shoney.arickathil
5ec60e8e77
- SHA-1 (WS-handshake hard req, RFC 6455 worked example as acceptance), SHA-256, HMAC-SHA256 over Bytes; hand-rolled C per doctrine, FIPS/RFC vector fixtures; four forks recorded (namespace, shape, source, file) - gates chain item 24; digest floor for held 21 + ETag row; 24's dependency note repointed; board + table rows (held seqs bumped) Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
101 lines
4.6 KiB
Markdown
101 lines
4.6 KiB
Markdown
---
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iteration: "34"
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status: refine
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---
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# Iteration 34 — crypto builtins: digests and HMAC in the runtime
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> Format: fiberloom `product/story-iteration-template`. Part of
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> [Story — one language, one runtime, one database, one binary](../00-story.md).
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>
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> **Inserted 2026-08-22** — the framework ledger's oldest unowned gap
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> gets an owner. The language has NO bitwise operators (a settled
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> surface decision), so digests cannot be written in `.wo`; the
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> ledger's recorded resolution stands: hand-rolled C builtins in the
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> runtime — the libc-only doctrine permits hand-rolled crypto, and the
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> code is bounded and well-specified. Off the concurrency chain but
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> **gates chain position 4**: iteration 24's WebSocket handshake needs
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> SHA-1 before chat can land.
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## Why this iteration exists
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Four consumers already wait on it, none able to proceed:
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[iteration 24](24-chat-websocket-workload.md)'s upgrade handshake
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(`Sec-WebSocket-Accept` = base64(SHA-1(key + GUID)) — SHA-1
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specifically, not a choice); the framework's ETag/conditional-request
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row (wants a content hash); HMAC-signed tokens the auth core can grow;
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and held [iteration 21](../hold/21-keypair-attach-auth.md), whose
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challenge–response needs primitives that "do not exist" (its demotion
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note). Bytes and base64 landed with iteration 19 — the carriers exist,
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only the digests are missing.
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## Goals
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- **Digest builtins over Bytes**: SHA-1 (the WS handshake's hard
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requirement), SHA-256 (the modern default for ETag/HMAC), each
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`Bytes -> Bytes`, streaming not required (whole-value, like every
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existing builtin).
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- **HMAC-SHA256** (`key: Bytes, msg: Bytes -> Bytes`) — the one
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composition real services need (signed tokens, webhook signatures);
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writing HMAC in `.wo` is impossible for the same no-bitwise reason.
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- **Test vectors are the acceptance**: FIPS 180 / RFC 2202 / RFC 4231
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vectors in a corpus fixture — a digest that "looks right" is worth
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nothing.
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- **The contract doc row**: names, arities, Bytes-in/Bytes-out, and the
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explicit note that SHA-1 exists for protocol compatibility (WS), not
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for new designs.
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## Acceptance Criteria (draft — the spec refines)
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- **Given** the published test vectors for SHA-1, SHA-256, and
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HMAC-SHA256, **when** the corpus fixture runs them through the
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builtins, **then** every output matches byte-for-byte (via the
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existing base64/Bytes surface).
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- **Given** the WS handshake's worked example from RFC 6455
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(`dGhlIHNhbXBsZSBub25jZQ==` → `s3pPLMBiTxaQ9kYGzzhZRbK+xOo=`),
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**when** composed in pure `.wo` from `sha1` + `base64_encode`,
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**then** the exact accept token comes out — iteration 24's handshake
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is provably one expression away.
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- **Given** the full battery, **when** it runs, **then** nothing
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regresses — new builtin ids only, no opcode, no `.wob` version bump
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(the iteration-19/`time.ticks` precedent).
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## Out Of Scope
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- Asymmetric crypto (ed25519 signatures/keypairs) — held iteration 21's
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spec decides what it needs when it unholds; this iteration lays the
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digest floor it will stand on.
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- TLS — permanently the proxy's job (framework doctrine).
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- CRC32 — the ledger lists it, but no consumer is blocked on it; it
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joins only if 24's spec finds a real need (rejecting speculative
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surface).
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- A password-hashing story (bcrypt/argon2) — no workload asks yet.
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- Bitwise operators in the language — a separate, bigger surface
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decision this iteration deliberately routes around.
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## Info
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Forks the spec must settle:
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1. **The namespace.** The reserved stdlib namespaces are exactly
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`fs`/`proc`/`net`/`time`/`json`/`env` (compiler-enforced list) — a
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new `crypto` namespace touches that list plus the typechecker
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table, or the functions ride an existing namespace. Leaning: a real
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`crypto` namespace (the list exists to be grown deliberately; this
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is deliberate).
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2. **Surface shape**: `crypto.sha1(b: Bytes) -> Bytes`,
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`crypto.sha256(b: Bytes) -> Bytes`,
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`crypto.hmac_sha256(key: Bytes, msg: Bytes) -> Bytes` — Text
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convenience overloads rejected (the caller has `bytes_of_text`).
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3. **Implementation source**: hand-rolled C from the FIPS pseudocode
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(~200 lines for both digests; well-trodden, vector-verified) — the
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doctrine's shape. No linking against OpenSSL, ever.
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4. **Where the code lives**: `runtime/src/crypto.c` beside sysio, or
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inside builtin.c — file layout, the executor decides.
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## Proposed Solution
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Brainstorm → (small) spec settling the four forks → implement with the
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`time.ticks` slice's shape (ids, one table row per compiler surface,
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contract-doc rows, vector fixtures). Lands any time before iteration
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24's spec; independent of 31/22/23.
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