PrivateBin/js/zerobin.js

/**
 * ZeroBin
 *
 * a zero-knowledge paste bin
 *
 * @link      http://sebsauvage.net/wiki/doku.php?id=php:zerobin
 * @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
 * @license   http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
 * @version   0.20
 */

// Immediately start random number generator collector.
sjcl.random.startCollectors();

$(function(){
    'use strict';
    
    /**
     * static helper methods
     */
    var helper = {

        /**
         * Converts a duration (in seconds) into human readable format.
         *
         * @param int seconds
         * @return string
         */
        secondsToHuman: function(seconds)
        {
            if (seconds < 60)
            {
                var v = Math.floor(seconds);
                return v + ' second' + ((v > 1) ? 's' : '');
            }
            if (seconds < 60 * 60)
            {
                var v = Math.floor(seconds / 60);
                return v + ' minute' + ((v > 1) ? 's' : '');
            }
            if (seconds < 60 * 60 * 24)
            {
                var v = Math.floor(seconds / (60 * 60));
                return v + ' hour' + ((v > 1) ? 's' : '');
            }
            // If less than 2 months, display in days:
            if (seconds < 60 * 60 * 24 * 60)
            {
                var v = Math.floor(seconds / (60 * 60 * 24));
                return v + ' day' + ((v > 1) ? 's' : '');
            }
            var v = Math.floor(seconds / (60 * 60 * 24 * 30));
            return v + ' month' + ((v > 1) ? 's' : '');
        },

        /**
         * Converts an associative array to an encoded string
         * for appending to the anchor.
         *
         * @param object associative_array Object to be serialized
         * @return string
         */
        hashToParameterString: function(associativeArray)
        {
            var parameterString = '';
            for (key in associativeArray)
            {
                if(parameterString === '')
                {
                    parameterString = encodeURIComponent(key);
                    parameterString += '=' + encodeURIComponent(associativeArray[key]);
                }
                else
                {
                    parameterString += '&' + encodeURIComponent(key);
                    parameterString += '=' + encodeURIComponent(associativeArray[key]);
                }
            }
            // padding for URL shorteners
            parameterString += '&p=p';

            return parameterString;
        },

        /**
         * Converts a string to an associative array.
         *
         * @param string parameter_string String containing parameters
         * @return object
         */
        parameterStringToHash: function(parameterString)
        {
            var parameterHash = {};
            var parameterArray = parameterString.split('&');
            for (var i = 0; i < parameterArray.length; i++)
            {
                var pair = parameterArray[i].split('=');
                var key = decodeURIComponent(pair[0]);
                var value = decodeURIComponent(pair[1]);
                parameterHash[key] = value;
            }

            return parameterHash;
        },

        /**
         * Get an associative array of the parameters found in the anchor
         *
         * @return object
         */
        getParameterHash: function()
        {
            var hashIndex = window.location.href.indexOf('#');
            if (hashIndex >= 0)
            {
                return this.parameterStringToHash(window.location.href.substring(hashIndex + 1));
            }
            else
            {
                return {};
            }
        },

        /**
         * Convert all applicable characters to HTML entities
         *
         * @param string str
         * @returns string encoded string
         */
        htmlEntities: function(str)
        {
            return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
        },

        /**
         * Text range selection.
         * From: http://stackoverflow.com/questions/985272/jquery-selecting-text-in-an-element-akin-to-highlighting-with-your-mouse
         *
         * @param string element : Indentifier of the element to select (id="").
         */
        selectText: function(element)
        {
            var doc = document,
                text = doc.getElementById(element),
                range,
                selection;

            // MS
            if (doc.body.createTextRange)
            {
                range = doc.body.createTextRange();
                range.moveToElementText(text);
                range.select();
            }
            // all others
            else if (window.getSelection)
            {
                selection = window.getSelection();
                range = doc.createRange();
                range.selectNodeContents(text);
                selection.removeAllRanges();
                selection.addRange(range);
            }
        },

        /**
         * Set text of a DOM element (required for IE)
         * This is equivalent to element.text(text)
         *
         * @param object element : a DOM element.
         * @param string text : the text to enter.
         */
        setElementText: function(element, text)
        {
            // For IE<10: Doesn't support white-space:pre-wrap; so we have to do this BIG UGLY STINKING THING.
            if ($('#oldienotice').is(':visible')) {
                var html = this.htmlEntities(text).replace(/\n/ig,'\r\n<br>');
                element.html('<pre>'+html+'</pre>');
            }
            // for other (sane) browsers:
            else
            {
                element.text(text);
            }
        },

        /**
         * Convert URLs to clickable links.
         * URLs to handle:
         * <code>
         *     magnet:?xt.1=urn:sha1:YNCKHTQCWBTRNJIV4WNAE52SJUQCZO5C&xt.2=urn:sha1:TXGCZQTH26NL6OUQAJJPFALHG2LTGBC7
         *     http://localhost:8800/zero/?6f09182b8ea51997#WtLEUO5Epj9UHAV9JFs+6pUQZp13TuspAUjnF+iM+dM=
         *     http://user:password@localhost:8800/zero/?6f09182b8ea51997#WtLEUO5Epj9UHAV9JFs+6pUQZp13TuspAUjnF+iM+dM=
         * </code>
         *
         * @param object element : a jQuery DOM element.
         */
        urls2links: function(element)
        {
            element.html(
                element.html().replace(
                    /((http|https|ftp):\/\/[\w?=&.\/-;#@~%+-]+(?![\w\s?&.\/;#~%"=-]*>))/ig,
                    '<a href="$1" rel="nofollow">$1</a>'
                )
            );
            element.html(
                element.html().replace(
                    /((magnet):[\w?=&.\/-;#@~%+-]+)/ig,
                    '<a href="$1">$1</a>'
                )
            );
        }
    };

    /**
     * filter methods
     */
    var filter = {
        /**
         * Compress a message (deflate compression). Returns base64 encoded data.
         *
         * @param string message
         * @return base64 string data
         */
        compress: function(message)
        {
            return Base64.toBase64( RawDeflate.deflate( Base64.utob(message) ) );
        },

        /**
         * Decompress a message compressed with compress().
         *
         * @param base64 string data
         * @return string message
         */
        decompress: function(data)
        {
            return Base64.btou( RawDeflate.inflate( Base64.fromBase64(data) ) );
        },

        /**
         * Compress, then encrypt message with key.
         *
         * @param string key
         * @param string password
         * @param string message
         * @return encrypted string data
         */
        cipher: function(key, password, message)
        {
            password = password.trim();
            if (password.length == 0)
            {
                return sjcl.encrypt(key, this.compress(message));
            }
            return sjcl.encrypt(key + sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password)), this.compress(message));
        },

        /**
         * Decrypt message with key, then decompress.
         *
         * @param string key
         * @param string password
         * @param encrypted string data
         * @return string readable message
         */
        decipher: function(key, password, data)
        {
            if (data != undefined)
            {
                try
                {
                    return this.decompress(sjcl.decrypt(key, data));
                }
                catch(err)
                {
                    try
                    {
                        return this.decompress(sjcl.decrypt(key + sjcl.codec.hex.fromBits(sjcl.hash.sha256.hash(password)), data));
                    }
                    catch(err)
                    {}
                }
            }
            return '';
        }
    };

    var zerobin = {
        /**
         * Get the current script location (without search or hash part of the URL).
         * eg. http://server.com/zero/?aaaa#bbbb --> http://server.com/zero/
         *
         * @return string current script location
         */
        scriptLocation: function()
        {
            var scriptLocation = window.location.href.substring(0,window.location.href.length
                - window.location.search.length - window.location.hash.length);
            var hashIndex = scriptLocation.indexOf('#');
            if (hashIndex !== -1)
            {
                scriptLocation = scriptLocation.substring(0, hashIndex);
            }
            return scriptLocation;
        },

        /**
         * Get the pastes unique identifier from the URL
         * eg. http://server.com/zero/?c05354954c49a487#xxx --> c05354954c49a487
         *
         * @return string unique identifier
         */
        pasteID: function()
        {
            return window.location.search.substring(1);
        },

        /**
         * Return the deciphering key stored in anchor part of the URL
         *
         * @return string key
         */
        pageKey: function()
        {
            var key = window.location.hash.substring(1);  // Get key

            // Some stupid web 2.0 services and redirectors add data AFTER the anchor
            // (such as &utm_source=...).
            // We will strip any additional data.

            // First, strip everything after the equal sign (=) which signals end of base64 string.
            var i = key.indexOf('=');
            if (i > -1)
            {
                key = key.substring(0, i + 1);
            }

            // If the equal sign was not present, some parameters may remain:
            i = key.indexOf('&');
            if (i > -1)
            {
                key = key.substring(0, i);
            }

            // Then add trailing equal sign if it's missing
            if (key.charAt(key.length - 1) !== '=') key += '=';

            return key;
        },

        /**
         * ask the user for the password and return it
         *
         * @throws error when dialog canceled
         * @return string password
         */
        requestPassword: function()
        {
            var password = prompt('Please enter the password for this paste:', '');
            if (password == null) throw 'password prompt canceled';
            if (password.length == 0) return this.requestPassword();
            return password;
        },

        /**
         * Show decrypted text in the display area, including discussion (if open)
         *
         * @param string key : decryption key
         * @param array comments : Array of messages to display (items = array with keys ('data','meta')
         */
        displayMessages: function(key, comments)
        {
            // Try to decrypt the paste.
            var password = this.passwordInput.val();
            if (!this.prettyPrint.hasClass('prettyprinted')) {
                try
                {
                    var cleartext = filter.decipher(key, password, comments[0].data);
                    if (cleartext.length == 0)
                    {
                        if (password.length == 0) password = this.requestPassword();
                        cleartext = filter.decipher(key, password, comments[0].data);
                    }
                    if (cleartext.length == 0) throw 'failed to decipher message';
                    this.passwordInput.val(password);

                    helper.setElementText(this.clearText, cleartext);
                    helper.setElementText(this.prettyPrint, cleartext);

                    // Convert URLs to clickable links.
                    helper.urls2links(this.clearText);
                    helper.urls2links(this.prettyPrint);
                    if (typeof prettyPrint == 'function') prettyPrint();
                }
                catch(err)
                {
                    this.clearText.addClass('hidden');
                    this.prettyMessage.addClass('hidden');
                    this.cloneButton.addClass('hidden');
                    this.showError('Could not decrypt data (Wrong key?)');
                    return;
                }
            }

            // Display paste expiration.
            if (comments[0].meta.expire_date)
            {
                this.remainingTime.removeClass('foryoureyesonly')
                                   .text('This document will expire in ' + helper.secondsToHuman(comments[0].meta.remaining_time) + '.')
                                   .removeClass('hidden');
            }
            if (comments[0].meta.burnafterreading)
            {
                var parent = this;
                $.get(this.scriptLocation() + '?pasteid=' + this.pasteID() + '&deletetoken=burnafterreading', 'json')
                .fail(function() {
                    parent.showError('Could not delete the paste, it was not stored in burn after reading mode.');
                });
                this.remainingTime.addClass('foryoureyesonly')
                                   .text('FOR YOUR EYES ONLY. Don\'t close this window, this message can\'t be displayed again.')
                                   .removeClass('hidden');
                // Discourage cloning (as it can't really be prevented).
                this.cloneButton.addClass('hidden');
            }

            // If the discussion is opened on this paste, display it.
            if (comments[0].meta.opendiscussion)
            {
                this.comments.html('');

                // iterate over comments
                for (var i = 1; i < comments.length; i++)
                {
                    var place = this.comments;
                    var comment=comments[i];
                    var cleartext='[Could not decrypt comment; Wrong key?]';
                    try
                    {
                        cleartext = filter.decipher(key, password, comment.data);
                    }
                    catch(err)
                    {}
                    // If parent comment exists, display below (CSS will automatically shift it right.)
                    var cname = '#comment_' + comment.meta.parentid;

                    // If the element exists in page
                    if ($(cname).length)
                    {
                        place = $(cname);
                    }
                    var divComment = $('<article><div class="comment" id="comment_' + comment.meta.commentid+'">'
                                   + '<div class="commentmeta"><span class="nickname"></span><span class="commentdate"></span></div><div class="commentdata"></div>'
                                   + '<button class="btn btn-default btn-sm">Reply</button>'
                                   + '</div></article>');
                    divComment.find('button').click({commentid: comment.meta.commentid}, $.proxy(this.openReply, this));
                    helper.setElementText(divComment.find('div.commentdata'), cleartext);
                    // Convert URLs to clickable links in comment.
                    helper.urls2links(divComment.find('div.commentdata'));

                    // Try to get optional nickname:
                    var nick = filter.decipher(key, password, comment.meta.nickname);
                    if (nick.length > 0)
                    {
                        divComment.find('span.nickname').text(nick);
                    }
                    else
                    {
                        divComment.find('span.nickname').html('<i>(Anonymous)</i>');
                    }
                    divComment.find('span.commentdate')
                              .text(' ('+(new Date(comment.meta.postdate*1000).toString())+')')
                              .attr('title','CommentID: ' + comment.meta.commentid);

                    // If an avatar is available, display it.
                    if (comment.meta.vizhash)
                    {
                        divComment.find('span.nickname')
                                  .before('<img src="' + comment.meta.vizhash + '" class="vizhash" title="Anonymous avatar (Vizhash of the IP address)" /> ');
                    }

                    place.append(divComment);
                }
                var divComment = $('<div class="comment"><button class="btn btn-default btn-sm">Add comment</button></div>');
                divComment.find('button').click({commentid: this.pasteID()}, $.proxy(this.openReply, this));
                this.comments.append(divComment);
                this.discussion.removeClass('hidden');
            }
        },

        /**
         * Open the comment entry when clicking the "Reply" button of a comment.
         *
         * @param Event event
         */
        openReply: function(event)
        {
            event.preventDefault();
            var source = $(event.target),
                commentid = event.data.commentid;

            // Remove any other reply area.
            $('div.reply').remove();
            var reply = $('<div class="reply">' +
                          '<input type="text" id="nickname" class="form-control" title="Optional nickname..." placeholder="Optional nickname..." />' +
                          '<textarea id="replymessage" class="replymessage form-control" cols="80" rows="7"></textarea>' +
                          '<br /><button id="replybutton" class="btn btn-default btn-sm">Post comment</button>' +
                          '<div id="replystatus"> </div>' +
                          '</div>');
            reply.find('button').click({parentid: commentid}, $.proxy(this.sendComment, this));
            source.after(reply);
            $('#nickname').focus(function() {
                if ($(this).val() == $(this).attr('title')) $(this).val('');
            });
            $('#replymessage').focus();
        },

        /**
         * Send a reply in a discussion.
         *
         * @param Event event
         */
        sendComment: function(event)
        {
            event.preventDefault();
            this.errorMessage.addClass('hidden');
            // Do not send if no data.
            var replyMessage = $('#replymessage');
            if (replyMessage.val().length == 0) return;

            this.showStatus('Sending comment...', true);
            var parentid = event.data.parentid;
            var cipherdata = filter.cipher(this.pageKey(), this.passwordInput.val(), replyMessage.val());
            var ciphernickname = '';
            var nick = $('#nickname').val();
            if (nick != '' && nick != 'Optional nickname...')
            {
                ciphernickname = filter.cipher(this.pageKey(), this.passwordInput.val(), nick);
            }
            var data_to_send = {
                data:     cipherdata,
                parentid: parentid,
                pasteid:  this.pasteID(),
                nickname: ciphernickname
            };

            var parent = this;
            $.post(this.scriptLocation(), data_to_send, function(data)
            {
                if (data.status == 0)
                {
                    parent.showStatus('Comment posted.', false);
                    $.get(parent.scriptLocation() + '?' + parent.pasteID() + '&json', function(data)
                    {
                        if (data.status == 0)
                        {
                            parent.displayMessages(parent.pageKey(), data.messages);
                        }
                        else if (data.status == 1)
                        {
                            parent.showError('Could not refresh display: ' + data.message);
                        }
                        else
                        {
                            parent.showError('Could not refresh display: unknown status');
                        }
                    }, 'json')
                    .fail(function() {
                        parent.showError('Could not refresh display (server error or not responding).');
                    });
                }
                else if (data.status == 1)
                {
                    parent.showError('Could not post comment: ' + data.message);
                }
                else
                {
                    parent.showError('Could not post comment: unknown status');
                }
            }, 'json')
            .fail(function() {
                parent.showError('Comment could not be sent (server error or not responding).');
            });
        },

        /**
         * Send a new paste to server
         *
         * @param Event event
         */
        sendData: function(event)
        {
            event.preventDefault();

            // Do not send if no data.
            if (this.message.val().length == 0) return;

            // If sjcl has not collected enough entropy yet, display a message.
            if (!sjcl.random.isReady())
            {
                this.showStatus('Sending paste (Please move your mouse for more entropy)...', true);
                sjcl.random.addEventListener('seeded', function() {
                    this.sendData(event);
                });
                return;
            }

            this.showStatus('Sending paste...', true);

            var randomkey = sjcl.codec.base64.fromBits(sjcl.random.randomWords(8, 0), 0);
            var cipherdata = filter.cipher(randomkey, this.passwordInput.val(), this.message.val());
            var data_to_send = {
                data:             cipherdata,
                expire:           $('#pasteExpiration').val(),
                burnafterreading: this.burnAfterReading.is(':checked') ? 1 : 0,
                opendiscussion:   this.openDiscussion.is(':checked') ? 1 : 0
            };
            var parent = this;
            $.post(this.scriptLocation(), data_to_send, function(data)
            {
                if (data.status == 0) {
                    parent.stateExistingPaste();
                    var url = parent.scriptLocation() + '?' + data.id + '#' + randomkey;
                    var deleteUrl = parent.scriptLocation() + '?pasteid=' + data.id + '&deletetoken=' + data.deletetoken;
                    parent.showStatus('', false);

                    $('#pastelink').html('Your paste is <a id="pasteurl" href="' + url + '">' + url + '</a> <span id="copyhint">(Hit CTRL+C to copy)</span>');
                    $('#deletelink').html('<a href="' + deleteUrl + '">Delete data</a>');
                    parent.pasteResult.removeClass('hidden');
                    // We pre-select the link so that the user only has to CTRL+C the link.
                    helper.selectText('pasteurl');

                    helper.setElementText(parent.clearText, parent.message.val());
                    helper.setElementText(parent.prettyPrint, parent.message.val());
                    // Convert URLs to clickable links.
                    helper.urls2links(parent.clearText);
                    helper.urls2links(parent.prettyPrint);
                    parent.showStatus('', false);
                    if (typeof prettyPrint == 'function') prettyPrint();
                }
                else if (data.status==1)
                {
                    parent.showError('Could not create paste: ' + data.message);
                }
                else
                {
                    parent.showError('Could not create paste.');
                }
            }, 'json')
            .fail(function() {
                parent.showError('Data could not be sent (server error or not responding).');
            });
        },

        /**
         * Put the screen in "New paste" mode.
         */
        stateNewPaste: function()
        {
            this.message.text('');
            this.cloneButton.addClass('hidden');
            this.rawTextButton.addClass('hidden');
            this.remainingTime.addClass('hidden');
            this.pasteResult.addClass('hidden');
            this.clearText.addClass('hidden');
            this.discussion.addClass('hidden');
            this.prettyMessage.addClass('hidden');
            this.sendButton.removeClass('hidden');
            this.expiration.removeClass('hidden');
            this.burnAfterReadingOption.removeClass('hidden');
            this.openDisc.removeClass('hidden');
            this.newButton.removeClass('hidden');
            this.password.removeClass('hidden');
            this.message.removeClass('hidden');
            this.message.focus();
        },

        /**
         * Put the screen in "Existing paste" mode.
         */
        stateExistingPaste: function()
        {
            this.sendButton.addClass('hidden');

            // No "clone" for IE<10.
            if ($('#oldienotice').is(":visible"))
            {
                this.cloneButton.addClass('hidden');
            }
            else
            {
                this.cloneButton.removeClass('hidden');
            }
            this.rawTextButton.removeClass('hidden');

            this.expiration.addClass('hidden');
            this.burnAfterReadingOption.addClass('hidden');
            this.openDisc.addClass('hidden');
            this.newButton.removeClass('hidden');
            this.pasteResult.addClass('hidden');
            this.message.addClass('hidden');
            this.clearText.addClass('hidden');
            this.prettyMessage.removeClass('hidden');
        },

        /**
         * If "burn after reading" is checked, disable discussion.
         */
        changeBurnAfterReading: function()
        {
            if (this.burnAfterReading.is(':checked') )
            {
                this.openDisc.addClass('buttondisabled');
                this.openDiscussion.attr({checked: false, disabled: true});
            }
            else
            {
                this.openDisc.removeClass('buttondisabled');
                this.openDiscussion.removeAttr('disabled');
            }
        },

        /**
         * Reload the page
         *
         * @param Event event
         */
        reloadPage: function(event)
        {
            event.preventDefault();
            window.location.href = this.scriptLocation();
        },

        /**
         * Return raw text
         *
         * @param Event event
         */
        rawText: function(event)
        {
            event.preventDefault();
            var paste = this.clearText.html();
            var newDoc = document.open('text/html', 'replace');
            newDoc.write('<pre>' + paste + '</pre>');
            newDoc.close();
        },

        /**
         * Clone the current paste.
         *
         * @param Event event
         */
        clonePaste: function(event)
        {
            event.preventDefault();
            this.stateNewPaste();

            // Erase the id and the key in url
            history.replaceState(document.title, document.title, this.scriptLocation());

            this.showStatus('', false);
            this.message.text(this.clearText.text());
        },

        /**
         * Create a new paste.
         */
        newPaste: function()
        {
            this.stateNewPaste();
            this.showStatus('', false);
            this.message.text('');
        },

        /**
         * Display an error message
         * (We use the same function for paste and reply to comments)
         *
         * @param string message : text to display
         */
        showError: function(message)
        {
            if (this.status.length)
            {
                this.status.addClass('errorMessage').text(message);
            }
            else
            {
                this.errorMessage.removeClass('hidden').append(message);
            }
            this.replyStatus.addClass('errorMessage').text(message);
        },

        /**
         * Display a status message
         * (We use the same function for paste and reply to comments)
         *
         * @param string message : text to display
         * @param boolean spin (optional) : tell if the "spinning" animation should be displayed.
         */
        showStatus: function(message, spin)
        {
            this.replyStatus.removeClass('errorMessage').text(message);
            if (!message)
            {
                this.status.html(' ');
                return;
            }
            if (message == '')
            {
                this.status.html(' ');
                return;
            }
            this.status.removeClass('errorMessage').text(message);
            if (spin)
            {
                var img = '<img src="img/busy.gif" style="width:16px;height:9px;margin:0 4px 0 0;" />';
                this.status.prepend(img);
                this.replyStatus.prepend(img);
            }
        },

        /**
         * bind events to DOM elements
         */
        bindEvents: function()
        {
            this.burnAfterReading.change($.proxy(this.changeBurnAfterReading, this));
            this.sendButton.click($.proxy(this.sendData, this));
            this.cloneButton.click($.proxy(this.clonePaste, this));
            this.rawTextButton.click($.proxy(this.rawText, this));
            $('.reloadlink').click($.proxy(this.reloadPage, this));
        },

        /**
         * main application
         */
        init: function()
        {
            // hide "no javascript" message
            $('#noscript').hide();

            // preload jQuery wrapped DOM elements and bind events
            this.burnAfterReading = $('#burnafterreading');
            this.burnAfterReadingOption = $('#burnafterreadingoption');
            this.cipherData = $('#cipherdata');
            this.clearText = $('#cleartext');
            this.cloneButton = $('#clonebutton');
            this.comments = $('#comments');
            this.discussion = $('#discussion');
            this.errorMessage = $('#errormessage');
            this.expiration = $('#expiration');
            this.message = $('#message');
            this.newButton = $('#newbutton');
            this.openDisc = $('#opendisc');
            this.openDiscussion = $('#opendiscussion');
            this.password = $('#password');
            this.passwordInput = $('#passwordinput');
            this.pasteResult = $('#pasteresult');
            this.prettyMessage = $('#prettymessage');
            this.prettyPrint = $('#prettyprint');
            this.rawTextButton = $('#rawtextbutton');
            this.remainingTime = $('#remainingtime');
            this.replyStatus = $('#replystatus');
            this.sendButton = $('#sendbutton');
            this.status = $('#status');
            this.bindEvents();

            // Display status returned by php code if any (eg. Paste was properly deleted.)
            if (this.status.text().length > 0)
            {
                this.showStatus(this.status.text(), false);
                return;
            }

            // Keep line height even if content empty.
            this.status.html(' ');

            // Display an existing paste
            if (this.cipherData.text().length > 1)
            {
                // Missing decryption key in URL?
                if (window.location.hash.length == 0)
                {
                    this.showError('Cannot decrypt paste: Decryption key missing in URL (Did you use a redirector or an URL shortener which strips part of the URL ?)');
                    return;
                }

                // List of messages to display.
                var messages = $.parseJSON(this.cipherData.text());

                // Show proper elements on screen.
                this.stateExistingPaste();

                this.displayMessages(this.pageKey(), messages);
            }
            // Display error message from php code.
            else if (this.errorMessage.text().length > 1)
            {
                this.showError(this.errorMessage.text());
            }
            // Create a new paste.
            else
            {
                this.newPaste();
            }
        }
    }

    /**
     * main application start, called when DOM is fully loaded
     */
    zerobin.init();
});