ParagonIE_Sodium_Core_Base64_Original::decode( string $src, bool $strictPadding = false ): string

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$srcstring

$strictPaddingbooloptional

Default: false

Return value

string

Performance profile

How much work a call to ParagonIE_Sodium_Core_Base64_Original::decode() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Light

Touches nothing outside its own arguments.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

9–95

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 198.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

2

2 places in core call this, so the cost is paid more often than your own code shows.

What one call costs · 8 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost ParagonIE_Sodium_Core_Base64_Original::decode() can have, taken from its control-flow graph on PHP 8.5.

Uses · 4

• ParagonIE_Sodium_Core_Util::strlen()Safe string length
• RangeException::__construct()
• ParagonIE_Sodium_Core_Util::substr()Safe substring
• ParagonIE_Sodium_Core_Base64_Original::decode6Bits()Uses bitwise operators instead of table-lookups to turn 6-bit integers into 8-bit integers.

Used by · 2

• ParagonIE_Sodium_Compat::base642bin()
• ParagonIE_Sodium_Core_Base64_Original::decodeNoPadding()

Source code

View on Trac ↗View on GitHub ↗

102    public static function decode($src, $strictPadding = false)103    {104        // Remove padding105        $srcLen = ParagonIE_Sodium_Core_Util::strlen($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) {

Changelog

Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/sodium_compat/src/Core/Base64/Original.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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