Untitled

<!DOCTYPE html>
<html>
<head>
    <title>Hash Calculator</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <style>td{padding:10px;}</style>
</head>
<body>
    <div>Hash Calculator</div>
    <br>
    <div>
        <form method="POST" id = "form1" enctype="multipart/form-data">
            <input id="file" type="file">
            <br>
            <table>
                <tr>
                    <td style="text-align: right;"> Beginning bit off-set:</td>
                    <td><input type = "text" name="start" id="start"></td>
                </tr>
                <tr>
                    <td style="text-align: right;"> Last bit off-set:</td>
                    <td><input type = "text" name="lastbit" id="lastbit"></td>
                </tr>
                <tr>
                    <td style="text-align: right;"> Segment Size:</td>
                    <td><input type = "text" name="chunksize" id="chunk"></td>
                </tr>
                <tr>
                    <td style="text-align: right;"> Hash Function:</td>
                    <td>
                        <select name="hashtype" id="hashtype">
                            <option value="MD5">MD5</option>
                            <option value="SHA1">SHA1</option>
                            <option value="SHA256">SHA256</option>
                        </select>
                    </td>
                </tr>
            </table>
            <br>
            <input type="button" name="calculate" id="calculate" value="Calculate Hash">
        </form>
        <pre id=log></pre>
        <br>
        <pre id=log1></pre>
        <br>
        <pre id=log2></pre>
    </div>
    <script src="js/jquery-3.1.1.min.js" type="text/javascript"></script>
    <script src="js/spark-md5.min.js" type="text/javascript"></script>
    <script src="js/asmcrypto.js" type="text/javascript"></script>
    <script src="js/script.js" type="text/javascript"></script>
</body>
</html>

/*
    * Setting initial value and global varible
    */
var startbit = 0;
var lastbit = 0;
var chunkSize = 0;
var type = 'md5';
var file = '';
var filesize = 0;
var percent = 0;
var log=document.getElementById("log");
var log1=document.getElementById("log1");
var log2=document.getElementById("log2");

/*
    * Function to add number of 0 to keep range so every number has same digit.
    * @param {type} number eg : 1
    * @param {type} targetLength eg: 4
    * @returns {leftPad.output|String} output : 0001
    */
function leftPad(number, targetLength)
{
    var output = number + '';
    while (output.length < targetLength) {
        output = '0' + output;
    }
    return output;
}

/*
    * it clear all the details which has been print on the screen
    */
function clearlog()
{
    log.style.display="inline-block";
    log.innerHTML="";
    log1.style.display="inline-block";
    log1.innerHTML="";
    log2.style.display="inline-block";
    log2.innerHTML="";
}

/*
    * Validating start bit, end bit, segment(chunk size)
    */
function validate()
{
    var output1 = true;
    //For starting bit
    if(startbit == '')
    {
        log.innerHTML+="n Beginning bit off-set cannot not be emptyn";
        output1 = false;
    }
    else if(isNaN(startbit) || startbit < 0 )
    {
        log.innerHTML+="n Beginning bit off-set should be a number and should be 0 greater than 0 n";
        output1 = false;
    }
    else if(startbit>filesize)
    {
        log.innerHTML+="n Beginning bit off-set should less than file size ("+filesize+") n";
        output1 = false;
    }

    //For Ending bit
    if(lastbit == '')
    {
        log.innerHTML+="n Last bit off-set cannot not be emptyn";
        output1 = false;
    }
    else if(isNaN(lastbit) || lastbit < 1 )
    {
        log.innerHTML+="n Last bit off-set should be a number and should be greater than 0 n";
        output1 = false;
    }
    else if(lastbit>filesize)
    {
        log.innerHTML+="n Last bit off-set should less than file size ("+filesize+") n";
        output1 = false;
    }

    //For segment
    if(chunkSize == '')
    {
        log.innerHTML+="n Segment Size cannot not be emptyn";
        output1 = false;
    }
    else if(isNaN(chunkSize) || chunkSize < 1 )
    {
        log.innerHTML+="n Segment Size should be a number and should be greater than 0 n";
        output1 = false;
    }
    else if(chunkSize>filesize)
    {
        log.innerHTML+="n Segment Size should less than file size ("+filesize+") n";
        output1 = false;
    }
    else if((chunkSize%8) != 0)
    {
        log.innerHTML+="n Segment Size should be a mulitple of 8 n";
        output1 = false;
    }
    return output1;
}

/*
    * Getting file Details on file select and setting default to input field
    */
$(document).on('change','#file',function ()
{
    file = this.files[0];
    chunkSize = 1048576*8; //in bytes read in chunks of 1MB
    chunks = Math.ceil(file.size / chunkSize);
    lastbit = (file.size*8);
    filesize = lastbit;
    $('#start').val(startbit);
    $('#lastbit').val(lastbit);
    $('#chunk').val(chunkSize);
    clearlog();
});


$("#calculate").click(function()
{

    clearlog();
    //Fetching value from input
    startbit = $('#start').val();
    lastbit = $('#lastbit').val();
    chunkSize = $('#chunk').val();
    type = $('#hashtype').val();
    if(file == '') //check for file is selected or not
    {
        log.innerHTML+="n Please Select file to proceed n";
        return false;
    }
    //validate for error if it does not rteurn error it will proceed else shows error
    if(validate())
    {
        //Conversion in bytes
        filesize = lastbit-startbit;
        var startbit1 = Math.ceil(startbit/8);
        var chunkSize1 = Math.ceil(chunkSize/8);
        var filesize1 = Math.ceil(filesize/8);
        chunks = Math.ceil(filesize1 / chunkSize1);
        //padding length of 0 for segment no
        var padd_length = parseInt((chunks+'').length);
        //Last segment size
        var last_segment = ((filesize1)%chunkSize1)*8;
        if(last_segment == 0) last_segment = (chunkSize1*8);

        if(type == 'SHA1') {var hash1 = new asmCrypto.SHA1; var hash2 = new asmCrypto.SHA1;}
        else if(type == 'SHA256') {var hash1 = new asmCrypto.SHA256; var hash2 = new asmCrypto.SHA256;}
        else {var hash1 = new SparkMD5.ArrayBuffer();var hash2  = new SparkMD5.ArrayBuffer();}
        //using bobslice to partion the file and process it
        var blobSlice = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice,
            currentChunk = 0,
            myChunk = 0,
            dummydata = new Array(),
            output1 = '', //Store hash value and display when called for column1
            output2 = '',  //Store hash value and display when called for column2
            frOnload = function(e) //for column1
            {
                dummydata.push(e.target.result);
                if(type == 'MD5')
                {
                    hash1.append(e.target.result); // append array buffer for collumn one
                    $.each(dummydata, function (index, value) {
                        hash2.append(value); // append array buffer for collumn two
                    });
                    output1 = hash1.end();
                    output2 = hash2.end();

                }
                else
                {
                    var arr1 ='';
                    var arr2 = '';
                    hash1.reset();
                    hash2.reset();
                    hash1.process(e.target.result); // append array buffer for collumn one
                    $.each(dummydata, function (index, value) {
                        hash2.process(value); //append array buffer for collumn two
                    });
                    //Getting output in decimal
                    arr1 = hash1.finish().result;
                    arr2 = hash2.finish().result;
                    output1 = '';
                    output2 = '';

                    //converting output in hexadecimal
                    $.each(arr1, function (index, value) {
                        value =  value.toString(16);
                        if(value.length == 1)
                        {
                            value = '0'+value;
                        }
                        output1 +=value;
                    });
                    $.each(arr2, function (index, value) {
                        value =  value.toString(16);
                        if(value.length == 1)
                        {
                            value = '0'+value;
                        }
                        output2 +=value;
                    });
                }
                //condition to process till the chunk is not completed
                currentChunk++;
                if(currentChunk <= chunks)
                {
                    loadNext();
                }
            },

            frOnerror = function () {
                log.innerHTML+="n oops, something went wrong.";
            };
            function loadNext()
            {
                //for column1
                var fileReader = new FileReader();
                fileReader.onload = frOnload;
                fileReader.onerror = frOnerror;
                var start = startbit1+(currentChunk * chunkSize1),
                        end = ((start + chunkSize1) >= filesize1) ? filesize1 : start + chunkSize1;

                //call to frOnload to get hash value for column1
                fileReader.readAsArrayBuffer(blobSlice.call(file, start, end));

                //print segemwnt with hash value on each line
                if(currentChunk !=0)
                {
                    log2.innerHTML+=" Segement Hash #"+leftPad(parseInt(currentChunk),padd_length)+":"+output1+" &nbsp&nbsp;"+output2+"n";
                    percent = Math.round((currentChunk/chunks)*100); //transform to near integer value 0.1-0.4 as 0% and 0.5-0.9 as 1%
                    log1.innerHTML = " Total: "+leftPad(parseInt(percent),3)+"%n";
                }
            };

            //Printing Details
            log.innerHTML = "n Filename: "+file.name+" n Hash: "+type+" n Segment Length: "+chunkSize+" n Segment Count:"+chunks+" n Last Segment Length: "+last_segment;
            log1.innerHTML = " Total: "+leftPad(parseInt(percent),3)+"%n"; //initial percent to 0
            //
            loadNext();
    }
    return false;
});