<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Hello,</div>
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<div>I have started the journey to write a driver for this device (138a:003c), <span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">I own this device, its</span></div>
<div><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">built in to the HP Elitebook 8560w. </span><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">From what i've gathered I need to sniff the USB data </span></div>
<div><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">from a working driver and send/receive the right data at the right moment with libusb.</span></div>
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<div><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">So i'm currently dumping all the traffic, and when I scan a finger, I get </span><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">~84059 bytes from </span></div>
<div><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">the device back to the host, sometimes twice or thrice. There is more data </span><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">sent and received </span></div>
<div><span style="font-family: Verdana, sans-serif, Arial, 'Trebuchet MS'; font-size: 13px; line-height: 1.6em;">but this is the biggest bulk, so i'm thinking this is the image itself, is that a solid assumption</span></div>
<div>or could it be the device sends something else this large. Also, how can I check if it's true, is there </div>
<div>a way to transform the bytes into an image just to see if its right? How can I make sure it's not encrypted,</div>
<div>and if it's encrypted what are my options?</div>
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<div>Thanks in advance,</div>
<div>J. Daniel</div>
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