> There was a time when the NSA was in the white hat business; securing networks, identifying vulnerabilities and contributing to net sec projects. SELinux has been their most famous contribution. This all changed with the war on terrorism. Finding and exploiting vulnerabilities was the mission.

No, they've always had both roles. For instance, their experience and knowledge of advanced code-breaking techniques allowed them to strengthen the DES cipher's S-boxes in ways that weren't publicly understood until decades later.

https://en.wikipedia.org/wiki/Data_Encryption_Standard#NSA%2...