We don't bother actually parsing errors from within a blinded path, since all
errors should be wiped by the introduction node by the time it gets back to us
(the sender).
When serialized, the TLVs in `OutboundOnionPayload`, unlike a normal
TLV stream, are prefixed with the length of the stream. To allow a user
to add arbitrary custom TLVs, we aren't able to communicate to our
serialization macros exactly which fields to expect, so this commit
adds new macro variants to allow appending an extra set of bytes (and
modifying the prefixed length accordingly).
Because the keysend preimage TLV has a type number in the custom type
range, and a user's TLVs may have type numbers above and/or below
keysend's type number, and because TLV streams must be serialized in
increasing order by type number, this commit also ensures the keysend
TLV is properly sorted/serialized amongst the custom TLVs.
To support route blinding, we want to split OnionHopData into two separate
structs, one for inbound onions and one for outbound onions. This is because
blinded payloads change the fields present in the onion hop data struct based
on whether we're sending vs receiving (outbound onions include encrypted blobs,
inbound onions can decrypt those blobs and contain the decrypted fields
themselves).
In upcoming commits, we'll add variants for blinded payloads to the new
InboundPayload enum.
This converts some required TLVs to `required_vec` which are, in
fact, required (and have been written forever).
* `HTLCFailReason` hasn't changed since many structs were converted
to TLVs in 66784e32fe.
* `NodeInfo::channels` has been written since `NetworkGraph`
structs were converted to TLVs in 321b19c4d9.
* Several test-only TLV writes were converted.
Previously, we would panic when failing to construct onion messages in
certain circumstances. Here we opt to always rather error out and don't
panic if something goes wrong during OM packet construction.
This was previously broken and would result in an invalid HMAC error, because
we had a hardcoded assumption that OM hop data would always be of size 1300.
Previously, we were requiring any `UPDATE` onion errors to include
a `channel_update`, as the spec mandates[1]. If we see an onion
error which is missing one we treat it as a misbehaving node that
isn't behaving according to the spec and simply remove the node.
Sadly, it appears at least some versions of CLN are such nodes, and
opt to not include `channel_update` at all if they're returning a
`temporary_channel_failure`. This causes us to completely remove
CLN nodes from our graph after they fail to forward our HTLC.
While CLN is violating the spec here, there's not a lot of reason
to not allow it, so we go ahead and do so here, treating it simply
as any other failure by letting the scorer handle it.
[1] The spec says `Please note that the channel_update field is
mandatory in messages whose failure_code includes the UPDATE flag`
however doesn't repeat it in the requirements section so its not
crazy that someone missed it when implementing.
This adds the new `payment_metadata` to `RecipientOnionFields`,
passing the metadata from BOLT11 invoices through the send pipeline
and finally copying them info the onion when sending HTLCs.
This completes send-side support for the new payment metadata
feature.
This passes the new `RecipientOnionFields` through the internal
sending APIs, ensuring we have access to the full struct when we
go to construct the sending onion so that we can include any new
fields added there.
When we're constructing an HTLCFailReason, we should check that we
set the data to at least the correct length for the given failure
code, which we do here.
Now that `HTLCFailReason` is opaque and in `onion_utils`, we should
encapsulate it so that `ChannelManager` can no longer directly
access its inner fields.
Soon we're going to need to return an error when ChannelManager is unable to
find a route, so we'll need a way to distinguish between that and the user
supplying an invalid route.
+ remove MaybeReadableArgs trait as it is now unused
+ remove onion_utils::DecodeInput as it would've now needed to be parameterized
by the CustomOnionMessageHandler trait, and we'd like to avoid either
implementing DecodeInput in messenger or having onion_utils depend on
onion_message::*
Co-authored-by: Matt Corallo <git@bluematt.me>
Co-authored-by: Valentine Wallace <vwallace@protonmail.com>
Currently we entirely ignore the BADONION bit when deciding how to
handle HTLC failures. This opens us up to an attack where a
malicious node always fails HTLCs backwards via
`update_fail_malformed_htlc` with an error code of
`BADONION|NODE|PERM|X`. In this case, we may decide to interpret
this as a permanent node failure for the node encrypting the onion,
i.e. the counterparty of the node who sent the
`update_fail_malformed_htlc` message and ultimately failed the
HTLC.
Thus, any node we route through could cause us to fully remove its
counterparty from our network graph. Luckily we do not do any
persistent tracking of removed nodes, and thus will re-add the
removed node once it is re-announced or on restart, however we are
likely to add such persistent tracking (at least in-memory) in the
future.
Pre-existing to this PR, we were reading next packet bytes with io::Read::read,
which is not guaranteed to read all the bytes we need, only guaranteed to read
*some* bytes.
We fix this to be read_exact, which is guaranteed to read all the next hop
packet bytes.
This required adapting `onion_utils::decode_next_hop` to work for both payments
and onion messages.
Currently we just print out the path_id of any onion messages we receive. In
the future, these received onion messages will be redirected to their
respective handlers: i.e. an invoice_request will go to an InvoiceHandler,
custom onion messages will go to a custom handler, etc.
This adds several utilities in service of then adding
OnionMessenger::send_onion_message, which can send to either an unblinded
pubkey or a blinded route. Sending custom TLVs and sending an onion message
containing a reply path are not yet supported.
We also need to split the construct_keys_callback macro into two macros to
avoid an unused assignment warning.
We need to add a new Packet struct because onion message packet hop_data fields
can be of variable length, whereas regular payment packets are always 1366
bytes.
Co-authored-by: Valentine Wallace <vwallace@protonmail.com>
Co-authored-by: Jeffrey Czyz <jkczyz@gmail.com>
Blinded routes can be provided as destinations for onion messages, when the
recipient prefers to remain anonymous.
We also add supporting utilities for constructing blinded path keys, and
control TLVs structs representing blinded payloads prior to being
encoded/encrypted. These utilities and struct will be re-used in upcoming
commits for sending and receiving/forwarding onion messages.
Finally, add utilities for reading the padding from an onion message's
encrypted TLVs without an intermediate Vec.
A NetworkUpdate indicating ChannelClosed actually corresponds to a
channel failure as described in BOLT 4:
0x2000 (NODE): node failure (otherwise channel)
Rename the enum variant to ChannelFailure and rename NetworkGraph
methods close_channel_from_update and fail_node to channel_failed and
node_failed, respectively.
