Initial curated chimera source from a8ae5b1db07fb49926c94585e2718e5130330974

test/autonomous/build-kstuff-diagnostic-loader.test.mjs

@@ -0,0 +1,61 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import {
+  buildDiagnosticLoader,
+  inspectFrankenElf,
+  sha256,
+} from '../../scripts/autonomous/build-kstuff-diagnostic-loader.mjs';
+
+const MARKER = Buffer.from([0xeb, 0x0b, 0x50, 0x4c, 0x44, 0x00]);
+
+function frankenElf(size) {
+  const buffer = Buffer.alloc(size, 0x41);
+  MARKER.copy(buffer);
+  buffer.writeBigUInt64LE(64n, 32);
+  buffer.writeUInt16LE(1, 56);
+  buffer.writeUInt32LE(1, 64);
+  buffer.writeUInt32LE(5, 68);
+  buffer.writeBigUInt64LE(0n, 72);
+  buffer.writeBigUInt64LE(BigInt(size), 96);
+  buffer.writeBigUInt64LE(BigInt(size), 104);
+  return buffer;
+}
+
+test('in-place diagnostic build preserves bytes after the exact embedded image span', () => {
+  const prefix = Buffer.alloc(96, 0x23);
+  const officialPayload = frankenElf(192);
+  const suffix = Buffer.alloc(80, 0x7d);
+  const officialLoader = Buffer.concat([prefix, officialPayload, suffix]);
+  const diagnosticPayload = frankenElf(160);
+  const manifest = { officialLoader: {
+    size: officialLoader.length,
+    sha256: sha256(officialLoader),
+    embeddedPayloadOffset: prefix.length,
+    embeddedPayloadSize: officialPayload.length,
+  } };
+
+  const result = buildDiagnosticLoader({ officialLoader, diagnosticPayload, manifest });
+  assert.deepEqual(result.output.subarray(prefix.length + officialPayload.length), suffix);
+  assert.equal(result.evidence.zeroPaddingBytes, 32);
+  assert.equal(inspectFrankenElf(diagnosticPayload).imageSpan, diagnosticPayload.length);
+});
+
+test('in-place diagnostic build rejects a payload larger than the official image span', () => {
+  const prefix = Buffer.alloc(96, 0x23);
+  const officialPayload = frankenElf(192);
+  const suffix = Buffer.alloc(80, 0x7d);
+  const officialLoader = Buffer.concat([prefix, officialPayload, suffix]);
+  const diagnosticPayload = frankenElf(208);
+  const manifest = { officialLoader: {
+    size: officialLoader.length,
+    sha256: sha256(officialLoader),
+    embeddedPayloadOffset: prefix.length,
+    embeddedPayloadSize: officialPayload.length,
+  } };
+
+  assert.throws(
+    () => buildDiagnosticLoader({ officialLoader, diagnosticPayload, manifest }),
+    /rebuild the loader from pinned source/,
+  );
+});