The CIA/BND connection wasn't known, but the collusion with certain agencies was known to different degrees for decades: https://en.wikipedia.org/w/index.php?title=Crypto_AG&oldid=7...
https://robert.sesek.com/2014/10/nsa_s_eci_compartments.html
> HISTORY HST NCSC (TS//SI//NF) Protects NSA and certain commercial cryptologic equipment manufacturer relationships.