feat: isolate privacy scanning and release signing

containers/privacy-matcher/Dockerfile

@@ -0,0 +1,8 @@
+ARG BASE_IMAGE
+FROM ${BASE_IMAGE}
+LABEL org.opencontainers.image.title="portfolio-privacy-matcher" \
+      org.opencontainers.image.description="Decoder-free independent privacy evidence matcher"
+WORKDIR /opt/matcher
+COPY containers/privacy-matcher/matcher.mjs /opt/matcher/matcher.mjs
+USER 65532:65532
+ENTRYPOINT ["node", "/opt/matcher/matcher.mjs"]

containers/privacy-matcher/matcher.mjs

@@ -0,0 +1,49 @@
+import { createHash } from "node:crypto";
+import { readFile, writeFile } from "node:fs/promises";
+
+const request = JSON.parse(await readFile("/input/request.json", "utf8"));
+const [a, b] = request.reports ?? [];
+if (
+  !a ||
+  !b ||
+  a.workerId !== "worker-a" ||
+  b.workerId !== "worker-b" ||
+  a.imageDigest === b.imageDigest ||
+  a.toolchain === b.toolchain ||
+  a.inputDigest !== b.inputDigest ||
+  a.checkId !== b.checkId ||
+  a.normalizedOutputDigest !== b.normalizedOutputDigest ||
+  JSON.stringify(a.normalizedMembers) !== JSON.stringify(b.normalizedMembers) ||
+  a.verdict !== "pass" ||
+  b.verdict !== "pass"
+)
+  throw new Error("Independent worker evidence does not agree.");
+const rules = request.rules;
+if (!Array.isArray(rules) || rules.length === 0)
+  throw new Error("Matcher rules are required.");
+const appliedRuleIds = rules
+  .map((rule) => rule.id)
+  .sort((left, right) => Buffer.from(left).compare(Buffer.from(right)));
+if (
+  new Set(appliedRuleIds).size !== appliedRuleIds.length ||
+  rules.some((rule) => !Array.isArray(rule.deniedMemberDigests))
+)
+  throw new Error("Matcher rules are invalid.");
+const denied = new Set(rules.flatMap((rule) => rule.deniedMemberDigests));
+if (a.normalizedMembers.some((member) => denied.has(member)))
+  throw new Error("Privacy rule matched normalized evidence.");
+const result = {
+  schema: "portfolio-privacy-matcher-result/v1",
+  inputDigest: a.inputDigest,
+  checkId: a.checkId,
+  normalizedOutputDigest: a.normalizedOutputDigest,
+  normalizedMembers: a.normalizedMembers,
+  ruleSetDigest: request.ruleSetDigest,
+  appliedRuleIds,
+  verdict: "pass",
+  workerImageDigests: [a.imageDigest, b.imageDigest],
+};
+await writeFile("/output/result.json", JSON.stringify(result), {
+  flag: "wx",
+  mode: 0o400,
+});