Before I begin, I must warn you that I'm not much of a web programmer so my methods may seem somewhat roundabout and the terminology I use may be awkward.
Here's the situation. I'm developing a website for users to visualize data.
I have a public php page sitting in /var/www/thepage/index.php path (yes, Linux server + apache). This is the main page of the site and is also where users make selections in a form.
Upon form submission, a second php page will be called and this is where the form selections from the first php page are passed to the javascript that creates the visualization. In order for that to happen, csv files are first written into this directory using a php script that queries from a MySQL database.
Thing is, I want users to be able to see the visualizations but not be able to download the csv files (unless they are admin). How I allow admin to download the files is to create a protected (.htaccess) subdirectory /var/www/thepage/secure/ which has an index html that runs a cgi script once an admin logs in (prompted when a download link is clicked). This script copies the latest files (with dynamic names) from the /var/www/thepage/ directory and moves them to the secure/ directory with static filenames. Download links pointing to these files with static names are on the protected index.html. However, if a user looks at the source code of the 2nd php page, they can also download the files as they know the paths and they are not protected.
If remove file permissions, the php script won't be able to read the files either, causing the visualization to fail (I want normal users to be able to see the visualizations). It is also important to have the files because I have a cgi script (bash + awk) running a mathematical function on the files which also requires permission
Obscuring the filenames doesn't really work either since the files are written on the fly and the source code of the html page will reveal the obscured csv filenames being written.
How can I get around this problem? I would prefer not to have to create sessions and log-ins for normal users, etc...
As previously said, it's hard to hide anything on the net, especially if you need to send it to javascript. You could try hacking it a bit, could cost you a bit of performance, but would be a deterrent against people who aren't web savvy... But could also be seen as a challenge by others :)
A rough example would be something like..
$csv = fgetcsv("/var/www/thepage/secure/file.csv");
echo "<script type'text/javascript'>";
echo json_encode($csv);
echo "</script>";
Bit rusty here, but javascript should interpret the json as an object, that you can use in your code. You could go a step further and break the php array into sections before sending it off, making it harder to know what's going on.
Like I said. It's rough, but it could be a solution.
I would have imagined the best way is to store the files in a secure directory that isn't accessible in a web browser (outside of the web root). You could then show a list of the available files to authenticated users with a download link. When they click the link you could check they are logged in and if so then begin the file download.
PHP readfile - May help
Related
Here is the flow I would like to achieve:
I have a set of template .php files on server.
Visitor of the website chooses some options
Options are added to template files as pieces of code
Visitor downloads customized files (.zip should contain both default template files if not customised, and customized ones)
Original files remain intact for the next visitor
The flow is similar to bootstrap customisation, only difference is that on bootstrap visitors are editing .less files, and my visitors would edit .php files
I would appreciate if you could point me to general direction how to execute steps 3,4 and 5, baring in mind that user input will be stored in objects and arrays with javascript.
My php knowledge is very rudimentary, so I don't know where would I start.
If you need any clarifications please do not hesitate to ask.
Thanks!
If the users only modify configuration options it seems the best way forward would be to use JSON as it is very easy to encode/decode with JS & PHP with $.parseJSON (jQuery) and json_decode() & json_encode() respectively.
You would provide a form and then convert these user inputs into the JSON format and store it in a .json file which can then be zipped up and sent as a download to your user.
This would also allow users to upload their zip files and have the form inputs defaulted to their original options.
So lets run through how bootstrap does it.
Page to customize the bootstrap file, you would do the same with a similar form.
Once the form is POSTed, take the array of form inputs and validate them for malicious input, correct data types such as a number etc and remove any form inputs that should not be there.
Convert the input into JSON, without validation this is easy as json_encode($_POST).
Write that to a JSON file and allow the user to download it (zip it up if you want).
In your case you have multiple PHP files, this seems a bit off and you should not be using PHP files to hold this sort of variable configuration data, JSON seems a lot better suited.
Take a look at this SO question: What is the best file format for configuration file?
Three methods are mentioned, PHP's way, JSON & XML. Take your pick, but I'm willing to bet that the easiest one for you is JSON.
If you have not used JSON before, create a new PHP script and try out the functions with multi-dimensional arrays and have a play around.
PHP Documention for JSON
If you are using JavaScript to store user selections etc., I recommend you don't actually use php for any of the functionality you described. So do it like this:
Store templates as static text file with demarcated sections to insert user options. Make the demarcated sections different from php syntax like ###Your option here###.
This is easy.
Fetch the relevant template using AJAX and do a simple string replace in JavaScript on the demarcated sections.
Put the resulting php code into a <textarea> using JavaScript for them copy and paste into Notepad or something
Original files are static and code is client-side, so this is fine
So I understand you want to ship php scripts customised for the user.
Consider having php files that cater for all possible user inputs. Then capture the user options into a configuration file where the structure is predictacable and easy to create.
For example
# config.inc.php
# Created by script that captures user options
$config['allow_shipping'] = true;
then in the php script
# file1.php
include config.inc.php
if ($config[$config['allow_shipping'] === true) {
some_php_code;
}
Your steps will be
I have a set of .php scripts files on server.
Visitor of the website chooses some options
Options are sent to a server script which creates a config file.
Visitor downloads customized files (.zip should contain both script files and config file)
Original files remain intact for the next visitor (less the config file)
Some posts to guide you
How I can create installer for website. PHP mysql
and
PHP Installer Script
I would consider making default code snippets and have every "option" link to various required snippets. That way every time an option is selected it uses the right code.
To continue with #Crafter's example, you could have the following code snippets
if (
$config[
]
===
) {
}
I have done this once before when I tried something similar in Java, and even though it seems to be more work than it should, it will end up quite useful once you get a sizeable "database" of code snippets.
Hope it was of any use?
-Peter
Hello everyone I was wondering if there's a way to have a random text generated and replaces my file names (and of course still have the link work) ?
I've noticed how people like to have files (mostly video) have very random characters as file names instead of a relevant file names. Are they generated as each user view the page? Or is it really a file with a name of random characters? I cannot imagine this can be efficient if you have large amounts of files.
I'm currently using the script from http://css-tricks.com/snippets/php/generate-expiring-amazon-s3-link/
This allows me to not share my files publicly but the users cannot access the file directly. I hope that makes sense, let me know what you think.
Thank you
As of today, you could probably use S3 Website Redirects to accomplish this.
Simply create a random new file with the correct HTTP header set, and have it redirect back to the real file. This uses an HTTP 301 redirect, so loading it in a web browser or requesting it with cURL or wget will end up resolving the real location.
I'm looking for a way to send a user a regular file (mp3s or pictures), and keeping count of how many times this file was accessed without going through an HTML/PHP page.
For example, the user will point his browser to bla.com/file.mp3 and start downloading it, while a server-side script will do something like saving data to a database.
Any idea where should I get started?
Thanks!
You will need to go through a php script, what you could do is rewrite the extensions you want to track, preferably at the folder level, to a php script which then does the calculations you need and serves the file to the user.
For Example:
If you want to track the /downloads/ folder you would create a rewrite on your webserver to rewrite all or just specific extensions to a php file we'll call proxy.php for this example.
An example uri would be proxy.php?file=file.mp3 the proxy.php script sanitizes the file parameter, checks if the user has permission to download if applicable, checks if the file exists, serves the file to the client and perform any operations needed on the backend like database updates etc..
Do you mean that you don't want your users to be presented with a specific page and interrupt their flow? If you do, you can still use a PHP page using the following steps. (I'm not up to date with PHP so it'll be pseudo-code, but you'll get the idea)
Provide links to your file as (for example) http://example.com/trackedDownloader.php?id=someUniqueIdentifer
In the tracedDownloader.php file, determine the real location on the server that relates to the unique id (e.g. 12345 could map to /uploadedFiles/AnExample.mp3)
Set an appropriate content type header in your output.
Log the request to your database.
Return the contents of the file directly as page output.
You would need to scan log files. Regardless you most likely would want to store counters in a database?
There is a great solution in serving static files using PHP:
https://tn123.org/mod_xsendfile/
I have a quick question if anyone could help. I am building a CMS for a client where they can log in, and change content (including pictures via upload file form) that are all stored in a database.
My question.. I have been researching, and everywhere says I need to store the image files outside the root folder. Is this necessary in my case if only a few people will be uploading files, inside an admin panel, where they must first log in to the site? I will have already taken steps client side by making sure of file type, size, extension etc... then changing the name of the file before adding it to my DB... Is this secure enough, or am I asking for trouble down the road?
Thanks
Its generally a good idea to store uploaded content someplace where it cant directly be addressed by a browser. You dont want someone uploading a .php file (or some other format you forgot to check for) and then being able execute it by pulling up the direct url. Rather, you'd have a wrapper script that delivered the file.
So yes, its a good idea, but not 'necessary' (by the dictionary definition of the word). You can certainly choose not to do so if in your judgement the admin area is otherwise secure.
That said, in the scenario you describe, as long as its only admin users who can upload images, I dont think its a huge deal either way.
btw, if you are not already, verify the images by their file headers or content, not file extension.
I'm putting together a portfolio website which includes a number of images, some of which I don't want to be viewable by the general public. I imagine that I'll email someone a user name and password, with which they can "log-in" to view my work.
I've seen various solutions to the "hide-an-image" problem on line including the following, which uses php's readfile. I've also seen another that uses .htaccess.
Use php's readfile() or redirect to display a image file?
I'm not crazy about the readfile solution, as it seems slow to load the images, and I'd like to be able to use Cabel Sasser's FancyZoom, which needs unfettered access to the image, (his library wants a link to the full sized image), so that rules out .htaccess.
To recap what I'm trying to do:
1) Provide a site where I give users the ability to authenticate themselves as someone I'd like looking at my images.
2) Restrict random web users from being able see those images.
3) Use FancyZoom to blow up thumbnails.
I don't care what technology this ends up using -- Javascript, PHP, etc. -- whatever's cleanest and easiest.
By the way, I'm a Java Developer, not a web developer, so I'm probably not thinking about the problem correctly.
Instead of providing a link to an image. Provide a link to a cgi script which will automatically provide the proper header and content of the image.
For example:
image.php?sample.jpg
You can then make sure they are already authenticated (e.g. pass a session id) as part of the link.
This would be part of the header, and then your image data can follow.
header('Content-Type: image/jpeg');
Edit: If it has to be fast, you can write this in C/C++ instead of php.
Using .htaccess should be the safest/simplest method, as it's built in functionality of the webserver itself.
I do not know if it fits your needs, but I solved a similar poblem(giving pictures to a restricted group of people) by using TinyWebGallery, which is a small gallery application without database.
You can allow access to different directories via password and you can upload pictures directly into the filesystem, as TinyWebGallery will check for new dirs/pics on the fly. It will generate thumbnails and gives users possibility to rate / comment pictures (You can disable this).
This is not the smallest tool, however I thik it is far easier to setup than using apache directives and it looks better as naked images.
If you're using Nginx, you could use the Secure Link module.