[Summary view] [Print] [Text view]

   1  <?php
   2  
   3  /**
   4   * Class ParagonIE_Sodium_Core_Base64UrlSafe
   5   *
   6   *  Copyright (c) 2016 - 2018 Paragon Initiative Enterprises.
   7   *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com)
   8   */
   9  class ParagonIE_Sodium_Core_Base64_UrlSafe
  10  {
  11      // COPY ParagonIE_Sodium_Core_Base64_Common STARTING HERE
  12      /**
  13       * Encode into Base64
  14       *
  15       * Base64 character set "[A-Z][a-z][0-9]+/"
  16       *
  17       * @param string $src
  18       * @return string
  19       * @throws TypeError
  20       */
  21      public static function encode($src)
  22      {
  23          return self::doEncode($src, true);
  24      }
  25  
  26      /**
  27       * Encode into Base64, no = padding
  28       *
  29       * Base64 character set "[A-Z][a-z][0-9]+/"
  30       *
  31       * @param string $src
  32       * @return string
  33       * @throws TypeError
  34       */
  35      public static function encodeUnpadded($src)
  36      {
  37          return self::doEncode($src, false);
  38      }
  39  
  40      /**
  41       * @param string $src
  42       * @param bool $pad   Include = padding?
  43       * @return string
  44       * @throws TypeError
  45       */
  46      protected static function doEncode($src, $pad = true)
  47      {
  48          $dest = '';
  49          $srcLen = ParagonIE_Sodium_Core_Util::strlen($src);
  50          // Main loop (no padding):
  51          for ($i = 0; $i + 3 <= $srcLen; $i += 3) {
  52              /** @var array<int, int> $chunk */
  53              $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, 3));
  54              $b0 = $chunk[1];
  55              $b1 = $chunk[2];
  56              $b2 = $chunk[3];
  57  
  58              $dest .=
  59                  self::encode6Bits(               $b0 >> 2       ) .
  60                  self::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) .
  61                  self::encode6Bits((($b1 << 2) | ($b2 >> 6)) & 63) .
  62                  self::encode6Bits(  $b2                     & 63);
  63          }
  64          // The last chunk, which may have padding:
  65          if ($i < $srcLen) {
  66              /** @var array<int, int> $chunk */
  67              $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, $srcLen - $i));
  68              $b0 = $chunk[1];
  69              if ($i + 1 < $srcLen) {
  70                  $b1 = $chunk[2];
  71                  $dest .=
  72                      self::encode6Bits($b0 >> 2) .
  73                      self::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) .
  74                      self::encode6Bits(($b1 << 2) & 63);
  75                  if ($pad) {
  76                      $dest .= '=';
  77                  }
  78              } else {
  79                  $dest .=
  80                      self::encode6Bits( $b0 >> 2) .
  81                      self::encode6Bits(($b0 << 4) & 63);
  82                  if ($pad) {
  83                      $dest .= '==';
  84                  }
  85              }
  86          }
  87          return $dest;
  88      }
  89  
  90      /**
  91       * decode from base64 into binary
  92       *
  93       * Base64 character set "./[A-Z][a-z][0-9]"
  94       *
  95       * @param string $src
  96       * @param bool $strictPadding
  97       * @return string
  98       * @throws RangeException
  99       * @throws TypeError
 100       * @psalm-suppress RedundantCondition
 101       */
 102      public static function decode($src, $strictPadding = false)
 103      {
 104          // Remove padding
 105          $srcLen = ParagonIE_Sodium_Core_Util::strlen($src);
 106          if ($srcLen === 0) {
 107              return '';
 108          }
 109  
 110          if ($strictPadding) {
 111              if (($srcLen & 3) === 0) {
 112                  if ($src[$srcLen - 1] === '=') {
 113                      $srcLen--;
 114                      if ($src[$srcLen - 1] === '=') {
 115                          $srcLen--;
 116                      }
 117                  }
 118              }
 119              if (($srcLen & 3) === 1) {
 120                  throw new RangeException(
 121                      'Incorrect padding'
 122                  );
 123              }
 124              if ($src[$srcLen - 1] === '=') {
 125                  throw new RangeException(
 126                      'Incorrect padding'
 127                  );
 128              }
 129          } else {
 130              $src = rtrim($src, '=');
 131              $srcLen =  ParagonIE_Sodium_Core_Util::strlen($src);
 132          }
 133  
 134          $err = 0;
 135          $dest = '';
 136          // Main loop (no padding):
 137          for ($i = 0; $i + 4 <= $srcLen; $i += 4) {
 138              /** @var array<int, int> $chunk */
 139              $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, 4));
 140              $c0 = self::decode6Bits($chunk[1]);
 141              $c1 = self::decode6Bits($chunk[2]);
 142              $c2 = self::decode6Bits($chunk[3]);
 143              $c3 = self::decode6Bits($chunk[4]);
 144  
 145              $dest .= pack(
 146                  'CCC',
 147                  ((($c0 << 2) | ($c1 >> 4)) & 0xff),
 148                  ((($c1 << 4) | ($c2 >> 2)) & 0xff),
 149                  ((($c2 << 6) | $c3) & 0xff)
 150              );
 151              $err |= ($c0 | $c1 | $c2 | $c3) >> 8;
 152          }
 153          // The last chunk, which may have padding:
 154          if ($i < $srcLen) {
 155              /** @var array<int, int> $chunk */
 156              $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, $srcLen - $i));
 157              $c0 = self::decode6Bits($chunk[1]);
 158  
 159              if ($i + 2 < $srcLen) {
 160                  $c1 = self::decode6Bits($chunk[2]);
 161                  $c2 = self::decode6Bits($chunk[3]);
 162                  $dest .= pack(
 163                      'CC',
 164                      ((($c0 << 2) | ($c1 >> 4)) & 0xff),
 165                      ((($c1 << 4) | ($c2 >> 2)) & 0xff)
 166                  );
 167                  $err |= ($c0 | $c1 | $c2) >> 8;
 168              } elseif ($i + 1 < $srcLen) {
 169                  $c1 = self::decode6Bits($chunk[2]);
 170                  $dest .= pack(
 171                      'C',
 172                      ((($c0 << 2) | ($c1 >> 4)) & 0xff)
 173                  );
 174                  $err |= ($c0 | $c1) >> 8;
 175              } elseif ($i < $srcLen && $strictPadding) {
 176                  $err |= 1;
 177              }
 178          }
 179          /** @var bool $check */
 180          $check = ($err === 0);
 181          if (!$check) {
 182              throw new RangeException(
 183                  'Base64::decode() only expects characters in the correct base64 alphabet'
 184              );
 185          }
 186          return $dest;
 187      }
 188      // COPY ParagonIE_Sodium_Core_Base64_Common ENDING HERE
 189      /**
 190       * Uses bitwise operators instead of table-lookups to turn 6-bit integers
 191       * into 8-bit integers.
 192       *
 193       * Base64 character set:
 194       * [A-Z]      [a-z]      [0-9]      +     /
 195       * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2b, 0x2f
 196       *
 197       * @param int $src
 198       * @return int
 199       */
 200      protected static function decode6Bits($src)
 201      {
 202          $ret = -1;
 203  
 204          // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64
 205          $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64);
 206  
 207          // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70
 208          $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70);
 209  
 210          // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5
 211          $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5);
 212  
 213          // if ($src == 0x2c) $ret += 62 + 1;
 214          $ret += (((0x2c - $src) & ($src - 0x2e)) >> 8) & 63;
 215  
 216          // if ($src == 0x5f) ret += 63 + 1;
 217          $ret += (((0x5e - $src) & ($src - 0x60)) >> 8) & 64;
 218  
 219          return $ret;
 220      }
 221  
 222      /**
 223       * Uses bitwise operators instead of table-lookups to turn 8-bit integers
 224       * into 6-bit integers.
 225       *
 226       * @param int $src
 227       * @return string
 228       */
 229      protected static function encode6Bits($src)
 230      {
 231          $diff = 0x41;
 232  
 233          // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6
 234          $diff += ((25 - $src) >> 8) & 6;
 235  
 236          // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75
 237          $diff -= ((51 - $src) >> 8) & 75;
 238  
 239          // if ($src > 61) $diff += 0x2d - 0x30 - 10; // -13
 240          $diff -= ((61 - $src) >> 8) & 13;
 241  
 242          // if ($src > 62) $diff += 0x5f - 0x2b - 1; // 3
 243          $diff += ((62 - $src) >> 8) & 49;
 244  
 245          return pack('C', $src + $diff);
 246      }
 247  }