nihilist/tor
1
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/core/tor.git synced 2024-11-24 12:23:32 +01:00
Code Issues Packages Projects Releases Wiki Activity

Merge branch 'maint-0.4.4' into maint-0.4.5

Browse Source
This commit is contained in:
Nick Mathewson 2021-06-10 08:42:15 -04:00
commit 1da8621c0a
2 changed files with 13 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
changes/bug40391 Normal file
View File

@ -0,0 +1,9 @@
o Major bugfixes (security):
- Resist a hashtable-based CPU denial-of-service attack against
relays. Previously we used a naive unkeyed hash function to look up
circuits in a circuitmux object. An attacker could exploit this to
construct circuits with chosen circuit IDs in order to try to create
collisions and make the hash table inefficient. Now we use a SipHash
construction for this hash table instead. Fixes bug 40391; bugfix on
0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005.
Reported by Jann Horn from Google's Project Zero.

7
src/core/or/circuitmux.c
View File

@ -169,9 +169,10 @@ chanid_circid_entries_eq(chanid_circid_muxinfo_t *a,
static inline unsigned int static inline unsigned int
chanid_circid_entry_hash(chanid_circid_muxinfo_t *a) chanid_circid_entry_hash(chanid_circid_muxinfo_t *a)
{ {
return (((unsigned int)(a->circ_id) << 8) ^ uint8_t data[8 + 4];
((unsigned int)((a->chan_id >> 32) & 0xffffffff)) ^ set_uint64(data, a->chan_id);
((unsigned int)(a->chan_id & 0xffffffff))); set_uint32(data + 8, a->circ_id);
return (unsigned) siphash24g(data, sizeof(data));
} }
/* Emit a bunch of hash table stuff */ /* Emit a bunch of hash table stuff */