array(
 189                  $this->limbs[0] & $a,
 190                  $this->limbs[1] & $b,
 191                  $this->limbs[2] & $c,
 192                  $this->limbs[3] & $d
 193              ),
 194              $this->unsignedInt
 195          );
 196      }
 197  
 198      /**
 199       * @param int $int
 200       * @param int $size
 201       * @return ParagonIE_Sodium_Core32_Int64
 202       * @throws SodiumException
 203       * @throws TypeError
 204       * @psalm-suppress MixedAssignment
 205       */
 206      public function mulInt($int = 0, $size = 0)
 207      {
 208          if (ParagonIE_Sodium_Compat::$fastMult) {
 209              return $this->mulIntFast($int);
 210          }
 211          ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
 212          ParagonIE_Sodium_Core32_Util::declareScalarType($size, 'int', 2);
 213          /** @var int $int */
 214          $int = (int) $int;
 215          /** @var int $size */
 216          $size = (int) $size;
 217  
 218          if (!$size) {
 219              $size = 63;
 220          }
 221  
 222          $a = clone $this;
 223          $return = new ParagonIE_Sodium_Core32_Int64();
 224          $return->unsignedInt = $this->unsignedInt;
 225  
 226          // Initialize:
 227          $ret0 = 0;
 228          $ret1 = 0;
 229          $ret2 = 0;
 230          $ret3 = 0;
 231          $a0 = $a->limbs[0];
 232          $a1 = $a->limbs[1];
 233          $a2 = $a->limbs[2];
 234          $a3 = $a->limbs[3];
 235  
 236          /** @var int $size */
 237          /** @var int $i */
 238          for ($i = $size; $i >= 0; --$i) {
 239              $mask = -($int & 1);
 240              $x0 = $a0 & $mask;
 241              $x1 = $a1 & $mask;
 242              $x2 = $a2 & $mask;
 243              $x3 = $a3 & $mask;
 244  
 245              $ret3 += $x3;
 246              $c = $ret3 >> 16;
 247  
 248              $ret2 += $x2 + $c;
 249              $c = $ret2 >> 16;
 250  
 251              $ret1 += $x1 + $c;
 252              $c = $ret1 >> 16;
 253  
 254              $ret0 += $x0 + $c;
 255  
 256              $ret0 &= 0xffff;
 257              $ret1 &= 0xffff;
 258              $ret2 &= 0xffff;
 259              $ret3 &= 0xffff;
 260  
 261              $a3 = $a3 << 1;
 262              $x3 = $a3 >> 16;
 263              $a2 = ($a2 << 1) | $x3;
 264              $x2 = $a2 >> 16;
 265              $a1 = ($a1 << 1) | $x2;
 266              $x1 = $a1 >> 16;
 267              $a0 = ($a0 << 1) | $x1;
 268              $a0 &= 0xffff;
 269              $a1 &= 0xffff;
 270              $a2 &= 0xffff;
 271              $a3 &= 0xffff;
 272  
 273              $int >>= 1;
 274          }
 275          $return->limbs[0] = $ret0;
 276          $return->limbs[1] = $ret1;
 277          $return->limbs[2] = $ret2;
 278          $return->limbs[3] = $ret3;
 279          return $return;
 280      }
 281  
 282      /**
 283       * @param ParagonIE_Sodium_Core32_Int64 $A
 284       * @param ParagonIE_Sodium_Core32_Int64 $B
 285       * @return array<int, ParagonIE_Sodium_Core32_Int64>
 286       * @throws SodiumException
 287       * @throws TypeError
 288       * @psalm-suppress MixedInferredReturnType
 289       */
 290      public static function ctSelect(
 291          ParagonIE_Sodium_Core32_Int64 $A,
 292          ParagonIE_Sodium_Core32_Int64 $B
 293      ) {
 294          $a = clone $A;
 295          $b = clone $B;
 296          /** @var int $aNeg */
 297          $aNeg = ($a->limbs[0] >> 15) & 1;
 298          /** @var int $bNeg */
 299          $bNeg = ($b->limbs[0] >> 15) & 1;
 300          /** @var int $m */
 301          $m = (-($aNeg & $bNeg)) | 1;
 302          /** @var int $swap */
 303          $swap = $bNeg & ~$aNeg;
 304          /** @var int $d */
 305          $d = -$swap;
 306  
 307          /*
 308          if ($bNeg && !$aNeg) {
 309              $a = clone $int;
 310              $b = clone $this;
 311          } elseif($bNeg && $aNeg) {
 312              $a = $this->mulInt(-1);
 313              $b = $int->mulInt(-1);
 314          }
 315           */
 316          $x = $a->xorInt64($b)->mask64($d, $d);
 317          return array(
 318              $a->xorInt64($x)->mulInt($m),
 319              $b->xorInt64($x)->mulInt($m)
 320          );
 321      }
 322  
 323      /**
 324       * @param array<int, int> $a
 325       * @param array<int, int> $b
 326       * @param int $baseLog2
 327       * @return array<int, int>
 328       */
 329      public function multiplyLong(array $a, array $b, $baseLog2 = 16)
 330      {
 331          $a_l = count($a);
 332          $b_l = count($b);
 333          /** @var array<int, int> $r */
 334          $r = array_fill(0, $a_l + $b_l + 1, 0);
 335          $base = 1 << $baseLog2;
 336          for ($i = 0; $i < $a_l; ++$i) {
 337              $a_i = $a[$i];
 338              for ($j = 0; $j < $a_l; ++$j) {
 339                  $b_j = $b[$j];
 340                  $product = (($a_i * $b_j) + $r[$i + $j]);
 341                  $carry = (((int) $product >> $baseLog2) & 0xffff);
 342                  $r[$i + $j] = ((int) $product - (int) ($carry * $base)) & 0xffff;
 343                  $r[$i + $j + 1] += $carry;
 344              }
 345          }
 346          return array_slice($r, 0, 5);
 347      }
 348  
 349      /**
 350       * @param int $int
 351       * @return ParagonIE_Sodium_Core32_Int64
 352       */
 353      public function mulIntFast($int)
 354      {
 355          // Handle negative numbers
 356          $aNeg = ($this->limbs[0] >> 15) & 1;
 357          $bNeg = ($int >> 31) & 1;
 358          $a = array_reverse($this->limbs);
 359          $b = array(
 360              $int & 0xffff,
 361              ($int >> 16) & 0xffff,
 362              -$bNeg & 0xffff,
 363              -$bNeg & 0xffff
 364          );
 365          if ($aNeg) {
 366              for ($i = 0; $i < 4; ++$i) {
 367                  $a[$i] = ($a[$i] ^ 0xffff) & 0xffff;
 368              }
 369              ++$a[0];
 370          }
 371          if ($bNeg) {
 372              for ($i = 0; $i < 4; ++$i) {
 373                  $b[$i] = ($b[$i] ^ 0xffff) & 0xffff;
 374              }
 375              ++$b[0];
 376          }
 377          // Multiply
 378          $res = $this->multiplyLong($a, $b);
 379  
 380          // Re-apply negation to results
 381          if ($aNeg !== $bNeg) {
 382              for ($i = 0; $i < 4; ++$i) {
 383                  $res[$i] = (0xffff ^ $res[$i]) & 0xffff;
 384              }
 385              // Handle integer overflow
 386              $c = 1;
 387              for ($i = 0; $i < 4; ++$i) {
 388                  $res[$i] += $c;
 389                  $c = $res[$i] >> 16;
 390                  $res[$i] &= 0xffff;
 391              }
 392          }
 393  
 394          // Return our values
 395          $return = new ParagonIE_Sodium_Core32_Int64();
 396          $return->limbs = array(
 397              $res[3] & 0xffff,
 398              $res[2] & 0xffff,
 399              $res[1] & 0xffff,
 400              $res[0] & 0xffff
 401          );
 402          if (count($res) > 4) {
 403              $return->overflow = $res[4] & 0xffff;
 404          }
 405          $return->unsignedInt = $this->unsignedInt;
 406          return $return;
 407      }
 408  
 409      /**
 410       * @param ParagonIE_Sodium_Core32_Int64 $right
 411       * @return ParagonIE_Sodium_Core32_Int64
 412       */
 413      public function mulInt64Fast(ParagonIE_Sodium_Core32_Int64 $right)
 414      {
 415          $aNeg = ($this->limbs[0] >> 15) & 1;
 416          $bNeg = ($right->limbs[0] >> 15) & 1;
 417  
 418          $a = array_reverse($this->limbs);
 419          $b = array_reverse($right->limbs);
 420          if ($aNeg) {
 421              for ($i = 0; $i < 4; ++$i) {
 422                  $a[$i] = ($a[$i] ^ 0xffff) & 0xffff;
 423              }
 424              ++$a[0];
 425          }
 426          if ($bNeg) {
 427              for ($i = 0; $i < 4; ++$i) {
 428                  $b[$i] = ($b[$i] ^ 0xffff) & 0xffff;
 429              }
 430              ++$b[0];
 431          }
 432          $res = $this->multiplyLong($a, $b);
 433          if ($aNeg !== $bNeg) {
 434              if ($aNeg !== $bNeg) {
 435                  for ($i = 0; $i < 4; ++$i) {
 436                      $res[$i] = ($res[$i] ^ 0xffff) & 0xffff;
 437                  }
 438                  $c = 1;
 439                  for ($i = 0; $i < 4; ++$i) {
 440                      $res[$i] += $c;
 441                      $c = $res[$i] >> 16;
 442                      $res[$i] &= 0xffff;
 443                  }
 444              }
 445          }
 446          $return = new ParagonIE_Sodium_Core32_Int64();
 447          $return->limbs = array(
 448              $res[3] & 0xffff,
 449              $res[2] & 0xffff,
 450              $res[1] & 0xffff,
 451              $res[0] & 0xffff
 452          );
 453          if (count($res) > 4) {
 454              $return->overflow = $res[4];
 455          }
 456          return $return;
 457      }
 458  
 459      /**
 460       * @param ParagonIE_Sodium_Core32_Int64 $int
 461       * @param int $size
 462       * @return ParagonIE_Sodium_Core32_Int64
 463       * @throws SodiumException
 464       * @throws TypeError
 465       * @psalm-suppress MixedAssignment
 466       */
 467      public function mulInt64(ParagonIE_Sodium_Core32_Int64 $int, $size = 0)
 468      {
 469          if (ParagonIE_Sodium_Compat::$fastMult) {
 470              return $this->mulInt64Fast($int);
 471          }
 472          ParagonIE_Sodium_Core32_Util::declareScalarType($size, 'int', 2);
 473          if (!$size) {
 474              $size = 63;
 475          }
 476          list($a, $b) = self::ctSelect($this, $int);
 477  
 478          $return = new ParagonIE_Sodium_Core32_Int64();
 479          $return->unsignedInt = $this->unsignedInt;
 480  
 481          // Initialize:
 482          $ret0 = 0;
 483          $ret1 = 0;
 484          $ret2 = 0;
 485          $ret3 = 0;
 486          $a0 = $a->limbs[0];
 487          $a1 = $a->limbs[1];
 488          $a2 = $a->limbs[2];
 489          $a3 = $a->limbs[3];
 490          $b0 = $b->limbs[0];
 491          $b1 = $b->limbs[1];
 492          $b2 = $b->limbs[2];
 493          $b3 = $b->limbs[3];
 494  
 495          /** @var int $size */
 496          /** @var int $i */
 497          for ($i = (int) $size; $i >= 0; --$i) {
 498              $mask = -($b3 & 1);
 499              $x0 = $a0 & $mask;
 500              $x1 = $a1 & $mask;
 501              $x2 = $a2 & $mask;
 502              $x3 = $a3 & $mask;
 503  
 504              $ret3 += $x3;
 505              $c = $ret3 >> 16;
 506  
 507              $ret2 += $x2 + $c;
 508              $c = $ret2 >> 16;
 509  
 510              $ret1 += $x1 + $c;
 511              $c = $ret1 >> 16;
 512  
 513              $ret0 += $x0 + $c;
 514  
 515              $ret0 &= 0xffff;
 516              $ret1 &= 0xffff;
 517              $ret2 &= 0xffff;
 518              $ret3 &= 0xffff;
 519  
 520              $a3 = $a3 << 1;
 521              $x3 = $a3 >> 16;
 522              $a2 = ($a2 << 1) | $x3;
 523              $x2 = $a2 >> 16;
 524              $a1 = ($a1 << 1) | $x2;
 525              $x1 = $a1 >> 16;
 526              $a0 = ($a0 << 1) | $x1;
 527              $a0 &= 0xffff;
 528              $a1 &= 0xffff;
 529              $a2 &= 0xffff;
 530              $a3 &= 0xffff;
 531  
 532              $x0 = ($b0 & 1) << 16;
 533              $x1 = ($b1 & 1) << 16;
 534              $x2 = ($b2 & 1) << 16;
 535  
 536              $b0 = ($b0 >> 1);
 537              $b1 = (($b1 | $x0) >> 1);
 538              $b2 = (($b2 | $x1) >> 1);
 539              $b3 = (($b3 | $x2) >> 1);
 540  
 541              $b0 &= 0xffff;
 542              $b1 &= 0xffff;
 543              $b2 &= 0xffff;
 544              $b3 &= 0xffff;
 545  
 546          }
 547          $return->limbs[0] = $ret0;
 548          $return->limbs[1] = $ret1;
 549          $return->limbs[2] = $ret2;
 550          $return->limbs[3] = $ret3;
 551  
 552          return $return;
 553      }
 554  
 555      /**
 556       * OR this 64-bit integer with another.
 557       *
 558       * @param ParagonIE_Sodium_Core32_Int64 $b
 559       * @return ParagonIE_Sodium_Core32_Int64
 560       */
 561      public function orInt64(ParagonIE_Sodium_Core32_Int64 $b)
 562      {
 563          $return = new ParagonIE_Sodium_Core32_Int64();
 564          $return->unsignedInt = $this->unsignedInt;
 565          $return->limbs = array(
 566              (int) ($this->limbs[0] | $b->limbs[0]),
 567              (int) ($this->limbs[1] | $b->limbs[1]),
 568              (int) ($this->limbs[2] | $b->limbs[2]),
 569              (int) ($this->limbs[3] | $b->limbs[3])
 570          );
 571          return $return;
 572      }
 573  
 574      /**
 575       * @param int $c
 576       * @return ParagonIE_Sodium_Core32_Int64
 577       * @throws SodiumException
 578       * @throws TypeError
 579       * @psalm-suppress MixedArrayAccess
 580       */
 581      public function rotateLeft($c = 0)
 582      {
 583          ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
 584          /** @var int $c */
 585          $c = (int) $c;
 586  
 587          $return = new ParagonIE_Sodium_Core32_Int64();
 588          $return->unsignedInt = $this->unsignedInt;
 589          $c &= 63;
 590          if ($c === 0) {
 591              // NOP, but we want a copy.
 592              $return->limbs = $this->limbs;
 593          } else {
 594              /** @var array<int, int> $limbs */
 595              $limbs =& $return->limbs;
 596  
 597              /** @var array<int, int> $myLimbs */
 598              $myLimbs =& $this->limbs;
 599  
 600              /** @var int $idx_shift */
 601              $idx_shift = ($c >> 4) & 3;
 602              /** @var int $sub_shift */
 603              $sub_shift = $c & 15;
 604  
 605              for ($i = 3; $i >= 0; --$i) {
 606                  /** @var int $j */
 607                  $j = ($i + $idx_shift) & 3;
 608                  /** @var int $k */
 609                  $k = ($i + $idx_shift + 1) & 3;
 610                  $limbs[$i] = (int) (
 611                      (
 612                          ((int) ($myLimbs[$j]) << $sub_shift)
 613                              |
 614                          ((int) ($myLimbs[$k]) >> (16 - $sub_shift))
 615                      ) & 0xffff
 616                  );
 617              }
 618          }
 619          return $return;
 620      }
 621  
 622      /**
 623       * Rotate to the right
 624       *
 625       * @param int $c
 626       * @return ParagonIE_Sodium_Core32_Int64
 627       * @throws SodiumException
 628       * @throws TypeError
 629       * @psalm-suppress MixedArrayAccess
 630       */
 631      public function rotateRight($c = 0)
 632      {
 633          ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
 634          /** @var int $c */
 635          $c = (int) $c;
 636  
 637          /** @var ParagonIE_Sodium_Core32_Int64 $return */
 638          $return = new ParagonIE_Sodium_Core32_Int64();
 639          $return->unsignedInt = $this->unsignedInt;
 640          $c &= 63;
 641          /** @var int $c */
 642          if ($c === 0) {
 643              // NOP, but we want a copy.
 644              $return->limbs = $this->limbs;
 645          } else {
 646              /** @var array<int, int> $limbs */
 647              $limbs =& $return->limbs;
 648  
 649              /** @var array<int, int> $myLimbs */
 650              $myLimbs =& $this->limbs;
 651  
 652              /** @var int $idx_shift */
 653              $idx_shift = ($c >> 4) & 3;
 654              /** @var int $sub_shift */
 655              $sub_shift = $c & 15;
 656  
 657              for ($i = 3; $i >= 0; --$i) {
 658                  /** @var int $j */
 659                  $j = ($i - $idx_shift) & 3;
 660                  /** @var int $k */
 661                  $k = ($i - $idx_shift - 1) & 3;
 662                  $limbs[$i] = (int) (
 663                      (
 664                          ((int) ($myLimbs[$j]) >> (int) ($sub_shift))
 665                              |
 666                          ((int) ($myLimbs[$k]) << (16 - (int) ($sub_shift)))
 667                      ) & 0xffff
 668                  );
 669              }
 670          }
 671          return $return;
 672      }
 673      /**
 674       * @param int $c
 675       * @return ParagonIE_Sodium_Core32_Int64
 676       * @throws SodiumException
 677       * @throws TypeError
 678       */
 679      public function shiftLeft($c = 0)
 680      {
 681          ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
 682          /** @var int $c */
 683          $c = (int) $c;
 684  
 685          $return = new ParagonIE_Sodium_Core32_Int64();
 686          $return->unsignedInt = $this->unsignedInt;
 687          $c &= 63;
 688  
 689          if ($c >= 16) {
 690              if ($c >= 48) {
 691                  $return->limbs = array(
 692                      $this->limbs[3], 0, 0, 0
 693                  );
 694              } elseif ($c >= 32) {
 695                  $return->limbs = array(
 696                      $this->limbs[2], $this->limbs[3], 0, 0
 697                  );
 698              } else {
 699                  $return->limbs = array(
 700                      $this->limbs[1], $this->limbs[2], $this->limbs[3], 0
 701                  );
 702              }
 703              return $return->shiftLeft($c & 15);
 704          }
 705          if ($c === 0) {
 706              $return->limbs = $this->limbs;
 707          } elseif ($c < 0) {
 708              /** @var int $c */
 709              return $this->shiftRight(-$c);
 710          } else {
 711              if (!is_int($c)) {
 712                  throw new TypeError();
 713              }
 714              /** @var int $carry */
 715              $carry = 0;
 716              for ($i = 3; $i >= 0; --$i) {
 717                  /** @var int $tmp */
 718                  $tmp = ($this->limbs[$i] << $c) | ($carry & 0xffff);
 719                  $return->limbs[$i] = (int) ($tmp & 0xffff);
 720                  /** @var int $carry */
 721                  $carry = $tmp >> 16;
 722              }
 723          }
 724          return $return;
 725      }
 726  
 727      /**
 728       * @param int $c
 729       * @return ParagonIE_Sodium_Core32_Int64
 730       * @throws SodiumException
 731       * @throws TypeError
 732       */
 733      public function shiftRight($c = 0)
 734      {
 735          ParagonIE_Sodium_Core32_Util::declareScalarType($c, 'int', 1);
 736          $c = (int) $c;
 737          /** @var int $c */
 738          $return = new ParagonIE_Sodium_Core32_Int64();
 739          $return->unsignedInt = $this->unsignedInt;
 740          $c &= 63;
 741  
 742          $negative = -(($this->limbs[0] >> 15) & 1);
 743          if ($c >= 16) {
 744              if ($c >= 48) {
 745                  $return->limbs = array(
 746                      (int) ($negative & 0xffff),
 747                      (int) ($negative & 0xffff),
 748                      (int) ($negative & 0xffff),
 749                      (int) $this->limbs[0]
 750                  );
 751              } elseif ($c >= 32) {
 752                  $return->limbs = array(
 753                      (int) ($negative & 0xffff),
 754                      (int) ($negative & 0xffff),
 755                      (int) $this->limbs[0],
 756                      (int) $this->limbs[1]
 757                  );
 758              } else {
 759                  $return->limbs = array(
 760                      (int) ($negative & 0xffff),
 761                      (int) $this->limbs[0],
 762                      (int) $this->limbs[1],
 763                      (int) $this->limbs[2]
 764                  );
 765              }
 766              return $return->shiftRight($c & 15);
 767          }
 768  
 769          if ($c === 0) {
 770              $return->limbs = $this->limbs;
 771          } elseif ($c < 0) {
 772              return $this->shiftLeft(-$c);
 773          } else {
 774              if (!is_int($c)) {
 775                  throw new TypeError();
 776              }
 777              /** @var int $carryRight */
 778              $carryRight = ($negative & 0xffff);
 779              $mask = (int) (((1 << ($c + 1)) - 1) & 0xffff);
 780              for ($i = 0; $i < 4; ++$i) {
 781                  $return->limbs[$i] = (int) (
 782                      (($this->limbs[$i] >> $c) | ($carryRight << (16 - $c))) & 0xffff
 783                  );
 784                  $carryRight = (int) ($this->limbs[$i] & $mask);
 785              }
 786          }
 787          return $return;
 788      }
 789  
 790  
 791      /**
 792       * Subtract a normal integer from an int64 object.
 793       *
 794       * @param int $int
 795       * @return ParagonIE_Sodium_Core32_Int64
 796       * @throws SodiumException
 797       * @throws TypeError
 798       */
 799      public function subInt($int)
 800      {
 801          ParagonIE_Sodium_Core32_Util::declareScalarType($int, 'int', 1);
 802          $int = (int) $int;
 803  
 804          $return = new ParagonIE_Sodium_Core32_Int64();
 805          $return->unsignedInt = $this->unsignedInt;
 806  
 807          /** @var int $carry */
 808          $carry = 0;
 809          for ($i = 3; $i >= 0; --$i) {
 810              /** @var int $tmp */
 811              $tmp = $this->limbs[$i] - (($int >> 16) & 0xffff) + $carry;
 812              /** @var int $carry */
 813              $carry = $tmp >> 16;
 814              $return->limbs[$i] = (int) ($tmp & 0xffff);
 815          }
 816          return $return;
 817      }
 818  
 819      /**
 820       * The difference between two Int64 objects.
 821       *
 822       * @param ParagonIE_Sodium_Core32_Int64 $b
 823       * @return ParagonIE_Sodium_Core32_Int64
 824       */
 825      public function subInt64(ParagonIE_Sodium_Core32_Int64 $b)
 826      {
 827          $return = new ParagonIE_Sodium_Core32_Int64();
 828          $return->unsignedInt = $this->unsignedInt;
 829          /** @var int $carry */
 830          $carry = 0;
 831          for ($i = 3; $i >= 0; --$i) {
 832              /** @var int $tmp */
 833              $tmp = $this->limbs[$i] - $b->limbs[$i] + $carry;
 834              /** @var int $carry */
 835              $carry = ($tmp >> 16);
 836              $return->limbs[$i] = (int) ($tmp & 0xffff);
 837          }
 838          return $return;
 839      }
 840  
 841      /**
 842       * XOR this 64-bit integer with another.
 843       *
 844       * @param ParagonIE_Sodium_Core32_Int64 $b
 845       * @return ParagonIE_Sodium_Core32_Int64
 846       */
 847      public function xorInt64(ParagonIE_Sodium_Core32_Int64 $b)
 848      {
 849          $return = new ParagonIE_Sodium_Core32_Int64();
 850          $return->unsignedInt = $this->unsignedInt;
 851          $return->limbs = array(
 852              (int) ($this->limbs[0] ^ $b->limbs[0]),
 853              (int) ($this->limbs[1] ^ $b->limbs[1]),
 854              (int) ($this->limbs[2] ^ $b->limbs[2]),
 855              (int) ($this->limbs[3] ^ $b->limbs[3])
 856          );
 857          return $return;
 858      }
 859  
 860      /**
 861       * @param int $low
 862       * @param int $high
 863       * @return self
 864       * @throws SodiumException
 865       * @throws TypeError
 866       */
 867      public static function fromInts($low, $high)
 868      {
 869          ParagonIE_Sodium_Core32_Util::declareScalarType($low, 'int', 1);
 870          ParagonIE_Sodium_Core32_Util::declareScalarType($high, 'int', 2);
 871  
 872          $high = (int) $high;
 873          $low = (int) $low;
 874          return new ParagonIE_Sodium_Core32_Int64(
 875              array(
 876                  (int) (($high >> 16) & 0xffff),
 877                  (int) ($high & 0xffff),
 878                  (int) (($low >> 16) & 0xffff),
 879                  (int) ($low & 0xffff)
 880              )
 881          );
 882      }
 883  
 884      /**
 885       * @param int $low
 886       * @return self
 887       * @throws SodiumException
 888       * @throws TypeError
 889       */
 890      public static function fromInt($low)
 891      {
 892          ParagonIE_Sodium_Core32_Util::declareScalarType($low, 'int', 1);
 893          $low = (int) $low;
 894  
 895          return new ParagonIE_Sodium_Core32_Int64(
 896              array(
 897                  0,
 898                  0,
 899                  (int) (($low >> 16) & 0xffff),
 900                  (int) ($low & 0xffff)
 901              )
 902          );
 903      }
 904  
 905      /**
 906       * @return int
 907       */
 908      public function toInt()
 909      {
 910          return (int) (
 911              (($this->limbs[2] & 0xffff) << 16)
 912                  |
 913              ($this->limbs[3] & 0xffff)
 914          );
 915      }
 916  
 917      /**
 918       * @param string $string
 919       * @return self
 920       * @throws SodiumException
 921       * @throws TypeError
 922       */
 923      public static function fromString($string)
 924      {
 925          ParagonIE_Sodium_Core32_Util::declareScalarType($string, 'string', 1);
 926          $string = (string) $string;
 927          if (ParagonIE_Sodium_Core32_Util::strlen($string) !== 8) {
 928              throw new RangeException(
 929                  'String must be 8 bytes; ' . ParagonIE_Sodium_Core32_Util::strlen($string) . ' given.'
 930              );
 931          }
 932          $return = new ParagonIE_Sodium_Core32_Int64();
 933  
 934          $return->limbs[0]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[0]) & 0xff) << 8);
 935          $return->limbs[0] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[1]) & 0xff);
 936          $return->limbs[1]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[2]) & 0xff) << 8);
 937          $return->limbs[1] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[3]) & 0xff);
 938          $return->limbs[2]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[4]) & 0xff) << 8);
 939          $return->limbs[2] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[5]) & 0xff);
 940          $return->limbs[3]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[6]) & 0xff) << 8);
 941          $return->limbs[3] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[7]) & 0xff);
 942          return $return;
 943      }
 944  
 945      /**
 946       * @param string $string
 947       * @return self
 948       * @throws SodiumException
 949       * @throws TypeError
 950       */
 951      public static function fromReverseString($string)
 952      {
 953          ParagonIE_Sodium_Core32_Util::declareScalarType($string, 'string', 1);
 954          $string = (string) $string;
 955          if (ParagonIE_Sodium_Core32_Util::strlen($string) !== 8) {
 956              throw new RangeException(
 957                  'String must be 8 bytes; ' . ParagonIE_Sodium_Core32_Util::strlen($string) . ' given.'
 958              );
 959          }
 960          $return = new ParagonIE_Sodium_Core32_Int64();
 961  
 962          $return->limbs[0]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[7]) & 0xff) << 8);
 963          $return->limbs[0] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[6]) & 0xff);
 964          $return->limbs[1]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[5]) & 0xff) << 8);
 965          $return->limbs[1] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[4]) & 0xff);
 966          $return->limbs[2]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[3]) & 0xff) << 8);
 967          $return->limbs[2] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[2]) & 0xff);
 968          $return->limbs[3]  = (int) ((ParagonIE_Sodium_Core32_Util::chrToInt($string[1]) & 0xff) << 8);
 969          $return->limbs[3] |= (ParagonIE_Sodium_Core32_Util::chrToInt($string[0]) & 0xff);
 970          return $return;
 971      }
 972  
 973      /**
 974       * @return array<int, int>
 975       */
 976      public function toArray()
 977      {
 978          return array(
 979              (int) ((($this->limbs[0] & 0xffff) << 16) | ($this->limbs[1] & 0xffff)),
 980              (int) ((($this->limbs[2] & 0xffff) << 16) | ($this->limbs[3] & 0xffff))
 981          );
 982      }
 983  
 984      /**
 985       * @return ParagonIE_Sodium_Core32_Int32
 986       */
 987      public function toInt32()
 988      {
 989          $return = new ParagonIE_Sodium_Core32_Int32();
 990          $return->limbs[0] = (int) ($this->limbs[2]);
 991          $return->limbs[1] = (int) ($this->limbs[3]);
 992          $return->unsignedInt = $this->unsignedInt;
 993          $return->overflow = (int) (ParagonIE_Sodium_Core32_Util::abs($this->limbs[1], 16) & 0xffff);
 994          return $return;
 995      }
 996  
 997      /**
 998       * @return ParagonIE_Sodium_Core32_Int64
 999       */
1000      public function toInt64()
1001      {
1002          $return = new ParagonIE_Sodium_Core32_Int64();
1003          $return->limbs[0] = (int) ($this->limbs[0]);
1004          $return->limbs[1] = (int) ($this->limbs[1]);
1005          $return->limbs[2] = (int) ($this->limbs[2]);
1006          $return->limbs[3] = (int) ($this->limbs[3]);
1007          $return->unsignedInt = $this->unsignedInt;
1008          $return->overflow = ParagonIE_Sodium_Core32_Util::abs($this->overflow);
1009          return $return;
1010      }
1011  
1012      /**
1013       * @param bool $bool
1014       * @return self
1015       */
1016      public function setUnsignedInt($bool = false)
1017      {
1018          $this->unsignedInt = !empty($bool);
1019          return $this;
1020      }
1021  
1022      /**
1023       * @return string
1024       * @throws TypeError
1025       */
1026      public function toString()
1027      {
1028          return ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[0] >> 8) & 0xff) .
1029              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[0] & 0xff) .
1030              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[1] >> 8) & 0xff) .
1031              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[1] & 0xff) .
1032              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[2] >> 8) & 0xff) .
1033              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[2] & 0xff) .
1034              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[3] >> 8) & 0xff) .
1035              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[3] & 0xff);
1036      }
1037  
1038      /**
1039       * @return string
1040       * @throws TypeError
1041       */
1042      public function toReverseString()
1043      {
1044          return ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[3] & 0xff) .
1045              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[3] >> 8) & 0xff) .
1046              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[2] & 0xff) .
1047              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[2] >> 8) & 0xff) .
1048              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[1] & 0xff) .
1049              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[1] >> 8) & 0xff) .
1050              ParagonIE_Sodium_Core32_Util::intToChr($this->limbs[0] & 0xff) .
1051              ParagonIE_Sodium_Core32_Util::intToChr(($this->limbs[0] >> 8) & 0xff);
1052      }
1053  
1054      /**
1055       * @return string
1056       */
1057      public function __toString()
1058      {
1059          try {
1060              return $this->toString();
1061          } catch (TypeError $ex) {
1062              // PHP engine can't handle exceptions from __toString()
1063              return '';
1064          }
1065      }
1066  }