I am trying to debug an issue where my data is stored in Azure Table Store as a byte[]. I am using the Cerebrata Azure Management Studio and it shows the byte[] column as:
16000000010000000E00000001010400000031343230
Does anyone know what format this is stored in? How can I convert this into a byte array? It does not look like a base 64 or UTF encoded string.
Haha... the data is literally stored as bytes, just in hex form.
i.e. 16000000010000000E00000001010400000031343230 is really:
16 00 00 00 01 00 00 00 0E 00 00 00 01 01 04 00 00 00 31 34 32 30
:-)
So the rest is trivial... I used a quick function like this:
var hex = "16000000010000000E00000001010400000031343230";
byte[] bytes = new byte[hex.Length/2];
for(int i=0; i<hex.Length;i+=2)
{
bytes[i/2] = byte.Parse(
hex.Substring(i, 2),
System.Globalization.NumberStyles.HexNumber);
}
Related
I'm trying to convert and write string data into the file as bytes.
I have already tried something to, but instead of seeing 00 inside hexdump, im seeing 0x30 inside file which is hexadecimal value for character 0.
Here is what I wrote:
local data = "000000010000000100000004000000080000000100000000"
for i=1,#data,2 do
file:write(tonumber(data:sub(i,i+1)))
end
io.close(file)
When I do hexdump of the file I'm getting this:
0000000 30 30 30 31 30 30 30 31 30 30 30 34 30 30 30 38
0000010 30 30 30 31 30 30 30 30
0000018
Expected is:
0000000 00 00 00 01 00 00 00 01 00 00 00 04 00 00 00 08
0000010 00 00 00 01 00 00 00 00
0000018
You want to use string.char in one way:
local data = "000000010000000100000004000000080000000100000000"
for i=1,#data,2 do
file:write(string.char(tonumber(data:sub(i,i+1), 16)))
end
io.close(file)
or another:
local data = string.char(0,0,0,1,0,0,0,1,0,0,0,4,0,0,0,8,0,0,0,1,0,0,0,0)
file:write(data)
io.close(file)
Note that strings in Lua may contain any bytes you want including null bytes. See Values and Types.
Hint: Use string.char to convert numbers to bytes:
file:write(string.char(tonumber(data:sub(i,i+1))))
If the strings contains hexadecimal, use tonumber(...,16).
How can i convert buffer data coming from fingerprint capture to byte array in nodejs
<Buffer ff d8 ff e0 00 10 4a 46 49 46 00 01 01 ...>
var arrByte = Uint8Array.from(data)
Also, see this similar question and the docs for Buffer.
how can I guess CRC algorithm by having some examples(line -> result). It`s 1 byte result. Seems like standard 1 byte CRC is not working here.
Examples are in hex
02 08 00 3E 00 00 -> 34
02 0C 00 3E FF 01 03 9F 1A 00 -> 48
P.S. This is Saturn NFC reader exchange. I can`t find the guide to get algorithm.
I want to generate gp secure channel 01. my trace is:
Send: 80 50 00 00 08 00 00 00 00 00 00 00 00
Recv: 00 00 00 00 00 00 00 00 00 00 FF 02 00 02 0E 5A 8F F4 57 DD 35 5C 49 A6 8B 15 E9 A5 9000
so I have :
Card challenge= 00 02 0E 5A 8F F4 57 DD
Host challenge=00 00 00 00 00 00 00 00
according SPC01: image
Derivation data== 8F F4 57 DD 00 00 00 00 00 02 0E 5A 00 00 00 00
IV=0000000000000000
c_ENC: 404142434445464748494A4B4C4D4E4F
according this image and 3Des online
session s_ENC= C72F032C8BAD55D4D2579295CCF0A6CA
now :
hot-auth_data = card challenge + host challenge + pad
host-auth= 00020E5A8FF457DD00000000000000008000000000000000
s_ENC=C72F032C8BAD55D4D2579295CCF0A6CA
IV=0000000000000000
===========
result= 93CC77E144488A031BFFCCC62EB3B5C233A485F8255FE90E
Host cryptogram= 33A485F8255FE90E
but when I send :
848200000833A485F8255FE90E
I have error 0x6700 in method SDInstruction in line
short len = sc.processSecurity(apdu);
public void process(APDU apdu) throws ISOException {
if (selectingApplet()) {
return;
}
byte[] buffer = apdu.getBuffer();
switch (buffer[ISO7816.OFFSET_INS]) {
case ISO7816.INS_SELECT:
select();
return;
case INS_INIT_UPDATE:
case INS_EXT_AUTH:
SDInstruction(apdu);
break;
}
}
private void SDInstruction(APDU apdu)
{
byte[] buf = apdu.getBuffer();
byte cla = buf[ISO7816.OFFSET_CLA];
byte ins = buf[ISO7816.OFFSET_INS];
apdu.setIncomingAndReceive();
if(ins == INS_INIT_UPDATE)
sc = GPSystem.getSecureChannel();
short len = sc.processSecurity(apdu);
apdu.setOutgoing();
apdu.setOutgoingLength(len);
apdu.sendBytes(ISO7816.OFFSET_CDATA, (short) len);
}
Your card is using SCP02 and not SCP01.
Given the response to the INITIALIZE UPDATE command:
00 00 00 00 00 00 00 00 00 00 FF 02 00 02 0E 5A 8F F4 57 DD 35 5C 49 A6 8B 15 E9 A5 9000
The highlighted part is the "Key Information" which contains:
"Key Version Number" -- in your trace 0xFF
"Secure Channel Protocol Identifier" -- in your trace it is 0x02 indicating SCP02
See the Global Platform Card Specification for further reference (sections describing the INITIALIZE UPDATE command).
So you need to establish the secure channel with the card according to the SCP02.
Some additional (random) notes:
be sure to check the "i" secure channel parameter encoded inside the "Card Recognition Data" (tag '64') as well
you might want to look at the method GlobalPlatform.openSecureChannel() and the inner class GlobalPlatform.SCP0102Wrapper in the GlobalPlatformPro tool source code
Good luck!
According to the GlobalPlatform specification, the EXTERNAL AUTHENTICATE command has to include the host cryptogram as well as the MAC. Both are 8 bytes long, hence, your command should be 16 bytes in total.
If you want to implement the generation of this MAC value yourself, you can follow the description in the GlobalPlatform spec. But I suggest you to make use of available open source implementation. For example: GPJ is a Java implementation of the GlobalPlatform specification and has all commands that you need. You can take a look at the class GlobalPlatformService, where you will find the implementation of the secure channel protocol. GPDroid (github.com/mobilesec/secure-element-gpdroid) is a wrapper for this project on Android.
I have a node application which runs on a raspberry pi that keeps track of a bunch of UPnP-players (Sonos), which I would like to be able to control through a physical remote. I have a couple of airmouses, which has small keyboards as well as volume buttons that I would like to use.
I have tried to get a grip on how to read out physical key strokes on a linux machine, and come to the conclusion that I need to read events from the input device, which in my case would be:
/dev/input/by-id/usb-Dell_Dell_QuietKey_Keyboard-event-kbd
How to find the device and stuff like that is not a problem, the real issue is how to interpret the data that you read from it.
I know that you would receive a C struct, like this:
struct input_event {
struct timeval time;
unsigned short type;
unsigned short code;
unsigned int value;
};
But I'm not sure how I would go about reading this from node. If I could run an external app that would be triggered from pre-defined keystrokes, and then invoke an HTTP-request against my node, that would be my second option, a python script or some native daemon. I have however looked at some hotkey-daemons, but none of them worked.
If would of course be nice if I could contain it within node somehow.
EDIT: So I did some testing, and made a simple snippet:
var fs = require('fs');
var buffer = new Buffer(16);
fs.open('/dev/input/by-id/usb-HJT_Air_Mouse-event-kbd', 'r', function (err, fd) {
while (true) {
fs.readSync(fd, buffer, 0, 16, null);
console.log(buffer)
}
});
This outputs something like this (for space):
<Buffer a4 3e 5b 51 ab cf 03 00 04 00 04 00 2c 00 07 00>
<Buffer a4 3e 5b 51 c3 cf 03 00 01 00 39 00 01 00 00 00>
<Buffer a4 3e 5b 51 cb cf 03 00 00 00 00 00 00 00 00 00>
<Buffer a4 3e 5b 51 ba 40 06 00 04 00 04 00 2c 00 07 00>
<Buffer a4 3e 5b 51 cd 40 06 00 01 00 39 00 00 00 00 00>
<Buffer a4 3e 5b 51 d2 40 06 00 00 00 00 00 00 00 00 00>
I realize that the first four bytes are some sort of timestamp, and the following 3 bytes could be something like a micro/millisecond thing.
Another odd thing is that not all keypresses produces output, but a subsequent press might sent twice as much data, and most of the time it starts blasting out data which would stop after subsequent keypresses (or after about 20 seconds or so). I'm not really sure how to interpret that. I have tried to read the source for this daemon https://github.com/baskerville/shkd/blob/master but C is not my strongest language and I can't identify how he handles it (or if it should even be handled). And that daemon didn't even work for me (compiled it on a raspberry pi).
Well, let's have a look at that struct.
struct input_event {
struct timeval time;
unsigned short type;
unsigned short code;
unsigned int value;
};
A struct timeval has this structure:
struct timeval
{
__time_t tv_sec; /* Seconds. */
__suseconds_t tv_usec; /* Microseconds. */
};
The definition of those time types are
typedef signed long time_t;
typedef signed long suseconds_t;
A signed long is 4 bytes (well, not if you just follow the spec, but in practice, it is), so the first 8 bytes are a typestamp. Next, you have a type and a code. Both are short, so in practice, they're 2 bytes each. Now there's just the value left, and that's an int again, which will be four bytes. Also, a compiler could theoretically add padding between the fields here, but I'm pretty sure he won't.
So, first chop the bytes you've read into chunks of 4+4+2+2+4=16 bytes. Each of those chunks is an event. This fits your sample data. Next, extract the values from the buffer (as little endian values because you're on an ARM system – on a normal PC, you'd need big endian) and interpret the values. For instructions on how to do that, read http://www.mjmwired.net/kernel/Documentation/input/event-codes.txt. The values of the constants aren't written down there, but you can usually find those using grep -R NAME_OF_CONSTANT /usr/include.
Let's chop up
<Buffer a4 3e 5b 51 ab cf 03 00 04 00 04 00 2c 00 07 00>
as an example.
<Buffer a4 3e 5b 51 ab cf 03 00 04 00 04 00 2c 00 07 00>
| tv_sec | tv_usec |type |code | value |
tv_sec in hex is 0x515b3ea4 (reversed order because it's little endian), which is 1364934308 in decimal. A simple unix time converter reports that this means 02.04.2013 - 22:25:08. Looks good!
tv_usec is 0x0003cfab=249771, so actually, the event happened 249771 microseconds after that time.
Type is 0x0004=4. /usr/include/linux/input.h tells us that this is a EV_MSC.
Given the type, we can also see the the code, 0x0004=4, means MSC_SCAN.
The value is 0x0007002c. Turns up nowhere in input.h. Hmm.
I think what you're looking for is fs.createReadStream, so you can install some event handlers.
You can parse input events into structs by using the Buffer.readX routines:
var i = 0;
while((buf.length-i) >= 16) {
var event = {
tssec: buf.readUInt32LE(i+0),
tsusec: buf.readUInt32LE(i+4),
type: buf.readUInt16LE(i+8),
code: buf.readUInt16LE(i+10),
value: buf.readUInt32LE(i+12)
};
i += 16;
}