Luadch-I2P Debian PoC - native Windows pair verified

Public experimental Debian 13 amd64 server PoC, security delta 2026-10-06

Includes Luadch-I2P, its SAM forwarder and a private bundled i2pd.
Install with sudo apt install ./luadch-i2p_0.1.0-poc1_amd64.deb, then run
sudo luadch-i2p info for the address and generated administrator credentials.
No manual SAM/tunnels, router changes or inbound firewall exception required.
Registration is required and the traffic manager remains enabled.

Source checkpoint: f2c86fc.
Confirmed security/availability issue: unrelated I2P sources shared the
forwarder's loopback connection/authentication counter. The fix consumes
the private SAM forwarder's source preamble before creating the hub user,
separates per-destination rate limits from the numeric local socket address,
and requires the advertised I2P destination to match the forwarded source.
Incomplete metadata is bounded to 16 KiB, 10 seconds and 64 pending sockets.
Local processes/the forwarder remain trusted; this preamble does not protect
against a compromised local machine. HTTP framing was not changed.

Targeted real hub tests passed: independent-source isolation, same-source
connection limit/release, authentication-failure isolation, pending cap and
timeout/recovery, malformed/oversized/missing/split/coalesced source metadata,
mismatched identity rejection, two-client login and I2P peer negotiation relay.

After the fix, two native Windows clients with independent private routers
passed fresh bidirectional hub/private chat, real peer file lists, hub-routed
searches and complete random 1 MiB transfers with matching SHA-256. The
clients used the production native application's Web API for automation.
Normal server shutdown returned success/exit 0 and left no managed children.

Earlier acceptance included full official Alpine ISO transfers and clean
GitHub-downloaded package installation. Those already-proven tests were not
rerun for this delta. The package was reassembled from cached binaries and
the tested Lua changes; its patched files match the committed source exactly.
Payload/source privacy and package permission checks passed. No dependencies
or router were rebuilt. The updated package was not reinstalled solely to
repeat unchanged maintainer-script behavior.

Users of an earlier private test package must
explicitly reinstall to apply it:
sudo apt install --reinstall ./luadch-i2p_0.1.0-poc1_amd64.deb
Private identities/configuration are retained. Never publish private state
under /var/lib/luadch-i2p or diagnostic logs.

Experimental candidate, not a stable release or blanket security/anonymity
guarantee. Broader native GUI fault and packet verification remain separate
work. The historical intermittent LeaseSet issue was not reinvestigated.
I2P may need several minutes; local SAM registration alone is not remote
reachability. Bundled router: Debian i2pd 2.56.0-1 with signed-SU3 verification.

Independent experimental forks; no changes are submitted upstream. Assets: Debian package,
complete committed source archive and SHA256SUMS.txt. See
docs/DEBIAN_POC_PACKAGE.md in the source for operation/build instructions.

Before inviting users, review the current I2P operator settings. Disable the inherited etc_forcetlstransfer.lua policy plugin; its ADCS/port-forwarding advice does not apply to I2P peer streams. The package defaults to registered members. Opening guest access is a separate operator choice. The optional audio filename moderation bot in current source is not included in this older binary package.

Checksum verification: download SHA256SUMS.txt alongside the Debian package and run sha256sum --ignore-missing -c SHA256SUMS.txt before installation.