Unknown bool indicates if RST files has any encrypted translation(trenc) entries.
If first character is 0xFF (invalid utf-8 codepoint) entry is encrypted.
Following 0xFF is uint16_t size of encrypted data.
Encrypted data was stored as base64 encoded string in plain fontconfig .txt files.
Data decryption would require fetching blowfish key from server.
This check is only done if encrypted entries are enabled.
Unknown bool indicates if RST files has any encrypted translation(trenc) entries.
If first character is 0xFF (invalid utf-8 codepoint) entry is encrypted. Following 0xFF is uint16_t size of encrypted data. Encrypted data was stored as base64 encoded string in plain fontconfig .txt files. Data decryption would require fetching blowfish key from server. This check is only done if encrypted entries are enabled.
To verify this you can fetch pre-RST plain fontconfig .txt from patch 9.22: https://lol.secure.dyn.riotcdn.net/channels/public/releases/29BA35F0FD7A06C9.manifest
And compare against first RST fontconfig from patch 9.23: https://lol.secure.dyn.riotcdn.net/channels/public/releases/320E81449AFA5BD0.manifest