Stage4verifier

The Stage4Verifier application is launched at startup by initrd to verify the integrity of the flashed dlink_boxee_runtime.img. If this check fails, the logo on the boxeebox will blink red and green and the only way to get the box back in working order is to reboot it into recovery-mode.

The binary is executed like:

/sbin/Stage4Verifier <file to verify> <signature file> <signature offset>

With the arguments in practise being the hardcoded (if you break out of the chroot jail):

/sbin/Stage4Verifier /ramtmp/p1/dlink_boxee_runtime.img /dev/spectra 70

or (if you don't break out fo the chroot jail)

./Stage4Verifier /dev/loop0 /dev/spectra 70

If the application is pulled off the boxee box and run on a linux i386 pc, you can use the dlink_boxee_runtime.img and run-time.sig from a boxee.iso like this:

./Stage4Verifier dlink_boxee_runtime.img run-time.sig 0

Public RSA key in PEM form

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvgigQMLWKQCxP6MMLNdK
aRMnzQx0WR5aVHGBqiNiwNShOoBhN0nXplECjyM6FvF+HDTLZ/OHjy+aUhOtf9eu
mP1exmeosJ9joDZyB4+JoJOXe1ZWrUzbD8/PzFZY5lNIUu0GXrOOhdpotQCKOzm0
KyK79gteawfkygYjsDWAFpikcI5Aavv5TbsA2hdLPokR8p5q36FlxlGuOhnU9smr
1plGZlzM56BpdVEdJv6DEysd/jxTYHRHUVwNNqM5wPw7vzX5Gs4+IYzlcaldGaKp
rm/Y22EiOF2nlx+ub6MZIG/DxGibCM0onigRn9g3/ldeuxL1boMLPXeH/f10QOas
NwIDAQAB
-----END PUBLIC KEY-----

Using the above key saved as public.pem, the Stage4Verifier functionality can be performed with the standard openssl command:

openssl dgst -sha256 -verify public.pem -signature run-time.sig dlink_boxee_runtime.img