When tested smartcard redirection against Win8 rdesktop reported some messages to console: WARNING: Bogus smart card control code 0x00fd0028 But it seemed to work as expected while testing tlclient remotely and authenticate using pin code.
Seeing this with Windows 2012 R2 as well, but a different code: WARNING: Bogus smart card control code 0x00fd0048 (process:23216): pcsctun-WARNING **: Invalid control code 0x00fd0048. Refusing command.
rdesktop (and associated tools) is being removed from the ThinLinc product.