Rails - Sep 2012 - How do you create a link to a resource that expires

I would like to send a link to a user (via email) that expires after a period of
time.

When a user takes a certain action, they are emailed a link that allows them
access to a certain resource.
What I want to do is make it so that the link will work for a period of time
(say 48 hours) and then will
no longer work.  I would like the link to look like:

    http://www.mysite.com/stuff/b39a8b314588d04e23f15ceb026196c5
or
    http://www.mysite.com/stuff/resourcea?b39a8b314588d04e23f15ceb026196c5

Rails would need to decrypt the url (it doesn''t need to be
cryptographically secure, but it
should be non obvious), determine if the timeframe is still valid and serve the
resource (or not).

I would rather that the timeframe be included in the link instead of having to
do a db lookup.

Are there any gems/plug-ins out there for this?  How would I go about creating
it from scratch?

Matt


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On 09/28/2012 06:21 PM, Matt Martini wrote:
> Are there any gems/plug-ins out there for this?  How would I go about
> creating it from scratch?
Not sure about existing gems, not having looked at this in Ruby or
Rails, but having solved it in another language: you create an entry in
your database with a token and a timestamp.  When a user sends the token
back, you check the current time against the token’s associated
timestamp, and reject it if the token is unknown or the timestamp is too
old.  (Periodically, you can garden your database to delete any entry
with an old timestamp.)

~Chris
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LIVE FREE: vote for Gary Johnson, Libertarian for President.
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I would use cancan.

https://github.com/ryanb/cancan/wiki/Authorizing-Controller-Actions

if valid(params[:token])
  authorize! :show, @stuff
end

==================*Alexandre Mondaini Calvão*

"*Nossa recompensa se encontra no esforço e não no resultado. Um esforço
total é uma vitória completa*." [Ghandi]


2012/9/29 Christopher R. Maden
<crism-KB/imElbUW3YtjvyW6yDsg@public.gmane.org>
> On 09/28/2012 06:21 PM, Matt Martini wrote:
> > Are there any gems/plug-ins out there for this?  How would I go about
> > creating it from scratch?
>
> Not sure about existing gems, not having looked at this in Ruby or
> Rails, but having solved it in another language: you create an entry in
> your database with a token and a timestamp.  When a user sends the token
> back, you check the current time against the token’s associated
> timestamp, and reject it if the token is unknown or the timestamp is too
> old.  (Periodically, you can garden your database to delete any entry
> with an old timestamp.)
>
> ~Chris
> --
> Chris Maden, text nerd  <URL: http://crism.maden.org/ >
> LIVE FREE: vote for Gary Johnson, Libertarian for President.
>      <URL: http://garyjohnson2012.com/ >  <URL: http://lp.org/
>
> GnuPG fingerprint: DB08 CF6C 2583 7F55 3BE9  A210 4A51 DBAC 5C5C 3D5E
>
> --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Talk" group.
> To post to this group, send email to
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> To unsubscribe from this group, send email to
>
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> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>
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