Robert Allan JamesandClaude Sonnet 5
53e6c5709f
Extends the previously verify-only ed25519.c with ed25519_keygen() and ed25519_sign() per RFC 8032 5.1.5/5.1.6, reusing every point-arithmetic primitive verify already had -- only seed expansion/clamping and per-message nonce derivation are new. Signing is deterministic; only keygen ever touches entropy, via a caller-supplied seed (virtio_rng, Phase A) -- keygen still generates nothing itself. New scalar_muladd() (scalar25519.c) for signing's S = (k*a + r) mod L, the one scalar op verify never needed. Schoolbook multiply into a u128 wide accumulator with one final carry pass -- deliberately the same shape as fe25519.c's existing multiply, which has a documented history of a real bug from carrying mid-accumulation instead of in one pass. Verified against an independent implementation, not self-consistency: a throwaway host harness against Python's cryptography library (OpenSSL- backed) across 6 trials (5 random seed/message pairs + the empty-message case) produced byte-for-byte identical pubkeys and signatures every time. Clean compile on all three architectures and a full 3-arch QEMU acceptance boot, conservation intact, no panics or guest errors. Nothing calls the new functions from the live kernel path yet -- that's Phase C (the MINT word itself), still open, documented in FABRIC-3.md. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01U14ET9CWAtbQMbYqomKgXd
lfs/
Per-architecture copies of the hosted starforth binary. The hosted
Makefile copies the freshly built binary here as its last build step
(cp $(BINARY) lfs/$(ARCH_DIR)/starforth), separate from
build/<arch>/<profile>/, which is the working build-output tree.
amd64/starforth,arm64/starforth,riscv64/starforth— one binary per architecture, rebuilt whenever that architecture's hosted build runs.