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pmf and case-sensitive matching

See original GitHub issue

_Issue originally created by user fgsch on date 2018-01-22 16:13:44. Link to original issue: https://github.com/SpiderLabs/owasp-modsecurity-crs/issues/998._

After c1a7652d2a57dafc16afbda56967b611e6aebaca, all @pmf occurrences have the lowercase transformation.

IMO this was not the right way to fix it since it implies @pmf is no longer case insensitive as the documentation states. Furthermore, although disabled there is code in the Aho-Cora implementation to support UTF8. If this ever gets enabled and rules start depending on it, having lowercase alone would not be enough.

We should either revert this or update the documentation (and code) to treat the input as case-sensitive.

Issue Analytics

State:
Created 3 years ago
Comments:7

Top GitHub Comments

1reaction

CRS-migration-botcommented, May 13, 2020

User dune73 commented on date 2020-01-08 16:03:45:

OK. I got you now.

We are based on an engine that defines @pmf as case-insensitive, yet we act as if it was sensitive in order to comfort implementations that do not follow the definition and implement a case sensitive A-C algorithm. Consequently users of compliant implementations suffer the performance penalty of an unnecessary t:lowercase transformation. And on top of it, we’re likely to face UTF-8 problems with out transformation.

Correct?

If yes, it would indeed make sense to roll back the change.

It would be nice, if p0pr0ck5 could chime in, before we perform the roll back, though.

0reactions

github-actions[bot]commented, Sep 12, 2020

This issue has been open 120 days with no activity. Remove the stale label or comment, or this will be closed in 14 days

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