0e2a5e448f tests: dumping and minimizing of script assets data (Pieter Wuille)
4567ba034c tests: add generic qa-asset-based script verification unit test (Pieter Wuille)
f06e6d0345 tests: functional tests for Schnorr/Taproot/Tapscript (Pieter Wuille)
3c226639eb tests: add BIP340 Schnorr signature support to test framework (Pieter Wuille)
206fb180ec --- [TAPROOT] Tests --- (Pieter Wuille)
d7ff237f29 Activate Taproot/Tapscript on regtest (BIP 341, BIP 342) (Pieter Wuille)
e9a021d7e6 Make Taproot spends standard + policy limits (Pieter Wuille)
865d2c37e2 --- [TAPROOT] Regtest activation and policy --- (Pieter Wuille)
72422ce396 Implement Tapscript script validation rules (BIP 342) (Johnson Lau)
330de894a9 Use ScriptExecutionData to pass through annex hash (Pieter Wuille)
8bbed4b7ac Implement Taproot validation (BIP 341) (Pieter Wuille)
0664f5fe1f Support for Schnorr signatures and integration in SignatureCheckers (BIP 340) (Pieter Wuille)
5de246ca81 Implement Taproot signature hashing (BIP 341) (Johnson Lau)
9eb590894f Add TaggedHash function (BIP 340) (Pieter Wuille)
450d2b2371 --- [TAPROOT] BIP340/341/342 consensus rules --- (Pieter Wuille)
5d62e3a68b refactor: keep spent outputs in PrecomputedTransactionData (Pieter Wuille)
8bd2b4e784 refactor: rename scriptPubKey in VerifyWitnessProgram to exec_script (Pieter Wuille)
107b57df9f scripted-diff: put ECDSA in name of signature functions (Pieter Wuille)
f8c099e220 --- [TAPROOT] Refactors --- (Pieter Wuille)
Pull request description:
This is an implementation of the Schnorr/taproot consensus rules proposed by BIPs [340](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), [341](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), and [342](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki).
See the list of commits [below](https://github.com/bitcoin/bitcoin/pull/19953#issuecomment-691815830). No signing or wallet support of any kind is included, as testing is done entirely through the Python test framework.
This is a successor to https://github.com/bitcoin/bitcoin/pull/17977 (see discussion following [this comment](https://github.com/bitcoin/bitcoin/pull/17977#issuecomment-682285983)), and will have further changes squashed/rebased. The history of this PR can be found in #19997.
ACKs for top commit:
instagibbs:
reACK 0e2a5e448f
benthecarman:
reACK 0e2a5e4
kallewoof:
reACK 0e2a5e448f
jonasnick:
ACK 0e2a5e448f almost only looked at bip340/libsecp related code
jonatack:
ACK 0e2a5e448f modulo the last four commits (tests) that I plan to finish reviewing tomorrow
fjahr:
reACK 0e2a5e448f
achow101:
ACK 0e2a5e448f
Tree-SHA512: 1b00314450a2938a22bccbb4e177230cf08bd365d72055f9d526891f334b364c997e260c10bc19ca78440b6767712c9feea7faad9a1045dd51a5b96f7ca8146e
fd9a0060f0 Report and verify expirations (Pieter Wuille)
86f50ed10f Delete limitedmap as it is unused now (Pieter Wuille)
cc16fff3e4 Make txid delay penalty also apply to fetches of orphan's parents (Pieter Wuille)
173a1d2d3f Expedite removal of tx requests that are no longer needed (Pieter Wuille)
de11b0a4ef Reduce MAX_PEER_TX_ANNOUNCEMENTS for non-PF_RELAY peers (Pieter Wuille)
242d16477d Change transaction request logic to use txrequest (Pieter Wuille)
5b03121d60 Add txrequest fuzz tests (Pieter Wuille)
3c7fe0e5a0 Add txrequest unit tests (Pieter Wuille)
da3b8fde03 Add txrequest module (Pieter Wuille)
Pull request description:
This replaces the transaction request logic with an encapsulated class that maintains all the state surrounding it. By keeping it stand alone, it can be easily tested (using included unit tests and fuzz tests).
The major changes are:
* Announcements from outbound (and whitelisted) peers are now always preferred over those from inbound peers. This used to be the case for the first request (by delaying the first request from inbound peers), and a bias afters. The 2s delay for requests from inbound peers still exists, but after that, if viable outbound peers remain for any given transaction, they will always be tried first.
* No more hard cap of 100 in flight transactions per peer, as there is less need for it (memory usage is linear in the number of announcements, but independent from the number in flight, and CPU usage isn't affected by it). Furthermore, if only one peer announces a transaction, and it has over 100 in flight already, we still want to request it from them. The cap is replaced with a rule that announcements from such overloaded peers get an additional 2s delay (possibly combined with the existing 2s delays for inbound connections, and for txid peers when wtxid peers are available).
* The limit of 100000 tracked announcements is reduced to 5000; this was excessive. This can be bypassed using the PF_RELAY permission (to accommodate locally dumping a batch of many transactions).
This replaces #19184, rebased on #18044 and with many small changes.
ACKs for top commit:
ariard:
Code Review ACK fd9a006. I've reviewed the new TxRequestTracker, its integration in net_processing, unit/functional/fuzzing test coverage. I looked more for soundness of new specification rather than functional consistency with old transaction request logic.
MarcoFalke:
Approach ACK fd9a0060f0🏹
naumenkogs:
Code Review ACK fd9a006. I've reviewed everything, mostly to see how this stuff works at the lower level (less documentation-wise, more implementation-wise), and to try breaking it with unexpected sequences of events.
jnewbery:
utACK fd9a0060f0
jonatack:
WIP light ACK fd9a0060f0 have read the code, verified that each commit is hygienic, e.g. debug build clean and tests green, and have been running a node on and off with this branch and grepping the net debug log. Am still unpacking the discussion hidden by GitHub by fetching it via the API and connecting the dots, storing notes and suggestions in a local branch; at this point none are blockers.
ryanofsky:
Light code review ACK fd9a0060f0, looking at txrequest implementation, unit test implementation, and net_processing integration, just trying to understand how it works and looking for anything potentially confusing in the implementation. Didn't look at functional tests or catch up on review discussion. Just a sanity check review focused on:
Tree-SHA512: ea7b52710371498b59d9c9cfb5230dd544fe9c6cb699e69178dea641646104f38a0b5ec7f5f0dbf1eb579b7ec25a31ea420593eff3b7556433daf92d4b0f0dd7
This adds a --dumptests flag to the feature_taproot.py test, to dump all its
generated test cases to files, in a format compatible with the
script_assets_test unit test. A fuzzer for said format is added as well, whose
primary purpose is coverage-based minimization of those dumps.
This enables the schnorrsig module in libsecp256k1, adds the relevant types
and functions to src/pubkey, as well as in higher-level `SignatureChecker`
classes. The (verification side of the) BIP340 test vectors is also added.
This adds a fuzz test that reimplements a naive reimplementation of
TxRequestTracker (with up to 16 fixed peers and 16 fixed txhashes),
and compares the real implementation against it.
3984b78cd7 test: Add tests for CNode::ConnectedThroughNetwork (Hennadii Stepanov)
49fba9c1aa net: Add CNode::ConnectedThroughNetwork member function (Hennadii Stepanov)
d4dde24034 net: Add CNode::m_inbound_onion data member (Hennadii Stepanov)
Pull request description:
This PR:
- adds `CNode::ConnectedThroughNetwork` member function
- is based on #19991, and only last two commits belong to it
- is required for https://github.com/bitcoin-core/gui/pull/86 and #20002
ACKs for top commit:
jonatack:
re-ACK 3984b78cd7 per `git diff 3989fcf 3984b78c`
laanwj:
Code review ACK 3984b78cd7
Tree-SHA512: 23a9c8bca8dca75113b5505fe443b294f2d42d03c98c7e34919da12d8396beb8d0ada3a58ae16e3da04b7044395f72cf9c216625afc078256cd6c897ac42bf3d
In preparation for adding Schnorr versions of `CheckSig`, `VerifySignature`, and
`ComputeEntry`, give them an ECDSA specific name.
-BEGIN VERIFY SCRIPT-
sed -i 's/CheckSig(/CheckECDSASignature(/g' $(git grep -l CheckSig ./src)
sed -i 's/VerifySignature(/VerifyECDSASignature(/g' $(git grep -l VerifySignature ./src)
sed -i 's/ComputeEntry(/ComputeEntryECDSA(/g' $(git grep -l ComputeEntry ./src)
-END VERIFY SCRIPT-
deb52711a1 Remove header checks out of net_processing (Troy Giorshev)
52d4ae46ab Give V1TransportDeserializer CChainParams& member (Troy Giorshev)
5bceef6b12 Change CMessageHeader Constructor (Troy Giorshev)
1ca20c1af8 Add doxygen comment for ReceiveMsgBytes (Troy Giorshev)
890b1d7c2b Move checksum check from net_processing to net (Troy Giorshev)
2716647ebf Give V1TransportDeserializer an m_node_id member (Troy Giorshev)
Pull request description:
Inspired by #15206 and #15197, this PR moves all message header verification from the message processing layer and into the network/transport layer.
In the previous PRs there is a change in behavior, where we would disconnect from peers upon a single failed checksum check. In various discussions there was concern over whether this was the right choice, and some expressed a desire to see how this would look if it was made to be a pure refactor.
For more context, see https://bitcoincore.reviews/15206.html#l-81.
This PR improves the separation between the p2p layers, helping improvements like [BIP324](https://github.com/bitcoin/bitcoin/pull/18242) and #18989.
ACKs for top commit:
ryanofsky:
Code review ACK deb52711a1 just rebase due to conflict on adjacent line
jnewbery:
Code review ACK deb52711a1.
Tree-SHA512: 1a3b7ae883b020cfee1bef968813e04df651ffdad9dd961a826bd80654f2c98676ce7f4721038a1b78d8790e4cebe8060419e3d8affc97ce2b9b4e4b72e6fa9f
This moves header size and netmagic checking out of net_processing and
into net. This check now runs in ReadHeader, so that net can exit early
out of receiving bytes from the peer. IsValid is now slimmed down, so
it no longer needs a MessageStartChars& parameter.
Additionally this removes the rest of the m_valid_* members from
CNetMessage.
This adds a CChainParams& member to V1TransportDeserializer member, and
use it in place of many Params() calls. In addition to reducing the
number of calls to a global, this removes a parameter from GetMessage
(and will later allow us to remove one from CMessageHeader::IsValid())
This commit removes the single-parameter contructor of CMessageHeader
and replaces it with a default constructor.
The single parameter contructor isn't used anywhere except for tests.
There is no reason to initialize a CMessageHeader with a particular
messagestart. This messagestart should always be replaced when
deserializing an actual message header so that we can run checks on it.
The default constructor initializes it to zero, just like the command
and checksum.
This also removes a parameter of a V1TransportDeserializer constructor,
as it was only used for this purpose.
This removes the m_valid_checksum member from CNetMessage. Instead,
GetMessage() returns an Optional.
Additionally, GetMessage() has been given an out parameter to be used to
hold error information. For now it is specifically a uint32_t used to
hold the raw size of the corrupt message.
The checksum check is now done in GetMessage.
This is intended to only be used for logging.
This will allow log messages in the following commits to keep recording
the peer's ID, even when logging is moved into V1TransportDeserializer.
m_valid implies the block solution has been checked, which is not the
case. It only means the txs could be parsed. C++17 comes with
std::optional, so just use that instead.
ddefb5c0b7 p2p: Use the greatest common version in peer logic (Hennadii Stepanov)
e084d45562 p2p: Remove SetCommonVersion() from VERACK handler (Hennadii Stepanov)
8d2026796a refactor: Rename local variable nSendVersion (Hennadii Stepanov)
e9a6d8b13b p2p: Unify Send and Receive protocol versions (Hennadii Stepanov)
Pull request description:
On master (6fef85bfa3) `CNode` has two members to keep protocol version:
- `nRecvVersion` for received messages
- `nSendVersion` for messages to send
After exchanging with `VERSION` and `VERACK` messages via protocol version `INIT_PROTO_VERSION`, both nodes set `nRecvVersion` _and_ `nSendVersion` to _the same_ value which is the greatest common protocol version.
This PR:
- replaces two `CNode` members, `nRecvVersion` `nSendVersion`, with `m_greatest_common_version`
- removes duplicated getter and setter
There is no change in behavior on the P2P network.
ACKs for top commit:
jnewbery:
ACK ddefb5c0b7
naumenkogs:
ACK ddefb5c0b7
fjahr:
Code review ACK ddefb5c0b7
amitiuttarwar:
code review but untested ACK ddefb5c0b7
benthecarman:
utACK `ddefb5c`
Tree-SHA512: 5305538dbaa5426b923b0afd20bdef4f248d310855d1d78427210c00716c67b7cb691515c421716b6157913e453076e293b10ff5fd2cd26a8e5375d42da7809d
-BEGIN VERIFY SCRIPT-
sed -i 's/PeerLogicValidation/PeerManager/g' $(git grep -l PeerLogicValidation ./src ./test)
sed -i 's/peer_logic/peerman/g' $(git grep -l peer_logic ./src ./test)
-END VERIFY SCRIPT-
PeerLogicValidation was originally net_processing's implementation to
the validation interface. It has since grown to contain much of
net_processing's logic. Therefore rename it to reflect its
responsibilities.
Suggested in
https://github.com/bitcoin/bitcoin/pull/10756#pullrequestreview-53892618.
Keep a references to chainparams, rather than calling the global
Params() function every time it's needed. This is fine, since
globalChainParams does not get updated once it's been set, and it's
available at the point of constructing the PeerLogicValidation object.
We previously identified if we relay addresses to the connection by checking
for the existence of the m_addr_known data structure. With this commit, we
answer this question based on the connection type.
IsAddrRelayPeer() checked for the existence of the m_addr_known
46fcac1e4b tests: Add fuzzing harness for ec_seckey_import_der(...) and ec_seckey_export_der(...) (practicalswift)
b667a90389 tests: Add fuzzing harness for SigHasLowR(...) and ecdsa_signature_parse_der_lax(...) (practicalswift)
Pull request description:
Add fuzzing harness for `SigHasLowR(...)` and `ecdsa_signature_parse_der_lax(...)`.
See [`doc/fuzzing.md`](https://github.com/bitcoin/bitcoin/blob/master/doc/fuzzing.md) for information on how to fuzz Bitcoin Core. Don't forget to contribute any coverage increasing inputs you find to the [Bitcoin Core fuzzing corpus repo](https://github.com/bitcoin-core/qa-assets).
Happy fuzzing :)
ACKs for top commit:
Crypt-iQ:
ACK 46fcac1e4b
Tree-SHA512: 11a4856a1efd9a04030a8c8aee2413fd5be1ea248147e649a48a55bacdf732bb48a19ee1ce2761d47d4dd61c9598aec53061b961b319ad824d539dda11a8ccf4
102867c587 net: change CNetAddr::ip to have flexible size (Vasil Dimov)
1ea57ad674 net: don't accept non-left-contiguous netmasks (Vasil Dimov)
Pull request description:
(chopped off from #19031 to ease review)
Before this change `CNetAddr::ip` was a fixed-size array of 16 bytes,
not being able to store larger addresses (e.g. TORv3) and encoded
smaller ones as 16-byte IPv6 addresses.
Change its type to `prevector`, so that it can hold larger addresses and
do not disguise non-IPv6 addresses as IPv6. So the IPv4 address
`1.2.3.4` is now encoded as `01020304` instead of
`00000000000000000000FFFF01020304`.
Rename `CNetAddr::ip` to `CNetAddr::m_addr` because it is not an "IP" or
"IP address" (TOR addresses are not IP addresses).
In order to preserve backward compatibility with serialization (where
e.g. `1.2.3.4` is serialized as `00000000000000000000FFFF01020304`)
introduce `CNetAddr` dedicated legacy serialize/unserialize methods.
Adjust `CSubNet` accordingly. Still use `CSubNet::netmask[]` of fixed 16
bytes, but use the first 4 for IPv4 (not the last 4). Do not accept
invalid netmasks that have 0-bits followed by 1-bits and only allow
subnetting for IPv4 and IPv6.
Co-authored-by: Carl Dong <contact@carldong.me>
ACKs for top commit:
sipa:
utACK 102867c587
MarcoFalke:
Concept ACK 102867c587
ryanofsky:
Code review ACK 102867c587. Just many suggested updates since last review. Thanks for following up on everything!
jonatack:
re-ACK 102867c587 diff review, code review, build/tests/running bitcoind with ipv4/ipv6/onion peers
kallewoof:
ACK 102867c587
Tree-SHA512: d60bf716cecf8d3e8146d2f90f897ebe956befb16f711a24cfe680024c5afc758fb9e4a0a22066b42f7630d52cf916318bedbcbc069ae07092d5250a11e8f762
Before this change `CNetAddr::ip` was a fixed-size array of 16 bytes,
not being able to store larger addresses (e.g. TORv3) and encoded
smaller ones as 16-byte IPv6 addresses.
Change its type to `prevector`, so that it can hold larger addresses and
do not disguise non-IPv6 addresses as IPv6. So the IPv4 address
`1.2.3.4` is now encoded as `01020304` instead of
`00000000000000000000FFFF01020304`.
Rename `CNetAddr::ip` to `CNetAddr::m_addr` because it is not an "IP" or
"IP address" (TOR addresses are not IP addresses).
In order to preserve backward compatibility with serialization (where
e.g. `1.2.3.4` is serialized as `00000000000000000000FFFF01020304`)
introduce `CNetAddr` dedicated legacy serialize/unserialize methods.
Adjust `CSubNet` accordingly. Still use `CSubNet::netmask[]` of fixed 16
bytes, but use the first 4 for IPv4 (not the last 4). Only allow
subnetting for IPv4 and IPv6.
Co-authored-by: Carl Dong <contact@carldong.me>
daed542a12 [net_processing] Move ProcessMessage to PeerLogicValidation (John Newbery)
c556770b5e [net_processing] Change PeerLogicValidation to hold a connman reference (John Newbery)
Pull request description:
Rather than ProcessMessage() being a static function in net_processing.cpp, make it a private member function of PeerLogicValidation. This is the start of moving static functions and global variables into PeerLogicValidation to make it better encapsulated.
ACKs for top commit:
jonatack:
ACK daed542a12 code review and debug tested
promag:
Code review ACK daed542a12.
MarcoFalke:
re-ACK daed542a12, only change is removing second commit 🎴
theStack:
Code Review ACK daed542a12
Tree-SHA512: ddebf410d114d9ad5a9e536950018ff333a347c035d74fcc101fb4a3f20a281782c7eac2b7d1bd1c8f6bc7e59f5b5630fb52c2e1b4c32df454fa584673bd021e
01e283068b [net] Remove unnecessary default args on CNode constructor (Amiti Uttarwar)
bc5d65b3ca [refactor] Remove IsOutboundDisconnectionCandidate (Amiti Uttarwar)
2f2e13b6c2 [net/refactor] Simplify multiple-connection checks (Amiti Uttarwar)
7f7b83deb2 [net/refactor] Rework ThreadOpenConnections logic (Amiti Uttarwar)
35839e963b [net] Fix bug where AddrFetch connections would be counted as outbound full relay (Amiti Uttarwar)
4972c21b67 [net/refactor] Clarify logic for selecting connections in ThreadOpenConnections (Amiti Uttarwar)
60156f5fc4 [net/refactor] Remove fInbound flag from CNode (Amiti Uttarwar)
7b322df629 [net/refactor] Remove m_addr_fetch member var from CNode (Amiti Uttarwar)
14923422b0 [net/refactor] Remove fFeeler flag from CNode (Amiti Uttarwar)
49efac5cae [net/refactor] Remove m_manual_connection flag from CNode (Amiti Uttarwar)
d3698b5ee3 [net/refactor] Add connection type as a member var to CNode (Amiti Uttarwar)
46578c03e9 [doc] Describe different connection types (Amiti Uttarwar)
442abae2ba [net/refactor] Add AddrFetch connections to ConnectionType enum (Amiti Uttarwar)
af59feb052 [net/refactor] Extract m_addr_known logic from initializer list (Amiti Uttarwar)
e1bc29812d [net/refactor] Add block relay only connections to ConnectionType enum (Amiti Uttarwar)
0e52a659a2 [net/refactor] Add feeler connections to ConnectionType enum (Amiti Uttarwar)
1521c47438 [net/refactor] Add manual connections to ConnectionType enum (Amiti Uttarwar)
26304b4100 [net/refactor] Introduce an enum to distinguish type of connection (Amiti Uttarwar)
3f1b7140e9 scripted-diff: Rename OneShot to AddrFetch (Amiti Uttarwar)
Pull request description:
**This is part 1 of #19315, which enables the ability to test `outbound` and `block-relay-only` connections from the functional tests.** Please see that PR for more information of overall functionality.
**This PR simplifies how we manage different connection types.** It introduces an enum with the various types of connections so we can explicitly define the connection type. The existing system relies on a series of independent flags, then has asserts scattered around to ensure that conflicting flags are not enabled at the same time. I find this approach to be both brittle and confusing. While making these changes, I found a small bug due to the silent assumptions.
This PR also proposes a rename from `OneShot` to `AddrFetch`. I find the name `OneShot` to be very confusing, especially when we also have `onetry` manual connections. Everyone I've talked to offline has agreed that the name is confusing, so I propose a potential alternative. I think this is a good opportunity for a rename since I'm creating an enum to explicitly define the connection types.
(some context for the unfamiliar: `oneshot` or `addrfetch` connections are short-lived connections created on startup. They connect to the seed peers, send a `getaddr` to solicit addresses, then close the connection.)
Overview of this PR:
* rename `oneshot` to `addrfetch`
* introduce `ConnectionType` enum
* one by one, add different connection types to the enum
* expose the `conn_type` on CNode, and use this to reduce reliance on flags (& asserts)
* fix the bug in counting different type of connections
* some additional cleanup to simplify logic and make expectations explicit/inclusive rather than implicit/exclusive.
ACKs for top commit:
jnewbery:
utACK 01e283068b
laanwj:
Code review ACK 01e283068b, the commits are pretty straightforward to follow, and I think this is a move in the right direction overall
vasild:
ACK 01e283068
sdaftuar:
ACK 01e283068b.
fanquake:
ACK 01e283068b - I don't have as much experience with the networking code but these changes look fairly straight forward, the new code seems more robust/understandable and the additional documentation is great. I'm glad that a followup branch is already underway. There might be some more review comments here later today, so keep an eye on the discussion, however I'm going to merge this now.
jb55:
wow this code was messy before... ACK 01e283068b
Tree-SHA512: 7bb644a6ed5849913d777ebc2ff89133ca0fbef680355a9a344e07496a979e6f9ff21a958e8eea93dcd7d5c343682b0c7174b1a3de380a4247eaae73da436e15
77c507358b Make Hash[160] consume range-like objects (Pieter Wuille)
02c4cc5c5d Make CHash256/CHash160 output to Span (Pieter Wuille)
0ef97b1b10 Make MurmurHash3 consume Spans (Pieter Wuille)
e549bf8a9a Make CHash256 and CHash160 consume Spans (Pieter Wuille)
2a2182c387 Make script/standard's BaseHash Span-convertible (Pieter Wuille)
e63dcc3a67 Add MakeUCharSpan, to help constructing Span<[const] unsigned char> (Pieter Wuille)
567825049f Make uint256 Span-convertible by adding ::data() (Pieter Wuille)
131a2f0337 scripted-diff: rename base_blob::data to m_data (Pieter Wuille)
Pull request description:
This makes use of the implicit constructions and conversions to Span introduced in #18468 to simplify the hash.h interface:
* All functions that take a pointer and a length are changed to take a Span instead.
* The Hash() and Hash160() functions are changed to take in "range" objects instead of begin/end iterators.
ACKs for top commit:
laanwj:
re-ACK 77c507358b
jonatack:
Code review re-ACK 77c5073 per `git range-diff 14ceddd 49fc016 77c5073`
Tree-SHA512: 9ec929891b1ddcf30eb14b946ee1bf142eca1442b9de0067ad6a3c181e0c7ea0c99c0e291e7f6e7a18bd7bdf78fe94ee3d5de66e167401674caf91e026269771
3bd67ba5a4 Test addr response caching (Gleb Naumenko)
cf1569e074 Add addr permission flag enabling non-cached addr sharing (Gleb Naumenko)
acd6135b43 Cache responses to addr requests (Gleb Naumenko)
7cc0e8101f Remove useless 2500 limit on AddrMan queries (Gleb Naumenko)
ded742bc5b Move filtering banned addrs inside GetAddresses() (Gleb Naumenko)
Pull request description:
This is a very simple code change with a big p2p privacy benefit.
It’s currently trivial to scrape any reachable node’s AddrMan (a database of all nodes known to them along with the timestamps).
We do have a limit of one GETADDR per connection, but a spy can disconnect and reconnect even from the same IP, and send GETADDR again and again.
Since we respond with 1,000 random records at most, depending on the AddrMan size it takes probably up to 100 requests for an spy to make sure they scraped (almost) everything.
I even have a script for that. It is totally doable within couple minutes.
Then, with some extra protocol knowledge a spy can infer the direct peers of the victim, and other topological stuff.
I suggest to cache responses to GETADDR on a daily basis, so that an attacker gets at most 1,000 records per day, and can’t track the changes in real time. I will be following up with more improvements to addr relay privacy, but this one alone is a very effective. And simple!
I doubt any of the real software does *reconnect to get new addrs from a given peer*, so we shouldn’t be cutting anyone.
I also believe it doesn’t have any negative implications on the overall topology quality. And the records being “outdated” for at most a day doesn’t break any honest assumptions either.
ACKs for top commit:
jnewbery:
reACK 3bd67ba5a4
promag:
Code review ACK 3bd67ba5a4.
ariard:
Code Review ACK 3bd67ba
Tree-SHA512: dfa5d03205c2424e40a3f8a41af9306227e1ca18beead3b3dda44aa2a082175bb1c6d929dbc7ea8e48e01aed0d50f0d54491caa1147471a2b72a46c3ca06b66f
