E-Mail Validation doesn't cover new TLDs

[einfallstoll]

The current RegEx for E-Mails doesn't work for my E-Mail Address which included a new TLD .solutions.

It does work with the RegEx found here: http://emailregex.com

$ node
> "[email protected]".match(/^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e])|(\\[\x01-\x09\x0b\x0c\x0d-\x7f])))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))$/i)
null
> "[email protected]".match(/(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])/)
[ '[email protected]',
  index: 0,
  input: '[email protected]' ]

[chriso]

Your email address is valid according to the library:

> validator.isEmail('[email protected]');
true

The isEmail validator isn't just one regex pattern. It validates the local user part with regex and then validates the domain part with the validator.isFQDN validator. It breaks the validation up in this way to prevent a ReDoS attack (#152). The regex you pasted from emailregex.com is also vulnerable and should not be used in production.

[einfallstoll]

@chriso Thanks for the explanation and the reference to ReDoS Attacks (first time I heard this, but definitely something I'll keep in mind in the future).

The reason I assumed that there's a bug in validator.js is because my E-Mail was rejected by sails.js and I tracked the validation code all the way down to validator.js where I looked for some useful code regarding E-Mail validation and then I came across the RegExp.

I later tested my E-Mail Address directly against validator.js and I can approve that there must be a problem in a higher level dependency of sails.

Thank you anyway for the explanation and the time to teach me something new. I really appreciate that!

[chriso]

@einfallstoll no problem. Support for gTLDs was added to this library at some stage, so I bet one of the dependencies is using an older version.