Building Def Con Ctf With Ruby
summary
A Ruby-based scoreboard runs on Ruby on Rails + Unicorn on Heroku backed by Postgres and New Relic, serving 24 qual challenges (Sinatra, x86, ARM) and finals that tie 20 teams to on-site ARM boxes and odroid servers. Finals deposit 50,000 flags, 5-minute rounds; scoring scripts run every round with a parallel worker rewrite after I/O problems. Known failures include a missing Postgres index that doubled points, unreclaimed flag remainders that skewed rankings, and flaky EC2 micros versus reliable Raspberry Pi arm challenges. Logging uses Kibana/Elasticsearch; client SSH auth is burned to CDs.
AI-written summary · about
chapters (14)
- 0:00Intro
- 0:47What is DEF CON?
- 2:04Attack Defense CTF
- 3:14Sample Challenges
- 3:56Team Building
- 6:47Quals Scoreboard
- 8:23Quals Challenges
- 9:02ARM Challenges
- 9:15Quals Problems
- 14:15Finals Scoring
- 14:49Finals Scoreboard
- 16:16Tokens and Uptime
- 17:12Finals Problems
- 19:59Finals Team Boxes
