ParagonIE_Sodium_Core_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_Core_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

12–111

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 146.

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 · 11 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost ParagonIE_Sodium_Core_Ed25519::verify_detached() can have, taken from its control-flow graph on PHP 8.5.

Uses · 12

• ParagonIE_Sodium_Core_Ed25519::strlen()
• SodiumException::__construct()
• ParagonIE_Sodium_Core_Ed25519::chrToInt()
• ParagonIE_Sodium_Core_Ed25519::check_S_lt_L()
• ParagonIE_Sodium_Core_Ed25519::substr()
• ParagonIE_Sodium_Core_Ed25519::small_order()
• ParagonIE_Sodium_Core_Ed25519::ge_frombytes_negate_vartime()
• ParagonIE_Sodium_Core_Ed25519::is_on_main_subgroup()Returns TRUE if $A represents a point on the order of the Edwards25519 prime order subgroup.
• ParagonIE_Sodium_Core_Ed25519::sc_reduce()
• ParagonIE_Sodium_Core_Ed25519::ge_double_scalarmult_vartime()
• ParagonIE_Sodium_Core_Ed25519::ge_tobytes()
• ParagonIE_Sodium_Core_Ed25519::verify_32()

Used by · 2

• ParagonIE_Sodium_Core_Ed25519::sign_open()
• ParagonIE_Sodium_Crypto::sign_verify_detached()Verify a detached signature of a given message and public key.

Source code

View on Trac ↗View on GitHub ↗

296    public static function verify_detached($sig, $message, $pk)297    {298        if (self::strlen($sig) !== 64) {299            throw new SodiumException('Argument 1 must be CRYPTO_SIGN_BYTES long');300        }301        if (self::strlen($pk) !== 32) {302            throw new SodiumException('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES long');303        }304        if ((self::chrToInt($sig[63]) & 240) && self::check_S_lt_L(self::substr($sig, 32, 32))) {305            throw new SodiumException('S >= L - Invalid signature');306        }307        if (self::small_order($sig)) {308            throw new SodiumException('Signature is on too small of an order');309        }310        if ((self::chrToInt($sig[63]) & 224) !== 0) {311            throw new SodiumException('Invalid signature');312        }313        $d = 0;314        for ($i = 0; $i < 32; ++$i) {315            $d |= self::chrToInt($pk[$i]);316        }317        if ($d === 0) {318            throw new SodiumException('All zero public key');319        }320 321        /** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */322        $orig = ParagonIE_Sodium_Compat::$fastMult;323 324        // Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.325        ParagonIE_Sodium_Compat::$fastMult = true;326 327        /** @var ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A */328        $A = self::ge_frombytes_negate_vartime($pk);329        if (!self::is_on_main_subgroup($A)) {330            throw new SodiumException('Public key is not on a member of the main subgroup');331        }332 333        /** @var string $hDigest */334        $hDigest = hash(335            'sha512',336            self::substr($sig, 0, 32) .337                self::substr($pk, 0, 32) .338                $message,339            true340        );341 342        /** @var string $h */343        $h = self::sc_reduce($hDigest) . self::substr($hDigest, 32);344 345        /** @var ParagonIE_Sodium_Core_Curve25519_Ge_P2 $R */346        $R = self::ge_double_scalarmult_vartime(347            $h,348            $A,349            self::substr($sig, 32)350        );351 352        /** @var string $rcheck */353        $rcheck = self::ge_tobytes($R);354 355        // Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.356        ParagonIE_Sodium_Compat::$fastMult = $orig;357 358        return self::verify_32($rcheck, self::substr($sig, 0, 32));359    }

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

Corrections

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