What is Web Security?

This is the process of securing confidential data stored online from unauthorized access and modification. This is accomplished by enforcing stringent policy measures. Security threats can compromise the data stored by an organization is hackers with malicious intentions try to gain access to sensitive information.

HTTPS

What is HTTPS?

Hyper Text Transfer Protocol Secure (HTTPS) is the secure version of HTTP, the protocol over which data is sent between your browser and the website that you are connected to. The 'S' at the end of HTTPS stands for 'Secure'. It means all communications between your browser and the website are encrypted. HTTPS is often used to protect highly confidential online transactions like online banking and online shopping order forms.

How Does HTTPS Work?

HTTPS pages typically use one of two secure protocols to encrypt communications - SSL (Secure Sockets Layer) or TLS (Transport Layer Security). Both the TLS and SSL protocols use what is known as an 'asymmetric' Public Key Infrastructure (PKI) system. An asymmetric system uses two 'keys' to encrypt communications, a 'public' key and a 'private' key. Anything encrypted with the public key can only be decrypted by the private key and vice-versa.

As the names suggest, the 'private' key should be kept strictly protected and should only be accessible the owner of the private key. In the case of a website, the private key remains securely ensconced on the web server. Conversely, the public key is intended to be distributed to anybody and everybody that needs to be able to decrypt information that was encrypted with the private key.

What is a HTTPS certificate??

When you request a HTTPS connection to a webpage, the website will initially send its SSL certificate to your browser. This certificate contains the public key needed to begin the secure session. Based on this initial exchange, your browser and the website then initiate the 'SSL handshake'. The SSL handshake involves the generation of shared secrets to establish a uniquely secure connection between yourself and the website.

When a trusted SSL Digital Certificate is used during a HTTPS connection, users will see a padlock icon in the browser address bar. When an Extended Validation Certificate is installed on a web site, the address bar will turn green.

Benefits of HTTPS

The major benefits of a HTTPS certificate are:

Hash

What Is Password Hashing

Hashing is not a new concept. It has been in practical use for quite a long time. To understand hashing, think about fingerprints. Every person has a unique fingerprint. Similarly, each string can have a unique fixed-size "digital fingerprint" called a hash. For a good hashing algorithm, it's very rare that two different strings will have same hash (called a collision).

The most important feature of hashes is that the hash generation process is one way. The one way property indicates that it is impossible to recover the original text from its hash. Therefore password hashing perfectly suits our need for secure password storage. Instead of storing a password in plain text, we can hash the password and store the resulting hash. If an attacker later gains access to the database, he can not recover original password from the hash.

How Hashing Is Done In PHP

There are different algorithms for generating hash of a text. The most popular ones are: MD5, SHA1, and Bcrypt. Each of these algorithms are supported in PHP.

Sample Code:


			$str = "Hello";
			echo md5($str);
			

Salted Hash

If you're a web developer, you've probably had to make a user account system. The most important aspect of a user account system is how user passwords are protected. User account databases are hacked frequently, so you absolutely must do something to protect your users' passwords if your website is ever breached. The best way to protect passwords is to employ salted password hashing. This page will explain why it's done the way it is.

There are a lot of conflicting ideas and misconceptions on how to do password hashing properly, probably due to the abundance of misinformation on the web. Password hashing is one of those things that's so simple, but yet so many people get wrong. With this page, I hope to explain not only the correct way to do it, but why it should be done that way.

Sample Code


			$password = "banana";
			$password = md5($salt.$password);
		

OWASP

The Open Web Application Security Project (OWASP) is a worldwide not-for-profit charitable organization focused on improving the security of software. Their mission is to make software security visible, so that individuals and organizations are able to make informed decisions. OWASP is in a unique position to provide impartial, practical information about AppSec to individuals, corporations, universities, government agencies and other organizations worldwide. Operating as a community of like-minded professionals, OWASP issues software tools and knowledge-based documentation on application security.

OWASP Top 10 Project

A1-Injection Injection flaws, such as SQL, OS, and LDAP injection occur when untrusted data is sent to an interpreter as part of a command or query. The attacker's hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization.
A2-Broken Authentication and Session Management Application functions related to authentication and session management are often not implemented correctly, allowing attackers to compromise passwords, keys, or session tokens, or to exploit other implementation flaws to assume other users' identities.
A3-Cross-Site Scripting (XSS) XSS flaws occur whenever an application takes untrusted data and sends it to a web browser without proper validation or escaping. XSS allows attackers to execute scripts in the victim's browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites.
A4-Insecure Direct Object References A direct object reference occurs when a developer exposes a reference to an internal implementation object, such as a file, directory, or database key. Without an access control check or other protection, attackers can manipulate these references to access unauthorized data.
A5-Security Misconfiguration Good security requires having a secure configuration defined and deployed for the application, frameworks, application server, web server, database server, and platform. Secure settings should be defined, implemented, and maintained, as defaults are often insecure. Additionally, software should be kept up to date.
A6-Sensitive Data Exposure Many web applications do not properly protect sensitive data, such as credit cards, tax IDs, and authentication credentials. Attackers may steal or modify such weakly protected data to conduct credit card fraud, identity theft, or other crimes. Sensitive data deserves extra protection such as encryption at rest or in transit, as well as special precautions when exchanged with the browser.
A7-Missing Function Level Access Control Most web applications verify function level access rights before making that functionality visible in the UI. However, applications need to perform the same access control checks on the server when each function is accessed. If requests are not verified, attackers will be able to forge requests in order to access functionality without proper authorization.
A8-Cross-Site Request Forgery (CSRF) A CSRF attack forces a logged-on victim's browser to send a forged HTTP request, including the victim's session cookie and any other automatically included authentication information, to a vulnerable web application. This allows the attacker to force the victim's browser to generate requests the vulnerable application thinks are legitimate requests from the victim.
A9-Using Components with Known Vulnerabilities Components, such as libraries, frameworks, and other software modules, almost always run with full privileges. If a vulnerable component is exploited, such an attack can facilitate serious data loss or server takeover. Applications using components with known vulnerabilities may undermine application defenses and enable a range of possible attacks and impacts.
A10-Unvalidated Redirects and Forwards Web applications frequently redirect and forward users to other pages and websites, and use untrusted data to determine the destination pages. Without proper validation, attackers can redirect victims to phishing or malware sites, or use forwards to access unauthorized pages.

References