diff options
Diffstat (limited to 'tor-spec.txt')
| -rw-r--r-- | tor-spec.txt | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/tor-spec.txt b/tor-spec.txt index e85634d..53158fe 100644 --- a/tor-spec.txt +++ b/tor-spec.txt @@ -428,6 +428,7 @@ see tor-design.pdf. 9 -- RELAY_EARLY (End-to-end data; limited)(See Sec 5.6) 10 -- CREATE2 (Extended CREATE cell) (See Sec 5.1) 11 -- CREATED2 (Extended CREATED cell) (See Sec 5.1) + 12 -- PADDING_NEGOTIATE (Padding negotiation) (See Sec 7.2) Variable-length command values are: 7 -- VERSIONS (Negotiate proto version) (See Sec 4) @@ -539,6 +540,7 @@ see tor-design.pdf. variable-length cells. 3 -- Uses the in-protocol handshake. 4 -- Increases circuit ID width to 4 bytes. + 5 -- Adds support for link padding and negotiation (padding-spec.txt). 4.2. CERTS cells @@ -1534,11 +1536,24 @@ see tor-design.pdf. long-range padding. The contents of a PADDING, VPADDING, or DROP cell SHOULD be chosen randomly, and MUST be ignored. - Currently nodes are not required to do any sort of link padding or - dummy traffic. Because strong attacks exist even with link padding, - and because link padding greatly increases the bandwidth requirements - for running a node, we plan to leave out link padding until this - tradeoff is better understood. + If the link protocol is version 5 or higher, link level padding is + enabled as per padding-spec.txt. On these connections, clients may + negotiate the use of padding with a CELL_PADDING_NEGOTIATE command + whose format is as follows: + Version [1 byte] + Command [1 byte] + ito_low_ms [2 bytes] + ito_high_ms [2 bytes] + + Currently, only version 0 of this cell is defined. In it, the command + field is either 1 (stop padding) or 2 (start padding). For the start + padding command, a pair of timeout values specifying a low and a high + range bounds for randomized padding timeouts may be specified as unsigned + integer values in milliseconds. The ito_low_ms field must not be lower than + the current consensus parameter value for nf_ito_low (default: 1500). + ito_high_ms must be greater than ito_low_ms. + + For more details on padding behavior, see padding-spec.txt. 7.3. Circuit-level flow control |