Only touch a bucket if a find request targets it.

[quix0rs-apt-p2p.git] / TODO

diff --git a/TODO b/TODO
index 7d6ec4d16995df9bd832d23395f8e2448daa8b87..bd8283c904d6ed372c9a84136ce204422bb6e183 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,6 +1,44 @@
-Some last few things to do before release.
+Rotate DNS entries for mirrors more reliably.
+
+Currently the mirrors are accessed by DNS name, which can cause some
+issues when there are mirror differences and the DNS gets rotated.
+Instead, the HTTP Downloader should handle DNS lookups itself, store
+the resulting addresses, and send requests to IP addresses. If there
+is an error from the mirror (hash check or 404 response), the next IP
+address in the rotation should be used.
+
+
+Use GPG signatures as a hash for files.
+
+A detached GPG signature, such as is found in Release.gpg, can be used
+as a hash for the file. This hash can be used to verify the file when
+it is downloaded, and a shortened version can be added to the DHT to
+look up peers for the file. To get the hash into a binary form from
+the ascii-armored detached file, use the command
+'gpg --no-options --no-default-keyring --output - --dearmor -'. The
+hash should be stored as the reverse of the resulting binary string,
+as the bytes at the beginning are headers that are the same for most
+signatures. That way the shortened hash stored in the DHT will have a
+better chance of being unique and being stored on different peers. To
+verify a file, first the binary hash must be re-reversed, armored, and
+written to a temporary file with the command
+'gpg --no-options --no-default-keyring --output $tempfile --enarmor -'.
+Then the incoming file can be verified with the command
+'gpg --no-options --no-default-keyring --keyring /etc/apt/trusted.gpg
+--verify $tempfile -'.
+
+All communication with the command-line gpg should be done using pipes
+and the python module python-gnupginterface. There needs to be a new
+module for GPG verification and hashing, which will make this easier.
+In particular, it would need to support hashlib-like functionality
+such as new(), update(), and digest(). Note that the verification
+would not involve signing the file again and comparing the signatures,
+as this is not possible. Instead, the verify() function would have to
+behave differently for GPG hashes, and check that the verification
+resulted in a VALIDSIG. CAUTION: the detached signature can have a
+variable length, though it seems to be usually 65 bytes, 64 bytes has
+also been observed.
 
-- Handle/investigate the HTTP client pipeline errors
 
 Consider what happens when multiple requests for a file are received.
 
@@ -19,6 +57,19 @@ distributions. They need to be dealt with properly by
 adding them to the tracking done by the AptPackages module.
 
 
+Improve the estimation of the total number of nodes
+
+The current total nodes estimation is based on the number of buckets.
+A better way is to look at the average inter-node spacing for the K
+closest nodes after a find_node/value completes. Be sure to measure
+the inter-node spacing in log2 space to dampen any ill effects. This
+can be used in the formula:
+        nodes = 2^160 / 2^(average of log2 spacing)
+The average should also be saved using an exponentially weighted
+moving average (of the log2 distance) over separate find_node/value
+actions to get a better calculation over time.
+
+
 Improve the downloaded and uploaded data measurements.
 
 There are 2 places that this data is measured: for statistics, and for