gchq/CyberChef · error · OperationError

Please provide an input.

Error message

Please provide an input.

What it means

Bzip2Compress requires at least one byte of input; an empty buffer has nothing to compress and the underlying emscripten module would error. The operation rejects empty input up front with a user-facing message.

Source

Thrown at src/core/operations/Bzip2Compress.mjs:53

                max: 9
            },
            {
                name: "Work factor",
                type: "number",
                value: 30
            }
        ];
    }

    /**
     * @param {ArrayBuffer} input
     * @param {Object[]} args
     * @returns {File}
     */
    async run(input, args) {
        const [blockSize, workFactor] = args;
        if (input.byteLength <= 0) {
            throw new OperationError("Please provide an input.");
        }
        if (isWorkerEnvironment()) self.sendStatusMessage("Loading Bzip2...");
        return new Promise((resolve, reject) => {
            Bzip2().then(bzip2 => {
                if (isWorkerEnvironment()) self.sendStatusMessage("Compressing data...");
                const inpArray = new Uint8Array(input);
                const bzip2cc = bzip2.compressBZ2(inpArray, blockSize, workFactor);
                if (bzip2cc.error !== 0) {
                    reject(new OperationError(bzip2cc.error_msg));
                } else {
                    const output = bzip2cc.output;
                    resolve(output.buffer.slice(output.byteOffset, output.byteLength + output.byteOffset));
                }
            });
        });
    }

}

View on GitHub (pinned to 4290ea7539)

Solutions

1. Provide non-empty input to the operation.
2. Guard the pipeline: skip compression when input.byteLength === 0.
3. Check the upstream step that should have produced data.

Example fix

// before
Bzip2Compress.run(emptyBuffer, args)
// after
Bzip2Compress.run(nonEmptyBuffer, args)

if (!input || input.byteLength <= 0) throw new Error('Bzip2Compress needs non-empty input');

function hasBytes(buf) { return buf && buf.byteLength > 0; }

When it happens

Trigger: Calling Bzip2Compress.run with an input ArrayBuffer whose byteLength is <= 0.

Common situations: Upstream operation produced empty output; user submitted an empty file; pipeline wired to an empty source.

Related errors

• Please provide an input.
• Data is not a valid ${Dish.enumLookup(type)}: ${sample}
• ${this.name} cannot be empty.
• ${this.name} length cannot exceed ${this.maxLength}.
• ${this.name} must be a number.

AI-assisted analysis of gchq/CyberChef@4290ea7539 (2026-08-13). Data as JSON: /api/errors/e577cddd5d96b523. Report an issue: GitHub.