Some more information on the error with libmrtd

[Clemens Gruber]

Hello,

we found out that it is the iso7816_select_application(ih); function, 
called in read_mrtd function in the file libmrtd.c!

Going into this function, we identified the following part in 
iso7816_util.c as source of the error in the iso7816_select_application 
function:

  rv = ih->fn.transceive(ih, cmd, sizeof(cmd), (char *)resp, &rlen);

It always returns -1!

What could be the reason for this error?

Now we also have an USB-HUB with an extra power connector, so this could 
not be the problem.

Best regards,
Clemens