Smithproxy is highly configurable, fast and transparent TCP/UDP/TLS (SSL) proxy written in C++17.
It uses our C++17 socket proxying library called socle.

Note: Snap and precompiled binary packages are no longer available from Russia Federation and Belarus as a response to their blatant war crimes being committed when invading Ukraine these days. For individuals from named countries: there are still sources which can be easily compiled; in the mean time seek more uncensored information!

Read fresh Release Notes to stay tuned!
Documentation: https://smithproxy.readthedocs.org
To replay captured traffic, check out the sister project pplay.

Availability:

• Linux - can be installed as a service (distro packages, or easily compiled from sources)
  • Download binary linux .deb (arm64, armhf, amd64) packages and source from: https://download.smithproxy. org/
  • Download and compile directly from source (known to work: Debian, Ubuntu, Alpine, Fedora, Kali, Arch)
• Docker - available as an image on docker hub
  • See our docker hub page: https://hub.docker.com/r/astibal/smithproxy
  • 
• Snap - install smithproxy service as a confined snap (with some limitations)!
  • Visit snap store here: https://snapcraft.io/smithproxy

Core features:

• TCP/UDP and TLS - intercept routed traffic, locally-originated traffic and SOCKS proxy requests
• configure policy based traffic matching similar to modern firewalls
• utilize per-policy applicable content, dns, tls, detection and authentication profiles
• re-route traffic (DNAT) and load-balance it, stickiness based on source-IP, L3 or L4 header data
• enjoy insightful CLI with configuration control
• export intercepted traffic to rotated pcap files, or emitting it to remote workstation in GRE

TLS features:

• TLS security checks (OCSP, OCSP stapling, automatic CRL download)
• custom certificates based on target IP or SNI
• Certificate Transparency checks for outbound connections
• HTML replacement browser warnings
• STARTTLS support for most starttls capable protocols, including HTTP proxy CONNECT
• Seamless HTTPS redirection to authentication portal
• Exporting sslkeylog
• KTLS support (level of acceleration depends on OpenSSL version)

Other:

• Local and LDAP user authentication using builtin web portal (using complementary package)
• SOCKS4/SOCKS5 explicit proxy with DNS hostname support
• Engines: limited HTTP1 and HTTP2 support
• DNS inspection allows FQDN policy objects, including DoH
• Policies based on FQDN and 2nd level DNS domain
• both IPv4 and IPv6 are supported
• detailed debugging messages in CLI if needed
• various sinkhole options - traffic is captured but not proxied

Tools:

• built-in tools to help with CA and certificate enrollment needed to run smithproxy
• auto-enrolling portal certificate based on system IP and hostname
• auto-detect inspection interface(s) based on system routing information
• check pplay tool: replays captures over the network with many cool features

Support and contacts

• Discord server: https://discord.gg/vf4Qwwt
• email support: <support@smithproxy.org>
• Documentation: https://smithproxy.readthedocs.org