On 2020-07-14, Lévai Dániel <[email protected]> wrote: > I'm trying to implement pledge(2) support into kc(1) (in ports) while using > it with a Yubikey. > So far this is my pledge string: > char *pledges = "cpath exec fattr flock proc rpath stdio tty unix > wpath"; > > This covers everything it would do without the Yubikey. But I can't seem to > find the proper "promise" that would allow it to use the Yubikey (I've tried > adding everything at one point). > The application dies with (on -current): > Abort trap (core dumped) > kc[35302]: pledge "tty", syscall 54
Most ioctls are blocked by pledge. To do this, you'll either need to avoid pledge completely, or handle device communications with a separate process that remains unpledged. > 35302 kc RET open -1 errno 13 Permission denied > 35302 kc CALL kbind(0x7f7ffffede88,24,0x18365a7b5e816bae) > 35302 kc RET kbind 0 > 35302 kc CALL open(0x7f7ffffee1f0,0x2<O_RDWR>) > 35302 kc NAMI "/dev/usb1" > 35302 kc RET open 7 > 35302 kc CALL kbind(0x7f7ffffede88,24,0x18365a7b5e816bae) > 35302 kc RET kbind 0 > 35302 kc CALL ioctl(7,USB_DEVICEINFO,0x7f7ffffedf50) > 35302 kc PLDG ioctl, "tty", errno 1 Operation not permitted > 35302 kc PSIG SIGABRT SIG_DFL > 35302 kc NAMI "kc.core" > > > I don't know if this matters, but for even ykinfo(1) (in the ykpers port) to > work, I had to: > # chmod g+w /dev/usb1 > # chmod g+rw /dev/ugen0.00 Known problem, there's no nice way around it though. The standard model used on most OS of controlling many simpler USB devices from a low privileged userland process does not work too well with the approach in https://cvsweb.openbsd.org/src/etc/MAKEDEV.common#rev1.105 afaik the options for this are chmod, run as root, or write a driver that works similar to fido(4) and modify the existing software that interfaces with the device to use that instead (I guess for yk it will need a way to hook into the keyboard driver too for the usual button-press keyboard emulation otp mode).
