The thing I had been calling blocked for weeks, built in an afternoon once it
was pointed out that it was already decided. 08-connectivity says of the
overlay keys: each node generates its own keypair, the private half never
leaves the machine, the public half is published -- and says outright this IS
ADR 0004's "a node holds its own identity". Nobody had applied it to node
identity itself.
identity now holds the public half of each node's key. Only the public half,
which is the property worth having: a copy of this database is a list of who to
believe, not a set of credentials, so compromise of a node really is compromise
of only that node.
Exactly one key is live per node, and re-enrolment revokes the one it replaced
in the same transaction -- two live identities is the stolen-laptop case with
the replaced machine still believed.
Fault injection was worth the time here. Three findings. The unique index was
defended by no test at all: sequential enrolment is already safe because the
code revokes before inserting, so removing the constraint changed nothing. The
constraint only matters when two enrolments race, and there is now a test that
runs six at once and fails without it.
My injection harness also lied to me. One injection matched nothing, changed no
file, and reported NO BITE identically to a real one -- so a test that defends
nothing and an injection that does nothing look the same. The harness now
checksums the files and says NO-OP when they did not change.
And one honest NO BITE left standing: making the key lookup return a zero key
for an unknown node does not fail the test, because the signature check refuses
it a line later. Two independent mechanisms, not a placebo.
61 tests, none skipped.
