A friend who is happening to write his own operating system just pointed out to me that a keyboard driver cannot use
- lookup tables, because timing accessing these lookup tables would yield information what key was pressed when entering a root password - tests and jumps, because the same would be possible with the BTB (branch target buffer). He said he had to write the whole driver using logical operation masking. Does OpenBSD also have this trick? How is the keyboard security designed in OpenBSD to prevent these covert channels leaking the information to an unprivileged process? CL<
