ModsFinder
MT

mTLS

by Arisa

mTLS adds mutual TLS authentication to Minecraft servers, so only players holding a valid client certificate can connect.

NeoForgeClient and serverGNU General Public License v3.0 or laterOpen source1.21.1 – 26.2

What it does

A server running mTLS checks each joining player against a certificate authority, and the connection is encrypted with the same certificates. The server needs three PKCS 8 files: a CA certificate (ca.crt), a server certificate (server.crt) and a server private key (server.key). Players without a certificate signed by that authority are refused, which works as a strict allowlist built on certificates rather than names.

The mod runs on client and server, so both sides need it. Builds are published for NeoForge only, across 12 release versions 1.21.1 – 26.2, and the latest file is 0.1.2 for 26.2, dated 2026-08-01. The code is open source under the GNU General Public License v3.0 or later.

Key features

  1. Mutual TLS authentication

    Both the server and each connecting client present certificates, so the server accepts only clients it can verify.

  2. Encrypted traffic

    Connections between the server and its players are encrypted through the TLS handshake.

  3. Certificate allowlist

    Only players with a valid client certificate connect, replacing a list of usernames.

  4. Settings in the server edit screen

    The mTLS options can be changed directly in the server edit screen, without editing files by hand.

Compatibility

Latest build for each game version and loader.

26.x1 of 1 version with builds
26.20.1.2
1.21.x11 of 11 versions with builds
1.21.110.1.2
1.21.100.1.2
1.21.90.1.2
1.21.80.1.2
1.21.70.1.2
1.21.60.1.2
1.21.50.1.2
1.21.40.1.2
1.21.30.1.2
1.21.20.1.2
1.21.10.1.2
ReleaseBetaAlphaNot available

Only full game releases are shown. This mod publishes no snapshot builds.

Questions

Does mTLS have to be installed on both sides?

Yes. Installation covers the server and each player's game.

Which files does the server need for mTLS?

The server needs ca.crt, server.crt and server.key in PKCS 8 format. Only clients holding a certificate signed by the same authority can connect.

Which game versions does mTLS support?

Files are published for NeoForge across 12 release versions, 1.21.1 – 26.2, with 0.1.2 for 26.2 as the latest.

What the author says

Adds Mutual TLS (mTLS) support to Minecraft. Encrypts traffic and acts as a strict player allowlist using certificates - only players with a valid client certificate can connect.
Arisa, on the Modrinth page

Official listing

Owner
Arisa
Published
2026-07-06
Updated on Modrinth
2026-08-01
Facts verified
2026-10-15
Open on ModrinthCompare