From: Rob Biedenharn <Rob@...>
Date: 2008-10-02T07:08:33+09:00
Subject: Re: Base64 for URL variant


On Oct 1, 2008, at 5:40 PM, ara.t.howard wrote:

>
> On Oct 1, 2008, at 3:33 PM, Kless wrote:
>
>> Does ruby core has any method to create a Base64 for URL variant?
>
>
>
> CGI.escape( Base64.encode( 'foobar' ) )
>
> is one way...
>
> a @ http://codeforpeople.com/
> --
> we can deny everything, except that we have the possibility of being  
> better. simply reflect on that.
> h.h. the 14th dalai lama


Here's another:
     # base64, but change + and / which are significant to URLs to -  
and _,
     # respectively, (which is what RFC4648 calls "base64url") and  
remove
     # embedded newlines (since they are recommended by MIME encoding  
and not
     # base64, per se)
     encoded_token = [cipher_token].pack('m').tr('+/','- 
_').gsub("\n",'')

the encoded_token is "safe" for a URL and the cipher_token is  
retrieved with:

     cipher_token = encoded_token.tr('-_','+/').unpack('m')[0]

The details of the cipher_token aren't important save that it can  
contain any byte values.

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com