Any peer that's behind us while syncing is useless to us (though
not to them). This ensures that we don't get our peer slots filled
with peers that we can't use. Once we've synced, we can connect
to them and they can then sync off us if they want.
Essentially, one can send such a large amount of IDs that core exhausts
all free memory. This issue can theoretically be exploited using very
large CN blockchains, such as Monero.
This is a partial fix. Thanks and credit given to CryptoNote author
'cryptozoidberg' for collaboration and the fix. Also thanks to
'moneromooo'. Referencing HackerOne report #506595.
When all our outgoing peer slots are filled, we cycle one peer at
a time looking for syncing peers until we have at least two such
peers. This brings two advantages:
- Peers without incoming connections will find more syncing peers
that before, thereby strengthening network decentralization
- Peers will have more resistance to isolation attacks, as they
are more likely to find a "good" peer than they were before
RPC connections now have optional tranparent SSL.
An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.
SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.
Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.
To generate long term certificates:
openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT
/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.
SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.
- Support for ".onion" in --add-exclusive-node and --add-peer
- Add --anonymizing-proxy for outbound Tor connections
- Add --anonymous-inbounds for inbound Tor connections
- Support for sharing ".onion" addresses over Tor connections
- Support for broadcasting transactions received over RPC exclusively
over Tor (else broadcast over public IP when Tor not enabled).
The blockchain prunes seven eighths of prunable tx data.
This saves about two thirds of the blockchain size, while
keeping the node useful as a sync source for an eighth
of the blockchain.
No other data is currently pruned.
There are three ways to prune a blockchain:
- run monerod with --prune-blockchain
- run "prune_blockchain" in the monerod console
- run the monero-blockchain-prune utility
The first two will prune in place. Due to how LMDB works, this
will not reduce the blockchain size on disk. Instead, it will
mark parts of the file as free, so that future data will use
that free space, causing the file to not grow until free space
grows scarce.
The third way will create a second database, a pruned copy of
the original one. Since this is a new file, this one will be
smaller than the original one.
Once the database is pruned, it will stay pruned as it syncs.
That is, there is no need to use --prune-blockchain again, etc.
To help protect one's privacy from traffic volume analysis
for people using Tor or I2P. This will really fly once we
relay txes on a timer rather than on demand, though.
Off by default for now since it's wasteful and doesn't bring
anything until I2P's in.
3880bf39 cryptonote_protocol_handler.inl: remove span read just now that failed to pass some basic tests (stoffu)
da249fd5 cryptonote_protocol_handler.inl: fix return type mismatches (int vs bool) (stoffu)
0e7ad2e2 Wallet API: generalize 'bool testnet' to 'NetworkType nettype' (stoffu)
af773211 Stagenet (stoffu)
cc9a0bee command_line: allow args to depend on more than one args (stoffu)
55f8d917 command_line::get_arg: remove 'required' for dependent args as they're always optional (stoffu)
450306a0 command line: allow has_arg to handle arg_descriptor<bool,false,true> #3318 (stoffu)
9f9e095a Use `genesis_tx` parameter in `generate_genesis_block`. #3261 (Jean Pierre Dudey)
This is safer, as we don't risk break expectations (eg, requesting
block hashes and then receiving a late set of blocks). Dropping a
connection means another will be attempted in a fresh state.
Also bump the kick timeout to 5 minutes, to ensure we only kick
really idle peers.
The last known hash was calculated incorrectly, causing
further chain hash downloads to restart from the current
chain. When the block queue has close to 10k blocks waiting,
this causes frequent downloads of 10k more hashes, but
with only the last few hashes actually being useful.
It is unused, as it was apparently a future optimization,
and it leaks some information (though since pools publish
thei blocks they find, that amount seems small).
c867357a cryptonote_protocol: error handling on cleanup_handle_incoming_blocks (moneromooo-monero)
ce901fcb Fix blockchain_import wedge on exception in cleanup_handle_incoming_blocks (moneromooo-monero)
84fa015e core: guard against exceptions in handle_incoming_{block,tx} (moneromooo-monero)
Fix sync wedge corner case:
It could happen if a connection went into standby mode, while
it was the one which had requested the next span, and that span
was still waiting for the data, and that peer is not on the
main chain. Other peers can then start asking for that data
again and again, but never get it as only that forked peer does.
And various other fixes
If monerod is started with default sync mode, set it to SAFE after
synchronization completes. Set it back to FAST if synchronization
restarts (e.g. because another peer has a longer blockchain).
If monerod is started with an explicit sync mode, none of this
automation takes effect.
