docker compose up --buildLocal development instructions are in the READMEs of the subdirectories.
back/Go APIfront/Next.js TypeScript frontendrp/Caddy reverse proxy
Go was chosen for its simplicity and speed.
The key-value db badger, was used because of its speed and the nature of the data being stored and queried (only checking the existence of a key in the dataset is needed). The DB lives in the same Go process as the HTTP server.
If there ever were a need to share the DB between several back-end instances, the code should easily be extractable into a separate service. However, it wasn't given much further considerations since network queries would add some latencies and our dataset should fit in most instance memory and hence allow for a quick and easy horizontal-scaling, should it be needed.
The rockyou.txt file is automatically downloaded as a convenience. And for local development, an
environment variable ROCKYOU_PATH can be set to point the file.
When loading the DB, we check if the DB was already loaded by checking for a key's existence. If it's not, we read the file, hash every password and store them in the DB.
The back has two routes, one for searching a whole password with its hash and another for searching a password with its hash prefix.
The first route was the first way this service was built and is kept as an example, but isn't used by the actual front-end.
The second route is the one used by the front-end and uses the same mechanism as the original project (Cloudflare, Privacy and k-Anonymity) to anonymize the passwords queried.
The hash used is xxh128 with a 128-bit digest.
The front uses Next.js in TypeScript.
Typescript was used for its type safety over JavaScript.
Next.js was chosen for its simplicity, quick setup, and previous knowledge of React.
HeroUI was used for the interactive components.
caddy was used as a reverse proxy in order to serve both the front and the api on the same address.
It also sets some HTTP cache headers and compresses responses (~50% size reduction).