Feature: two new middlebox fingerprinting

[xhdix]

In the study, I came across an article that described a fingerprint I accidentally found. (Identification based on TTL mirroring) This article also mentions two other fingerprints. Which would be great if we could implement it. This is because the article mentions that these middleboxes are used in parallel in China.

https://www.usenix.org/conference/foci20/presentation/anonymous