Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xls.php
private function readRangeProtection()
    {
        $length = self::getUInt2d($this->data, $this->pos + 2);
        $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);

        // move stream pointer to next record
        $this->pos += 4 + $length;

        // local pointer in record data
        $offset = 0;

        if (!$this->readDataOnly) {
            $offset += 12;

            // offset: 12; size: 2; shared feature type, 2 = enhanced protection, 4 = smart tag
            $isf = self::getUInt2d($recordData, 12);
            if ($isf != 2) {
                // we only read FEAT records of type 2
                return;
            }
            $offset += 2;

            $offset += 5;

            // offset: 19; size: 2; count of ref ranges this feature is on
            $cref = self::getUInt2d($recordData, 19);
            $offset += 2;

            $offset += 6;

            // offset: 27; size: 8 * $cref; list of cell ranges (like in hyperlink record)
            $cellRanges = [];
            for ($i = 0; $i < $cref; ++$i) {
                try {
                    $cellRange = $this->readBIFF8CellRangeAddressFixed(substr($recordData, 27 + 8 * $i, 8));
                } catch (PhpSpreadsheetException $e) {
                    return;
                }
                $cellRanges[] = $cellRange;
                $offset += 8;
            }

            // offset: var; size: var; variable length of feature specific data
            $rgbFeat = substr($recordData, $offset);
            $offset += 4;

            // offset: var; size: 4; the encrypted password (only 16-bit although field is 32-bit)
            $wPassword = self::getInt4d($recordData, $offset);
            $offset += 4;

            // Apply range protection to sheet
            if ($cellRanges) {
                $this->phpSheet->protectCells(implode(' ', $cellRanges), strtoupper(dechex($wPassword)), true);
            }
        }
    }
private function readRangeProtection()
    {
        $length = self::getUInt2d($this->data, $this->pos + 2);
        $recordData = $this->readRecordData($this->data, $this->pos + 4, $length);

        // move stream pointer to next record
        $this->pos += 4 + $length;

        // local pointer in record data
        $offset = 0;

        if (!$this->readDataOnly) {
            $offset += 12;

            // offset: 12; size: 2; shared feature type, 2 = enhanced protection, 4 = smart tag
            $isf = self::getUInt2d($recordData, 12);
            if ($isf != 2) {
                // we only read FEAT records of type 2
                return;
            }
            $offset += 2;

            $offset += 5;

            // offset: 19; size: 2; count of ref ranges this feature is on
            $cref = self::getUInt2d($recordData, 19);
            $offset += 2;

            $offset += 6;

            // offset: 27; size: 8 * $cref; list of cell ranges (like in hyperlink record)
            $cellRanges = [];
            for ($i = 0; $i < $cref; ++$i) {
                try {
                    $cellRange = $this->readBIFF8CellRangeAddressFixed(substr($recordData, 27 + 8 * $i, 8));
                } catch (PhpSpreadsheetException $e) {
                    return;
                }
                $cellRanges[] = $cellRange;
                $offset += 8;
            }

            // offset: var; size: var; variable length of feature specific data
            $rgbFeat = substr($recordData, $offset);
            $offset += 4;

            // offset: var; size: 4; the encrypted password (only 16-bit although field is 32-bit)
            $wPassword = self::getInt4d($recordData, $offset);
            $offset += 4;

            // Apply range protection to sheet
            if ($cellRanges) {
                $this->phpSheet->protectCells(implode(' ', $cellRanges), strtoupper(dechex($wPassword)), true);
            }
        }
    }
Read RANGEPROTECTION record
Reading of this record is based on Microsoft Office Excel 97-2000 Binary File Format Specification,
where it is referred to as FEAT record.