Phase B of the identity pipeline (FABRIC-3.md §F.7/§F.17): - x509_ed25519.c/.h: two new DER walkers alongside the existing pubkey extractor -- x509_verify_signature() (verifies a cert's outer Ed25519 signature over the raw, exactly-as-encoded tbsCertificate bytes, real signature verification against issuer_pubkey, rejects non-Ed25519 signatureAlgorithm) and x509_extract_serial() (extracts the serialNumber INTEGER, stripping a DER padding byte if present, for the drive_uuid binding decided in §F.7). - vm_identity.c: vm_identity_from_cert(), ties the three DER primitives together into the actual CERTVERIFY check -- signature verifies against issuer_pubkey, serialNumber matches this drive's own drive_uuid, subject pubkey extracts cleanly -- and populates a VMIdentity on success. acl_caps is caller-supplied, not read from the cert (nothing in the decided cert fields encodes capabilities); deciding what a verified identity is allowed to do is policy for the caller (WIREBIND, not yet built), not this function's job. Verified two ways: a standalone host-side test harness (not part of the kernel build) links the real source files against a real openssl- generated Ed25519 X.509 cert -- extracted pubkey, extracted serial, and signature verification all match ground truth, plus two negative tests (wrong issuer pubkey, corrupted signature) both correctly rejected. Then the actual kernel build verified live on all three architectures: clean compile, clean boot to ok>, Hermes/Artemis both live with no KILL. Same pre-existing, unrelated Zuse fence-write anomaly observed on all three (not caused by this change, not chased here). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019ZGkimpfyh63EZyRkNbkPD
capsules/
FORTH personality files loaded by the VM at boot. A capsule is an immutable, content-addressed payload; its XXHash64 hash is its identity. Any mutation changes the hash and the birth protocol rejects the image.
Key files
| File | Type | Purpose |
|---|---|---|
init.4th |
(m) MAMA_INIT |
Default Mama VM personality — loaded at LBN 2048 |
ACL.4th |
user | Word-level ACL system; self-activating at boot |
zuse.4th |
user | Bootstrap superuser; loaded by ACL.4th |
doe.4th |
user | DoE workload words (EXEC-DOE) — opt-in |
init-0.4th … init-9.4th |
(p) |
Numbered personality variants |
init-l8-*.4th |
(p) |
L8 Jacquard mode variants (stable/volatile/diverse/temporal/transition/omni) |
hermes/init.4th |
(p) |
Hermes baby VM personality |
artemis/init.4th |
(p) |
Artemis baby VM personality |
Block namespace
Block ranges are shared across all loaded capsules — collisions cause silent word-definition overwrites.
| Range | Owner |
|---|---|
| 2048–2099 | init.4th |
| 2100–2199 | doe.4th |
| 3000–3999 | workload capsules |
| 4000+ | user-defined (ACL.4th, zuse.4th, …) |
Each block is limited to 1024 bytes. Verify with wc -c before committing.
See also
experiments/bare_metal/README.md— DoE protocols and block namespace rulesdocs/03-architecture/word-acl/DESIGN.md— ACL system designtools/mkcapsule.c— assembles capsules intocapsule_generated.c- Project root