ACS ACR122U LED/Buzzer settings - nfc

I'm having issues trying to set the LED and buzzer using APDUs on an ACR122U (firmware version 2.1.5).
This command should set the Buzzer Output for Card Detection, but I always get an error response:
> FF 00 52 00 00
< 63 00
Also, when trying to use one of the examples from the official documentation (v 2.04), I don't get the expected behavior, and the wrong response code (should be 90 02):
> FF 00 40 50 04 05 05 03 01
< 90 03
Other commands, like reading the firmware version, work as expected:
> FF 00 48 00 00
< 41 43 52 31 32 32 55 32 31 35
Has anyone had the same issues before?

Buzzer Output for Card Detection
I have two older versions of this reader here that do not seem to have a buzzer. Both of these readers always return 63 00 for that command. I'm not quite sure why this command might fail on versions that do have a buzzer though. However, looking at diffferent versions of the ACR122U API documentation, this command was only added in later versions of the reader.
Bi-color LED and Buzzer Control
The status code that you receive will only reflect the current state of the LEDs after you set the final state of the LEDs at least once. E.g. to set the final state off:
FF 00 40 0C 04 00 00 00 00

Related

NSIS installer defaults to previous startup preferences

Im able to install application with NSIS installer and later I update TaskManager->Startup preferences to disabled. After I uninstall and reinstall the application, Startup preferences defaults to previous user preference of "disabled". I want the installer to enforce Enabled always after new install, so application startups on reboot. How to achieve this with NSIS coding.
Thanks
I believe Microsoft wants this to be a purely user-controlled setting, but in any case the method Task Manager uses is to modify the appropriate REG_BINARY value in the following registry locations in either HKEY_CURRENT_USER or HKEY_LOCAL_MACHINE, as appropriate:
SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run
SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run32
SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\StartupFolder
Enabled items contain the data:
02 00 00 00 00 00 00 00 00 00 00 00
or
06 00 00 00 00 00 00 00 00 00 00 00
Disabled items contain data starting with 03000000... or 07000000... and followed by some hex values [perhaps it's a timestamp?], e.g.:
03 00 00 00 F4 0B 28 C9 9D 79 D1 01
I'm unclear what the distinction is between the ones that start with 02 and 06, but it seems 02s become 03s and 06s becomes 07s when disabled.
To ensure your startup item is enabled, either use WriteRegBin to set it back to 020000000000000000000000 or 060000000000000000000000, or just use DeleteRegValue and delete the value entirely.

Using registers to specify memory to read with LLDB

I'm trying to teach myself assembly, and am using LLDB to debug. So far, so good, but I'm wondering whether there's a quick way to inspect the memory at an address stored in a register?
Of course, I can do
register read rbp
(for example), and then use the address via
memory read <address> ...
but really I'd like to use the register name directly in the arguments to the 'memory' command (possibly with an offset). That seems like a natural thing to want to do, but so far I haven't been able to find anything about this.
You can use
(lldb) x $eax
0x799be060: f0 e6 1c 01 04 00 00 00 88 23 04 00 98 23 04 00 .........#...#..
0x799be070: a8 23 04 00 b8 23 04 00 00 00 00 00 00 00 00 00 .#...#..........
To see the memory contents displayed as e.g. 4 floats, use
(lldb) x/4f $eax
0x799be060: 0.0000000000000000000000000000000000000288183643
0x799be064: 0.00000000000000000000000000000000000000000000560519386
0x799be068: 0.000000000000000000000000000000000000000380088195
0x799be06c: 0.000000000000000000000000000000000000000380110616

Cann't Access NFC Card in SDK on windows 7

I have ACR122U reader and Mifare1k card, When I try sdk on windows 7 It's can't access the card, But XP It's can.(XP test in VMware)
result in Mifare Programming(SDK Project)
I can Initialize and get Reader name but I can't Connect the card.(on Windows 7)
Program ready
?
?
When I try on XP I can get Reader name, connect card, load authen key and authen key.
Program ready
Successful connection to ACR122 0
<FF 82 00 00 06 FF FF FF FF FF FF
>90 00
<FF 86 00 00 05 01 00 00 61 01
>90 00
Authentication success!
*in ACR122UTool(application come with sdk),It's not sdk, but It's can send Direct command and got a result.(run on windows 7)
ACR122U PICC Interface
Connected to : ACS ACR122 0
ACR122U APDU Command
< FF 82 00 00 06 FF FF FF FF FF FF
> 90 00
ACR122U APDU Command
< FF 86 00 00 05 01 00 00 61 01
> 90 00
I don't understand, code from sdk can't access the card but application come with sdk can access the card and read write to card(run on windows 7)
PM. Sorry for my Eng (-_-")

How do I see full strings in dtruss output?

I am using dtruss on MacOS X 10.8.5 in an attempt to see the conversation between a running application and an SSL server it talks to. Unlike strace on Linux, I'm not seeing full strings of data in the output, like I would expect to find as the program does send and recv on the file descriptor.
How can I get dtruss to show me the data which the app is sending and receiving with the SSL server?
Before anyone tells me to proxy the connections to an SSL server I control, yes I know this trick, and no this particular app is too smart to fall for it.
dtruss is both an elegant example of a script written for DTrace and a demonstration of what DTrace can accomplish. However, although its similarity to truss or strace is deeply welcome on the relatively barren OS X, I suspect that dtruss was never intended to be a complete substitute for either.
In any case, your question is a bit ambiguous: I'm not sure whether you are concerned that the strings that you see are truncated or that you don't see any strings at all for sendto() or recvfrom() (the underlying interfaces revealed by DTrace). I'll address both.
Firstly, DTrace collects data in the kernel; user-land buffers are obtained with the D language's copyin() or copyinstr() before being recorded and transmitted back to the consumer --- typically the dtrace(1) command. DTrace requires that its kernel buffer size be known at compile-time and therefore imposes a limit on the otherwise unpredictable length of a string. This limit is 256 bytes by default; if you are seeing truncation then you could change the limit by adding, e.g.,
#pragma D option strsize=512
below dtruss's existing pragma.
Secondly, dtruss is hard-coded to know about the formatting requirements of a variety of system calls. You don't see any buffer interpretation for sendto() or recvfrom() in its output because they're not handled explicitly in the source. There's nothing to stop you finding somewhere suitable to add them but you could instead write your own script:
bash-3.2# cat sr.d
#pragma D option rawbytes
syscall::sendto:entry,
syscall::recvfrom:entry
/pid == $target/
{
self->bufp = arg1;
self->size = arg2;
}
syscall::sendto:return,
syscall::recvfrom:return
/pid == $target && self->bufp && self->size/
{
printf("%s():\n", probefunc);
tracemem(copyin(self->bufp, self->size), 64);
printf("\n");
self->bufp = self->size = NULL;
}
bash-3.2# dtrace -qs ./sr.d -p 16988
sendto():
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
0: 68 65 6c 6c 6f 00 00 00 00 00 00 00 00 00 00 00 hello...........
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
^C
bash-3.2#
Note that, as for strings, we're obliged to provide a hard limit on tracemem()'s use of DTrace's data-recording buffer. If the limit is rarely approached then this has the irritating result that the output can be overwhelming and mostly redundant. If you know that you're looking for strings then you could simply use copyinstr() instead; if you have a more modern DTrace implementation than my OS X 10.6.8 then you may find that you can write
tracemem(copyin(self->bufp, self->size), 64, self->size);
where the second argument is still a hard limit on the number of bytes recorded but the number of bytes displayed is limited by the optional third argument.
Finally, note that the user-land address is recorded on entry to the system call but used only on exit. This is a common idiom that allows the system call to fault-in the data if necessary --- DTrace won't do so itself and will produce an error at run-time if asked to trace a non-resident address.

Firefox breaks pdf after download

Our web application provides ability to download pdf.
When user clicks on download link we open the pdf in a new tab.
My firefox uses pdfjs as a pdf viewer and I can save pdf through it's interface.
Everything was fine in Firefox 19, but version 24 download file which looks like corrupted (it displays that file, but can't download it correctly).
I noticed that result size of file is a nearest power of 2, for example if my original pdf size is 97kb then after downloading it through Firefox's pdfjs its size becomes 128kb and my desktop pdf viewers (like acrobat) can't open it.
I tested it on the same version of our app.
update
Demo pdf file - everything is fine with downloading through linux google chrome viewer and linux firefox 21 (pdfjs), but the same problem with linux firefox 23.0.1
Is something wrong with pdfjs or with our server?
update #2
I looked at binary contents of broken and not-broken file:
$ git diff not-broken.dump broken.dump
diff --git a/not-broken.dump b/broken.dump
index 3621089..5de337c 100644
--- a/not-broken.dump
+++ b/broken.dump
## -336,5 +336,7 ##
000014f0 b8 d0 3d 76 85 f8 76 9d e6 50 74 df e7 a7 bd b0 |..=v..v..Pt.....|
00001500 00 f1 6e 05 63 0a 65 6e 64 73 74 72 65 61 6d 0a |..n.c.endstream.|
00001510 65 6e 64 6f 62 6a 0a 73 74 61 72 74 78 72 65 66 |endobj.startxref|
-00001520 0a 35 32 31 33 0a 25 25 45 4f 46 0a |.5213.%%EOF.|
-0000152c
+00001520 0a 35 32 31 33 0a 25 25 45 4f 46 0a 00 00 00 00 |.5213.%%EOF.....|
+00001530 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+*
+00010000
What we have here is a genuine bug. I filed: https://github.com/mozilla/pdf.js/issues/3634
Since the data transfer does not specify a content-length, but uses chunked transfer encoding, pdf.js will use an initial buffer of 64kb that is doubled each time it would overflow. However, once the transfer is complete pdf.js will not shrink that buffer to the actual size, nor will it remember the actual size, so that upon download the whole over-sized buffer (still the initial 64kb in your example) will be transferred.
I don't think there is a real work-around, short of not using pdf.js at all (which is a user choice).

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