got it.... i thought you meant that in a general term, for other APDU
commands such as GET RECORD or BINARY READ
sending PROCEDURE would not help as REMOTE SIM side will not start
sending data until after we ACK with INS and subsequent
bytes are obtained and relayed to remote before it will start answering
On 11/10/17 1:38 AM, Harald Welte wrote:
Hi Thomas,
On Thu, Nov 09, 2017 at 08:59:45PM -0500, Thomas Chen wrote:
my understand of the protocol is that
ME => SIM (first 5 bytes of APDU)
SIM <=== PROCEDURE (either INS as ack, or 0x60 to hold up the protocol)
but that does not help remote sim, as remote SIM would need the susequent bytes
which will not come until we send back INS, so just holding off ME with 0x60
does not alleviate the problem of network delay
you don't hold off the ME at
that point. Presuming it is "RUN GSM ALGORITHM"
command, then the actual command from ME to card continues here with the random
challenge.
Later, a GET RESPONSE is issued from ME to SIM to obtain the SRES + Kc values,
and this is where we can delay with waiting time extension (0x60) until we
have the result.