Description

Add TLS SNI support to ffuf.

I opted not to include support for the FUZZ target here as each new request would require a full new TLS connection which introduces significant overhead. There might be some value in adding support for this later for VHOST discovery using TLS SNI.

Fixes: #440

For background: https://tools.ietf.org/html/rfc6066#section-3

Example:

./ffuf -H "Host: www.erbbysam.com" -u https://104.154.120.133:443/FUZZ -sni www.erbbysam.com -w ~/wordlist.txt 

Tests:

• I have confirmed this new field works.
• I have confirmed this new code does not impact existing SNI values when run without the -sni flag using.
• I have confirmed this new field can be specified via configuration file.

(all tests were done using using tcpdump+wireshark -- example: tcpdump port 443 -w ~/output.pcap)

Additonally

• If this is the first time you are contributing to ffuf, add your name to CONTRIBUTORS.md.
  The file should be alphabetically ordered.
• Add a short description of the fix to CHANGELOG.md

Thanks for contributing to ffuf :)