This commit makes an lnwallet.BlockChainIO available to the gossiper and
uses it to construct a helper that can be used to fetch the pk script
for a given SCID. This will be used for channel announcement
verification in an upcoming commit.
Add new FirstBlockHeight and BlockRange TLV fields to the
GossipTimestampRange message. This will be used to query for Gossip 1.75
messages which are timestamped using block height instead of Unix
timestamps.
In preparation for Gossip 1.75, we add new TLV's to the `ChannelReady`
message. Namely: `AnnouncementBitcoinNonce` and `AnnouncementNodeNonce`.
These will be used to exchange nones required for producing the partial
signature to be send in the `AnnouncementSignatures2` message.
The type numbers for these new fields are even because if they are set,
then a peer is expecting its peer to understand gossip 1.75 and the new
fields.
In preparation for adding the new ChannelAnnouncement2 message along
with a ChannelAnnouncement interface, we rename the existing message to
ChannelAnnouncement1.
In preparation for adding a new message, AnnounceSignatures2 along with
an AnnounceSignatures interface, we rename the existing message to
AnnounceSignatures1.
This commit fixes the instantiation of the BlindingPoint member of
PaymentDescriptor during the conversion from persisted LogUpdates.
Previously, the blinding point was not set correctly. The test from the
previous commit is also updated to now assert that this behaviour is now
correct.
This commit adds a new route blinding itest that demonstrates that the
reloading and re-forwarding of an UpdateAddHTLC message on restart
currently is done incorrectly for a blinded path payment. This is due to
the fact that the blinding point member is not currently set correctly.
This is fixed in the next commit which will also change the test to
assert that the behaviour is now correct.
The BlindedPathConfig struct is nice for invoice creation but when we
use the Invoice message for viewing an invoice, it would be nicer to see
an "is_blinded" field.
This commit adds two functional options to the zpay32.Decode function.
`WithKnownFeatureBits` allows the caller to overwrite the default set of
known feature bits used by the function.
`WithErrorOnUnknownFeatureBit` allows the caller to instruct the
function to error out if the invoice that is decoded contaijns unknown
feature bits. We then use this new error-out option from the
`rpcServer`'s `extractPaymentIntent` method.
In this commit, we adjust BuildBlindedPaymentPaths to only error out
completely if none of the paths it received from FindRoutes resulted in
a usable blinded path.
since `AddInvoiceData` is config _per invoice_ where as `AddInvoiceConfig`
is config for the invoice server itself and so pretty much should stay
the same for the lifetime of LND. This change sets us up for moving some
of the blinded path config options to be changeable per AddInvoice call
rather that having fixed config values in the config file.
Continue adding some complexity behind the BlindedPaymentPathSet. What
we do here is add a new IntroNodeOnlyPath method. The assumption we
make here is: If multiple blinded paths are provided to us in an invoice
but one of those paths only includes an intro node, then there is no
point in looking at any other path since we know that the intro node is
the destination node. So in such a case, we would have discarded any
other path in the `NewBlindedPaymentPathSet` constructor. So then we
would only have a single blinded path made up of an introduction node
only. In this specific case, in the `newRoute` function, no edge passed
to the function would have a blindedPayment associated with it (since
there are no blinded hops in this case). So we will have a case where
`blindedPathSet` passed to `newRoute` is not nil but `blindedPayment` is
nil since nonce was extacted from any edge. If this happens then we can
assume that this is the Intro-Node-Only situation described above. And
so we grabe the associated payment from the path set.
Instead of needing to remember how to handle the FinalCLTV value of a
blinded payment path at various points in the code base, we hide the
logic behind a unified FinalCLTVDelta method on the blinded path.
If multiple blinded paths are provided, they will each have a different
pub key for the destination node. This makes using our existing
pathfinding logic tricky since it depends on having a single destination
node (characterised by a single pub key). We want to re-use this logic.
So what we do is swap out the pub keys of the destinaion hop with a
pseudo target pub key. This will then be used during pathfinding. Later
on once a path is found, we will swap the real destination keys back in
so that onion creation can be done.
This commit introduces a new type, `BlindedPaymentPathSet`. For now, it
holds only a single `BlindedPayment` but eventually it will hold and
manage a set of blinded payments provided for a specific payment. To
make the PR easier to follow though, we start off just letting it hold a
single one and do some basic replacements.
This commit introduces more sophisticated code for selecting dummy hop
policy values for dummy hops in blinded paths.
For the case where the path does contain real hops, the dummy hop policy
values are derived by taking the average of those hop polices. For the
case where there are no real hops (in other words, we are the
introduction node), we use the default policy values used for normal
ChannelUpdates but then for the MaxHTLC value, we take the average of
all our open channel capacities.
Add an itest that tests the addition of dummy hops to a blinded path. By
testing that invoices containing such a path can be paid, it also tests
the peeling of dummy hops by the receiver.
Make various sender side adjustments so that a sender is able to send an
MP payment to a single blinded path without actually including an MPP
record in the payment.
Update one of the route blinding itests to do a full end-to-end test
where the recipient generates and invoice with a blinded path and the
sender just provides that invoice to SendPayment.
The tests also covers the edge case where the recipient is the
introduction node.
The route blinding itests are now updated so that recipient logic is
tested. The creation of a blinded route is also now done through the
AddInvoice API instead of manually.
If a blinded path payload contains a signal that the following hop on
the path is a dummy hop, then we iteratively peel the dummy hops until
the final payload is reached.
We've covered all the logic for building a blinded path to ourselves and
putting that into an invoice - so now we start preparing to actually be
able to recognise the incoming payment as one from a blinded path we
created.
The incoming update_add_htlc will have an `encrypted_recipient_data`
blob for us that we would have put in the original invoice. From this we
extract the PathID which we wrote. We consider this the payment address
and we use this to derive the associated invoice location.
Blinded path payments will not include MPP records, so the payment
address and total payment amount must be gleaned from the pathID and new
totalAmtMsat onion field respectively.
This commit only covers the final hop payload of a hop in a blinded
path. Dummy hops will be handled in the following commit.
We further break up the extracTLVPayload into more modular pieces. The
pieces are structured in such a way as to prepare for extracTLVPayload
being called in a recursive manner from within
`deriveBlindedRouteForwardingInfo` when we add the logic for handling
dummy hops in a later commit. With this refactor, we completey remove
the BlindingKit's DecryptAndValidateFwdInfo method.
In this refactor commit, we extract all the steps from extractTLVPayload
that have to do with parsing the payload from the sender and verifying
the presence of various fields from the sender.
In preparation for calling the TLV payload parsing logic recursively for
when we need to peel dummy hops from an onion, this commit creates a new
extractTLVPayload function. This is a pure refactor.
Expose the ability to add blinded paths to an invoice. Also expose
various configuration values.
We also let the lncfg.Invoices struct satisfy the Validator interface so
that we can verify all its config values in one place.
Add a `FindBlindedPaths` method to the `ChannelRouter` which will use
the new `findBlindedPaths` function to get a set of candidate blinded
path routes. It then uses mission control to select the best of these
paths.
Note that as of this commit, the MC data we get from these queries won't
mean much since we wont have data about a channel in the direction
towards us. But we do this now in preparation for a future PR which will
start writing mission control success pairs for successful receives from
blinded route paths.
This commit adds a new function, `findBlindedPaths`, that does a depth
first search from the target node to find a set of blinded paths to the
target node given the set of restrictions. This function will select and
return any candidate path. A candidate path is a path to the target node
with a size determined by the given hop number constraints where all the
nodes on the path signal the route blinding feature _and_ the
introduction node for the path has more than one public channel. Any
filtering of paths based on payment value or success probabilities is
left to the caller.
Here we add a new `Blind` option to the `AddInvoiceData` which will
signal that the new invoice should encode a blinded route.
Certain other changes are also made in the case that this invoice
contains a blinded route:
1) the payment address/secret no longer needs to be in the invoice
itself since it will be put in the `PathID` recored of the encrypted
recipient record for our hop.
2) When we sign the invoice, we now use an ephemeral key since we dont
want the sender to be able to derive our real node pub key from the
invoice signature.
3) The invoice's FinalCLTV field should be zero for blinded invoices
since the CLTV delta info will be communicated in the accumulated
route policy values.
This commit adds all the logic for building a blinded path (from a given
route) and packaging it up in a zpay32.BlindedPaymentPath struct so that
it is ready for adding to an invoice. It also includes logic for padding
a path with dummy hops.
Note that in this commit, the logic for choosing an actual path to us
that can then be used in a blinded path is abstracted away. This logic
will be fleshed out in a future commit.
This commit adds a helper function that will be used to adjust a hops
policy values by certain given increase and decrease multipliers. This
will be used in blinded paths to give policy values some buffer to avoid
easy probing of blinded paths.
This commit adds a helper function called `padHopInfo` along with a test
for it. This function will be used later on when building a blinded
path. It is used to ensure that all encrypted blobs of a blinded path
that we construct are padded to the same size.
We need a new feature bit for BOLT11 invoices in order to indicate that
they contain the new blinded path tagged field. Tagged fields pre-date
TLV and so nodes who dont understand them will simply skip them.
Therefore the feature bit helps them to fail fast.
This commit is a large refactor that moves over various responsibilities
from the ChannelRouter to the graph.Builder. These include all graph
related tasks such as:
- graph pruning
- validation of new network updates & persisting new updates
- notifying topology update clients of any changes.
This is a large commit but:
- many of the files are purely moved from `routing` to `graph`
- the business logic put in the graph Builder is copied exactly as is
from the ChannelRouter with one exception:
- The ChannelRouter just needs to be able to call the Builder's
`ApplyChannelUpdate` method. So this is now exported and provided to
the ChannelRouter as a config option.
- The trickiest part was just moving over the test code since quite a
bit had to be duplicated.
This is preparation for an upcoming commit that will move over various
responsibilities from the ChannelRouter to the graph Builder. So that
that commit can be a pure code-move commit, the template for the new
sub-system is added up front here.
In preparation for adding a clean Graph DB interface, we create a
version of FetchLightningNode that doesnt allow a caller to provide in a
transaction.
Elle Mouton