ParagonIE_Sodium_File::verify( string $sig, string $filePath, string $publicKey ): bool

694    public static function verify(695        $sig,696        $filePath,697        $publicKey698    ) {699        /* Type checks: */700        if (!is_string($sig)) {701            throw new TypeError('Argument 1 must be a string, ' . gettype($sig) . ' given.');702        }703        if (!is_string($filePath)) {704            throw new TypeError('Argument 2 must be a string, ' . gettype($filePath) . ' given.');705        }706        if (!is_string($publicKey)) {707            throw new TypeError('Argument 3 must be a string, ' . gettype($publicKey) . ' given.');708        }709 710        /* Input validation: */711        if (self::strlen($sig) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_BYTES) {712            throw new TypeError('Argument 1 must be CRYPTO_SIGN_BYTES bytes');713        }714        if (self::strlen($publicKey) !== ParagonIE_Sodium_Compat::CRYPTO_SIGN_PUBLICKEYBYTES) {715            throw new TypeError('Argument 3 must be CRYPTO_SIGN_PUBLICKEYBYTES bytes');716        }717        if (self::strlen($sig) < 64) {718            throw new SodiumException('Signature is too short');719        }720 721        if (PHP_INT_SIZE === 4) {722            return self::verify_core32($sig, $filePath, $publicKey);723        }724 725        /* Security checks */726        if (727            (ParagonIE_Sodium_Core_Ed25519::chrToInt($sig[63]) & 240)728                &&729            ParagonIE_Sodium_Core_Ed25519::check_S_lt_L(self::substr($sig, 32, 32))730        ) {731            throw new SodiumException('S < L - Invalid signature');732        }733        if (ParagonIE_Sodium_Core_Ed25519::small_order($sig)) {734            throw new SodiumException('Signature is on too small of an order');735        }736        if ((self::chrToInt($sig[63]) & 224) !== 0) {737            throw new SodiumException('Invalid signature');738        }739        $d = 0;740        for ($i = 0; $i < 32; ++$i) {741            $d |= self::chrToInt($publicKey[$i]);742        }743        if ($d === 0) {744            throw new SodiumException('All zero public key');745        }746 747        /** @var int $size */748        $size = filesize($filePath);749        if (!is_int($size)) {750            throw new SodiumException('Could not obtain the file size');751        }752 753        /** @var resource $fp */754        $fp = fopen($filePath, 'rb');755        if (!is_resource($fp)) {756            throw new SodiumException('Could not open input file for reading');757        }758 759        /** @var bool The original value of ParagonIE_Sodium_Compat::$fastMult */760        $orig = ParagonIE_Sodium_Compat::$fastMult;761 762        // Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.763        ParagonIE_Sodium_Compat::$fastMult = true;764 765        /** @var ParagonIE_Sodium_Core_Curve25519_Ge_P3 $A */766        $A = ParagonIE_Sodium_Core_Ed25519::ge_frombytes_negate_vartime($publicKey);767 768        $hs = hash_init('sha512');769        self::hash_update($hs, self::substr($sig, 0, 32));770        self::hash_update($hs, self::substr($publicKey, 0, 32));771        /** @var resource $hs */772        $hs = self::updateHashWithFile($hs, $fp, $size);773        /** @var string $hDigest */