[OAUTH-WG] Out-of-band code delivery and alternate redirect_uri schemes

Pedro Felix <pmhsfelix@gmail.com> Wed, 10 October 2012 14:25 UTC

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Date: Wed, 10 Oct 2012 15:25:46 +0100
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From: Pedro Felix <pmhsfelix@gmail.com>
To: oauth@ietf.org
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Subject: [OAUTH-WG] Out-of-band code delivery and alternate redirect_uri schemes
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1) Out-of-band code transmission

Currently Google OAuth2 implementation uses the special
"urn:ietf:wg:oauth:2.0:oob" to signal the Authorization Endpoint to return
an HTML page with the code, instead of a redirect. At first sight, it seems
a good idea, however it isn't in the OAuth 2 RFC.
  a) What is the reason for the absence in the spec?
  b) Is there any security problem associated with this usage?

2) Alternative "redirect_uri" schemes

I'm also considering the use of alternative schemes on the "redirect_uri".
For instance, a client app could use the "mailto:" scheme to instruct the
Authorization Endpoint to send the code via email. I know that a naive
implementation can be subject to fixation attacks, however
  a) Weren't these scenarios considered by the working group?
  b) Is there a major security flaw on this usage?