gchq/CyberChef · error · OperationError

${err.toString()}

Error message

${err.toString()}

What it means

Generic catch-all thrown by BSONSerialise.run when either JSON.parse(input) or the bson serialize() throws. The operation first parses the input as JSON, then serialises the resulting value to BSON; a JSON syntax error or a value BSON cannot represent (e.g. deeply nested object, unsupported type, key containing a null byte) surfaces as the original Error.toString() in the message.

Source

Thrown at src/core/operations/BSONSerialise.mjs:44

        this.inputType = "string";
        this.outputType = "ArrayBuffer";
        this.args = [];
    }

    /**
     * @param {string} input
     * @param {Object[]} args
     * @returns {ArrayBuffer}
     */
    run(input, args) {
        if (!input) return new ArrayBuffer();

        try {
            const data = JSON.parse(input);
            const result = serialize(data);
            return result.buffer.slice(result.byteOffset, result.byteOffset + result.byteLength);
        } catch (err) {
            throw new OperationError(err.toString());
        }
    }

}

export default BSONSerialise;

View on GitHub (pinned to 4290ea7539)

Solutions

1. Validate the input as well-formed JSON first (e.g. with a JSON linter or JSON.parse in isolation).
2. Ensure all values are BSON-compatible types (use strings/dates for large numbers).
3. Inspect the forwarded Error.toString() message for the exact parse or serialise failure.

Example fix

// before - single quotes / unquoted keys
chef.bSONSerialise("{a: '1'}");

// after - valid JSON
chef.bSONSerialise('{"a":1}');

function assertJsonForBson(input) {
  let data;
  try { data = JSON.parse(input); } catch (e) {
    throw new Error(`Input is not valid JSON: ${e.message}`);
  }
  if (data === undefined) throw new Error("JSON parsed to undefined; not BSON-representable");
  return data;
}
assertJsonForBson(input);

function isParsableJson(s) {
  try { JSON.parse(s); return true; } catch { return false; }
}

try {
  chef.bSONSerialise(input);
} catch (e) {
  if (/JSON|position|Unexpected/i.test(e.message)) {
    throw new Error(`Invalid JSON for BSON: ${e.message}`);
  }
  throw e;
}

When it happens

Trigger: Input that is not valid JSON (trailing comma, unquoted keys, single quotes), or valid JSON whose values are not BSON-representable (e.g. very large numbers losing precision, undefined, functions, or symbol-keyed objects).

Common situations: Pasting hand-written JSON with syntax errors; feeding a JS object literal instead of JSON; numbers exceeding BSON's 64-bit integer range; keys with null bytes.

Related errors

• ${err.toString()}
• Unable to stringify YAML: ${err}
• Could not encode JSON to MessagePack: ${err}
• Unsupported QR code format.
• Invalid hash

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/ca242da57f26ddf6. Report an issue: GitHub.