gchq/CyberChef · error · OperationError

${error}

Error message

${error}

What it means

Protobuf Encode delegates to Protobuf.encode and wraps any thrown error in an OperationError surfaced as ${error}. Encode failures come from JSON that does not conform to the .proto schema: wrong field types, unknown field numbers, missing required fields, an invalid schema, or values that cannot be encoded (e.g. non-integer for an int64 field). The wrapper normalizes internal library errors into CyberChef's OperationError channel.

Source

Thrown at src/core/operations/ProtobufEncode.mjs:48

                name: "Schema (.proto text)",
                type: "text",
                value: "",
                rows: 8,
                hint: "Drag and drop is enabled on this ingredient"
            }
        ];
    }

    /**
     * @param {Object} input
     * @param {Object[]} args
     * @returns {ArrayBuffer}
     */
    run(input, args) {
        try {
            return Protobuf.encode(input, args);
        } catch (error) {
            throw new OperationError(error);
        }
    }

}

export default ProtobufEncode;

View on GitHub (pinned to 4290ea7539)

Solutions

1. Ensure the .proto schema is valid (validate with protoc).
2. Match JSON field names/numbers and types to the schema exactly.
3. Read the wrapped ${error} message — it identifies the offending field/type.
4. Start with 'Show Types' on a decode of a known-good message to learn the expected shape, then encode to match.

Example fix

// before: string where int64 expected
run({ id: "abc" }, [schema]);

// after: numeric value matching schema
run({ id: 123 }, [schema]);

// Validate schema parses and JSON keys match declared field numbers/types before encoding.
import protobuf from "protobufjs";
async function schemaIsValid(protoText) {
  try { await protobuf.parse(protoText); return true; } catch { return false; }
}

function isPlainObject(v) {
  return typeof v === "object" && v !== null && !Array.isArray(v);
}

try {
  return protobufEncode.run(inputObj, [schema]);
} catch (e) {
  // e.message is the wrapped Protobuf.encode error; fix the offending field
  throw e;
}

When it happens

Trigger: Passing a JSON object whose keys/types do not match the .proto schema; an unparseable schema; a field value of the wrong type (string for an int field); missing required fields; enum values outside the declared set.

Common situations: Schema/data mismatch (encoding against a different schema than the producer used); hand-written JSON with typos in field names or numbers; an empty or invalid .proto; values like floats where integers are required.

Related errors

• ${err}
• Schema Error: Schema not defined
• Input Error: ${error}
• Schema ${error}
• Input ${error}

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/219eaa9259bf9f3f. Report an issue: GitHub.