If the peer (whether pruned or not itself) supports sending pruned blocks
to syncing nodes, the pruned version will be sent along with the hash
of the pruned data and the block weight. The original tx hashes can be
reconstructed from the pruned txes and theur prunable data hash. Those
hashes and the block weights are hashes and checked against the set of
precompiled hashes, ensuring the data we received is the original data.
It is currently not possible to use this system when not using the set
of precompiled hashes, since block weights can not otherwise be checked
for validity.
This is off by default for now, and is enabled by --sync-pruned-blocks
2cd4fd8 Changed the use of boost:value_initialized for C++ list initializer (JesusRami)
4ad191f Removed unused boost/value_init header (whyamiroot)
928f4be Make null hash constants constexpr (whyamiroot)
The check added here (in #5732/#5733) is supposed to disconnect behind
peers when the current node is syncing, but actually disconnects behind
peers always.
We are syncing when `target > our_height`, but the check here triggers
when `target > remote_height`, which is basically always true when the
preceding `m_core.have_block(hshd.top_id)` check is true.
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.
