Files
SilverMetal/linux
SysAdmin 36f7672c6f fix(linux/build): make builder image actually build (M1.1)
- Pin debian:bookworm-slim by real digest (resolved 2026-04-26).
- Two-phase install: seed ca-certificates from the default mirror first
  so HTTPS to snapshot.debian.org works, then swap to the pinned snapshot
  for the toolchain itself. Slim images don't ship the CA bundle, so the
  one-shot pinned-source-only install would deadlock on cert verification.

Validated locally: image builds clean, 302MB, all live-build / debootstrap /
mksquashfs / xorriso / diffoscope-minimal present.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-26 04:49:34 +01:00
..

SilverMetal OS — Linux

Status: Phase 1 (planning) → moving to milestone 1.1 (reproducible Kicksecure fork build)

🔒 SilverMetal OS product line — we ship the operating system.

The reference SilverMetal flavour. Tier A — full kernel-level hardening, verified boot we control, Debian/Kicksecure-based.

Scope (v1)

See ../docs/roadmap.md Phase 1.

Hardening must-haves

  • Kicksecure base (Debian-derived, hardened upstream)
  • linux-hardened kernel + KSPP sysctl/build flags
  • Secure Boot with our shim/MOK
  • TPM2 PCR-bound LUKS2 unlock (Argon2id), full-disk encryption mandatory
  • AppArmor strict profiles for browsers, mail, viewers, networked daemons
  • GrapheneOS hardened_malloc as system allocator
  • bubblewrap + Flatpak primary; firejail for legacy .deb
  • nftables default-deny inbound, encrypted DNS, SilverVPN always-on default
  • Zero upstream telemetry — verified by integration test
  • SilverBrowser default (ungoogled-chromium-rebranded v1)
  • SilverVPN integrated from existing SilverLABS/SilverVPN (Linux client + tunnel service)
  • SilverSync v1 (Nextcloud-backed, client-side encryption)
  • A/B updates with rollback, signed by our keys
  • Optional amnesic session mode

Out of scope (v1)

  • Atomic / immutable root (v1.1 — ostree experiment)
  • dm-verity on / (v1.1)
  • ARM64 / Apple Silicon (v2)
  • Tor-by-default variant (sibling product later)

Directory layout

linux/
├── build/             # live-build pipeline, reproducible-build config
├── kernel/            # config fragments, linux-hardened pinning
├── overlay/           # /etc + /usr/share/silvermetal + skel hardening overlay
├── packages/
│   ├── include.list   # what's installed
│   └── exclude.list   # what's purged (snap, telemetry, etc.)
├── apparmor/          # custom strict profiles
├── nftables/          # default ruleset
├── installer/         # Calamares branding + hardened defaults
├── update-server/     # signing + repo hosting (infra-as-code)
└── tests/
    ├── lynis-baseline/
    ├── kspp-check/
    └── telemetry-leak/

Verification gates (must pass before public alpha)

  • Two clean builds from same commit → identical SHA256
  • kconfig-hardened-check passes
  • Lynis hardening score ≥ 90
  • 30-min idle telemetry capture: zero packets to MS/Google/Apple/Mozilla/Canonical/Debian/analytics
  • TPM tamper test: LUKS correctly falls back to passphrase
  • AppArmor: every networked binary confined or documented
  • Independent privacy-engineering review

Upstream we depend on

  • Kicksecure — fork base
  • linux-hardened — kernel patchset
  • GrapheneOS hardened_malloc — allocator
  • KSPP — kernel config authority
  • secureblue — reference for v1.1 immutable design
  • SilverLABS/SilverVPN — VPN client + tunnel service (existing, integrated)