Commit Graph

292 Commits

Author SHA1 Message Date
Olaoluwa Osuntokun
8a682d9ec3
lnwallet: add a MaturityDelay field to UnilateralCloseSummary
This commit adds a new field: MaturityDelay, to the
UnilateralCloseSummary struct. This new field will be required, in an
upcoming update as it’s needed in order to properly sweep the
second-level HTLC outputs after MaturityDelay blocks has passed since
confirmation.
2017-09-26 18:00:24 -07:00
Olaoluwa Osuntokun
34604f6214
lnwallet: properly use the p2wkh script in SignDesc for retributions
This commit fixes a minor bug (that doesn’t affect anything atm) when
crafting the SignDesc for sweeping breached outputs. Previously, we
would take the p2wkh script and then p2wsh-ify that, placing that into
the SignDesc. This is incorrect as the p2wkh script is “injected” into
the sighash when signing, and thus doesn’t need another encoding layer.
2017-09-26 17:57:29 -07:00
Olaoluwa Osuntokun
1d487ea78b Merge pull request #341 from cfromknecht/breach-filter-commit-dust
Breach Arbiter Ignore Dust Commitment Outputs
2017-09-26 17:10:12 -07:00
Conner Fromknecht
223f77d135
lnwallet/channel: filter commitment outputs if dust 2017-09-25 18:57:03 -07:00
Olaoluwa Osuntokun
21d151d2ce
lnwallet: ensure the goroutines of all channels are stopped after test execution 2017-09-24 20:20:15 -07:00
Olaoluwa Osuntokun
9164cc218a
lnwallet: modify ReceiveFailHTLC to return value of HTLC failed 2017-09-24 20:17:53 -07:00
Olaoluwa Osuntokun
f576a74bf6
lnwallet: modify SettleHTLC to return value of HTLC settled
This commit adds an additional return value to SettleHTLC in order to
make way for an upcoming change to modify the way bandwidth status from
the link to the switch is reported.
2017-09-24 20:17:14 -07:00
Olaoluwa Osuntokun
815826caac
lnwallet: remove public LocalAvailableBalance method from channel
This commit removes the current active LocalAvailableBalance method
from the channel state machine itself. We still maintain the internal
availableLocalBalance method locally as this is used to ensure that we
don’t add an HTLC which puts our available balance below zero.
2017-09-24 20:13:04 -07:00
Conner Fromknecht
faf1d40bd0
lnwallet/channel: adds directionality htlc retributions
This commit also adds an incoming flag to
        HtlcRetribution struct to allow the breach arbiter to
        generate the appropriate witness based on the htlc's
        directionality.

        It also ensures that the size of the htlc retribution
        slice is now determined by the size of the number of
        htlcs present in the revoked snapshot, which fixes a
        minor bug that could lead to nil pointer deferences.
2017-09-19 19:18:20 -07:00
Olaoluwa Osuntokun
a52d405998
lnwallet: ensure HTLC values are properly converted to SAT in commit tx
This commit fixes a bug within the HTLC construction and commitment
transaction construction that would result in HTLC _values_ within the
commitment transaction being off by a factor of 1000. This was due to
the fact that we failed to convert the amount of an HTLC, in mSAT, to
SAT before placing it as an output within the commitment transaction.
When attempt to locate the output index of a particular half, we use
the unconverted amount, meaning it was unnoticed.

This commit adds a new assertion within the TestSimpleAddSettleWorkflow
test to ensure that the HTLC is found within the commitment transaction
with the proper value in satoshi.
2017-08-30 15:34:18 -07:00
Olaoluwa Osuntokun
6e54aba7ac
lnwallet: convert channel state machine accounting to milli-satoshi 2017-08-22 00:52:50 -07:00
Johan T. Halseth
b9516b7cdd
lnwallet: make CreateCloseProposal take absolute fee instead of fee rate 2017-08-11 12:09:39 +02:00
Olaoluwa Osuntokun
43b736225b
multi: add new method to generate fresh node announcments 2017-08-04 18:32:33 -07:00
Olaoluwa Osuntokun
db793991ac
lnwallet: don't add trimmed HTLC value to initiator commitment fees
This commit fixes a lingering bug in the way the internal channel state
machine handled fee calculation. Previously, we would count the dust
HTLC’s that were trimmed towards the fee that the initiator paid. This
is invalid as otherwise, the initiator would always benefit from dust
HTLC’s. Instead, we now simply “donate” the dust HTLC’s to the miner in
the commitment transaction. This change puts us in compliance with
BOLT-0003.
2017-07-31 20:41:23 -07:00
Olaoluwa Osuntokun
5ece7fec2d
lnwallet: add a String() method to updateType 2017-07-31 20:37:51 -07:00
Olaoluwa Osuntokun
747e0f57d1
multi: fix linter errors 2017-07-30 18:22:45 -07:00
Olaoluwa Osuntokun
899fa1ea3e
lnwallet: properly populate the signDesc within UnilateralCloseSummary
This commit modifies the closeObserver code to populate the signDesc in
the case we have a non-trimmed balance. Additionally, we now also add a
*wire.OutPoint field to the struct in order to allow receivers of the
message to construct a witness that can spend the newly created output
to their wallet.
2017-07-30 17:52:18 -07:00
Olaoluwa Osuntokun
8a23de5303
lnwallet: consult current state instead of revocation log during unilateral closure 2017-07-30 17:52:14 -07:00
Olaoluwa Osuntokun
8121bc77ce
lnwallet: add delivery scripts as a param to CreateCloseProposal+ CompleteCooperativeClose
This commit modifies the methods that transition the state of the
channel into an active closing state. With the new commitment design,
the delivery scripts are no longer pre-committed to the initial funding
messages. Instead, the scripts are sent at the instant that either side
decides to shutdown within the Shutdown message.
2017-07-30 17:51:05 -07:00
Olaoluwa Osuntokun
40e9120c04
lnwallet: populate HTLC resolutions after observing a unilateral channel close 2017-07-30 17:51:02 -07:00
Olaoluwa Osuntokun
01aa4eb2ae
lnwallet: populate HTLC resolutions within the ForceCloseSummary 2017-07-30 17:50:59 -07:00
Olaoluwa Osuntokun
83e0116d7e
lnwallet: extend the UnilateralCloseSummary to include HTLC resolutions
This commit adds a new companion struct: OutgoingHtlcResolution to the
commitment state machine. The purpose of this struct is the provide the
caller with the information necessary to sweep all outgoing HTLC’s in
the case of a broadcast up-to-date commitment transaction.

The HTLC resolutions allow a caller to sweep an outgoing HTLC into
their wallet after the absolute timeout of the HTLc has passed. This is
a two step process, with the first portion consisting of broadcasting
the HTLC timeout transaction itself, and the second portion consisting
of claiming the HTLC itself after a CSV delay.
2017-07-30 17:50:55 -07:00
Olaoluwa Osuntokun
a4c07d061e
lnwallet: the BreachRetribution struct is now aware of HTLC outputs
This commit adds awareness of active HTLC outputs to the
BreachRetribution struct. Previously, in the case of a breach, the
struct was only populated with enough information to sweep the two
commitment outputs. With this commit, the struct now has enough
information to sweep _all_ outputs within the commitment transaction.
2017-07-30 17:50:51 -07:00
Olaoluwa Osuntokun
5a78f80ffe
lnwallet: update restoreStateLogs to be aware of new commitment scheme 2017-07-30 17:50:47 -07:00
Olaoluwa Osuntokun
b9da43a2b8
lnwallet: update fetchCommitmentView due to new commitment design
This commit updates the central fetchCommitmentView method to manage
and derive the necessary easy required to create new commitments due to
the new state machine design within the specification. Each state now
requires us to derive a number of keys for each commitment state:
localDelay, remoteDelay, localKey, remoteKey, the commitment point, and
finally the revocation key itself.
2017-07-30 17:50:43 -07:00
Olaoluwa Osuntokun
3a052d2874
lnwallet: when creating new states, dispatch HTLC signing to sigPool 2017-07-30 17:50:40 -07:00
Olaoluwa Osuntokun
f569b80a80
lnwallet: when verifying new states, dispatch HTLC sig validation to sigPool 2017-07-30 17:50:37 -07:00
Olaoluwa Osuntokun
cd8672f824
lnwallet: update CreateCommitTx due to new key derivation 2017-07-30 17:50:34 -07:00
Olaoluwa Osuntokun
e314b83559
lnwallet: update HTLC script generation to account for new covenant HTLC's
This commit updates the set of functions tasked with generating HTLC’s
scripts for new commitments to now adhere to the new commitment
transaction design. With this change, the process of claiming an HTLC
now requires a second-level HTLC transaction, which solves a prior
issues due to the tight coupling of the timeout and delay clauses when
claiming an HTLC.
2017-07-30 17:50:31 -07:00
Olaoluwa Osuntokun
8b9a58cb15
lnwallet: add a sigPool instances to the state machine struct 2017-07-30 17:50:27 -07:00
Olaoluwa Osuntokun
4c9bd9dc54
lnwallet: when handling possible channel breach, only log if contract breach 2017-07-30 17:50:24 -07:00
Olaoluwa Osuntokun
e56258917e
lnwallet: introduce populateHtlcIndexes for tracking HTLC indexes in commitments
This commit adds a new method to the commitment struct:
populateHtlcIndexes.  populateHtlcIndexes modifies the set of HTLC's
locked-into the target view to have full indexing information
populated. This information is required as we need to keep track of the
indexes of each HTLC in order to properly write the current state to
disk, and also to locate the PaymentDescriptor corresponding to HTLC
outputs in the commitment transaction.

We also modify toChannelDelta to take not of these new changes, and
access the appropriate index directly.
2017-07-30 17:50:21 -07:00
Olaoluwa Osuntokun
549688d793
lnwallet: remove isDustLocal and isDustRemote, replace w/ htlcIsDust
This commit modifies the way we account for dust HTLC’s within the
commitment state machine when creating and validating new states.
Previously, an HTLC was dust if the amount of the HTLC was below the
dustLimit of the commitment chain. Now, with the HTLC covenant
transaction, the value of the HTLC also needs to cover the required fee
of the HTLC covenant transaction at the specified fee rate of the
commitment chain.

As a result, we now determine if an HTLC is dust or not, only at the
commitment site, using the new htlcIsDust function.
2017-07-30 17:50:16 -07:00
Olaoluwa Osuntokun
91165d98bb
lnwallet: eliminate the InitialRevocationWindow within the state machine
This commit modifies the current core channel state machine in order to
may a step towards BOLT-0002 and BOLT-0003 compliance. In this change,
we abandon the prior revocation window, in favor of a fixed revocation
window of size two. The revocation window will be filled at the start
of the lifetime of the channel, and never extended from there until the
channel has been fully closed.

We now maintain two variables, the current un-revoked commitment point,
and the next commitment point to use when creating a new state. The
next commitment point must initially be inserted into the channel state
with the InitNextRevocation method.

A major difference between the prior revocation key handling is that
the remote party now instead sends us the _commitment point_ in
isolation, which we then use locally (with our revocation base point)
to create the next full revocation key for _their_ commitment
transaction.
2017-07-30 17:50:13 -07:00
Olaoluwa Osuntokun
c7df82ab68
lnwallet: update the LightningChannel API usage for recent channels changes
This commit updates much of the state interaction within the
LightningChannel structure to account for the recent changes within the
chanenldb involving the OpenChannel struct, namely the introduction of
ChannelConfig and ChannelConstraints.
2017-07-30 17:50:10 -07:00
Olaoluwa Osuntokun
14832d8c09
lnwallet+lnwire: minor grammatical fixes after UpdateFee merge 2017-07-14 17:10:42 -07:00
Johan T. Halseth
ebe05f6568 lnwallet: add update_fee message support.
This commit adds the possibility for the initiator of a
channel to send the update_fee message, as specified
in BOLT#2. After the message is sent and both parties
have committed to the updated fee, all new commitment
messages in the channel will use the specified fee.
2017-07-14 16:39:15 -07:00
bryanvu
5068541044 lnwallet: apply dust HTLC amounts to fees
If an HTLC’s value is below a node’s dust limit, the amount for that
HTLC should be applied to to the fee used for the channel’s commitment
transaction.
2017-07-06 18:05:43 -07:00
Olaoluwa Osuntokun
5dd7b157a0
lnwallet: fix race condition when forwarding by creating new pubkey
This commit fixes a race condition that would at times occur in the
htlcswitch.TestChannelLinkBidirectionalOneHopPayments test case. A race
condition would occur in the goroutine running ReceiveNewCommitment
compared with the grouting that would obtain the snapshot in order to
make a forwarding decision.

We fix this by creating a new public key for each new commitment
transaction such that we complete avoid the read/write race condition.
2017-06-19 17:43:57 +02:00
Olaoluwa Osuntokun
6937a42f2d
lnwallet: add new ShortChanID method to LightningChannel 2017-06-16 23:25:13 +02:00
Olaoluwa Osuntokun
2e05051176
lnwallet: clarify comment within commitment state sanity function 2017-06-08 22:25:06 -07:00
Olaoluwa Osuntokun
9676d476c9
lnwallet: fix race condition in channel state machine, use single mutex
This commit fixes a race condition that was discovered as a result of
the new htlcswitch package. The StateSnapshot method and all of the
other methods which mutate the state of the channel state machine were
using distinct mutexes. The fix is trivial: all methods accessing the
internal channel state variable now use the same mutex.
2017-06-08 22:24:20 -07:00
Olaoluwa Osuntokun
54f849a62e
lnwallet: use the FundingBroadcastHeight as height hint for spend ntfns 2017-06-05 19:17:13 -07:00
Andrey Samokhvalov
f774e3d9bf lnwallet: add missed addition of RHash
add rhash to the payment descriptor when receiving the settle htlc in
order to be able to pass it during settle htlc packet generation and
later find the user pending payment by rhash without additional hashing.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
0e51b1d22d channeldb: add available balance function
In this commit we made state machine to be responsible for returning
proper available balance - amount of satoshi which we able to use at
current moment. This will help us in constrction channel link
abstraction.
2017-05-31 11:06:08 -07:00
Andrey Samokhvalov
fde27716d1 channeldb: add restriction to to use only half of the capacity locally
In this commit severe bug have been fixed which allows the state of the
nodes to be desychnorinesed in the moments of high htlc flow. We limit
the number of the htlc which we can add to commitment transaction
to half of the available capcity. This change fixes the bug when
commimtment transaction on the verge of being full, in this case race
condition might occures and remote htlc will be rejected, but at the
same time they will be added on remote side, the same situiation will
happen with htlc we have added, which cause the commitment transactions
to be different.
2017-05-31 11:06:08 -07:00
bryanvu
408be356fb lnwallet: update channel close to use fee estimation interface
This commit switches the channel close workflow to use the lnwallet fee
estimation interface rather than the hardcoded proposedFee.
2017-05-23 14:31:20 -07:00
bryanvu
514760f529 peer: handling for channel shutdown messages
This commit changes the cooperative channel close workflow to comply
with the latest spec. This adds steps to handle and send shutdown
messages as well as moving responsibility for sending the channel close
message from the initiator to the responder.
2017-05-23 14:31:20 -07:00
Olaoluwa Osuntokun
e689ef61dd
lnwallet: when calc'ing fee for commitment tx, use current fee-per-kw
This commit modifies the fee calculation logic when creating or
accepting a new commitment transaction to use the set FeePerKw within
the channel rather then re-query the estimator each time. The prior
behavior was benign as we currently use a static fee estimator, but the
dynamic setting this could’ve caused a state divergence.
2017-05-16 19:05:18 -07:00
Olaoluwa Osuntokun
82f591dbab
lnwallet: add TODO to properly roll dust outputs into initiator's paid fee 2017-05-16 19:02:52 -07:00
bryanvu
4ac7cc719f lnwallet: replace hard-coded fees and adjust tests accordingly
This commit replaces the hard-coded 5000 satoshi fees with calls to the
FeeEstimator interface. This should provide a way to cleanly plug in
additional fee calculation algorithms in the future. This change
affected quite a few tests. When possible, the tests were changed to
assert amounts sent rather than balances so that fees wouldn't need to
be taken into account. There were several tests for which this wasn't
possible, so calls to the static fee calculator were made.
2017-05-15 20:26:11 -07:00
bryanvu
abe2e502d5 lnwallet: add FeeEstimator interface, StaticFeeEstimator implementation
This commit adds the FeeEstimator interface, which can be used for
future fee calculation implementations. Currently, there is only the
StaticFeeEstimator implementation, which returns the same fee rate for
any transaction.
2017-05-15 20:26:11 -07:00
bryanvu
320bed7e6b lnwallet: add CommitFee field to OpenChannel
In order to cleanly handle shutdowns and restarts during state machine operation, the fee for the current
commitment transaction must be persisted. This allows the fee to be
reapplied when the current state is reloaded.
2017-05-15 20:26:11 -07:00
Olaoluwa Osuntokun
80598dff11
lnwallet: in closeObserver if commitment is is ours, exit early 2017-05-15 18:21:02 -07:00
Olaoluwa Osuntokun
d2585ae6e5
lnwallet: add new struct UnilateralCloseSummary to provide complete channel close details 2017-05-15 18:20:59 -07:00
Olaoluwa Osuntokun
34959e4648
peer+lnwallet: update API usage to recent channeldb changes 2017-05-14 19:23:57 -07:00
Olaoluwa Osuntokun
1b4862d815
lnwallet: use new ChainNotifier API, typo fixes 2017-05-11 15:21:05 -07:00
Olaoluwa Osuntokun
521c76d65a
lnwallet: add distinct channel to send close details over
This commit modifies the actions of the closeObserver goroutine to
utilize a _new_ channel to send channel close details over. The
original close signal channel is still used to notify observers that a
channel _has_ been closed, but this new channel will provide a single
observer with details w.r.t _how_ a channel was closed.
2017-05-04 17:39:24 -07:00
Olaoluwa Osuntokun
5e48cf1273
lnwallet: upon force close detection populate close summary 2017-05-04 17:39:22 -07:00
Olaoluwa Osuntokun
be583306ab
lnwallet: include the origin chanPoint in the ForceCloseSummary
This commit adds an additional field to the ForceCloseSummary that
allows observers of the channel that sends this struct to track _which_
channel the force close came from.
2017-05-04 17:39:20 -07:00
Olaoluwa Osuntokun
77ae9f560e
lnwallet: update DeleteState method to latest DB API change 2017-05-04 17:39:17 -07:00
Olaoluwa Osuntokun
c06894a2e6
lnwire: replace ChannelPoint with ChannelID, use new PendingChanID 2017-04-16 15:22:27 -07:00
Olaoluwa Osuntokun
17d6835861
lnwallet: removed unused sync.RWMutex in PaymentDescriptor 2017-04-11 22:08:25 -07:00
Olaoluwa Osuntokun
31acace692
lnwallet: convert PendingUpdates to FullySynced
This commit improves the channel state machine by converting the
objective PendingUpdates method to a subjective FullySynced method
which is to be used in place of PendingUpdates. The new FullySynced
method is fully encompassing and replaces any upper state required by
the state machine which wraps this one.

The new FullySynced method is identical to PendingUpdates aside from
the fact that: it now also factors in the log message index of the
remote commitment chain, and also introduces a concept of an “owed
commitment”. A commitment chain owes a commitment if the height of the
local commitment chain is higher than that of the remote chain.
2017-04-11 22:02:33 -07:00
Olaoluwa Osuntokun
4cd277c8da
lnwallet: eliminate usage of LightningChannel.theirPrevPkScript
This commit removes the theirPrevPkScript field from the
LightningChannel struct all together. It’s no longer needed as the more
fundamental mutation bug has been fixed within the channel state
machine.
2017-04-11 22:02:30 -07:00
Olaoluwa Osuntokun
a3fd738491
lnwallet: fix HTLC mutation bug in commitment chain
This commit fixes a class of bug that can arise in the channel state
machine when a very high throughput workflow is attempted. Since the
PaymentDescriptor’s within a commitment pointed directly into the log,
any changes to a payment descriptor would also be reflected in all
other ones. Due to this mutation possibility, at times, the
locateOutputIndex method would fail since the HTLC’s pkScript was
modified, causing the channel to fail.

We fix this class of bug by simply ensure that once an HTLC has been
associated with a particular commitment, then it becomes immutable.
2017-04-11 22:02:26 -07:00
Olaoluwa Osuntokun
eca3a10064
lnwallet: reorder PaymentDescriptor attributes to reduce padding 2017-04-11 22:02:23 -07:00
Olaoluwa Osuntokun
d6c863e2d1
lnwallet: initialize the height of both commitment chains independently
This commit fixes a slight oversight in the current state machine which
assumes that both commitment chains are always at the same height. In a
future where we move back to allowing nodes to pipeline commitment
updates, this will not always be the case.
2017-03-24 16:26:03 -07:00
Olaoluwa Osuntokun
a8671c485f
lnwallet: properly observe dust limits during cooperative chan closure
This commit fixes a lingering TODO within the wallet portion of the
codebase by properly adhering to the set dust limits when closing a
channel. With this new commit if a party’s current settled balance is
below their current dust-limit, then it will be omitted from the
commitment transaction.

The prior test that asserted negative outputs are rejected has been
removed as they’ll now be avoided by ensuring we omit dust outputs from
the commitment transaction.
2017-03-24 16:20:12 -07:00
Olaoluwa Osuntokun
2dd1c0de3d
lnwallet: adhere to project code-style in restoreStateLogs
This commit does some minor shuffling around and also adds some
additional comments to the restoreStateLogs method within the channel
state machine. After the latest merge in this area, the code has
diverged slightly from what’s considered typical within the rest of the
codebase.
2017-03-24 16:15:19 -07:00
Olaoluwa Osuntokun
c241892104
lnwallet: use full struct initialization for outputs in CreateCommitmentTx 2017-03-24 16:13:36 -07:00
Christopher Jämthagen
d958ea005f lnwallet: check for correct value in HTLC outputs in commitment transaction
It is possible that that there are multiple HTLCs with different values,
but the same public key script. As such, a check against the value should
be performed when looking for HTLC outputs in a commitment transaction.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
17d29ba62e lnwallet: properly restore public key scripts for HTLCs
Create a new helper method called genHtlcScript which will
generate the public key scripts for a supplied HTLC. This functionality
from addHTLC is removed, and addHTLC will instead call this new
method.

In restoreStateLogs we will regenerate the public key scripts for the
HTLCs with genHtlcScript and restore the proper values.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
78e102f08d lnwallet: fix settled/cancelled HTLCs remote pkScripts + cleanup
When an HTLC is either cancelled or settled we must properly set the
pkScript for the HTLC on the remote commitment, such that we can
generate a valid ChannelDelta.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
2222df21f3 lnwallet: fix dust limit checks and toChannelDelta() handling of dust 2017-03-21 21:21:46 -07:00
Christopher Jämthagen
05a90df67a lnwallet: return error from toChannelDelta() if htlc output is not found 2017-03-21 21:21:46 -07:00
Christopher Jämthagen
9083007ece lnwallet: fix bug that retrieves incorrect pkScript in toChannelDelta()
Description of bug:
When calling ReceiveNewCommitment() we will progress through methods
fetchCommitmentView and addHTLC which will add HTLC outputs to the
commitment transaction in the local commitment chain and save the
pkScript to the relevant PaymentDescriptor which resides in the
corresponding updateLog. Finally the local commitment will be added
to the local commitment chain.

When the same user next calls SignNextCommitment we will again
progress through fetchCommitmentView and addHTLC. In addHTLC we will
now overwrite the pkScripts in the PaymentDescriptors with the
pkScript from the context of the remote commitment. When we later
call RevokeCurrentCommitment and proceed into toChannelDelta, we
will not be able to find the correct pkScript in the PaymentDescriptor
to match it against the outputs in the commitment transaction.
This will lead to the nested function locateOutputIndex returning
incorrect values.

Fixing the bug:
We introduce three new fields in PaymentDescriptor:
* ourPkScript
* theirPkScript
* theirPrevPkScript

ourPkScript will include the pkScript for the HTLC from the context
of the local commitment.

theirPkScript will take the value of the latest pkScript for the HTLC
from the context of the remote commitment.

theirPrevPkScript will take the second-latest pkScript for the HTLC
from the context of the remote commitment. This is the value we use
in toChannelDelta when we save a revoked commitment from our peer.

The appropriate value of these fields are set in the addHTLC method.

Additionally we pass a boolean value to toChannelDelta so we know
whether we are operating on a local or remote commitment and grab
the correct pkScript in locateUpdateIndex.
2017-03-21 21:21:46 -07:00
Christopher Jämthagen
4d03f60e40 lnwallet: handle duplicate payment hashes in toChannelDelta() 2017-03-21 21:21:46 -07:00
Thomas Preindl
a1bb36730a lnd: fix typos in comments 2017-03-16 12:39:40 -07:00
Olaoluwa Osuntokun
f217093c00
multi: replace usage of fastsha256 with crypto/sha256
This commit removes all instances of the fastsha256 library and
replaces it with the sha256 library in the standard library. This
change should see a number of performance improvements as the standard
library has highly optimized assembly instructions with use vectorized
instructions as the platform supports.
2017-03-15 18:56:41 -07:00
Andrey Samokhvalov
ee2379775c lnd: fix golint warning which requires to add additional comments 2017-03-13 16:30:23 -07:00
Christopher Jämthagen
a6a503bf28 lnwallet: ForceCloseSummary should check if to-local output exists
If the value of the to-local output is below the dust limit, the
ForceCloseSummary should not include a sign descriptor for this output.

We also find the proper to-self output by looking for the expected public
key script and not assume that no HTLC outputs exist.
2017-03-09 15:32:31 -08:00
Christopher Jämthagen
52b56b8cf2 lnwallet+test: no dust outputs in commitment transaction + tests
Currently non-HTLC outputs will be accepted in the commitment
transaction as long as it is non-zero. We change this by not allowing
outputs with a value lower than the dust limit. The value of such
an output will go towards transaction fees.
2017-03-09 15:32:31 -08:00
Olaoluwa Osuntokun
fc54c5d8d8
lnwallet: perform sanity check on cooperative closure transacitons
This commit fixes a class of bug that currently exists within the
cooperative closure methods for the channel state machine. As an
example, due to the current hard coded fees, if one of the outputs
generated within the generated closure transaction has a negative
output, then the initiating node would gladly forward this to the
remote node. The remote node would then reject the closure as the
transaction is invalid. However, the act of completing the closure
would cause the remote node’s state machine to shift into a “closed”
state. As a result, any further closure attempts by the first node
(force or regular) would go unnoticed by the remote node.

We fix this issue by ensuring the transaction is “sane” before
initiating of completing a cooperative channel closure.

At test case has been added exercising the particular erroneous case
reported by “moli” on IRC.
2017-02-27 21:00:25 -06:00
Olaoluwa Osuntokun
8283ff2da6
lnwallet: during cooperative closure don't shift status until end
This commit avoids a class of bug wherein the state of the channel
would be marked as closing enough though an error occurred somewhere in
the function. The bug was due to the fact that the channel `status` was
shifted before any actual logic within the function(s) were executed.

We fix this bug by _only_ shifting the channel status once the function
has completed without any error.
2017-02-27 20:52:30 -06:00
Olaoluwa Osuntokun
f0c13c5a15
lnwallet: expose a NextRevocationKey method in channel state machine
This commit adds a new method to the channel’s state machine:
NextRevocationKey. This method is being added in preparation for the
upcoming change to switch to the commitment transaction format outlined
in the spec. When this comes to pass, the ExtendRevocationWindow method
will be removed, as it will no longer be needed.

The NextRevocationKey method will be needed as to conform to the spec,
we’ll need to send the next revocation key within the `fundingLocked`
message.
2017-02-24 16:31:48 -08:00
Olaoluwa Osuntokun
9adc5f6484
lnwallet+channeldb: update callers to shachain API changes 2017-02-24 16:31:45 -08:00
Andrey Samokhvalov
f86557c3e4 channeldb+lnwallet: replace elkrem with shachain
In this commit the initial implementation of revocation hash
generation 'elkrem' was replaced with 'shachain' Rusty Russel
implementation which currently enshrined in the spec. This alghoritm has
the same asymptotic characteristics but has more complex scheme
to determine wish hash we can drop and what needs to be stored
in order to be able to achive full compression.
2017-02-22 16:49:29 -08:00
Christopher Jämthagen
873211c02f Use 48-bit commitment transaction numbers
Fix SetStateNumHint and GetStateNumHint to properly
set and get the stateNumHints using the lower 24 bits
of the locktime of the commitment transaction as the
lower 24 bits of the obfuscated state number and the
lower 24 bits of the sequence field as the higher 24
bits.
2017-02-22 15:46:59 -08:00
Olaoluwa Osuntokun
75787b3e4d
lnwallet: use spew when logging logging retribution 2017-02-21 01:43:39 -08:00
Olaoluwa Osuntokun
f2e077c10c
lnwallet: account for de-sync'd channels within closeObserver
This commit adds an additional case of the closeObserver that will
properly handle the case of a channel being closed by a de-sync’d
commitment transaction from the PoV of the local node. In the case of a
minor 1-state divergence, the commitment transaction broadcast by the
remote node will be 1 state ahead of the commitment transaction we have
locally. This should be seen as a regular unilateral close as they
remote peer didn’t violate the channel contract in any way.

We address this case by changing the `==` to a `>=`.
2017-02-21 01:43:27 -08:00
Olaoluwa Osuntokun
0e0e207802
lnwallet: update state machine to the version within the spec
This commit updates the internal channel state machine to the one as
described within the spec and currently implemented within the rest of
the other Lightning implementations.

At a high level the following modifications have been made:
    * When signing we no loner include the index of the remote party’s
log
      that our signature covers. Instead we include ALL of our current
      updates, but only the updates of the remote party that we’ve
ACK’d.
    * A pending change is considered ACK’d once a revocation message
      has been received, locking in the changes in the remote party’s
      commitment transaction.
   * When sending a new commitment, we remember the index of our
     log at that point so we can mark that portion of the log as ACK’d
     once we receive a revocation message from the remote party.
   * When receiving a new commitment signature, we include ALL of
     the remote party’s changes that we’ve received but only our set
     of changes that’ve been ACK’d by the remote party.
   * Implicitly a revocation message now also implicitly serves to ACK
     all the changes that were included in the CommitSig message
     received before it.

The resulting change is a rather minor diff. However, with this state
machine it’s important to note that the order to sig/revoke messages
has been swapped. A proper exchange now looks like the following:
    * Alice -> Add, Add, Add
    * Alice -> Sig
    * Revoke <- Bob
    * Sig <- Bob
    * Alice -> Revoke

One other thing that’s worth noting is that with this state machine,
since what’s included in an update is implicit, both side may need to
at times send a new commitment update in the case of a concurrent state
transition initiated by both sides.

Finally, all counters/indexes have been made 64-bit integers in order
to properly match the spec.
2017-02-21 01:43:15 -08:00
Olaoluwa Osuntokun
6cf905088c
lnwallet: create new updateLog abstraction within channel state machine
This commit adds a new struct to the channel state machine: updateLog.
updateLog encapsulates the update log linked list itself, a series of
new counters we’ll need in order to switch to the spec’s state machine
and also the index into the log itself. This new struct serves to
simplify much of the logic surrounding the update log and also
elminates a bit of code duplication within the current state machine.

This commit only adds the new struct. The rest of the state machine
will be updated in a later commit to use the new log and its new
counters.
2017-02-21 01:43:13 -08:00
Olaoluwa Osuntokun
39f0300995
lnwallet: add godoc comments to a channel's updateTypes 2017-02-21 01:43:10 -08:00
Olaoluwa Osuntokun
a9416300e5
lnwallet: ensure that total satoshi sent/received aren't counted twice
This commit fixes a bug in the LightingChannel commitment state machine
which could occasionally result in the total number of satoshis sent or
received being counted twice if a redundant state transition were
initiated.

To fix this bug, we now only increment the number of satoshi
sent/recv’d iff it’s the first time the HTLC has been processed.
2017-02-21 01:43:07 -08:00
Olaoluwa Osuntokun
fb9bf054cc
lnwallet: cancel the spend notification when a channel's closeObserver exits
This commit ensures that when a channel’s closeObserver is signaled to
exit before a channel closure has been detected, then the resources
dedicated to the pending spend notification can be freed up.
2017-02-21 01:43:04 -08:00
Christopher Jämthagen
a2403d9c07 lnwallet: optimize PaymentDescriptor lookup on HTLC state transitions
rHashMap is used to store the PaymentDescriptor belonging to a received
HTLC's revocation hash. This improves the efficiency of looking up
PaymentDescriptors from their RHash whenever we want to settle or cancel
that HTLC.
2017-02-08 18:22:01 -08:00
Olaoluwa Osuntokun
62bcd59db4
lnwallet: add ability to cancel the channel's closeObserver
This commit adds the ability to cancel a channel’s internal
closeObserver goroutine by adding a new public facing Stop method.

Additionally, we now make passing a ChainNotifier interface completely
optional. If the ChainNotifier isn’t passed in as a constructor, then
the closeObserver goroutine will never be launched. This new feature
lets the caller ensure that only a single closeObsever for any given
channels exists.
2017-02-02 17:11:03 -08:00
Olaoluwa Osuntokun
f4b403679b
lnwallet: remove BlockChainIO as a dependency to LightningChannel
This commit removes the BlockChainIO interface as a dependency to the
LightningChannel struct as the interface is no longer used within the
operation of the LightningChannel.
2017-02-02 17:05:40 -08:00
Trevin Hofmann
40c7bac3aa multi: fix a variety of typos throughout the repo 2017-01-17 17:02:56 -08:00
Olaoluwa Osuntokun
55f89be10f
lnwallet+lnd: ensure curve parameters are set to avoid panics
This commit fixes a bug introduced by the past attempt to Make Logging
Great Again. Since we unset the curve parameters when reading/writing
the messages, if we have a lingering reference that’s active elsewhere
in the daemon, then we’ll modify that reference. To fix this, we now
explicitly set the Curve parameters in two areas.

A similar commit has been pushed to lightning-onion.
2017-01-14 19:44:37 -08:00
Olaoluwa Osuntokun
ae72475612
lnwallet: create channel close summary when commitment broadcast detected
This commit modifies the closeObserver goroutine to ensure that a close
summary has been inserted into the database before signalling any
observers that a unilateral channel closure was detected. This fixes a
slight bug where a peer would force close a channel, but we wouldn’t
properly detect that and clean up the channel state if had a failed
cooperative channel closure.
2017-01-14 18:01:28 -08:00
Olaoluwa Osuntokun
c451258fd2
lnwallet: properly detect initiator cooperative close in closeObserver
This commit modifies the logic of the closeObserver slightly to not
incorrectly mark the broadcast of the commitment transaction triggered
by a cooperative channel closure as an unprompted broadcast.
2017-01-12 18:30:07 -08:00
Olaoluwa Osuntokun
c9dbaa1403
lnwallet: include r-hash of canceled htlc in log entry for cancel
This commit modifies the logic around adding cancel entries to the
update log for the commitment state machine slightly by also including
the r-hash of the HTLC that’s been cancelled in the entry for the
cancellation. With this change, we can accurately track which HTLC is
being cancelled within outer sub-systems.
2017-01-07 21:22:01 -08:00
Olaoluwa Osuntokun
9bb5a45f89
lnwallet: the canceller of an HTLC targets by payment hash not index
This commit alters the new HTLC cancellation logic to instead allow the
canceller of an HTLC to cancel the HTLC by the payment hash rather than
the index of the HTLC.
2017-01-07 21:20:57 -08:00
Olaoluwa Osuntokun
fd0c0574e6
lnwallet: add send/recv of HTLC cancellations to state machine
This commit adds the ability to send/recv HTLC cancellation to the
commitment state machine. Previously this feature had been
unimplemented within the state machine, with only adds/settles working.

With this change, there’s now now no concept of “timing” out HTLC’s,
only the cancellation of HTLC’s which may be triggered for various
reasons.
2017-01-07 21:20:51 -08:00
Olaoluwa Osuntokun
5affed38fc
multi: update btcsuite API's to latest upstream changes
This commit makes a large number of minor changes concerning API usage
within the deamon to match the latest version on the upstream btcsuite
libraries.

The major changes are the switch from wire.ShaHash to chainhash.Hash,
and that wire.NewMsgTx() now takes a paramter indicating the version of
the transaction to be created.
2017-01-05 13:56:34 -08:00
Olaoluwa Osuntokun
0585ed93be
lnwallet: use in-memory height within channel's closeObserver
This commit partially rectifies a quick hack that was previously thrown
in to address an issue discovered due to possible state inconsistencies
between an active channel object and the daemon’s breachAbrbiter.

A prior commit has modified the interaction between the peer and the
breachArbiter to eliminate the state in consistency. Therefore, we no
longer need to access the database to ensure that we’re observing the
latest channel state in order to correctly make a decision about
whether a broadcast commitment transaction is a breach or not.
2016-12-27 16:45:10 -08:00
Olaoluwa Osuntokun
4790ce96a8
lnwallet: public expose funding keys in channel state machine
This commit modifies the attributes of the LightningChannel struct to
publicly expose the funding keys used within the channel for the local
and remote party. Exposing these keys publicly will allow callers to
use the keys involved to generate authenticated channel advertisements
for the routing layer.
2016-12-27 16:43:34 -08:00
Andrey Samokhvalov
d01f1b5ff4 fundingmanager+lnwallet: add HTLC dust limit logic 2016-12-13 11:01:57 -08:00
Andrey Samokhvalov
5a82240c6a lnwire+lnwallet+fundingmanager: general improvements 2016-12-13 11:01:57 -08:00
Olaoluwa Osuntokun
e0c09a016b
lnwallet: use stored initiator bool to properly construct close tx
This commit modifies the channel closing logic to remove the hard coded
bools indicating which side is attempting the closure. With the recent
changes, the initiator must always pay the channel closure fees.

This information is recently stored on disk, therefore we can use the
boolean to ensure that the closure transaction is created properly no
matter who initiates the close.

This fixes a bug.
2016-12-07 22:39:33 -08:00
Olaoluwa Osuntokun
494fcec874
breacharbiter: introduce new sub-system to watch for breaches
This commit introduces a new sub-system into the daemon whose job it is
to vigilantly watch for any potential channel breaches throughout the
up-time of the daemon. The logic which was moved from the utxoNursery
in a prior commit now resides within the breachArbiter.

Upon start-up the breachArbiter will query the database for all active
channels, launching a goroutine for each channel in order to be able to
take action if a channel breach is detected. The breachArbiter is also
responsible for notifying the htlcSwitch about channel breaches in
order to black-list the breached linked during any multi-hop forwarding
decisions.
2016-11-28 19:44:09 -08:00
Andrey Samokhvalov
da3028e10c lnwallet: add HTLC count validation 2016-11-23 20:02:29 -06:00
Andrey Samokhvalov
391d5cd401 lnwallet: add commitment transaction estimation 2016-11-23 20:02:29 -06:00
Andrey Samokhvalov
5b9e4ae61e general: fix typos, rename variables, add comments 2016-11-23 20:02:29 -06:00
bryanvu
faf9daddf6 lnwallet: calculate channel's total satoshis sent and received
When HTLCs are settled, the channel’s TotalSatoshisSent and
TotalSatoshisReceived fields are updated.
2016-11-22 14:57:03 -06:00
Olaoluwa Osuntokun
cc63db0aee
lnwallet: add detection+handling of contract breaches in channel
This commit adds detection of contract breaches within the commitment
state-machine for a channel. A contract breach is defined as the event
wherein a channel counter-party broadcasts a previously revoked
commitment transaction. Such an event immediately closes a channel as
the funds are now in a state of dispute.

Once a breach is detected, a snapshot of the breached state is
retrieved from the database’s revocation log. This snapshot is then
used to generate the revocation leaf used within this particular state
along with all the other information ncessary to sweep ALL active funds
within the channel. This information is encapsulated within the
BreachRetribution struct which is sent over a new channel dedicated to
sending/receiving BreachRetributions.
2016-11-21 00:54:45 -06:00
Olaoluwa Osuntokun
188811cf05
lnwallet: populate the output index of an HTLC in ChannelDeltas
This commit modifies the logic within the state machine to properly
populate the new field of `OutputIndex` which the HTLC stored within a
channel delta.

With this change, in the future we’ll be able to quickly locate a
particular HTLC output in the scenario that the commitment transaction
has been broadcast on-chain and we need to sweep it. Allocating a few
extra bytes on-disk saves us from the guess-and-check logic+code
required otherwise.
2016-11-20 23:54:24 -06:00
Olaoluwa Osuntokun
2d884618aa
lnwallet: ensure all channel state machine methods are thread-safe
This commit adds some necessary locking to ensure that all updates to
the internal state of the commitment state machine are fully serial and
thread-safe. This change is required to ensure future actions w.r.t
taking action once a revoked commitment transaction has been broadcast
are not carried out while the channel’s state is being updated.
2016-11-20 23:33:27 -06:00
Olaoluwa Osuntokun
74122a0901
lnwallet: encode obfuscated state hints in the commitment tx
This commit modifies the channel state machine slightly to encode the
current state number using 30-bits of the sequence number within the
commitment transaction’s only input.

Such a modification reduces up the processing time required to punish
the counter party for breaching the contract established within the
channel by broadcasting an older revoked state.

This fixes #58 with a minor modification to what was originally
suggested.
2016-11-16 12:49:44 -08:00
Olaoluwa Osuntokun
4113260f9f
lnwallet: minor comment correction 2016-11-10 17:38:59 -08:00
Olaoluwa Osuntokun
e1d9d9c8d2
lnwallet: update to adhere to new channeldb API change
This commit modifies the lnwallet code and related tests in order to
adhere to the recent field-name change to channeldb.OpenChannel.
Instead of having the field ‘TheirLNID’ which is the sha256 of the
node’s public key, we now instead use the public key directly in all
contexts.
2016-10-25 16:41:22 -07:00
Andrey Samokhvalov
14c6770b76 general: fix typos 2016-10-22 01:48:05 +03:00
andrew.shvv
e515710a7d multi: use witnessScript everywhere instead of redeemScript
This commit consists of a mass variable renaming to call the pkScript being executed for segwit outputs the `witnessScript` instead of `redeemScript`. The latter naming convention is generally considered to be reserved for the context of BIP 16 execution. With segwit to be deployed soon, we should be using the correct terminology uniformly through the codebase. 

In addition some minor typos throughout the codebase has been fixed.
2016-10-15 16:02:09 -07:00
Olaoluwa Osuntokun
9d5b0885d4
lnwallet/channel: add r-preimages to the PaymentDescriptor for settles 2016-09-21 19:49:07 -07:00
Olaoluwa Osuntokun
d0353b2864
lnwallet: add ability to trigger a force closure within channel state machine
This commit introduces the concept of a manually initiated “force”
closer within the channel state machine. A force closure is a closure
initiated by a  local subsystem which broadcasts the current commitment
state directly on-chain rather than attempting to cooperatively
negotiate a closure with the remote party.

A force closure returns a ForceCloseSummary which includes all the
details required for claiming all rightfully owned outputs within the
broadcast commitment transaction.

Additionally two new publicly exported channels are introduced, one
which is closed due a locally initiated force closure, and the other
which is closed once we detect that the remote party has executed a
unilateral closure by broadcasting their version of the commitment
transaction.
2016-09-12 19:07:35 -07:00
Olaoluwa Osuntokun
affd7793b3
lnwallet: add htlc persistence, state log restoration to channel state machine
This commit adds full persistence logic of the current lowest
un-revoked height within each commitment chain. The newly added
channeldb methods for record state transitions within both commitment
chains are now utilized. This un-settled HTLC state is now read upon
initialization, with the proper log entries inserted into the state
update log which reflect the garbage collected log right before the
restart.

A new set of tests have been added to exercise a few edge cases around
HTLC persistence to ensure the in-memory log is properly restored based
on the on-disk snapshot.
2016-09-12 19:07:04 -07:00
Olaoluwa Osuntokun
671098325d
lnwallet: refactor all wallet/channel interaction to use the WalletController.
This commit performs a major refactor of the current wallet,
reservation, and channel code in order to call into a WalletController
implementation rather than directly into btcwallet.

The current set of wallets tests have been modified in order to test
against *all* registered WalletController implementations rather than
only btcwallet. As a result, all future WalletControllers primary need
to ensure that their implementation passes the current set of tests
(which will be expanded into the future), providing an easy path of
integration assurance.

Rather than directly holding the private keys throughout funding and
channel creation, the burden of securing keys has been shifted to the
specified WalletController and Signer interfaces. All signing is done
via the Signer interface rather than directly, increasing flexibility
dramatically.

During channel funding, rather than creating a txscript.Engine to
verify commitment signatures, regular ECDSA sig verification is now
used instead. This is faster and more efficient.

Finally certain fields/methods within ChannelReservation and
LightningChannel have been exposed publicly in order to restrict the
amount of modifications the prior tests needed to undergo in order to
support testing directly agains the WalletController interface.
2016-09-08 12:25:54 -07:00
Olaoluwa Osuntokun
8bbd010f74
lnwallet: use the ChainNotifier interface throughout instead of BtcdNotifier
This commit refactors the code within lnwallet interacting with the
ChainNotifier to accept, and call against the implementation rather
than a single concrete implementation.

LightningWallet no longer creates it’s own BtcdNotifier implementation
doing construction, now instead accepting a pre-started `ChainNotifier`
interface.  All imports have been updated to reflect the new naming
scheme.
2016-09-01 19:13:19 -07:00
Olaoluwa Osuntokun
4104a9bcde
lnwallet: never create zero-value outputs within the commitment transaction 2016-07-27 12:15:50 -07:00
Olaoluwa Osuntokun
c0614c0478
lnwallet: add basic tests for cooperative channel closure
This commit adds a basic test for cooperative channel closure. The
current test ensures correctness of the cooperative closure procedure
initiated by either the channel initiator, or the channel responder.
2016-07-27 11:32:35 -07:00
Olaoluwa Osuntokun
e01dd7f18d
lnwallet: properly make channelState an enum by using iota 2016-07-27 11:29:49 -07:00
Olaoluwa Osuntokun
8a56fbf196
lnwallet: switch name of package logger to avoid module collision 2016-07-27 11:29:07 -07:00
Olaoluwa Osuntokun
2bb65a3fb8
lnwallet: add PendingUpdates method to channel state machine
This commit adds a new method, “PendingUpdates” to the channel state
machine which is intended to be a source to give callers a hint as to
when an additional commitment signature should be sent independent of
any request/response book keeping.
2016-07-21 16:52:18 -07:00
Olaoluwa Osuntokun
4063171918
lnwallet: partition state update logs within channel state machine
This commit patrons the state update logs properly within the channel
state machine. This change fixes a number of bugs caused by treating a
central log as two logically distinct logs. Rather than having a bit
indicating if the entry is incoming/outgoing, an entry is added to a
remote or local log depending on which modification method is used.

As a result the code is much easier to follow due to separation of
concerts.

Finally, when attempting to sign a new update with an exhausted
renovation window a distinct error is returned in order to allow higher
level callers to properly back-off and handle the protocol event.
2016-07-21 16:50:38 -07:00
Olaoluwa Osuntokun
b60270f3f7
lnwallet: include htlcs to settle in returned set of htlc's to forward
This commit fixes a slight bug in the channel state machine’s code
executed when processing a revocation messages. With this commit after
processing a revocation, log entries which we should forward to the
downstream or upstream peer for settling/adding HTLC’s are now properly
returned.

The testa have also been updated to ensure to correct htlc’s are
returned “for forwarding”.
2016-07-16 18:12:49 -07:00
Olaoluwa Osuntokun
2c303a1879
lnwallet: AddHTLC now returns log index of created log entry 2016-07-16 18:02:09 -07:00
Olaoluwa Osuntokun
7dea354711
lnwallet: properly handle HTLC settles in channel state-machine
We no longer track HTLC’s by their r-hash within the log into the
index, as we may have multiple HTLC’s that can be redeemed by the same
pre-image. Instead we now use a separate index which is keyed by a
log-index.

Additionally, the SettleHTLC method now also returns the index of the
HTLC being settled which allows the remote party to quickly locate the
HTLC within their log.

This commit also introduces a few trace/debug log messages which will
likely be pruned in the near future
2016-07-12 17:35:57 -07:00
Olaoluwa Osuntokun
06f062e678
lnwallet: sync revocation state after receiving a revocation 2016-07-12 17:32:42 -07:00
Olaoluwa Osuntokun
14d669dfd1
lnwallet: decrease initial revocation window to 4 2016-07-12 17:31:01 -07:00
Olaoluwa Osuntokun
94c242073a
lnwallet: finish initial draft of LightningChannel state machine
This commit finishes the initial draft of the commitment state machine.
A full re-write of the prior protocol which combines aspects of the
former ‘lnstate’ package has replaced the prior un-finished
stop-and-wait protocol.

This new protocol is designed to operate in an asynchronous environment
and to facilitate non-blocking batched and pipelined updates to the
committed channel states. The protocol is also de-synchronized meaning
that either side can propose new commitment states independent of the
actions of the other party.

The state machine implemented is very similar to that of c-lightning,
however we allow multiple unrevoked commentates in order to minimize
blocking, and also to reduce latency across several hops in a
bi-directional setting.

The current implementation consists of 3 main data structures: a
commitment chain which consist of unrevoked commitment transactions
(one for each side), and a (mostly) append-only log of HTLC updates
shared between both sides. New commitments proposed index into the log
denoting which updates they include, this allows both parties to
progress chains independent of one another. Revoked commitments, reduce
the length of the chain by one, and free up space within the revocation
window.

At this point only basic tests are in place for the state machine,
however more extensive testing infrastructure along with formal proofs
using PlusCall are planned.
2016-07-05 17:02:03 -07:00
Olaoluwa Osuntokun
1b490c52ed
lnwallet: createCommitTx now a revocation key 2016-06-30 12:12:19 -07:00
Olaoluwa Osuntokun
e22734f9cf
lnwallet: update HTLC+commitment scripts
This commit updates the previous HTLC and commitment scripts to their
current latest evolution.

The HTLC scripts have been optimized for space savings, the
functionality itself has remained relatively unchanged. A trade off was
made to add additional bytes into the sigScript in order to avoid
extraneous CHECKSIG’s. The rationale is that an extra 1-2 bytes in the
sigScript to guide execution, are worthwhile since they’re in the
witness, and witness data may be pruned in the near future.

The primary change is within the commitment transaction itself. Instead
of using revocation hashes, we now use signature based revocation. This
saves space in the Script, and optimizes away an extra hashing
operation. Elkrem/shachain is still used but, we now use the pre-images
to homomorphically derive a public key which the other party will be
able to sign with, once we disclose the pre-image itself.

Finally, we have switched to using SHA-256 everywhere uniformly for
both revocation hashes, and payment hashes. The rationale is that the
output of ripemd160 is too small for modern security margins, and that
other coins/chains are more likely to have SHA-256 implemented, than
ripemd160.

A set of tests has also been included which contain (mostly) exhaustive
tests of all possible redemption paths for both commitment and HTLC.
2016-06-27 11:35:32 -07:00
Olaoluwa Osuntokun
ac8736ff99
lnwallet: convert commitment no-delay output to p2wsh 2016-06-27 11:21:13 -07:00
Olaoluwa Osuntokun
05fb9b5a6d
lnwallet: payment and revocation hashes are now 32 bytes
This unifies some inconstancies across the code-base with hashes being
32 vs 20 bytes. All hashes, whether payment or revocation are now
uniformly 32 bytes everywhere. As a result, only OP_SHA256 will be used
within commitment and HTLC scripts. The rationale for using sha256
instead of hash160 for the HTLC payment pre-image is that alternative
chains are more likely to have sha256 implemented, rather than
ripemd160.

A forthcoming commit will update the current commitment, and HTLC
scripts.
2016-06-26 23:04:14 -07:00
Olaoluwa Osuntokun
77a006f03b
lnwallet: ChannelPoint() now returns a pointer to outpoint 2016-06-22 22:15:13 -07:00
Olaoluwa Osuntokun
e17bdf08ea
lnwallet: expose db channel deletion+snapshotting 2016-06-22 22:12:37 -07:00
Olaoluwa Osuntokun
45236fa092
lnwallet: implement cooperative closure for LightningChannel
A cooperative closure of a LightningChannel proceeds in two steps.
First, the party who wishes to close the channel sends a signature for
the closing transaction. Next, the responder reconstructs the closing
transaction identically as the initiator did using a canonical
input/output ordering, and the currently settled balance within the
channel. At this point, the responder then broadcasts the closure
transaction. It is the responsibility of the initiator to watch for
this transaction broadcast within the network to clean up any resources
they committed to the active channel.
2016-06-21 13:13:22 -07:00
Olaoluwa Osuntokun
27e6839060
lnwallet: publicly export constructor for LightningChannel 2016-06-21 13:13:18 -07:00