In Ghidra, search for the string "FROSTY_KEY" → cross‑reference to a function get_encryption_key() .
So the hardcoded key = . 5. Decrypting the Config The file frosty_config.bin is provided. frosty mod encryption key
char* get_encryption_key() char *env_key = getenv("FROSTY_KEY"); if (env_key != NULL && strlen(env_key) == 32) return env_key; // Hardcoded fallback key (hex string) return "5f4dcc3b5aa765d61d8327deb882cf99"; In Ghidra, search for the string "FROSTY_KEY" →
from Crypto.Cipher import AES import binascii def decrypt_frosty_config(enc_file, key_hex): key = binascii.unhexlify(key_hex) with open(enc_file, 'rb') as f: iv = f.read(16) ciphertext = f.read() Decrypting the Config The file frosty_config
That hex string 5f4dcc3b5aa765d61d8327deb882cf99 looks like an MD5 hash. Decode it as ASCII? No – it’s 32 hex characters → 16 bytes when decoded → likely the AES‑128 key. Further reversing shows the config file is encrypted with AES‑128‑CBC , IV is the first 16 bytes of the file.
[!] Missing encryption key. [+] Key loaded from environment variable FROSTY_KEY. [...] But the challenge states the key is hardcoded – so maybe a fallback exists.