Validation (in contrast with verification) is assurance that a product, service, or system meets the needs of the stakeholders. It could contain the acceptance phase.

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4answers
1k views

Is it ever safe to skip server-side validations?

I am working on a web app with a sign up form like below. The validations are all done client side using http://formvalidator.net/. I am well aware that client-side validations can be bypassed, but I ...
3
votes
2answers
506 views

Valid Characters For Magnetic stripe

We bought some Magnetic stripe cards and I'm writing a program that will get talked to by a mag card reader. What I need help with is that I can't, for the life of me, find out what characters are ...
3
votes
2answers
891 views

How to ensure an email address is not free webmail or ISP address?

I notice security companies such as Rapid 7 prevent people signing up with either free email accounts, or accounts provided by ISPs: https://www.rapid7.com/products/metasploit/metasploit-pro-...
3
votes
1answer
89 views

Validating correctness amongst untrusted answers

I'm toying around a distributed computing project. The client application asks for a problem to solve. The server returns a problem description from a "problems pool". When the client finishes, it ...
4
votes
2answers
138 views

Could server honesty be audited by remote peers without said peers having sole (or any) control of the server?

Suppose for some reason, you and your peers absolutely positively have know that a server is acting honestly. Could the server behaviour be audited remotely through some mechanism of randomly ...
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votes
1answer
1k views

ESAPI: Input and output validation [closed]

I am new to IT Security and I have been tasked with coming up with input and output validation for ESAPI. So for input validation, so far I got: Data Type Name Email ...
4
votes
3answers
2k views

SQL injection using letters and numbers?

I was wondering if it is at all possible for a hacker to perform an SQL injection attack using just letters and numbers. For example, let's take a look at this PHP code which uses regular expressions ...
4
votes
2answers
578 views

Server checking client's password without ever coming into possession of it

tl;dr: I am wondering what the best way is to check a password when the client does not trust the server. I know of two common ways servers can check if a user's password is correct: The server ...
6
votes
3answers
223 views

Obtaining e-mail address at registration

In a registration form the user is asked for his e-mail address. The e-mail address will be validated for the correct format (e.g. at the least contains @) and I'm considering checking if it's already ...
7
votes
3answers
671 views

What are the risk implications of not verifying referer header on login form?

Imagine a generic web application with a login form to access the application. Regardless of how the actual authentication is performed, what are the implications of not checking the referer header to ...
3
votes
4answers
2k views

Bypassing Web Application input validation

A malicious user can use Base-64 or other encoding scheme to bypass web application input validation or to bypass some external Web application firewall. Since these encoding schemes are infinite how ...
3
votes
1answer
94 views

Server Certification Processes

We are considering a certification process for new internal server builds before they are allowed to be placed into production. That is, the system administration team will send the server up to the ...
1
vote
1answer
922 views

Behavior when validating an expired certificate chain

I have the following situation: A server certificate (CServ) is signed by self-signed certificate (C0) A client certificate (CCli) is signed by CServ Client's trust-store contains C0, so the client ...
5
votes
2answers
205 views

How can a certificate be valid in the Hybrid Model but not in the Chain Model?

All dates in European format! I am learning about validity models, but the solution for this assignment confuses me. Translation: The relevant data for the applicable certificates are shown ...
1
vote
3answers
2k views

Validate hmac with hashed stored key

What if an HMAC is correctly generated and sent with the data to the server, so far I know the server needs to know the original data with which the MAC was created in order to re-create the MAC and ...
4
votes
1answer
2k views

Is ASP.NET Event Validation completely secure?

I am currently testing a ASP.NET web application for its security. Doing so I came across the event validation mechanism. Is there some way to bypass it? How much assurance is there that it cannot be ...
-1
votes
1answer
177 views

Mac app purchase validation

How do I sell a mac app off of my website without somebody being able to copy-and-paste the app to some friends after he buys it, etc.. I understand that you can use receipt validation when selling ...
6
votes
5answers
8k views

XSS : Blacklist characters vs. whitelist

I have been studying to prevent my web app against XSS. I read about it on OWASP and other security channels, they all say that use ESAPI and similar library, and also do input filtering through ...
3
votes
5answers
2k views

Is it secure to use jQuery on the server-side for user input validation?

I'm thinking about using jQuery on the server-side (node.js) to validate user input (filter tags, remove every attributes except href, rel, target & style, modify css rules which are applied ...
6
votes
2answers
2k views

Canonicalization & Output Encoding

I'm reading OWASP's Secure Coding Practices Checklist and under their "Input Validation" section they have an item that reads: If any potentially hazardous characters (<>"'%()&+\\'\") ...
10
votes
3answers
2k views

Should IP addresses be validated to prevent SQL Injection?

In PHP I retrieve a user's IP address ($_SERVER['REMOTE_ADDR']) to use it in some MySQL queries, but I do not validate them to be true IP addresses. Should I validate user IP addresses before using ...
4
votes
2answers
186 views

In practice, does crypto software accept a *.com or or even a *. certificate?

Assuming this will be done with your own PKI, and not a public trusted CA. Considering that *.sub.domain.com is valid, and so is *.domain.com is valid, is it technically possible to issue *.com and ...
2
votes
2answers
194 views

Using External Certificates on a network that doesn't permit outbound HTTP/S access

Some highly secure networks and DMZs prevent all communication to outside hosts. This can cause issues with validating externally signed data I can guess that issues with signature validation occur ...
4
votes
2answers
195 views

Email & Domain ownership?

Most hosting companies, such as mine (hostgator) give the following notice when providing a contact email: Email address that you can be contacted at. This should be an email address that is not ...
5
votes
3answers
10k views

What data should I validate when validating X.509 certificates using Java?

Well I began with PKI a year ago with RFID system at school. Now I'm asked to implement this in my job. I understand most part of the idea. The doubt is about the certificate validation. I know it ...
13
votes
6answers
3k views

Filter user input before the database or upon display?

Given a web application where user data must be properly escaped to avoid XSS, is it better to try to remove the "bad stuff" before it enters the database, or is it best to allow it in the database ...
11
votes
3answers
783 views

White list or black list sanitation for international input?

There seem to be so many ways to create nefarious input that white-listing what input is good usually feels like the safer, simpler option. For instance, one can fairly easily craft a white list ...