Password Manager

Phase 1 — Vault basics & crypto setup

  • Create a single vault file pwmanager.db (SQLite) with a single table: website, username, encrypted_password, created_at, updated_at.
  • Derive an encryption key from <master_password> using a secure KDF with a stored random salt.
  • Encrypt/decrypt the password field using an authenticated cipher (e.g., AES-GCM or equivalent).

Functional result: First run creates the vault; adding one sample entry and reading it back (with the same master) returns the original plaintext password.

Phase 2 — CLI & core operations

  • Parse: pwmanager.py <master_password> -add <website> <username> <password>, -get <website>, -remove <website>, -list.
  • -add inserts or updates the site entry; -get prints username + decrypted password; -remove deletes the site; -list prints website + username only.
  • Update created_at on first insert and updated_at on changes.

Functional result: Running the four sample commands creates an entry, retrieves it in plaintext, lists sites without passwords, and removes the entry exactly as specified.

Phase 3 — Master verification & data consistency

  • On startup, verify the master password by attempting a controlled decryption (e.g., a canary/known record); abort if it fails.
  • Enforce one entry per website (unique constraint) so -add behaves as upsert.
  • Keep timestamps consistent and store data as UTF-8.

Functional result: Supplying a wrong master cleanly stops any operation; re-adding an existing site updates its password and timestamp while preserving a single row per site.

Phase 4 — Light UX & Error handling

  • Default vault location is the current directory; create it on first use.
  • Display simple, readable console messages for each operation.
  • Minimal error handling: show a concise usage hint on bad/missing args and a clear message on failed decryption (wrong master/corrupt entry).

Functional result: Typical mistakes (missing args or wrong master) produce short, clear messages without corrupting the vault; valid commands complete and persist correctly.