mischard
good-vibes
dicectf_2026
Task: Analyze PCAP with custom VPN traffic (VibePN). Solution: Reverse-engineered VPN client revealed broken key derivation using LCG seeded with time(0) instead of ECDH result; brute-forced timestamp to recover AES-256-GCM session key and decrypt chat containing flag.
$ ls tags/ techniques/
reverse_engineeringopensslpcapudplcgcustom_protocolvpnaes_gcmecdhlinux_cooked_capturechat_extractionvibe_coding
lcg_key_recoveryaes256_gcm_decryptionpcap_traffic_analysiscustom_vpn_protocol_reversingbinary_reverse_engineeringtimestamp_bruteforce
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