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   1  <?php
   2  
   3  if (class_exists('ParagonIE_Sodium_Core32_X25519', false)) {
   4      return;
   5  }
   6  
   7  /**
   8   * Class ParagonIE_Sodium_Core32_X25519
   9   */
  10  abstract class ParagonIE_Sodium_Core32_X25519 extends ParagonIE_Sodium_Core32_Curve25519
  11  {
  12      /**
  13       * Alters the objects passed to this method in place.
  14       *
  15       * @internal You should not use this directly from another application
  16       *
  17       * @param ParagonIE_Sodium_Core32_Curve25519_Fe $f
  18       * @param ParagonIE_Sodium_Core32_Curve25519_Fe $g
  19       * @param int $b
  20       * @return void
  21       * @throws SodiumException
  22       * @throws TypeError
  23       * @psalm-suppress MixedMethodCall
  24       */
  25      public static function fe_cswap(
  26          ParagonIE_Sodium_Core32_Curve25519_Fe $f,
  27          ParagonIE_Sodium_Core32_Curve25519_Fe $g,
  28          $b = 0
  29      ) {
  30          $f0 = (int) $f[0]->toInt();
  31          $f1 = (int) $f[1]->toInt();
  32          $f2 = (int) $f[2]->toInt();
  33          $f3 = (int) $f[3]->toInt();
  34          $f4 = (int) $f[4]->toInt();
  35          $f5 = (int) $f[5]->toInt();
  36          $f6 = (int) $f[6]->toInt();
  37          $f7 = (int) $f[7]->toInt();
  38          $f8 = (int) $f[8]->toInt();
  39          $f9 = (int) $f[9]->toInt();
  40          $g0 = (int) $g[0]->toInt();
  41          $g1 = (int) $g[1]->toInt();
  42          $g2 = (int) $g[2]->toInt();
  43          $g3 = (int) $g[3]->toInt();
  44          $g4 = (int) $g[4]->toInt();
  45          $g5 = (int) $g[5]->toInt();
  46          $g6 = (int) $g[6]->toInt();
  47          $g7 = (int) $g[7]->toInt();
  48          $g8 = (int) $g[8]->toInt();
  49          $g9 = (int) $g[9]->toInt();
  50          $b = -$b;
  51          /** @var int $x0 */
  52          $x0 = ($f0 ^ $g0) & $b;
  53          /** @var int $x1 */
  54          $x1 = ($f1 ^ $g1) & $b;
  55          /** @var int $x2 */
  56          $x2 = ($f2 ^ $g2) & $b;
  57          /** @var int $x3 */
  58          $x3 = ($f3 ^ $g3) & $b;
  59          /** @var int $x4 */
  60          $x4 = ($f4 ^ $g4) & $b;
  61          /** @var int $x5 */
  62          $x5 = ($f5 ^ $g5) & $b;
  63          /** @var int $x6 */
  64          $x6 = ($f6 ^ $g6) & $b;
  65          /** @var int $x7 */
  66          $x7 = ($f7 ^ $g7) & $b;
  67          /** @var int $x8 */
  68          $x8 = ($f8 ^ $g8) & $b;
  69          /** @var int $x9 */
  70          $x9 = ($f9 ^ $g9) & $b;
  71          $f[0] = ParagonIE_Sodium_Core32_Int32::fromInt($f0 ^ $x0);
  72          $f[1] = ParagonIE_Sodium_Core32_Int32::fromInt($f1 ^ $x1);
  73          $f[2] = ParagonIE_Sodium_Core32_Int32::fromInt($f2 ^ $x2);
  74          $f[3] = ParagonIE_Sodium_Core32_Int32::fromInt($f3 ^ $x3);
  75          $f[4] = ParagonIE_Sodium_Core32_Int32::fromInt($f4 ^ $x4);
  76          $f[5] = ParagonIE_Sodium_Core32_Int32::fromInt($f5 ^ $x5);
  77          $f[6] = ParagonIE_Sodium_Core32_Int32::fromInt($f6 ^ $x6);
  78          $f[7] = ParagonIE_Sodium_Core32_Int32::fromInt($f7 ^ $x7);
  79          $f[8] = ParagonIE_Sodium_Core32_Int32::fromInt($f8 ^ $x8);
  80          $f[9] = ParagonIE_Sodium_Core32_Int32::fromInt($f9 ^ $x9);
  81          $g[0] = ParagonIE_Sodium_Core32_Int32::fromInt($g0 ^ $x0);
  82          $g[1] = ParagonIE_Sodium_Core32_Int32::fromInt($g1 ^ $x1);
  83          $g[2] = ParagonIE_Sodium_Core32_Int32::fromInt($g2 ^ $x2);
  84          $g[3] = ParagonIE_Sodium_Core32_Int32::fromInt($g3 ^ $x3);
  85          $g[4] = ParagonIE_Sodium_Core32_Int32::fromInt($g4 ^ $x4);
  86          $g[5] = ParagonIE_Sodium_Core32_Int32::fromInt($g5 ^ $x5);
  87          $g[6] = ParagonIE_Sodium_Core32_Int32::fromInt($g6 ^ $x6);
  88          $g[7] = ParagonIE_Sodium_Core32_Int32::fromInt($g7 ^ $x7);
  89          $g[8] = ParagonIE_Sodium_Core32_Int32::fromInt($g8 ^ $x8);
  90          $g[9] = ParagonIE_Sodium_Core32_Int32::fromInt($g9 ^ $x9);
  91      }
  92  
  93      /**
  94       * @internal You should not use this directly from another application
  95       *
  96       * @param ParagonIE_Sodium_Core32_Curve25519_Fe $f
  97       * @return ParagonIE_Sodium_Core32_Curve25519_Fe
  98       * @throws SodiumException
  99       * @throws TypeError
 100       * @psalm-suppress MixedAssignment
 101       * @psalm-suppress MixedMethodCall
 102       */
 103      public static function fe_mul121666(ParagonIE_Sodium_Core32_Curve25519_Fe $f)
 104      {
 105          /** @var array<int, ParagonIE_Sodium_Core32_Int64> $h */
 106          $h = array();
 107          for ($i = 0; $i < 10; ++$i) {
 108              $h[$i] = $f[$i]->toInt64()->mulInt(121666, 17);
 109          }
 110  
 111          $carry9 = $h[9]->addInt(1 << 24)->shiftRight(25);
 112          $h[0] = $h[0]->addInt64($carry9->mulInt(19, 5));
 113          $h[9] = $h[9]->subInt64($carry9->shiftLeft(25));
 114  
 115          $carry1 = $h[1]->addInt(1 << 24)->shiftRight(25);
 116          $h[2] = $h[2]->addInt64($carry1);
 117          $h[1] = $h[1]->subInt64($carry1->shiftLeft(25));
 118  
 119          $carry3 = $h[3]->addInt(1 << 24)->shiftRight(25);
 120          $h[4] = $h[4]->addInt64($carry3);
 121          $h[3] = $h[3]->subInt64($carry3->shiftLeft(25));
 122  
 123          $carry5 = $h[5]->addInt(1 << 24)->shiftRight(25);
 124          $h[6] = $h[6]->addInt64($carry5);
 125          $h[5] = $h[5]->subInt64($carry5->shiftLeft(25));
 126  
 127          $carry7 = $h[7]->addInt(1 << 24)->shiftRight(25);
 128          $h[8] = $h[8]->addInt64($carry7);
 129          $h[7] = $h[7]->subInt64($carry7->shiftLeft(25));
 130  
 131          $carry0 = $h[0]->addInt(1 << 25)->shiftRight(26);
 132          $h[1] = $h[1]->addInt64($carry0);
 133          $h[0] = $h[0]->subInt64($carry0->shiftLeft(26));
 134  
 135          $carry2 = $h[2]->addInt(1 << 25)->shiftRight(26);
 136          $h[3] = $h[3]->addInt64($carry2);
 137          $h[2] = $h[2]->subInt64($carry2->shiftLeft(26));
 138  
 139          $carry4 = $h[4]->addInt(1 << 25)->shiftRight(26);
 140          $h[5] = $h[5]->addInt64($carry4);
 141          $h[4] = $h[4]->subInt64($carry4->shiftLeft(26));
 142  
 143          $carry6 = $h[6]->addInt(1 << 25)->shiftRight(26);
 144          $h[7] = $h[7]->addInt64($carry6);
 145          $h[6] = $h[6]->subInt64($carry6->shiftLeft(26));
 146  
 147          $carry8 = $h[8]->addInt(1 << 25)->shiftRight(26);
 148          $h[9] = $h[9]->addInt64($carry8);
 149          $h[8] = $h[8]->subInt64($carry8->shiftLeft(26));
 150  
 151          for ($i = 0; $i < 10; ++$i) {
 152              $h[$i] = $h[$i]->toInt32();
 153          }
 154          /** @var array<int, ParagonIE_Sodium_Core32_Int32> $h2 */
 155          $h2 = $h;
 156          return ParagonIE_Sodium_Core32_Curve25519_Fe::fromArray($h2);
 157      }
 158  
 159      /**
 160       * @internal You should not use this directly from another application
 161       *
 162       * Inline comments preceded by # are from libsodium's ref10 code.
 163       *
 164       * @param string $n
 165       * @param string $p
 166       * @return string
 167       * @throws SodiumException
 168       * @throws TypeError
 169       */
 170      public static function crypto_scalarmult_curve25519_ref10($n, $p)
 171      {
 172          # for (i = 0;i < 32;++i) e[i] = n[i];
 173          $e = '' . $n;
 174          # e[0] &= 248;
 175          $e[0] = self::intToChr(
 176              self::chrToInt($e[0]) & 248
 177          );
 178          # e[31] &= 127;
 179          # e[31] |= 64;
 180          $e[31] = self::intToChr(
 181              (self::chrToInt($e[31]) & 127) | 64
 182          );
 183          # fe_frombytes(x1,p);
 184          $x1 = self::fe_frombytes($p);
 185          # fe_1(x2);
 186          $x2 = self::fe_1();
 187          # fe_0(z2);
 188          $z2 = self::fe_0();
 189          # fe_copy(x3,x1);
 190          $x3 = self::fe_copy($x1);
 191          # fe_1(z3);
 192          $z3 = self::fe_1();
 193  
 194          # swap = 0;
 195          /** @var int $swap */
 196          $swap = 0;
 197  
 198          # for (pos = 254;pos >= 0;--pos) {
 199          for ($pos = 254; $pos >= 0; --$pos) {
 200              # b = e[pos / 8] >> (pos & 7);
 201              /** @var int $b */
 202              $b = self::chrToInt(
 203                      $e[(int) floor($pos / 8)]
 204                  ) >> ($pos & 7);
 205              # b &= 1;
 206              $b &= 1;
 207  
 208              # swap ^= b;
 209              $swap ^= $b;
 210  
 211              # fe_cswap(x2,x3,swap);
 212              self::fe_cswap($x2, $x3, $swap);
 213  
 214              # fe_cswap(z2,z3,swap);
 215              self::fe_cswap($z2, $z3, $swap);
 216  
 217              # swap = b;
 218              /** @var int $swap */
 219              $swap = $b;
 220  
 221              # fe_sub(tmp0,x3,z3);
 222              $tmp0 = self::fe_sub($x3, $z3);
 223  
 224              # fe_sub(tmp1,x2,z2);
 225              $tmp1 = self::fe_sub($x2, $z2);
 226  
 227              # fe_add(x2,x2,z2);
 228              $x2 = self::fe_add($x2, $z2);
 229  
 230              # fe_add(z2,x3,z3);
 231              $z2 = self::fe_add($x3, $z3);
 232  
 233              # fe_mul(z3,tmp0,x2);
 234              $z3 = self::fe_mul($tmp0, $x2);
 235  
 236              # fe_mul(z2,z2,tmp1);
 237              $z2 = self::fe_mul($z2, $tmp1);
 238  
 239              # fe_sq(tmp0,tmp1);
 240              $tmp0 = self::fe_sq($tmp1);
 241  
 242              # fe_sq(tmp1,x2);
 243              $tmp1 = self::fe_sq($x2);
 244  
 245              # fe_add(x3,z3,z2);
 246              $x3 = self::fe_add($z3, $z2);
 247  
 248              # fe_sub(z2,z3,z2);
 249              $z2 = self::fe_sub($z3, $z2);
 250  
 251              # fe_mul(x2,tmp1,tmp0);
 252              $x2 = self::fe_mul($tmp1, $tmp0);
 253  
 254              # fe_sub(tmp1,tmp1,tmp0);
 255              $tmp1 = self::fe_sub($tmp1, $tmp0);
 256  
 257              # fe_sq(z2,z2);
 258              $z2 = self::fe_sq($z2);
 259  
 260              # fe_mul121666(z3,tmp1);
 261              $z3 = self::fe_mul121666($tmp1);
 262  
 263              # fe_sq(x3,x3);
 264              $x3 = self::fe_sq($x3);
 265  
 266              # fe_add(tmp0,tmp0,z3);
 267              $tmp0 = self::fe_add($tmp0, $z3);
 268  
 269              # fe_mul(z3,x1,z2);
 270              $z3 = self::fe_mul($x1, $z2);
 271  
 272              # fe_mul(z2,tmp1,tmp0);
 273              $z2 = self::fe_mul($tmp1, $tmp0);
 274          }
 275  
 276          # fe_cswap(x2,x3,swap);
 277          self::fe_cswap($x2, $x3, $swap);
 278  
 279          # fe_cswap(z2,z3,swap);
 280          self::fe_cswap($z2, $z3, $swap);
 281  
 282          # fe_invert(z2,z2);
 283          $z2 = self::fe_invert($z2);
 284  
 285          # fe_mul(x2,x2,z2);
 286          $x2 = self::fe_mul($x2, $z2);
 287          # fe_tobytes(q,x2);
 288          return (string) self::fe_tobytes($x2);
 289      }
 290  
 291      /**
 292       * @internal You should not use this directly from another application
 293       *
 294       * @param ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsY
 295       * @param ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsZ
 296       * @return ParagonIE_Sodium_Core32_Curve25519_Fe
 297       * @throws SodiumException
 298       * @throws TypeError
 299       */
 300      public static function edwards_to_montgomery(
 301          ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsY,
 302          ParagonIE_Sodium_Core32_Curve25519_Fe $edwardsZ
 303      ) {
 304          $tempX = self::fe_add($edwardsZ, $edwardsY);
 305          $tempZ = self::fe_sub($edwardsZ, $edwardsY);
 306          $tempZ = self::fe_invert($tempZ);
 307          return self::fe_mul($tempX, $tempZ);
 308      }
 309  
 310      /**
 311       * @internal You should not use this directly from another application
 312       *
 313       * @param string $n
 314       * @return string
 315       * @throws SodiumException
 316       * @throws TypeError
 317       */
 318      public static function crypto_scalarmult_curve25519_ref10_base($n)
 319      {
 320          # for (i = 0;i < 32;++i) e[i] = n[i];
 321          $e = '' . $n;
 322  
 323          # e[0] &= 248;
 324          $e[0] = self::intToChr(
 325              self::chrToInt($e[0]) & 248
 326          );
 327  
 328          # e[31] &= 127;
 329          # e[31] |= 64;
 330          $e[31] = self::intToChr(
 331              (self::chrToInt($e[31]) & 127) | 64
 332          );
 333  
 334          $A = self::ge_scalarmult_base($e);
 335          if (
 336              !($A->Y instanceof ParagonIE_Sodium_Core32_Curve25519_Fe)
 337                  ||
 338              !($A->Z instanceof ParagonIE_Sodium_Core32_Curve25519_Fe)
 339          ) {
 340              throw new TypeError('Null points encountered');
 341          }
 342          $pk = self::edwards_to_montgomery($A->Y, $A->Z);
 343          return self::fe_tobytes($pk);
 344      }
 345  }