I am attempting to use SendDirectNotificationAsync to send notifications to unregistered iOS devices that obtain and update their 66 character device handle on each initialization to make sure it current. However, the outcome of the push from the hub reports "Device handle is invalid. It is either null or empty or has invalid value." I know that a handle is being entered into the method, so only being invalid is the error. A example of the handle is:
<70ff27b5b101103fe462613da74c2f073c99479760db3e1c848b239e3a6b7553>
Base on research, I read that the "<" & ">" should be excluded and the length should be 64 characters. I have tried both variations with the same results. What else is needed to make the handle valid?
What I discover that there is an overload of SendDirectNotificationAsync for each platform based on the notification parameter class, e.g. WindowsNotification, AppleNotification or FcmNotification.
For APNS, the device handle is without spaces in it or <> at the ends.
Related
I can encoded an NFC Sticker with a website that will open when I tap it with a mobile phone. For the application I want to use it for I need to be able to expire that link so the user can't just save the URL and use it again. Basically I need to be able to put a random string in the URL that changes each time it gets scanned, such as www.mywebsite.com/TCHQ23, www.mywebsite.com/LQ8FT, ect.
Is this possible with a regular NFC sticker? If not, what kind of device would I use to make this happen? I know there are Arduino modules that can do this, but is there a simpler method or a ready made product that can act as an NFC but have the URL changed by a computer via a USB cable?
Thanks
NFC tags (some) have a feature called "Mirroring". You can mirror the read counter value to the URL, which gets incremented every time you tap it to reader i.e. Every time read command is called, the counter increases by 1. Tags like NTAG 213, NTAG 215 etc have that feature.
Update:
If your requirement is to get a portion of URL to to return random data and on a cheaper tag or sticker then I would suggest considering NTAG 213 tag, which is cost friendly and also have Mirroring feature supported.
If your URL data is http://www.abc#xyz.com then once the counter Mirroring is enabled (read counter must be enabled first) it will look something like
http://www.abc#xyz.com?000001
The last 6 digit value gets increased by value 1,every time a read command is invoked. (000002, 000003, 000004 and so on)
you can refer this link for more info
So your card/device has to present when read a NDEF record with a link in it (A "Well Known Type 1 with a record type definition of type U, etc), this will cause most phones to open a browser automatically
Some details on the Record type needed at https://www.oreilly.com/library/view/beginning-nfc/9781449324094/ch04.html
Most cards have the ability to store some static data, some have as #Adarsh Rotte says have counters, random number generators, crypto, password protection, mirroring (backup) of data, other functions but non of these will help as these custom functions and are card specific and don't / cannot present the data to match the NFC NDEF specification.
There is one type of card that can do this called JavaCard as these can run fully programmable Java Apps. These can be programmed to respond to NFC read request with the right NDEF measure where the URL can be generated on the fly.
There is a github repo with an example Java App to run on these cards that shows how to respond with and NDEF message at https://github.com/OpenJavaCard/openjavacard-ndef.
Watch out for https://github.com/OpenJavaCard/openjavacard-ndef/issues/10 if trying to use this, the default magic AID number is not the right one for NDEF and should be configured at the time you install the App on the Card.
This app emulates the behaviour of an NFC Type 4 spec card.
You would also need to customise it to have the right NDEF payload data with the right generated URL ending.
There are examples of the Card make/model supported by this App listed on the the github pages some are dual interface cards but there are some without the chip contacts and only NFC interface.
Generating the URL ending could be challenging or easy depending on level of security/validation you need.
Starting from a Random String which would be easy to fake because it has no level of validation, to a obfuscated counter, to a public key type encrypted counter.
There are also other solutions to generating the NDEF data with the right URL that don't use a Card and usually require there own power to run.
Some options:-
An Android phone can do what is call Host Card Emulation (HCE) which is very like what the JavaCard is doing, it is pretending to be a NFC Type 4 Card and the response it sends if fully programmable and could be the right type of NDEF message as per the JavaCard.
There are some "Card Reader" Devices that can be attach to a PC/Raspberry Pie via USB can also do HCE like the Android phone. e.g. https://www.acs.com.hk/en/products/342/acr1252u-usb-nfc-reader-iii-nfc-forum-certified-reader/ - this is well documented in the datasheets on how to do.
There are some other "Card Reader" modules that can connect via I2C to Arduino that can do HCE as well. (Technically most Arduino PN532 Chip's which are used in a lot of USB readers as well can do HCE but it is a bit undocumented on how to do it - see section 4 of https://www.nxp.com/docs/en/user-guide/141520.pdf)
There are some other chips that can act as static data NFC devices the also have an I2C interface to write the static data but allow a "pass through" mode to the I2C interface, again these tend to be NFC Type 4 but do some of the HCE type work for you.
e.g. the M24SR04-Y https://www.st.com/resource/en/datasheet/m24sr04-g.pdf can do it
So technically possible with a variety of methods but all not that simple to implement BUT not "Sticker" type format of NFC devices tend to be very simple NFC device as the format restricts the complexity of the hardware contained in them.
I'm trying to understand how I can retrieve the WINBIO_SENSOR_ATTRIBUTES buffer by using WBF APIs.
I found this link: https://msdn.microsoft.com/en-us/library/windows/hardware/ff536431
It mentions about sending IOCTL command, however, I'm not able to understand how exactly I can invoke this from C++ code and receive the sensor attributes structure. Can anybody help? or point me to some sample code which does the similar stuff?
First take a look at DeviceIoControl - this is the function to which you must supply the IOCTL_BIOMETRIC_GET_ATTRIBUTES value as the second parameter to obtain the biometric data (the link you included describes how to handle the size ouf the output buffer - first supply a DWORD sized buffer to get the actual size of the output and then allocate a properly sized buffer and retrieve the actual data). But to do this you also need a valid device handle (first parameter of DeviceIoControl). This handle should be obtained by calling CreateFile and passing the device name of the driver. If you do not know the PDO then either you can try looking in Device Manager if the shows that to you under the "Details" tab or you have to use the SetupDi* family functions to enumerate the biometrics device class and get the name from there.
I am using WIA2.0 on VB6.
I could do scanning without anyissues..
But, the problem is i could not figure out the number of pages scanned when it's ADF.
I could see something like this in msdn.
WIA_DPS_ENDORSER_STRING with a token as
$PAGE_COUNT$ The number of pages transferred.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms630195(v=vs.85).aspx
But, i don't know how to access this in VB6.
Any help would be appriciated.
Thanks.
-Dinakaran.AS
As far as I can tell this count is probably strictly local to the scanner itself when it has an endorser printer. It may even be a "hardware" counter much like photocopier counters. It probably can only be reset using a physical key or administrative password at the scanner to unlock and reset it. Looks as if it is meant for auditing purposes.
WIA_DPS_ENDORSER_CHARACTERS (ScannerDeviceEndorserCharacters)
Contains all the valid characters that an application can use to
create valid endorser strings. An endorser is a printer installed on a
scanner that imprints a text message on every page scanned. The
minidriver should validate the setting of the WIA_DPS_ENDORSER_STRING
property against the valid character set in this property. The
minidriver creates and maintains this property.
WIA_DPS_ENDORSER_STRING (ScannerDeviceEndorserString)
Contains a string that is to be endorsed (in other words, printed) on
each page that the minidriver scans. An application sets this property
using the valid character set that is reported in the
WIA_DPS_ENDORSER_CHARACTERS property. The minidriver should endorse
documents only if a string is set in this property. An empty string
means that the endorser functionality is disabled.
Then we have:
WIA_IPS_PAGES (ScannerPicturePages)
Note: This property is supported only by Windows Vista and later.
Contains the current number of pages to be acquired from an automatic
document feeder. The minidriver creates and maintains this property.
Type: VT_I4; Access: Read/Write; Valid values: WIA_PROP_RANGE This is
zero through the maximum number of pages that the scanner can scan.
The value is ALL_PAGES (= 0) if the scanner can scan continuously.
An application reads this property to determine the document feeder's
page capacity. The application also sets this property to the number
of pages it is going to scan.
I am currently in the process of writing a Linux kernel module in C. The module provides an extremely basic driver for a USB light (the device consists of three colored LEDs). I have managed to get the driver to load and unload without problems and also create the device (/dev/wn0, /dev/wn1, etc.). However, I keep getting errors when attempting to write to the device:
$ echo "1" >/dev/wn0
bash: echo: write error: Broken pipe
The entire code for the module is here. However, the interesting part is the wn_set_color() function:
/* Create the data buffer to be sent to the device. */
u8 buf[8] = {
red, green, blue, 0, 0, 0, 0x1F, 0x05
};
/* Send the data to the device. */
return usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
0, 0, 0, 0,
buf, 8, 0);
For some reason, it returns -32 instead of sending the data to the device.
I am completely new to Linux kernel programming so I'm likely doing something silly. If you can shed some light on this at all, it would be greatly appreciated.
Edit: here is some further information:
lsusb -v output is here
the bDescriptorType member of the usb_endpoint_descriptor class contains '5' for the single endpoint exposed by the device (bEndpointAddress is 129 - or 0x81 in hex)
here is a screengrab of one of the control URBs sent to the device
usb_control_msg() eventually calls down to usb_submit_urb(). The Documentation/usb/error-codes.txt file describes the errors that this function can return:
-EPIPE The pipe type specified in the URB doesn't match the
endpoint's actual type.
If usb_submit_urb() succeeded, then usb_control_msg() returns an urb->status value. This lists under EPIPE:
-EPIPE (**) Endpoint stalled. For non-control endpoints,
reset this status with usb_clear_halt().
(**) This is also one of several codes that different kinds of host
controller use to indicate a transfer has failed because of device
disconnect. In the interval before the hub driver starts disconnect
processing, devices may receive such fault reports for every request.
Have you checked for any messages in the kernel log?
I have a feeling it has to do with your usb_sndctrlpipe call. The definition of this function is as follows: unsigned int usb_sndctrlpipe(struct usb_device *dev, unsigned int
endpoint).
You seem to be passing the device pointer appropriately, however your pass in the value 0 for your control endpoint, which as you mention, is not the address of your endpoint. I would recommend defining a constant at the beginning with the hex value of your endpoint and passing that to your calls.
However, I believe you have a bigger problem.
Looking at your lsusb, it seems that your endpoint is not actually a control endpoint, but an interrupt endpoint. This changes the functions that you need to call to communicate. For example, instead of usb_sndctrlpipe you will need usb_rcvintpipe(struct usb_device *dev, unsigned int endpoint) to generate the pipe (since it is an IN endpoint as listed in your lsusb) and use a different function instead of usb_control_msg. Unfortunately, from what I can gather, it seems like there are no functions available to automatically construct interrupt urbs so you will need to create a urb struct as described in section 13.3.2.1 of http://www.makelinux.net/ldd3/chp-13-sect-3. Even worse news is that (unless I am missing something) because your only endpoint seems to be the interrupt IN endpoint, it would seem that you can only receive interrupts from the device and are not able to send anything to the device. Do you know for sure that changing the colors of the lamp via usb is a functionality supported by the device?
More information can be found at the following:
http://www.beyondlogic.org/usbnutshell/usb4.shtml (thorough information on endpoints and how to read the descriptors)
http://www.makelinux.net/ldd3/chp-13-sect-3 and
http://www.makelinux.net/ldd3/chp-13-sect-5 (function definitions for usb communication)
I am currently trying to figure out how sms classes are correctly represented in SMPP. However I am by now completely confused by the standard and it's documentation.
In normal sms we have
Class0: Flash sms, which are shown on the display
Class1: Normal Sms to be stored on the sim or internally in the device
Looking at the SMPP spec, I first find the parameter data_coding in the submit_sm operation, which is used to set the DCS sent via MAP. As far as I understand this, if we want to explicitly set the message class we need to set the first four bits of this parameter to ones, then two bits indicating the coding and then another two bits indicating the message class. So for Class1 Sms, we would set 1111xx01. Is this correct so far?
If we try to set this DCS, however currently we also set the data coding to "8-Bit data". It seems, several phones are not able to understand this. Is this specified anywhere, and can we just change this, or is a special coding needed when sending other message classes.
More confusion arises, when we try to use the SMPPv3.4 recommended way of setting the Message class. Since 3.4 there is an optional parameter in the submit_sm operation, called dest_addr_subunit. According to the standard this parameter should be set to 0 for unknown, 1 for MS-Display, 2 for Mobile equipment, etc. If I look at this, it seems the parameters are shifted by one compared to GSM message classes. Class0 is encoded as 1, Class1 is encoded as 2 and so on. Is this correct or is there any more complicated mapping behind this?
Also, if we set dest_addr_subunit, do we still have to set DCS as well, or can we just leave this parameter at it's default value?
I recommend to read 3GPP TS 23.038 specification with detailed DCS (Data Coding Scheme) description.
In case of DCS bits 7654 are 00xx, you should check DCS for bit 4 value.
bit 4 == 0 - no message class for this message (bits 1 and 0 are reserved)
bit 4 == 1 - bits 1 and 0 contains message class
So you should set data_coding SMPP parameter in accordance to 3GPP TS 23.038 specification to handle message_class properly.
By default GSM SMS message has no message_class and this is not the same as message_class = 1.