Closes [nimbus-eth1#767](https://github.com/status-im/nimbus-eth1/issues/767).
Crashes occur when certain invalid RLPx messages are received from a peer.
Specifically, `msgId` out of range. Because any peer can easily trigger this
crash, we'd consider it a DOS vulnerability if Nimbus-eth1 was in general use.
We noticed when syncing to Goerli, there were some rare crashes with this
exception. It turned out one peer with custom code, perhaps malfunctioning,
was sending these messages if we were unlucky enough to connect to it.
`invokeThunk` is called from `dispatchMessages` and checks the range of
`msgId`. It correctly recognise that it's out of range, raises and exception
and produces a message. Job done.
Except the code in `dispatchMessage` treats all that as a warning instead of
error, and continues to process the message. A bit lower down, `msgId` is used
again without a range check.
The trivial fix is to check array bounds before access.
--
ps. Here's the stack trace ("reraised" sections hidden):
```
WRN 2021-11-08 21:29:33.238+00:00 Error while handling RLPx message topics="rlpx" tid=2003472 file=rlpx.nim:607 peer=Node[<IP>:45456] msg=45 err="RLPx message with an invalid id 45 on a connection supporting eth,snap"
/home/jamie/Status/nimbus-eth1/nimbus/p2p/chain/chain_desc.nim(437) main
/home/jamie/Status/nimbus-eth1/nimbus/p2p/chain/chain_desc.nim(430) NimMain
/home/jamie/Status/nimbus-eth1/nimbus/nimbus.nim(258) process
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncloop.nim(279) poll
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(74) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(1218) rlpxAccept
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(101) postHelloSteps
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(74) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(985) postHelloSteps
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(101) dispatchMessages
/home/jamie/Status/nimbus-eth1/vendor/nim-chronos/chronos/asyncmacro2.nim(77) colonanonymous
/home/jamie/Status/nimbus-eth1/vendor/nim-eth/eth/p2p/rlpx.nim(614) dispatchMessages
/home/jamie/Status/nimbus-eth1/vendor/nimbus-build-system/vendor/Nim/lib/system/chcks.nim(23) raiseIndexError2
/home/jamie/Status/nimbus-eth1/vendor/nimbus-build-system/vendor/Nim/lib/system/fatal.nim(49) sysFatal
[[reraised from: ... ]]
[[reraised from: ... ]]
[[reraised from: ... ]]
[[reraised from: ... ]]
Error: unhandled exception: index 45 not in 0 .. 40 [IndexError]
```
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Don't treat 3 characters as special in `cmp`. `cmp` for `ProtocolInfo` was
wrong because it ignored all characters after the first 3.
In the wild we have seen protocol names longer than 3 characters. `snap`,
`hive`, `istanbul`, `bzzeth`, `bzz-stream`, `bzz-retrieve`, `dbix`, `opera`,
`pchain`, `pchain_child_0`, `sero`, `smilobft`, `spock`.
There was never a 3 character limit in the [specification]
(https://github.com/ethereum/devp2p/blob/master/rlpx.md).
It always said "short ASCII name", until recently on 2021-02-25 it was changed
to an 8 characters limit.
Also `pi.nameStr` can be removed. Nothing uses it, and it has the same actual
effect as just copying the string `pi.name`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
* Add build_dcli target and add it to CI
* Fix local imports for dcli
* And use local imports for all other files too
* Use local imports in tests and rlpx protocols
* use bearssl rng throughout
* seeder can fail
* imports and exports
* modules, sigh
* one more try
* move var
* even fewer thread vars
* remove out-of-date genrated files
* simplify some modules
* mark several modules with raises
* fix clearing of keys in auth.nim
* fix keyfile case dropping off
* fix keyfile stream storage
* uuid should be output in lowercase
* enode: simplify API
Jamie Lokier
Kim De Mey
Zahary Karadjov
Jacek Sieka
Ștefan Talpalaru
Bruno Škvorc
nolash