ParagonIE_Sodium_Core32_Ed25519::verify_detached( string $sig, string $message, string $pk ): 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

$sigstring

$messagestring

$pkstring

Return value

bool

Performance profile

How much work a call to ParagonIE_Sodium_Core32_Ed25519::verify_detached() 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

12–102

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 129.

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_Core32_Ed25519::verify_detached() can have, taken from its control-flow graph on PHP 8.5.

Uses · 11

• ParagonIE_Sodium_Core32_Ed25519::strlen()
• SodiumException::__construct()
• ParagonIE_Sodium_Core32_Ed25519::chrToInt()
• ParagonIE_Sodium_Core32_Ed25519::check_S_lt_L()
• ParagonIE_Sodium_Core32_Ed25519::substr()
• ParagonIE_Sodium_Core32_Ed25519::small_order()
• ParagonIE_Sodium_Core32_Ed25519::ge_frombytes_negate_vartime()
• ParagonIE_Sodium_Core32_Ed25519::sc_reduce()
• ParagonIE_Sodium_Core32_Ed25519::ge_double_scalarmult_vartime()
• ParagonIE_Sodium_Core32_Ed25519::ge_tobytes()
• ParagonIE_Sodium_Core32_Ed25519::verify_32()

Used by · 2

• ParagonIE_Sodium_Core32_Ed25519::sign_open()
• ParagonIE_Sodium_Crypto32::sign_verify_detached()Verify a detached signature of a given message and public key.

Source code

View on Trac ↗View on GitHub ↗

280    public static function verify_detached($sig, $message, $pk)281    {282        if (self::strlen($sig) < 64) {283            throw new SodiumException('Signature is too short');284        }285        if ((self::chrToInt($sig[63]) & 240) && self::check_S_lt_L(self::substr($sig, 32, 32))) {286            throw new SodiumException('S < L - Invalid signature');287        }288        if (self::small_order($sig)) {289            throw new SodiumException('Signature is on too small of an order');290        }291        if ((self::chrToInt($sig[63]) & 224) !== 0) {292            throw new SodiumException('Invalid signature');293        }294        $d = 0;295        for ($i = 0; $i < 32; ++$i) {296            $d |= self::chrToInt($pk[$i]);297        }298        if ($d === 0) {299            throw new SodiumException('All zero public key');300        }301 302        /** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */303        $orig = ParagonIE_Sodium_Compat::$fastMult;304 305        // Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.306        ParagonIE_Sodium_Compat::$fastMult = true;307 308        /** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P3 $A */309        $A = self::ge_frombytes_negate_vartime($pk);310 311        /** @var string $hDigest */312        $hDigest = hash(313            'sha512',314            self::substr($sig, 0, 32) .315            self::substr($pk, 0, 32) .316            $message,317            true318        );319 320        /** @var string $h */321        $h = self::sc_reduce($hDigest) . self::substr($hDigest, 32);322 323        /** @var ParagonIE_Sodium_Core32_Curve25519_Ge_P2 $R */324        $R = self::ge_double_scalarmult_vartime(325            $h,326            $A,327            self::substr($sig, 32)328        );329 330        /** @var string $rcheck */331        $rcheck = self::ge_tobytes($R);332 333        // Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.334        ParagonIE_Sodium_Compat::$fastMult = $orig;335 336        return self::verify_32($rcheck, self::substr($sig, 0, 32));337    }

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/Core32/Ed25519.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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