A Canary Trap for URI Escaping
Subject:   Escaping vs Encoding.
Date:   2006-07-31 12:55:50
From:   rdeforest
Response to: Escaping vs Encoding.

I agree with BasSchulte - Escaping is a kind of Encoding. Both are ways of translating between one symbol system and another. Escaping is a the subset of encodinng where the contents are enveloped within the target coding. It is irrelevant that escaping uses prefixes to tag metacharachters. The problem (over-encoding) can still exist in other contexts.

I like the idea of adding a 'canary' to detect over-coding, but I would prefer to use something more robust, like a CRC and I don't like the idea of using it to determine when to stop decoding.

In the multiple redirect situation described in the article, I would prefer to fix the root problem: the redirects should not have been re-escaping the original data. This canary solution just hides the problem.