by merging it with the version packet. Or more accurately, by merging
it with the first packet sent after garbage termination, which may be
a decoy packet or the version packet.
The new protocol simplifies implementations:
- A protocol state machine won't need separate states for garbage
authentication and version phases.
- The special case of "ignoring the ignore bit" is removed.
- The freedom to choose the contents of the garbage authentication
packet is removed. This simplifies testing.
The reason for having a separate garbage authentication packet was
to materialize the separation of the key exchange phase and version
negotiation phase even in the bytestream on the wire. However, this
is not necessary, and arguably, these phases are still properly
separated: Since the AEAD will ensure that AAD (=garbage) is checked
before looking at the contents (=version), the peers won't interpret
version data before having authenticated the garbage.
Python requires a colon at the end of an if statement to denote the beginning of the block of code that will be executed if the condition is True. If the colon is omitted, a syntax error will occur, and the code will not run. Since the syntax error will prevent the code from running, it won't introduce any vulnerabilities by itself. However, it will cause the application to fail at the point where the code is parsed, which might expose other issues if error handling is not implemented properly.
Allow trigger/recovery output nValues to exceed the amounts supplied by
constituent vault inputs. This allows future compatibility for e.g.
trigger collateral.
This change makes the amount being revaulted (if any) explicit to avoid
issues surfaced by AJ Towns (e.g. multiple compatible vault inputs
duplicating triggers and revaults to confuse the old deferred check
logic).
Pseudocode is also provided for the deferred checks, and their inline
validation description has been changed to be more faithful to the
implementation - we make mention of queueing deferred checks, and then
later describe the algorithm used to aggregate and perform them.
