<?php 
declare(strict_types=1); 
 
/** 
 * Class ParagonIE_Sodium_Core_Base64UrlSafe 
 * 
 *  Copyright (c) 2016 - 2018 Paragon Initiative Enterprises. 
 *  Copyright (c) 2014 Steve "Sc00bz" Thomas (steve at tobtu dot com) 
 */ 
class ParagonIE_Sodium_Core_Base64_UrlSafe 
{ 
    // COPY ParagonIE_Sodium_Core_Base64_Common STARTING HERE 
    /** 
     * Encode into Base64 
     * 
     * Base64 character set "[A-Z][a-z][0-9]+/" 
     * 
     * @param string $src 
     * @return string 
     * @throws TypeError 
     */ 
    public static function encode( 
        #[SensitiveParameter] 
        string $src 
    ): string { 
        return self::doEncode($src); 
    } 
 
    /** 
     * Encode into Base64, no = padding 
     * 
     * Base64 character set "[A-Z][a-z][0-9]+/" 
     * 
     * @param string $src 
     * @return string 
     * @throws TypeError 
     */ 
    public static function encodeUnpadded( 
        #[SensitiveParameter] 
        string $src 
    ): string { 
        return self::doEncode($src, false); 
    } 
 
    /** 
     * @param string $src 
     * @param bool $pad   Include = padding? 
     * @return string 
     * @throws TypeError 
     */ 
    protected static function doEncode( 
        #[SensitiveParameter] 
        string $src, 
        bool $pad = true 
    ): string { 
        $dest = ''; 
        $srcLen = ParagonIE_Sodium_Core_Util::strlen($src); 
        // Main loop (no padding): 
        for ($i = 0; $i + 3 <= $srcLen; $i += 3) { 
            /** @var array<int, int> $chunk */ 
            $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, 3)); 
            $b0 = $chunk[1]; 
            $b1 = $chunk[2]; 
            $b2 = $chunk[3]; 
 
            $dest .= 
                self::encode6Bits(               $b0 >> 2       ) . 
                self::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) . 
                self::encode6Bits((($b1 << 2) | ($b2 >> 6)) & 63) . 
                self::encode6Bits(  $b2                     & 63); 
        } 
        // The last chunk, which may have padding: 
        if ($i < $srcLen) { 
            /** @var array<int, int> $chunk */ 
            $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, $srcLen - $i)); 
            $b0 = $chunk[1]; 
            if ($i + 1 < $srcLen) { 
                $b1 = $chunk[2]; 
                $dest .= 
                    self::encode6Bits($b0 >> 2) . 
                    self::encode6Bits((($b0 << 4) | ($b1 >> 4)) & 63) . 
                    self::encode6Bits(($b1 << 2) & 63); 
                if ($pad) { 
                    $dest .= '='; 
                } 
            } else { 
                $dest .= 
                    self::encode6Bits( $b0 >> 2) . 
                    self::encode6Bits(($b0 << 4) & 63); 
                if ($pad) { 
                    $dest .= '=='; 
                } 
            } 
        } 
        return $dest; 
    } 
 
    /** 
     * decode from base64 into binary 
     * 
     * Base64 character set "./[A-Z][a-z][0-9]" 
     * 
     * @param string $src 
     * @param bool $strictPadding 
     * @return string 
     * @throws RangeException 
     * @throws TypeError 
     */ 
    public static function decode( 
        #[SensitiveParameter] 
        string $src, 
        bool $strictPadding = false 
    ): string { 
        // Remove padding 
        $srcLen = ParagonIE_Sodium_Core_Util::strlen($src); 
        if ($srcLen === 0) { 
            return ''; 
        } 
 
        if ($strictPadding) { 
            if (($srcLen & 3) === 0) { 
                if ($src[$srcLen - 1] === '=') { 
                    $srcLen--; 
                    if ($src[$srcLen - 1] === '=') { 
                        $srcLen--; 
                    } 
                } 
            } 
            if (($srcLen & 3) === 1) { 
                throw new RangeException( 
                    'Incorrect padding' 
                ); 
            } 
            if ($src[$srcLen - 1] === '=') { 
                throw new RangeException( 
                    'Incorrect padding' 
                ); 
            } 
        } else { 
            $src = rtrim($src, '='); 
            $srcLen =  ParagonIE_Sodium_Core_Util::strlen($src); 
        } 
 
        $err = 0; 
        $dest = ''; 
        // Main loop (no padding): 
        for ($i = 0; $i + 4 <= $srcLen; $i += 4) { 
            /** @var array<int, int> $chunk */ 
            $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, 4)); 
            $c0 = self::decode6Bits($chunk[1]); 
            $c1 = self::decode6Bits($chunk[2]); 
            $c2 = self::decode6Bits($chunk[3]); 
            $c3 = self::decode6Bits($chunk[4]); 
 
            $dest .= pack( 
                'CCC', 
                ((($c0 << 2) | ($c1 >> 4)) & 0xff), 
                ((($c1 << 4) | ($c2 >> 2)) & 0xff), 
                ((($c2 << 6) | $c3) & 0xff) 
            ); 
            $err |= ($c0 | $c1 | $c2 | $c3) >> 8; 
        } 
        // The last chunk, which may have padding: 
        if ($i < $srcLen) { 
            /** @var array<int, int> $chunk */ 
            $chunk = unpack('C*', ParagonIE_Sodium_Core_Util::substr($src, $i, $srcLen - $i)); 
            $c0 = self::decode6Bits($chunk[1]); 
 
            if ($i + 2 < $srcLen) { 
                $c1 = self::decode6Bits($chunk[2]); 
                $c2 = self::decode6Bits($chunk[3]); 
                $dest .= pack( 
                    'CC', 
                    ((($c0 << 2) | ($c1 >> 4)) & 0xff), 
                    ((($c1 << 4) | ($c2 >> 2)) & 0xff) 
                ); 
                $err |= ($c0 | $c1 | $c2) >> 8; 
            } elseif ($i + 1 < $srcLen) { 
                $c1 = self::decode6Bits($chunk[2]); 
                $dest .= pack( 
                    'C', 
                    ((($c0 << 2) | ($c1 >> 4)) & 0xff) 
                ); 
                $err |= ($c0 | $c1) >> 8; 
            } 
        } 
        $check = ($err === 0); 
        if (!$check) { 
            throw new RangeException( 
                'Base64::decode() only expects characters in the correct base64 alphabet' 
            ); 
        } 
        return $dest; 
    } 
    // COPY ParagonIE_Sodium_Core_Base64_Common ENDING HERE 
    /** 
     * Uses bitwise operators instead of table-lookups to turn 6-bit integers 
     * into 8-bit integers. 
     * 
     * Base64 character set: 
     * [A-Z]      [a-z]      [0-9]      +     / 
     * 0x41-0x5a, 0x61-0x7a, 0x30-0x39, 0x2b, 0x2f 
     * 
     * @param int $src 
     * @return int 
     */ 
    protected static function decode6Bits( 
        #[SensitiveParameter] 
        int $src 
    ): int { 
        $ret = -1; 
 
        // if ($src > 0x40 && $src < 0x5b) $ret += $src - 0x41 + 1; // -64 
        $ret += (((0x40 - $src) & ($src - 0x5b)) >> 8) & ($src - 64); 
 
        // if ($src > 0x60 && $src < 0x7b) $ret += $src - 0x61 + 26 + 1; // -70 
        $ret += (((0x60 - $src) & ($src - 0x7b)) >> 8) & ($src - 70); 
 
        // if ($src > 0x2f && $src < 0x3a) $ret += $src - 0x30 + 52 + 1; // 5 
        $ret += (((0x2f - $src) & ($src - 0x3a)) >> 8) & ($src + 5); 
 
        // if ($src == 0x2c) $ret += 62 + 1; 
        $ret += (((0x2c - $src) & ($src - 0x2e)) >> 8) & 63; 
 
        // if ($src == 0x5f) ret += 63 + 1; 
        $ret += (((0x5e - $src) & ($src - 0x60)) >> 8) & 64; 
 
        return $ret; 
    } 
 
    /** 
     * Uses bitwise operators instead of table-lookups to turn 8-bit integers 
     * into 6-bit integers. 
     * 
     * @param int $src 
     * @return string 
     */ 
    protected static function encode6Bits( 
        int $src 
    ): string { 
        $diff = 0x41; 
 
        // if ($src > 25) $diff += 0x61 - 0x41 - 26; // 6 
        $diff += ((25 - $src) >> 8) & 6; 
 
        // if ($src > 51) $diff += 0x30 - 0x61 - 26; // -75 
        $diff -= ((51 - $src) >> 8) & 75; 
 
        // if ($src > 61) $diff += 0x2d - 0x30 - 10; // -13 
        $diff -= ((61 - $src) >> 8) & 13; 
 
        // if ($src > 62) $diff += 0x5f - 0x2b - 1; // 3 
        $diff += ((62 - $src) >> 8) & 49; 
 
        return pack('C', $src + $diff); 
    } 
} 
 
 |