security

Are sessions modifiable by the client/user?

In my PHP Web-App I use sessions to store the user's data. For exmaple, if a user logs in, then an instance of the User class is generated and stored in a Session. I have access levels associated with each user to determine their privileges. Store the user in a session by: $_SESSION['currentUser'] = new User($_POST['username']); F...

Uploading PDF or .doc and security

I have a script that lets the user upload text files (PDF or doc) to the server, then the plan is to convert them to raw text. But until the file is converted, it's in its raw format, which makes me worried about viruses and all kinds of nasty things. Any ideas what I need to do to minimize the risk of these unknown files. How to check...

How to verify a digital signature with openssl

I'm using a thirdparty credit card processing service (Paybox) that, after a successful transaction, redirects back to the website with a signature in the URL as a security measure to prevent people from manipulating data. It's supposed to prove that the request originated from this service. So my success URL looks something like this: ...

Write Mysql tables to XML : Security Issue

I want to make a news portal(php) with minimum mysql force. :create a cron, fetch data from mysql and write to a php file . (I dont know is it right way) But Can I use xml instead of php file? Write mysql data to xml. Is this a secure way? What is the best way? XML or php file? Thanks in advance ...

Post data with jQuery to ASP.net, am I doing this secure enough?

For a website I am building, I am using jQuery to post data to Generic Handlers I created for this purpose. Because you need to be logged in, to do most post actions (like 'rate a picture'), I am currently using the following technique: User visits page Page determines if user is logged in On Page_Load the page fills a hidden field wi...

standard encryption decryption across different platforms

hey guys i need to implement a standard encryption decryption logic across an entire project platform which has different clients implemented using different platforms as follows: iphone app (objectiv c) website (classic asp) webservice (asp.net) samsung bada app (c++) the iphone app as well as the website need to send info to webser...

Cakephp - how to encrypt and then decrypt data that is being stored and retrieved from the database.

Err.... like the question says. How do I go about encrypting and then decrypting data that is being stored and retrieved from the database. By the way it's not just for storing a password which has been md5ed, I need to retrieve the data too. Thanks! ...

Would showing primary key to the public be potential security risk?

Well the question is self-explanatory. One more thing would be, if it is a security risk then please provide an example of what the user could do. In this case the primary key would be something like : "Product ID" Thanks! ...

What is this hacker trying to do?

If you do a search for: http://www.google.co.uk/search?q=0x57414954464F522044454C4159202730303A30303A313527&hl=en&start=30&sa=N you will see a lot of examples of an attempted hack along the lines of: 1) declare @q varchar(8000) select @q = 0x57414954464F522044454C4159202730303A30303A313527 exec(@q) -- What is exactly is ...

authentication on gui application written on perl

Its not specific perl question I am building a perl gui/wxperl application that connect to DB . I want my application to be a password protected i.e first the user should enter the user and password and then use the appication . what is the best secure method to store the password could someone provide an idea what is the best method t...

Which Java MVC Framework best aligns with the Web Application Security Framework Manifesto?

Has anyone in the stackoverflow community ever studied the security characteristics of various J2EE frameworks? I would love to understand what framework best aligns with the Web Application Security Framework Manifesto http://labs.securitycompass.com/papers/secure-web-application-framework-manifesto-v0-08.pdf ...

REST authentication S3 like hmac sha1 signature vs symetric data encryption.

Hello stackers, I was arguing about an S3 like aproach using authorization hash with a secret key as the seed and some data on the request as the message signed with hmac sha1 (Amazon S3 way) vs an other developer supporting symetric encryption of the data with a secret key known by the emiter and the server. What are the advantage of...

HTTP requests and Apache modules: Creative attack vectors

Slightly unorthodox question here: I'm currently trying to break an Apache with a handful of custom modules. What spawned the testing is that Apache internally forwards requests that it considers too large (e.g. 1 MB trash) to modules hooked in appropriately, forcing them to deal with the garbage data - and lack of handling in the cust...

How can I securely check if a username is already taken?

I have a form where someone can create a new user. I'd like to add some AJAX to check if a username is taken, as soon as the input field loses focus. I'm not really sure how to go about this, as this could pave the way to bruteforce attack, since you could check for any username and see whether or not it exists. Any suggestions? ...

Encrypt URL in asp.net

Hi All, My site is in asp.net 3.5 and C#. I am sending link to my user through mail, now I want to send each user a specific URL. so instead of sending the clear text I want to send link with encrypted string URL, which I will decrypt on my home page. Like instead of www.mysite.aspx\mypage?userId=12 i'll send www.mysite.aspx\mypage?User...

User account design and security...

Before I begin, I am using Ruby on Rails and the Devise gem for user authentication. Hi, I was doing some research about account security and I found a blog post about the topic awhile ago but I can no longer find it again. I read something about when making a login system you should have 1 model for User, this contains a user's usernam...

include() Why should I not use it?

I am working through an older php mysql book written in 2003. The author uses the include() function to construct html pages by including header.inc, footer.inc, main.inc files, etc. Now I find out that this is not allowed in the default ini settings, (allow_url_include is set to Off) after I got many warnings from the server. I noticed...

Best way to Store Passwords, User information/Profile data and Photo/Video albums for a social website?

Need some help figuring out how to best Store Passwords, User information/Profile data and Photo/Video albums for a social website? For photos/videos the actual photo/video + even encrypting the URL with the IDs to the photo/videos so other users cannot figure it out. Creating a site like myspace and designing retirement documents but i ...

how to implement window based authentication for web service

how to implement window based authentication for web service ...

Simulating O_NOFOLLOW (2): Is this other approach safe?

As a follow-up question to this one, I thought of another approach which builds off of @caf's answer for the case where I want to append to file name and create it if it does not exist. Here is what I came up with: Create a temporary directory with mode 0700 in a system temporary directory on the same filesystem as file name. Open fil...