A symbol of industrial resurgence in West Bengal, HPL has led the economic growth of the region by propelling significant investments in downstream processing industries, which generate huge employment opportunities for skilled and unskilled workers.Through strategic market focus, innovative product application development and excellent customer support services, HPL has played the role of a catalyst in emergence of more than 500 downstream processing industries in West Bengal with a capacity to process more than 3,50,000 TPA of polymers and generating more than 1,50,000 employment opportunities in the process.Data from all potentially untrusted sources should be subject to input validation, including not only Internet-facing web clients but also backend feeds over extranets, from suppliers, partners, vendors or regulators, each of which may be compromised on their own and start sending malformed data.Input Validation should not be used as the primary method of preventing XSS, SQL Injection and other attacks which are covered in respective cheat sheets but can significantly contribute to reducing their impact if implemented properly.Detailed information on XSS prevention here: OWASP XSS Prevention Cheat Sheet Many websites allow users to upload files, such as a profile picture or more. Many web applications do not treat email addresses correctly due to common misconceptions about what constitutes a valid address.Specifically, it is completely valid to have an mailbox address which: At the time of writing, RFC 5321 is the current standard defining SMTP and what constitutes a valid mailbox address.If the input field comes from a fixed set of options, like a drop down list or radio buttons, then the input needs to match exactly one of the values offered to the user in the first place.
White list validation involves defining exactly what IS authorized, and by definition, everything else is not authorized.
It is very difficult to validate rich content submitted by a user.
For more information, please see the cheatsheet on Sanitizing HTML Markup with a Library Designed for the Job.
To normalise an email address input, you would convert the domain part ONLY to lowercase.
Unfortunately this does and will make input harder to normalise and correctly match to a users intent.