Opened 3 years ago

Closed 3 years ago

#25365 closed defect (not a bug)

Use uint64_t for Tor's hash tables, even if int is 32 bits

Reported by: teor Owned by:
Priority: Medium Milestone: Tor: 0.3.4.x-final
Component: Core Tor/Tor Version:
Severity: Normal Keywords:
Cc: Actual Points:
Parent ID: Points: 1
Reviewer: Sponsor:


64-bit macOS and BSD are LP64, which means that their ints are 32 bits. This makes Tor's hash tables 32 bits, reducing their security.

This issue also occurs on 32-bit systems, where using uint64_t might be slower. I don't know if speed matters, as siphash is 64 bit anyway.

Child Tickets

Change History (2)

comment:1 Changed 3 years ago by nickm

I'm not sure how this actually affects security. Could you walk me through the argument there?

comment:2 Changed 3 years ago by teor

Keywords: security-low removed
Resolution: not a bug
Status: newclosed

I was thinking about the birthday paradox, but that doesn't apply, because an adversary needs to get many entries in the same bucket, rather than just one collision.

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