erlang: wire crypto:hash/2 against crypto-sha256/512/sha3-256 (Phase 8, +6 ffi tests)

lib/erlang/runtime.sx

@@ -1372,6 +1372,97 @@
                   (er-classify-file-error (nth err 0))))
               :else (er-mk-atom "ok")))))))
 
+
+;; ── crypto / cid / file:list_dir (Phase 8 FFI — host primitives) ──
+;; Wired against loops/fed-prims host primitives (see plans Blockers
+;; "RESOLVED 2026-05-18"). Term marshalling at the boundary:
+;; Erlang binary/string/charlist -> SX byte-string via er-source-to-string;
+;; results -> Erlang binary via er-mk-binary.
+
+(define er-hexval
+  (fn (c)
+    (let ((v (char->integer c)))
+      (cond
+        (and (>= v 48) (<= v 57)) (- v 48)        ;; 0-9
+        (and (>= v 97) (<= v 102)) (+ 10 (- v 97)) ;; a-f
+        (and (>= v 65) (<= v 70)) (+ 10 (- v 65))  ;; A-F
+        :else 0))))
+
+(define er-hex->bytes
+  (fn (hex)
+    (let ((cs (string->list hex)) (out (list)) (n (string-length hex)))
+      (for-each
+        (fn (i)
+          (append! out
+            (+ (* 16 (er-hexval (nth cs (* i 2))))
+               (er-hexval (nth cs (+ (* i 2) 1))))))
+        (range 0 (truncate (/ n 2))))
+      out)))
+
+;; crypto:hash(Type, Data) -> raw digest binary. Type is an Erlang
+;; atom (sha256 | sha512 | sha3_256). Bad type / non-binary -> badarg.
+(define er-bif-crypto-hash
+  (fn (vs)
+    (let ((ty (nth vs 0)) (data (er-source-to-string (nth vs 1))))
+      (cond
+        (or (not (er-atom? ty)) (= data nil))
+          (raise (er-mk-error-marker (er-mk-atom "badarg")))
+        :else
+          (let ((name (get ty :name)))
+            (let ((hex (cond
+                         (= name "sha256") (crypto-sha256 data)
+                         (= name "sha512") (crypto-sha512 data)
+                         (= name "sha3_256") (crypto-sha3-256 data)
+                         :else nil)))
+              (cond
+                (= hex nil) (raise (er-mk-error-marker (er-mk-atom "badarg")))
+                :else (er-mk-binary (er-hex->bytes hex)))))))))
+
+;; cid:from_bytes(Bin) -> CIDv1 (raw codec 0x55, sha2-256 multihash)
+;; as an Erlang binary string.
+(define er-bif-cid-from-bytes
+  (fn (vs)
+    (let ((data (er-source-to-string (nth vs 0))))
+      (cond
+        (= data nil) (raise (er-mk-error-marker (er-mk-atom "badarg")))
+        :else
+          (let ((digest (er-hex->bytes (crypto-sha256 data))))
+            (let ((mh (list->string
+                        (map integer->char (append (list 18 32) digest)))))
+              (er-mk-binary
+                (map char->integer
+                  (string->list (cid-from-bytes 85 mh))))))))))
+
+;; cid:to_string(Term) -> canonical CIDv1 (dag-cbor) of the term,
+;; as an Erlang binary string.
+(define er-bif-cid-to-string
+  (fn (vs)
+    ;; Canonical CID of the term's stable string form. (cbor-encode
+    ;; rejects symbols, so er-to-sx of compound terms is unencodable;
+    ;; er-format-value yields a canonical SX string per term value.)
+    (er-mk-binary
+      (map char->integer
+        (string->list (cid-from-sx (er-format-value (nth vs 0))))))))
+
+;; file:list_dir(Path) -> {ok, [Binary]} | {error, Reason}
+(define er-bif-file-list-dir
+  (fn (vs)
+    (let ((path (er-source-to-string (nth vs 0))))
+      (cond
+        (= path nil)
+          (er-mk-tuple (list (er-mk-atom "error") (er-mk-atom "badarg")))
+        :else
+          (let ((res (list nil)) (err (list nil)))
+            (guard (c (:else (set-nth! err 0 c)))
+              (set-nth! res 0 (file-list-dir path)))
+            (cond
+              (not (= (nth err 0) nil))
+                (er-mk-tuple (list (er-mk-atom "error")
+                  (er-classify-file-error (nth err 0))))
+              :else
+                (er-mk-tuple (list (er-mk-atom "ok")
+                  (er-of-sx (nth res 0))))))))))
+
 ;; ── builtin BIF registrations (Phase 8 migration) ────────────────
 ;; Populates `er-bif-registry` with every existing built-in BIF. Each
 ;; entry is keyed by "Module/Name/Arity"; multi-arity BIFs register
@@ -1466,6 +1557,8 @@
     (er-register-bif! "file" "read_file" 1 er-bif-file-read-file)
     (er-register-bif! "file" "write_file" 2 er-bif-file-write-file)
     (er-register-bif! "file" "delete" 1 er-bif-file-delete)
+    ;; Phase 8 FFI — host-primitive BIFs (loops/fed-prims)
+    (er-register-pure-bif! "crypto" "hash" 2 er-bif-crypto-hash)
     (er-mk-atom "ok")))
 
 ;; Register everything at load time.

lib/erlang/tests/ffi.sx

@@ -75,18 +75,35 @@
       "file:write_file(\"/tmp/er-ffi-del2.txt\", \"x\"), file:delete(\"/tmp/er-ffi-del2.txt\"), element(2, file:read_file(\"/tmp/er-ffi-del2.txt\"))"))
   "enoent")
 
-;; ── Blocked BIFs (placeholder asserts so the suite documents intent) ──
-;; crypto:hash/2, cid:from_bytes/1, cid:to_string/1, file:list_dir/1,
-;; httpc:request/4, sqlite:* — documented in plans/erlang-on-sx.md
-;; under Blockers. When the host runtime gains the underlying primitive,
-;; the wrappers land in runtime.sx and tests appear here. For now we
-;; assert each is NOT registered, so a future iteration that adds them
-;; without updating this file fails fast.
+(er-ffi-test
+  "crypto:hash sha256 -> 32-byte binary"
+  (ffi-ev "byte_size(crypto:hash(sha256, <<97,98,99>>))")
+  32)
 
 (er-ffi-test
-  "crypto:hash unregistered"
-  (er-lookup-bif "crypto" "hash" 2)
-  nil)
+  "crypto:hash sha512 -> 64-byte binary"
+  (ffi-ev "byte_size(crypto:hash(sha512, <<97,98,99>>))")
+  64)
+
+(er-ffi-test
+  "crypto:hash sha3_256 is_binary"
+  (ffi-nm (ffi-ev "is_binary(crypto:hash(sha3_256, <<120>>))"))
+  "true")
+
+(er-ffi-test
+  "crypto:hash deterministic"
+  (ffi-nm (ffi-ev "crypto:hash(sha256, <<97>>) =:= crypto:hash(sha256, <<97>>)"))
+  "true")
+
+(er-ffi-test
+  "crypto:hash distinct inputs distinct digests"
+  (ffi-nm (ffi-ev "crypto:hash(sha256, <<97>>) =/= crypto:hash(sha256, <<98>>)"))
+  "true")
+
+(er-ffi-test
+  "crypto:hash bad type -> error:badarg"
+  (ffi-nm (ffi-ev "try crypto:hash(md5, <<120>>) catch error:badarg -> ok end"))
+  "ok")
 
 (er-ffi-test
   "cid:from_bytes unregistered"
@@ -98,6 +115,9 @@
   (er-lookup-bif "file" "list_dir" 1)
   nil)
 
+;; ── Still deferred (no host primitive): httpc (HTTP client, v2),
+;; sqlite-* (v2 indexes). Assert NOT registered so a future iteration
+;; that wires them without updating this suite fails fast.
 (er-ffi-test
   "httpc:request unregistered"
   (er-lookup-bif "httpc" "request" 4)

plans/erlang-on-sx.md

@@ -115,7 +115,7 @@ Replace today's hardcoded BIF dispatch (`er-apply-bif`/`er-apply-remote-bif` in
 - [x] BIF registry: `er-bif-registry` global dict keyed by `"Module/Name/Arity"`, with `er-register-bif!`/`er-register-pure-bif!`/`er-lookup-bif`/`er-list-bifs`/`er-bif-registry-reset!` helpers — **+18 runtime tests** (600/600 total). Entries are `{:module :name :arity :fn :pure?}`. Arity is part of the key so `m:f/1` and `m:f/2` are independent. Re-registering the same key replaces the previous entry; reset clears.
 - [x] Migrate existing local + remote BIFs (length/hd/tl/lists:*/io:format/ets:*/etc.) onto the registry; delete the giant `cond` dispatch in `er-apply-bif`/`er-apply-remote-bif`. Conformance held at **600/600** after migration (baseline was 600, not the plan-text's 530 — the text was authored before Phase 7 work added rows). 67 builtin registrations across `erlang`/`lists`/`io`/`ets`/`code` modules; multi-arity BIFs (`is_function`, `spawn`, `exit`, `io:format`, `lists:seq`, `ets:delete`) register once per arity, all pointing at the same impl which dispatches on `(len vs)` internally. The four per-module cond dispatchers (`er-apply-lists-bif`, `er-apply-io-bif`, `er-apply-ets-bif`, `er-apply-code-bif`) are deleted. `er-apply-bif` and `er-apply-remote-bif` are now ~5-line registry lookups; user modules still win precedence over the registry.
 - [x] Term-marshalling helpers: `er-of-sx` (SX → Erlang) and `er-to-sx` (Erlang → SX). atom ↔ symbol, nil ↔ `()`, cons → list, tuple → list (one-way; tuples flatten), binary ↔ SX string, integer / float / boolean passthrough. **+23 runtime tests** (623/623 total). Erlang maps (`dict ↔ map`) deferred — Erlang map term not implemented in this port; will land when `#{}` syntax does. Pids, refs, funs pass through unchanged. SX strings on the way back become Erlang binaries (most useful FFI return shape).
-- [ ] `crypto:hash/2` — **BLOCKED** (no `sha256`/`sha512`/`blake3` primitive in this SX runtime). See Blockers.
+- [x] `crypto:hash/2` — **WIRED 2026-05-18** against `crypto-sha256`/`crypto-sha512`/`crypto-sha3-256` (loops/fed-prims). `crypto:hash(Type, Data)`: `Type` ∈ `sha256|sha512|sha3_256` atom; `Data` an Erlang binary/string/charlist (→ SX byte-string via `er-source-to-string`). Returns the **raw digest as an Erlang binary** (host hex → bytes via `er-hex->bytes`). Bad type / non-binary → `error:badarg`. 6 ffi tests (digest sizes 32/64, sha3 is_binary, deterministic, distinct, badarg).
 - [ ] `cid:from_bytes/1`, `cid:to_string/1` — **BLOCKED** (needs `crypto:hash/2`). See Blockers.
 - [x] `file:read_file/1`, `file:write_file/2`, `file:delete/1` — **+10 eval tests** (633/633 total). Returns `{ok, Binary}` / `ok` / `{error, Reason}` where Reason is `enoent`/`eacces`/`enotdir`/`eisdir`/`posix_error` (classified from the SX `file-read`/`-write`/`-delete` exception string). Path accepts SX string, Erlang binary, or Erlang char-code list. `file:list_dir/1` deferred — no directory-listing primitive in this SX runtime; see Blockers.
 - [ ] `httpc:request/4` — **BLOCKED** (no HTTP client primitive). See Blockers.