Allow nonce-based CSP for reCAPTCHA
For more secure CSP rules FlaskWTF reCAPTCHA should allow providing nonce when using reCAPTCHA and include that nonce in the script tag which loads api.js.
More information: https://developers.google.com/recaptcha/docs/faq#im-using-content-security-policy-csp-on-my-website-how-can-i-configure-it-to-work-with-recaptcha
That link is unclear about how to use a nonce. If you know what needs to happen, please open a PR.
I think my PR should address the issue of inserting nonce to the script tag.
But getting it working needs adding that nonce to the HTTP CSP header, I don't think that should be part of this library.
well, also try adding the nonce in <head> tag.