14 Jul
2017
14 Jul
'17
6:07 p.m.
Hi,
What is the BAUD rate of the phone clock? You must know it for sniffing the communication
between the phone and SIM card. And does Wireshark output all the communication between
the phone and the SIM card? Please let me know.
Thanks,
Vishal
14 Jul
14 Jul
6:40 p.m.
On 14. Jul 2017, at 18:07, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi,
Hi Vishal,
What is the BAUD rate of the phone clock? You must know it for sniffing the communication
between the phone and SIM card. And does Wireshark output all the communication between
the phone and the SIM card? Please let me know.
It depends on the ATR. SIMtrace firmware sniffes and then adjusts clock. Have a look at
the sourcecode.
What do you think is missing in wireshark?
holger
6:54 p.m.
On 14. Jul 2017, at 18:50, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi Holger,
Hi!
please don't take a public discussion private. It is considered rude in the FOSS
community. But I (and others) offer consulting services too.
So I receive the ATR at 9600 Baud rate. After that I
send the APDU commands in the exact order I see in Wireshark. One SIM card responds
exactly as I see in Wireshark. Few other SIM cards don’t respond after ATR. So I want to
know how the phone does it and want to verify that Wireshark is not missing something
after ATR. This is the reason I want to know the baud rate of the phone clock.
Where exactly should I look at the source to figure out the Baud rate of the phone?
http://git.osmocom.org/openpcd/tree/firmware/src/simtrace/iso7816_uart.c#n1…
follow the usage of the fi_table and di_table
7:13 p.m.
Hi,
Sorry about that. Didn’t realize I was taking it private. I’ve a couple more questions. If
the ATR comes back at 9600, doesn’t it stay the same until we send PPS?
So I went through that link, according to that, after ATR, we use the Fi and Di values to
calculate UART Baud rate and send commands in that rate? But I want to know what baud rate
the phone uses? Does it change using PPS? Wireshark doesn’t show any PPS after ATR. Does
that mean the phone read the ATR and adjusted the clock accordingly? Basically I’m trying
to sniff the entire phone communication to SIM in a file and I need the correct Baud rate
to do that?
Thanks,
Vishal
On Jul 14, 2017, at 9:54 AM, Holger Freyther
<holger(a)freyther.de> wrote:
On 14. Jul 2017, at 18:50, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi Holger,
Hi!
please don't take a public discussion private. It is considered rude in the FOSS
community. But I (and others) offer consulting services too.
So I receive the ATR at 9600 Baud rate. After
that I send the APDU commands in the exact order I see in Wireshark. One SIM card responds
exactly as I see in Wireshark. Few other SIM cards don’t respond after ATR. So I want to
know how the phone does it and want to verify that Wireshark is not missing something
after ATR. This is the reason I want to know the baud rate of the phone clock.
Where exactly should I look at the source to figure out the Baud rate of the phone?
http://git.osmocom.org/openpcd/tree/firmware/src/simtrace/iso7816_uart.c#n1…
follow the usage of the fi_table and di_table
7:23 p.m.
On 14. Jul 2017, at 19:13, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi,
Hi!
Sorry about that. Didn’t realize I was taking it
private. I’ve a couple more questions. If the ATR comes back at 9600, doesn’t it stay the
same until we send PPS?
Right.
So I went through that link, according to that, after
ATR, we use the Fi and Di values to calculate UART Baud rate and send commands in that
rate? But I want to know what baud rate the phone uses? Does it change using PPS?
Wireshark doesn’t show any PPS after ATR. Does that mean the phone read the ATR and
adjusted the clock accordingly? Basically I’m trying to sniff the entire phone
communication to SIM in a file and I need the correct Baud rate to do that?
You are right. If you look at process_byte it will not forward PTS related bytes (goto
out_silent). At least in the debug output of the SIMtrace you should be able to see fi/di
changes.
holger
10:50 p.m.
Hi Holger,
Well I looked into the code and figured ATMEL MCU used here takes Fi/Di as an input
parameter for setting it’s UART. My question how do you figure the phone clock speed and
baud rate?
I know that Baud Rate = Phone clock speed/(Fi/Di). So I need to know these parameters to
sniff communication.
My Goal is to sniff the entire process of phone communication with SIM and store in a
File. For that I need to know the phone’s clock speed and Baud rate of UART at different
times.
Thanks,
Vishal
On Jul 14, 2017, at 10:23 AM, Holger Freyther
<holger(a)freyther.de> wrote:
On 14. Jul 2017, at 19:13, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi,
Hi!
Sorry about that. Didn’t realize I was taking it
private. I’ve a couple more questions. If the ATR comes back at 9600, doesn’t it stay the
same until we send PPS?
Right.
So I went through that link, according to that,
after ATR, we use the Fi and Di values to calculate UART Baud rate and send commands in
that rate? But I want to know what baud rate the phone uses? Does it change using PPS?
Wireshark doesn’t show any PPS after ATR. Does that mean the phone read the ATR and
adjusted the clock accordingly? Basically I’m trying to sniff the entire phone
communication to SIM in a file and I need the correct Baud rate to do that?
You are right. If you look at process_byte it will not forward PTS related bytes (goto
out_silent). At least in the debug output of the SIMtrace you should be able to see fi/di
changes.
holger
16 Jul
16 Jul
11:54 p.m.
On Fri, Jul 14, 2017 at 08:50:27PM +0000, Vishal Vaidhyanathan wrote:
Hi Holger,
Well I looked into the code and figured ATMEL MCU used here takes Fi/Di as an input
parameter for setting it’s UART. My question how do you figure the phone clock speed and
baud rate?
the ISO7816 mode of the USART peripheral is used, where the micro-controller doesn't
need to know the clock speed.
compared to UART where both sides need to know the clock speed (asynchronous mode), in
ISO7816 mode there is a dedicated clock signal provided by the phone (synchronous mode)
and the bit is sampled on the rising edge of the clock (no matter the frequency).
the phone (i.e. the master) can change the frequency (1 to 5 MHz at the beginning) while
communicating.
if you are using a simple UART adapter you would have to synchronise to the clock signal
(or measure its frequency using a timer, most of the time this works too).
17 Jul
17 Jul
8:58 p.m.
Hi Holger,
You said simtrace doesn’t show PTS related information. Is there an option to enable it
and see it on Wireshark? How do I enable debug mode?
Thanks,
Vishal
On Jul 14, 2017, at 10:23 AM, Holger Freyther
<holger(a)freyther.de> wrote:
On 14. Jul 2017, at 19:13, Vishal Vaidhyanathan
<Vishal.Vaidhyanathan(a)privoro.com> wrote:
Hi,
Hi!
Sorry about that. Didn’t realize I was taking it
private. I’ve a couple more questions. If the ATR comes back at 9600, doesn’t it stay the
same until we send PPS?
Right.
So I went through that link, according to that,
after ATR, we use the Fi and Di values to calculate UART Baud rate and send commands in
that rate? But I want to know what baud rate the phone uses? Does it change using PPS?
Wireshark doesn’t show any PPS after ATR. Does that mean the phone read the ATR and
adjusted the clock accordingly? Basically I’m trying to sniff the entire phone
communication to SIM in a file and I need the correct Baud rate to do that?
You are right. If you look at process_byte it will not forward PTS related bytes (goto
out_silent). At least in the debug output of the SIMtrace you should be able to see fi/di
changes.
holger
2499
days inactive
2502
days old
7 comments
3 participants
participants (3)
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Holger Freyther -
Kévin Redon -
Vishal Vaidhyanathan