b64 regex token checks

[jankapunkt]

@jorenvandeweyer commented on pr #105:

In the spec it is defined as it should start with Bearer followed with a whitespace. That's what the additional ^ in the regex is for. I think we should not support BeArEr @Uzlopak

b64token = 1*( ALPHA / DIGIT /
"-" / "." / "_" / "~" / "+" / "/" ) "="
credentials = "Bearer" 1SP b64token

But I do like the check provided for the second part. But that should be a different issue/pull request. Because that check should also be done on the result of generateAccessToken and generateRefreshToken.

[jankapunkt]

Does it make sense to implement this here: https://github.com/node-oauth/formats ?

[jorenvandeweyer]

The correct regex would be ^Bearer\s[0-9a-zA-Z-._~+/]+=*$