Security Recommendations For a website

SSL Certificate
When you connect to a secure web server such as https://www.yourwebsite.com, the server authenticates itself to the web browser by presenting a digital certificate. The certificate is proof that an independent trusted third party has verified that the website belongs to the company it claims to belong to. A valid certificate gives customers confidence that they are sending personal information securely, and to the right place.
SSL certificates can provide you with non-forgeable proof of your website's identity, and customer confidence in the integrity and security of your online business. Customers are becoming increasingly aware of the advantages of SSL security and will often not purchase online from non-secure stores. All major web merchants use SSL security to encourage customers to buy online
An SSL certificate contains the following information:
The domain name for which the certificate was issued.
The owner of the certificate and the domain name.
The physical location of the owner.
The validity dates of the certificate.


Coding Recommendations


1.Run application with minimum previleges
To run with the minimum number of privileges needed, follow these guidelines:
Do not run your application with the identity of a system user (administrator).
Run the application in the context of a user with the minimum practical privileges.
Set permissions (ACLs, or Access Control Lists) on all the resources required for your application. Use the most restrictive setting. For example, if practical in your application, set files to be read-only. For a list of the minimum ACL permissions required for the identity of your web application.
Keep files for your Web application in a folder below the application root. Do not allow users the option of specifying a path for any file access in your application. This helps prevent users from getting access to the root of your server.
2.Guard Against Malicious user input
As a general rule, never assume that input you get from users is safe. It is easy for malicious users to send potentially dangerous information from the client to your application. To help guard against malicious input, follow these guidelines:
In forms, filter user input to check for HTML tags, which might contain script.
Never echo (display) unfiltered user input. Before displaying untrusted information, encode HTML to turn potentially harmful script into display strings.
Similarly, never store unfiltered user input in a database.
If you want to accept some HTML from a user, filter it manually. In your filter, explicitly define what you will accept. Do not create a filter that tries to filter out malicious input; it is very difficult to anticipate all possible malicious input.
Do not assume that information you get from the header (usually via the Request object) is safe. Use safeguards for query strings, cookies, and so on. Be aware that information that the browser reports to the server (user agent information) can be spoofed, in case that is important in your application.
If possible, do not store sensitive information in a place that is accessible from the browser, such as hidden fields or cookies. For example, do not store a password in a cookie.
3.Access data securely
Databases typically have their own security. An important aspect Web application security is designing a way for the application to access the database securely.
Use the inherent security of your database to limit who can access database resources. The exact strategy depends on your database and your application:
If practical in your application, use Windows Integrated security so that only Windows-authenticated users can access the database. Integrated security is more secure than using SQL Server standard security.
If your application uses anonymous access, create a single user with very limited permissions, and perform queries by connecting as this user.
Do not create SQL statements by concatenating strings that involve user input. Instead, create a parameterized query and use user input to set parameter values.
If you must store a user name and password somewhere to use as the database login credential, store them securely. If practical, encrypt or hash them.
4.Keep sensitive information safely
If our application transmits sensitive information between the browser and the server, consider using Secure Sockets Layer (SSL).
Use Protected Configuration to secure sensitive information in configuration files such as the Web.config or Machine.config files.
If you must store sensitive information, do not keep it in a Web page, even in a form that you think people will not be able to view (such as in server code).
Use the strong encryption algorithms.
5.Use cookies Securely
Do not store any critical information in cookies. For example, do not store a user's password in a cookie, even temporarily. As a rule, do not store any sensitive information in a cookie that. Instead, keep a reference in the cookie to a location on the server where the information is located.
Set expiration dates on cookies to the shortest practical time you can. Avoid permanent cookies if possible.
Consider encrypting information in cookies.
6.Guard against Denial of service threats
Use error handling (for example, try/catch blocks). Include a finally block in which you release resources in case of failure.
Configure IIS to use throttling, which prevents an application from using a disproportionate amount of CPU.
Test size limits of user input before using or storing it.
Put size safeguards on database queries to help guard against large queries using up system resources.
Put a size limit on file uploads, if those are part of your application.



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