[tor-bugs] #19168 [Core Tor/Tor]: Integer overflows in case conversion tables

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#19168: Integer overflows in case conversion tables
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 Reporter:  cypherpunks   |          Owner:
     Type:  defect        |         Status:  needs_revision
 Priority:  Medium        |      Milestone:  Tor: 0.2.9.x-final
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by cypherpunks):

 Sorry for mixing up the terminology. It came from the message GCC was
 giving me
 {{{
 error: overflow in implicit constant conversion [-Werror=overflow]
 }}}
 Because the tables contain integers, i figured they are integer overflows
 but i stand corrected.

 This error was thrown by compiling Tor with GCC in pedantic mode. As you
 mention, this behavior is implementation-defined. To quote the document
 for this specific case
 {{{
 Otherwise, the new type is signed and the value cannot be represented in
 it; either the
 result is implementation-defined or an implementation-defined signal is
 raised.
 }}}
 In the first case, the resulting values differ from what is expected. In
 cases where it matters, future developers will have to waste time again to
 trace these difference back to these tables. In the second case, some
 implementations are free to raise signals which Tor would need handle.
 This would require new code with the chance of introducing new bugs. To
 avoid all this, I think applying the patch (after changing it to use
 proper terminology) would prevent future headaches.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19168#comment:3>
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