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desowin / usbpcap

USB packet capture for Windows
http://desowin.org/usbpcap
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Communicate with filter driver without admin rights #130

Closed bowtiejicode closed 1 year ago

bowtiejicode commented 1 year ago

I am aware that USBPcapCMD.exe forces the application to run in elevated mode, but is it possible for someone to build their own user-land application (such that it runs without admin rights) to communicate with the filter driver (USBPcapDriver)?

I am not familiar with driver stuffs, so would appreciate if you can clarify my doubts

desowin commented 1 year ago

You can do that but USBPcapDriver will refuse to give capture data to not-elevated user-space applications. In fact, USBPcapCMD does not require elevated mode to query the corresponding root hub (which is used by extcap interface) - but that is the only action that non-elevated user-space application can do.

If you want to access capture data from not-elevated user-space, then you have to modify USBPcapDriver to allow it. The relevant code in driver is https://github.com/desowin/usbpcap/blob/1a8893cf4b704a9812a82440ef2e476e194cdd65/USBPcapDriver/USBPcapRootHubControl.c#L70-L78 and the SDDL string is https://github.com/desowin/usbpcap/blob/1a8893cf4b704a9812a82440ef2e476e194cdd65/USBPcapDriver/USBPcapRootHubControl.c#L21-L24

bowtiejicode commented 1 year ago

Thank you very much for the clarification!