ParagonIE_Sodium_File::secretbox_decrypt_core32( resource $ifp, resource $ofp, int $mlen, string $nonce, string $key ): bool

Compatibility

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

Parameters

$ifpresource

$ofpresource

$mlenint

$noncestring

$keystring

Return value

bool

Performance profile

How much work a call to ParagonIE_Sodium_File::secretbox_decrypt_core32() 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

Heavy

Reads or writes the filesystem via fread().

Scaling

Scales with input

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

Instructions

16–103

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 131.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

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

What it touches

• filesystemfilesystem accessfread()called directly

What one call costs · 5 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost ParagonIE_Sodium_File::secretbox_decrypt_core32() can have, taken from its control-flow graph on PHP 8.5.

Uses · 10

• SodiumException::__construct()
• ParagonIE_Sodium_Core32_HSalsa20::hsalsa20()Calculate an hsalsa20 hash of a single block
• ParagonIE_Sodium_Core32_Util::substr()
• ParagonIE_Sodium_Core32_Salsa20::salsa20()
• ParagonIE_Sodium_Core32_Poly1305_State::__construct()ParagonIE_Sodium_Core32_Poly1305_State constructor.
• ParagonIE_Sodium_File::substr()
• ParagonIE_Sodium_File::onetimeauth_verify_core32()One-time message authentication for 32-bit systems
• ParagonIE_Sodium_File::strlen()
• ParagonIE_Sodium_File::xorStrings()
• ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic()

Used by · 1

• ParagonIE_Sodium_File::secretbox_decrypt()Decrypt a file

Source code

View on Trac ↗View on GitHub ↗

1493    protected static function secretbox_decrypt_core32($ifp, $ofp, $mlen, $nonce, $key)1494    {1495        $tag = fread($ifp, 16);1496        if (!is_string($tag)) {1497            throw new SodiumException('Could not read input file');1498        }1499 1500        /** @var string $subkey */1501        $subkey = ParagonIE_Sodium_Core32_HSalsa20::hsalsa20($nonce, $key);1502 1503        /** @var string $realNonce */1504        $realNonce = ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8);1505 1506        /** @var string $block0 */1507        $block0 = ParagonIE_Sodium_Core32_Salsa20::salsa20(1508            64,1509            ParagonIE_Sodium_Core32_Util::substr($nonce, 16, 8),1510            $subkey1511        );1512 1513        /* Verify the Poly1305 MAC -before- attempting to decrypt! */1514        $state = new ParagonIE_Sodium_Core32_Poly1305_State(self::substr($block0, 0, 32));1515        if (!self::onetimeauth_verify_core32($state, $ifp, $tag, $mlen)) {1516            throw new SodiumException('Invalid MAC');1517        }1518 1519        /*1520         * Set the cursor to the end of the first half-block. All future bytes will1521         * generated from salsa20_xor_ic, starting from 1 (second block).1522         */1523        $first32 = fread($ifp, 32);1524        if (!is_string($first32)) {1525            throw new SodiumException('Could not read input file');1526        }1527        $first32len = self::strlen($first32);1528        fwrite(1529            $ofp,1530            self::xorStrings(1531                self::substr($block0, 32, $first32len),1532                self::substr($first32, 0, $first32len)1533            )1534        );1535        $mlen -= 32;1536 1537        /** @var int $iter */1538        $iter = 1;1539 1540        /** @var int $incr */1541        $incr = self::BUFFER_SIZE >> 6;1542 1543        /* Decrypts ciphertext, writes to output file. */1544        while ($mlen > 0) {1545            $blockSize = $mlen > self::BUFFER_SIZE1546                ? self::BUFFER_SIZE1547                : $mlen;1548            $ciphertext = fread($ifp, $blockSize);1549            if (!is_string($ciphertext)) {1550                throw new SodiumException('Could not read input file');1551            }1552            $pBlock = ParagonIE_Sodium_Core32_Salsa20::salsa20_xor_ic(1553                $ciphertext,1554                $realNonce,1555                $iter,1556                $subkey1557            );1558            fwrite($ofp, $pBlock, $blockSize);1559            $mlen -= $blockSize;1560            $iter += $incr;1561        }1562        return true;1563    }

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/File.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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