When converting from CounterpartyForwardingInfo to PaymentRelay, the
cltv_expiry_delta is copied. Then, when forming a blinded payment path,
the value is mutated so that esoteric values don't reveal information
about the path. However, the value was only used in computing
PaymentConstraints and wasn't actually updated in PaymentRelay. Move the
logic for modifying the cltv_expiry_delta to the conversion code to
avoid this inconsistency.
The excess delta is included in the final RouteHop::cltv_expiry_delta, so by
adding it explicitly to cur_cltv we were erroneously including it twice in the
total cltv expiry.
This could've add up to an extra MAX_SHADOW_CLTV_DELTA_OFFSET (432) blocks to
the total cltv expiry.
As we'd generally like the `lightning` crate to, over time, have
more modules rather than being very monolithic, we should move the
cryptographic things into their own module, which we do here.
We also take this opportunity to move stream adapters into their
own module and make clear that the ChaChaPoly `decrypt` method is
variable time.
ChannelManager provides utilities to create offers and refunds along
with utilities to initiate and request payment for them, respectively.
It also manages the payment flow via implementing OffersMessageHandler.
Test that functionality, including the resulting event generation.
An upcoming rust-bitcoin release will remove the "no-std" feature.
Replace "no-std" in feature checks with "std", negating as needed. Using
a single feature flag makes the checks more consistent across modules.
TestRouter checks route and scoring expectations before delegating to
the standalone find_route function. Refactor it to wrap DefaultRouter
and delegate to it instead. This allows TestRouter to implement
create_blinded_payment_paths by delegating to DefaultRouter.
OnionMessenger is needed to write functional tests for ChannelManager's
OffersMessageHandler implementation. Also adds a TestMessageRouter,
which simply wraps DefaultMessageRouter for now.
The ChaCha20-based EntropySource implementation is duplicated within the
sign module. Refactor those into a RandomBytes implementation so that it
may be reused both there. Also useful as a standalone EntropySource
implementation for tests where an independent EntropySource is needed to
ensure that backwards-compatibility testing is not broken.
When testing OnionMessenger in functional tests, it would be useful to
examine the contents of an OnionMessage response. Expose the standalone
peel_onion_message on OnionMessenger to facilitate this.
