* It is now an invariant that all constructed Public Keys are valid,
non-empty and contain 33 bytes of data.
* Additionally, the memory footprint of the PublicKey class is reduced.
The size_ data member is declared as static.
* Distinguish and identify the PublisherList retrieved from the local
config file, versus the ones obtained from other validators.
* Fixes#2942
Modify the `XChainBridge` amendment.
Before this patch, two door accounts on the same chain could could own
the same bridge spec (of course, one would have to be the issuer and one
would have to be the locker). While this is silly, it does not violate
any bridge invariants. However, on further review, if we allow this then
the `claim` transactions would need to change. Since it's hard to see a
use case for two doors to own the same bridge, this patch disallows
it. (The transaction will return tecDUPLICATE).
A bridge connects two blockchains: a locking chain and an issuing
chain (also called a mainchain and a sidechain). Both are independent
ledgers, with their own validators and potentially their own custom
transactions. Importantly, there is a way to move assets from the
locking chain to the issuing chain and a way to return those assets from
the issuing chain back to the locking chain: the bridge. This key
operation is called a cross-chain transfer. A cross-chain transfer is
not a single transaction. It happens on two chains, requires multiple
transactions, and involves an additional server type called a "witness".
A bridge does not exchange assets between two ledgers. Instead, it locks
assets on one ledger (the "locking chain") and represents those assets
with wrapped assets on another chain (the "issuing chain"). A good model
to keep in mind is a box with an infinite supply of wrapped assets.
Putting an asset from the locking chain into the box will release a
wrapped asset onto the issuing chain. Putting a wrapped asset from the
issuing chain back into the box will release one of the existing locking
chain assets back onto the locking chain. There is no other way to get
assets into or out of the box. Note that there is no way for the box to
"run out of" wrapped assets - it has an infinite supply.
Co-authored-by: Gregory Popovitch <greg7mdp@gmail.com>
