We might argue this does not apply if you set `minimum_depth` to 0, since
you're assuming trust (TurboChannels-style), but it needs to be specified.
See: CVE-2019-12998 / CVE-2019-12999 / CVE-2019-13000
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This separates out the static remotekey changes from the more ambitious
option_simplified_commitment (which also included pushme outputs and
bring-your-own-fee for HTLC outputs).
As per http://www.erisian.com.au/meetbot/lightning-dev/2019/lightning-dev.2019-09-02-20.06.html
Thanks to everyone for feedback: @araspitzu @roasbeef @bitconner
Suggested-by: @roasbeef
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Added descriptions of how a 2-of-2 multisignature verification is used for enforcing timelocks when timing out on-chain offered HTLCs as well as spending on-chain received HTLCs in the success case.
(No spec change, just wording)
The "local" and "remote" here are just *confusing*. Each side says
where it's at, and the other side retransmits based on that.
We could call it 'number_of_next_commitment_i_expect_to_receive' and
'number_of_next_revocation_i_expect_to_receive' but that's getting
silly.
These names were a major source of confusion while writing tests!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's trivial to make types->lengths, but not so much the other way.
The types I used here are the ones I found useful in implementation, and
I think add some clarity, though we can certainly argue about them.
There's no normative changes to the spec in here.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Saying "the risk is only to the node *accepting* the HTLC" is confusing
because merely accepting an HTLC is risk-free. The risk comes from
accepting *responsibility to route the payment*, i.e. offering an HTLC
of your own in the next channel on the path, where a too-small
difference in the HTLC values could end up with you cheated out of a
payment.
This revised paragraph hopefully makes that clearer.
Uses more specific and consistent language ("the"/"that" instead of "an"
where possible). Also helps avoid confusion with unrelated HTLCs that
serve other payments but are shared by the same two nodes.
We express it has how the outputs are ordered, but the only way you can
detect that is by the htlc_signatures order, which is the part which really
matters.
I finally reproduced this, BTW, which is why I'm digging it up!
Closes: #448
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This seems to be a cause of stuck HTLCs on the network: c-lightning has
done this for a while now (since 0.6.1).
[ Minor wording clarification merged --RR ]
Decided-at: Adelaide Summit 2018
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Although commitment numbers are explained in the
[glossary](00-introduction.md#glossary-and-terminology-guide),
it's helpful to re-iterate at the place that it's first used.
To 'fail a channel' is mentioned multiple places in this
BOLT without any mention or definition of what that means.
This adds a link to the relevant text in BOLT 05 in the
first place that we mention 'fail the channel'.
Even with push_msat, we need to make sure that funder can pay the fees,
so require that.
Also require that there be some funds above reserve on one side, otherwise
the channel is useless, and we risk that all outputs are dust.
Note: a side *may* reject the channel if funding_satoshis is too small
already, but this sets a clear minimum bar.
Fixes: #393
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add requirements on accept_channel, so each side doesn't consider the
*other* reserve dust either.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
After more consideration, I believe that this is sufficient to ensure
one reserve is always non-dust.
The races which make us dig into the reserves can't currently take from
the fundee's reserve, so either the fundee has sufficient reserves, or
it can't add HTLCs which means no race.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Clarify that field `channel_reestablish`.`your_last_per_commitment_secret`
should be set to an all-zero array when no `per_commitment_secret` has
been received yet.
Make it clear what kind of key we're talking about. We use the abbreviation
pubkey for public key (as it's quite common to use in field names), but
generally spell out 'private'.
(I generally prefer 'secret' to 'private' but we use private far more often
already, and we use 'secret' for things which don't directly derive keys).
Fixes: #368
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I got an unexpected update_fee message after `shutdown` exchange,
which is currently legal:
A: shutdown (no htlcs)
B: receive shutdown
B: reply with shutdown & closing_signed
A: send update_fee & commitment_signed
A: receive shutdown
Simplest to ban any updates (currently, just update_fee) from adding a
new commitment tx while we're at the end of shutdown.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Fixed warnings:
.copy-edit-stylesheet-checklist.md: 49: MD030/list-marker-space Spaces after list markers [Expected: 1; Actual: 0]
.copy-edit-stylesheet-checklist.md: 1: MD041/first-line-h1 First line in file should be a top level header [Context: "Basic checklist/stylesheet use..."]
02-peer-protocol.md: 161: MD018/no-missing-space-atx No space after hash on atx style header [Context: "#7](07-routing-gossip.md#bolt-..."]
Usually the counterparty would only hurt itself if it chooses too low a `dust_limit`, but in the specific scenario of a data loss, we want the counterparty's commitment tx to be relayed and confirmed on the network.
Some slightly larger scale revisions for BOLT-2, notably including a reorganization of the "open_channel" function with the introduction of two missing arguments.
Also, the addition of MSAT to the glossary in BOLT-0.
This is Fabrice's #243 "BOLT2, BOLT3: reduce attack surface", split
out with minor polishing:
- Made it an optional feature (we can insist on it if we choose even bit).
- Rename from "final_scriptpubkey" to "shutdown_scriptpubkey".
- Make requirements the same as shutdown's scriptpubkey, or zero-len.
- Leave shutdown's scriptpubkey, just make sure it's the same or fail.
- Add to accept_channel as well as open_channel.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It *is* 2R+G+S, which is 7, not six. It's also identical to the previous one,
so just say that.
Reported-by: Shannon Appelcline <shannona@skotos.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
update stylesheet to reflect appropriate structure of Requirement sub-items and format of digits, numerations, and quantities;
copy edit BOLTs 0,1,2 to adhere to these changes;
This is stolen from @sstone's #243 "reduce attack surface".
This breaks compatibility, as agreed at the 2017-11-13 meeting.
Note also that it does not update the test vectors.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is the best I could come up with. You can't know future
revocation secrets, so if you send onw I know you're ahead of me
somehow. That means I *MUST NOT* broadcast my latest commitment
transaction, but at least if you're not malicious I'll salvage
something.
We adapt BOLT 5 in a fairly trivial way to specify to say you should
try to handle as much as you can (in fact, you should always be able
to collect their commitment transaction's direct-to-you output).
Fixes: #209
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Complete rewrite, including a routing example and the new
min_final_cltv expirt. I hope this makes it clear.
(Thanks to everyone who reviewed and gave feedback; you rock!)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1. We say you can't fail an HTLC until it's removed outgoing; make it clear
that this could also be on-chain.
2. Insist that you fail an expired HTLC (we never actually said this!)
3. You MUST fulfill an incoming HTLC for which the output was fulfilled
(otherwise you'll lose money), and of course, even if fulfilled on-chain.
Add an explanation paragraph to BOLT 5 as well, where it discusses on-chain
HTLC output cases (though the requirements about what to do about incoming
HTLCs is actually in BOLT 2).
[ Extra wording clarification thanks to roasbeef ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit modifies the glossary to add a new entry which defines the
usage of `chain_hash` throughout the remainder of the documents.
Additionally, we now also specify which chain hash we expect for
Bitcoin within the glossary.
This commit also modifies BOLT #2 and #7 to omit the definition of the
expected `chain_hash` value for Bitcoin.
