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If Wireshark is licensed under GPL2, does NpCap licensing even come into play for distribution?

asked 2020-04-28 15:59:39 +0000

shall9 gravatar image

Wireshark® is a network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. It has a rich and powerful feature set and is world’s most popular tool of its kind. It runs on most computing platforms including Windows, macOS, Linux, and UNIX. Network professionals, security experts, developers, and educators around the world use it regularly. It is freely available as open source, and is released under the GNU General Public License version 2. Does the NpCap product included with Wireshark fall under the GPL2 or is a purchased license required for distribution?

From License --Even though Npcap source code is publicly available for review, it is not open source software and may not be redistributed without special permission from the Nmap Project

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answered 2020-04-28 16:28:07 +0000

grahamb gravatar image

updated 2020-04-28 16:32:12 +0000

This is my opinion:

  1. Wireshark is GPL v2, all sources available, does not link with any non-free software.
  2. Wireshark is linked with the WinPcap SDK, that defines a binary interface that both WinPcap and npcap offer, thus Wireshark does not depend on any non-free software
  3. There is an exception in the npcap licence that allows npcap distribution by the Wireshark project as part of the Wireshark installer.
  4. At runtime, Wireshark loads the user-mode portion of a capture library that supports the defined binary interface.

The fact that the user-mode portion may come from non-free software doesn't invalidate the Wireshark GPL2 licence, in a similar way to a Linux kernel loading non-free modules.

For parties other than the Wireshark project, the npcap licence may prevent distribution, that's a matter for those parties and the npcap project to resolve.

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Thank you for the quick response!! Appreciate the feedback

shall9 gravatar imageshall9 ( 2020-04-28 18:10:31 +0000 )edit

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Asked: 2020-04-28 15:59:39 +0000

Seen: 346 times

Last updated: Apr 28