ruvnet/ruflo · error

Buffer too small to be a valid RVFA file

Error message

Buffer too small to be a valid RVFA file

What it means

parseRvfaBinary in rvfa-signing.ts rejects any buffer shorter than 44 bytes (12-byte preamble + 32-byte SHA256 footer) before reading the magic. An RVFA image is at minimum preamble + empty header + footer, so anything smaller cannot be a well-formed file. This is the coarsest gate in the signing/verification path — unlike RvfaReader it reports 'too small' before magic/version checks.

Solutions

1. Stat the file before verifying: it must be > 44 bytes and ideally match the expected published size
2. Fix the upstream fetch — an empty file almost always means the download failed silently (check HTTP status before writing)
3. If writing then verifying in one pipeline, await the write fully (and fsync) before invoking signing APIs
4. Add a guard in your code: if (buf.length < 44) skip verification and re-fetch

Example fix

// before — verify whatever landed on disk
const sig = await signer.signFile(await readFile(p));

// after — gate on a plausible minimum size
const buf = await readFile(p);
if (buf.length < 44) throw new Error(`suspect download: ${p} is ${buf.length} bytes`);
const sig = await signer.signFile(buf);

const MIN = 12 + 32; // preamble + footer
if (buf.length < MIN) throw new Error(`not an RVFA image (${buf.length} bytes)`);

function isPossiblyRvfa(buf: Buffer): boolean { return buf.length >= 44; }

try { await verifyFile(buf, pub); }
catch (e) {
  if (/too small to be a valid RVFA/.test(String((e as Error).message))) {
    // empty/partial download: re-fetch and check HTTP status before saving
  }
  throw e;
}

When it happens

Trigger: Calling signing/verification helpers (e.g. detached-signature computation or verify flows built on parseRvfaBinary) with an empty or near-empty buffer: readFile on a 0-byte file, an empty response body saved as .rvfa, or a placeholder/stub file created before the real download ran.

Common situations: Download pipeline wrote an empty file on a 404/204 and verification ran anyway; touch-ing a placeholder path in a script; race where verification starts before the writer finishes; passing a directory path or /dev/null by configuration mistake.

Related errors

• Header length extends beyond buffer
• Buffer too small to contain declared header
• Failed to parse RVFA header JSON
• Footer hash must be bytes, got
• Invalid RVFA magic: expected "RVFA", got

AI-assisted analysis of ruvnet/ruflo@fa13ee4ad6 (2026-08-18). Data as JSON: /api/errors/47dd913ce1c99619. Report an issue: GitHub.

Appendix: source

Thrown at v3/@claude-flow/cli/src/appliance/rvfa-signing.ts:170

      return sorted;
    }
    return val;
  });
}

/**
 * Parse an RVFA binary into its components without full validation.
 * Returns the header object, header JSON bytes, section data region, and footer.
 */
function parseRvfaBinary(buf: Buffer): {
  header: Record<string, unknown>;
  headerStart: number;
  headerEnd: number;
  sectionData: Buffer;
  footer: Buffer;
} {
  if (buf.length < PREAMBLE_SIZE + SHA256_SIZE) {
    throw new Error('Buffer too small to be a valid RVFA file');
  }

  const magic = buf.subarray(0, 4).toString('ascii');
  if (magic !== 'RVFA') {
    throw new Error(`Invalid RVFA magic: expected "RVFA", got "${magic}"`);
  }

  const headerLen = buf.readUInt32LE(8);
  const headerStart = PREAMBLE_SIZE;
  const headerEnd = headerStart + headerLen;

  if (headerEnd > buf.length - SHA256_SIZE) {
    throw new Error('Header length extends beyond buffer');
  }

  const headerJson = buf.subarray(headerStart, headerEnd).toString('utf-8');
  let header: Record<string, unknown>;
  try {

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