## Issue:
This is an approach to fixing secret connection that is more noise-ish than actually noise.
but it essentially fixes the problem that #3315 is trying to solve by making the secret connection handshake non-malleable. It's easy to understand and I think will be acceptable to @jaekwon
.. the formal reasoning is basically, if the "view" of the transcript between diverges between the sender and the receiver at any point in the protocol, the handshake would terminate.
The base protocol of Station to Station mistakenly assumes that if the sender and receiver arrive at shared secret they have the same view. This is only true for a DH on prime order groups.
This robustly solves the problem by having each cryptographic operation commit to operators view of the protocol.
Another nice thing about a transcript is it provides the basis for "secure" (barring cryptographic breakages, horrible design flaws, or implementation bugs) downgrades, where a backwards compatible handshake can be used to offer newer protocol features/extensions, peers agree to the common subset of what they support, and both sides have to agree on what the other offered for the transcript MAC to verify.
With something like Protos/Amino you already get "extensions" for free (TLS uses a simple TLV format https://tools.ietf.org/html/rfc8446#section-4.2 for extensions not too far off from Protos/Amino), so as long as you cryptographically commit to what they contain in the transcript, it should be possible to extend the protocol in a backwards-compatible manner.
## Commits:
* Minimal changes to remove malleability of secret connection removes the need to check for lower order points.
Breaks compatibility. Secret connections that have no been updated will fail
* Remove the redundant blacklist
* remove remainders of blacklist in tests to make the code compile again
Signed-off-by: Ismail Khoffi <Ismail.Khoffi@gmail.com>
* Apply suggestions from code review
Apply Ismail's error handling
Co-Authored-By: Ismail Khoffi <Ismail.Khoffi@gmail.com>
* fix error check for io.ReadFull
Signed-off-by: Ismail Khoffi <Ismail.Khoffi@gmail.com>
* Update p2p/conn/secret_connection.go
Co-Authored-By: Ismail Khoffi <Ismail.Khoffi@gmail.com>
* Update p2p/conn/secret_connection.go
Co-Authored-By: Bot from GolangCI <42910462+golangcibot@users.noreply.github.com>
* update changelog and format the code
* move hkdfInit closer to where it's used