Identityserver4.admin: Add reCaptcha plugin

[skoruba]

[martinussuherman]

@skoruba lol I've been thinking the same ...
What do you think about this one: DNTCaptcha.Core ?

[skoruba]

I am considering this helper for google reCaptcha: https://github.com/TimothyMeadows/reCAPTCHA.AspNetCore
What do you think?

[martinussuherman]

I personally prefer self hosted alternative, but google reCaptcha probably fine.
Maybe we could make option for which captcha to use ?

[skoruba]

I will check your link, but I think that google has great algorithms how to recognize that user is not a bot and you are not required to put random codes. 😊 But I understand that for some scenarios is better something self-hosted.

[DrQwertySilence]

We use google reCaptcha in our fork (our security area demanded it). Is pretty easy to implement. I added in in some places (login, change password and delete account pages). I can implement it if you give me all the forms where it should appear.