smithproxy

Smithproxy is fast transparent TCP/UDP/TLS (SSL) proxy. It's highly configurable and got many features.

Core features:

* intercept routed traffic, locally-originated traffic and SOCKS requests
* Policy based traffic matching
* Per-policy applicable profiles
* Insightful CLI with configuration control

Policy profiles:

* content - replacing data online, writing to disk
* dns - dns inspection settings
* tls - per-policy specific settings
* auth - match users and enforce authentication
* detection - match specific patterns in the traffic

TLS protocol:

* dumping traffic plaintext into pcapng, text or remote GRE, exporting sslkeylog
* TLS security checks (ocsp, ocsp stapling, automatic crl download)
* Certificate Transparency checks for outbound connections
* Html replacement warnings
* STARTTLS support
* Seamless redirection to login portal

Other:

* Simple authentication portal with local and ldap user support
* SOCKS4/SOCKS5 support with DNS
* DNS ALG
* policies based on FQDN or 2nd level domain
* both IPv4 and IPv6 is supported

Complementary tools:

* built-in tools to help with network redirections and certificates
* check pplay tool (https://pypi.org/project/pplay/): replays captures
  over the network

... and many more!