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[cporter]

Hi,

I would like to share some thoughts upon which I have been pondering for the last few weeks. I am sure that I'll get some positive feedback from this forum. So let me start (there's no particular ordering):

1. STK Triggers
------------------

There are many ways on how one may access an STK app on TurboSIM (or SIM card for that matter), including: ECMAScript + EFI (which is not so documented, except for generic non-techical standards), STK Triggers (e.g. SMS with a particular header), Direct user invocation through STK Menu, and so on.

I am aware that a number of STK triggers exist, but would it be possible that an STK Application is automatically loaded (triggered) with a particular value (parametrized), after an SMS is sent from another terminal (authentication server)? And are there any limitations or conditions for this to work properly?

How does Turbo STK API handle this? What special properties are required on both the Short message formulation and also on the STK application trigger registrations? Are there any demos with this regard?


2. Cryptographic Capabilities
---------------------------------

Having seen the ECC Key Signing example application provided within the Turbo Packages, I would like to clarify some aspects:

It isn't apparently clear how the message hashing is being carried out. Is there any documentation on both technical and usage aspects of the application?

I am aware of the need for EEPROM storage through the usage of reg_app_data() and app_data(). But is that the way one can store the private keys on TS? What are the best practices suggested?


3. STK Publications
----------------------

Are there any specialized forums/publications for SIM Application Toolkit development? I have encountered the following book:

Mobile Application Development with SMS and the SIM Toolkit - Guthery and Cronin, but it is tailored around the SmartTrust Toolkit.


I thank you all in advance.

Regards,

Chris Porter

[pz]

[cporter]

Hi,

The analysis on how to create a 3-state process as described in the use case (above) proved to be feasible, or rather, achievable.

I've created an STK application which is triggered by a server-side message (SMS) sent using DCS 0xF6 and PID 0x00. THis in turn is to allow the user to sign some information and sends it back to the server.

There is one issue here (which may be extremely trivial), which is keeping me from proceeding further:

If I send the message using the normal SMS DCS and PID, the user gets to read whatever has been sent by the server in clear text (e.g. "Transaction 203").

But, if I send the TSMS/SMS over 0xF6 and 0x00, then issues arise:

- Although the app is triggered, I cannot read the message properly (so as to store into a msg variable for further processing). I am only getting the famous characters which in no way are related to the original message. I am assuming that it has something to do with pointer manipulation in C, but I have followed all example applications provided (such as pager.c, procsms.c, locserver.c, smspal.c), unfortunately, all in vain.

- I am trying to get to the tpdu, and then use tpdu_seek(s, T_SMS_UD), from which I then memcpy into my msg var.

- When I send messages using TSMS, I get the same behavior, or worse. The message is not silently recieved... Moreover, after I skip_head(paramData), I still do not get the user data (but some sort of uninitialized memory location dump).

Can you please guide me further into this area? Do you have any example application which displays the T_SMS_UD section recieved, on the ME's display? I just want to prompt the user with the following server side text:

"Please verify the following data: [I have to extract the message content and place it here] ".

I thank you beforehand for your time!

Regards,

Chris

[pz]

[cporter]

Hi Pavel,

I thank you for your reply.

[pz]

[cporter]

Good morning Pavel,

The following are some code extracts I have been using to create a 2-way communication channel between an STK Client and SMS Server (Although it is not technically correct to call it a Client/Server app). |

As a sending mechanism, both from Client ME and also from SMS Gateway, the following command set is being used:

res = send_sms (msg, msg_len, ms, MSISDN_ADN, 0xF6, 0x00, NULL, NULL);

.. whereby msg is being generated by another section of the application (both at the client and at the serving side)

On the recieving side (ME), the following code is being used:

void mt_eventSMSHandler(File_apdu_data * fd)
{

//As suggested by all rec_sms methods in example code
u8 *t;
u8 *data = fd->data;
u8 i;
u16 j;
u8 *s;
u8 *msg;

//------- reaching TPDU ---------------
s = data;

// Skip State
s++;
i = *s;

// Skip SMSC Address
s += i + 1;
i = *s;

//Initialize Msg variable
msg = malloc (161);
if (msg)
{
//Obtain length of User Data
t = tpdu_seek (s, T_SMS_UDL);
i = *t;

//Get SMS Body
memcpy (msg, t + 1, 140);

//Given that it was sent using 0xF6, convert back to default alphabet
dcs_78 (msg, i, DCS_8_TO_7);

//Should be \0 terminated?
msg[i] = '\0';
}

display_text(locale(lc_Confirm_Transaction), NULL);
display_text (msg, NULL);

//Trigger another method
stk_thread (smsSignData, NULL);
}

Through the above approach, the message being displayed is somehow composed of the extended characters found in the Default Alphabet table (6.2.1 of 03.3. Hence, being illegible.

I am quite sure that I am overlooking some details here. Any suggestions on how I should be re-constucting the message body?

I thank you in advance for your time.

Yours,

Chris

[pz]

[cporter]

Hi Pavel,

[pz]

[cporter]

Hi Pavel,