diff options
| author | Roger Dingledine <arma@torproject.org> | 2008-08-20 05:21:43 +0000 |
|---|---|---|
| committer | Roger Dingledine <arma@torproject.org> | 2008-08-20 05:21:43 +0000 |
| commit | 8f5642edbc9549e260b923186bc98e0fb4e8cf6e (patch) | |
| tree | d1f6bb74744e742c5f65edd66a92afa125246f75 /doc | |
| parent | cc8b2247bfcecae2fe96d4133c8f403db06c93f7 (diff) | |
| download | tor-8f5642edbc9549e260b923186bc98e0fb4e8cf6e.tar.gz tor-8f5642edbc9549e260b923186bc98e0fb4e8cf6e.zip | |
Relays now reject risky extend cells: if the extend cell includes
a digest of all zeroes, or asks to extend back to the relay that
sent the extend cell, tear down the circuit. Ideas suggested
by rovv.
svn:r16605
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/spec/tor-spec.txt | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/doc/spec/tor-spec.txt b/doc/spec/tor-spec.txt index 74b3a250b6..e0a10a32d6 100644 --- a/doc/spec/tor-spec.txt +++ b/doc/spec/tor-spec.txt @@ -398,9 +398,9 @@ see tor-design.pdf. The port and address field denote the IPV4 address and port of the next onion router in the circuit; the public key hash is the hash of the PKCS#1 ASN1 encoding of the next onion router's identity (signing) key. (See 0.3 - above.) (Including this hash allows the extending OR verify that it is + above.) Including this hash allows the extending OR verify that it is indeed connected to the correct target OR, and prevents certain - man-in-the-middle attacks.) + man-in-the-middle attacks. The payload for a CREATED cell, or the relay payload for an EXTENDED cell, contains: @@ -525,10 +525,12 @@ see tor-design.pdf. When an onion router receives an EXTEND relay cell, it sends a CREATE cell to the next onion router, with the enclosed onion skin as its - payload. The initiating onion router chooses some circID not yet - used on the connection between the two onion routers. (But see - section 5.1. above, concerning choosing circIDs based on - lexicographic order of nicknames.) + payload. As special cases, if the extend cell includes a digest of + all zeroes, or asks to extend back to the relay that sent the extend + cell, the circuit will fail and be torn down. The initiating onion + router chooses some circID not yet used on the connection between the + two onion routers. (But see section 5.1. above, concerning choosing + circIDs based on lexicographic order of nicknames.) When an onion router receives a CREATE cell, if it already has a circuit on the given connection with the given circID, it drops the |