rathole/docs/security.md

Security

Noise Protocol

Quickstart for the Noise Protocl

In one word, the Noise Protocol is a lightweigt, easy to configure and drop-in replacement of TLS. No need to create a self-sign certificate to secure the connection.

rathole comes with a reasonable default configuration for noise protocol. You can a glimpse of the minimal example for how it will look like.

The default noise protocol that rathole uses, which is Noise_NK_25519_ChaChaPoly_BLAKE2s, providing the authentication of the server, just like TLS with properly configured certificates. So MITM is no more a problem.

To use it, a X25519 keypair is needed.

Generate a Keypair

1. Run rathole --genkey, which will generate a keypair using the default X25519 algorithm.

It emits:

$ rathole --genkey
Private Key:
cQ/vwIqNPJZmuM/OikglzBo/+jlYGrOt9i0k5h5vn1Q=

Public Key:
GQYTKSbWLBUSZiGfdWPSgek9yoOuaiwGD/GIX8Z1kkE=

(WARNING: Don't use the keypair from the Internet, including this one)

1. The server should keep the private key to identify itself. And the client should keep the public key, which is used to verify whether the peer is the authentic server.

So relevant snippets of configuration are:

# Client Side Configuration
[client.transport]
type = "noise"
[client.transport.noise]
remote_public_key = "GQYTKSbWLBUSZiGfdWPSgek9yoOuaiwGD/GIX8Z1kkE="

# Server Side Configuration
[server.transport]
type = "noise"
[server.transport.noise]
local_private_key = "cQ/vwIqNPJZmuM/OikglzBo/+jlYGrOt9i0k5h5vn1Q="

Then rathole will run under the protection of the Noise Protocol.

Specifying the Pattern of Noise Protocol

The default configuration of Noise Protocol that comes with rathole satifies most use cases, which is described above. But there're other patterns that can be useful.

No Authentication

This configuration provides encryption of the traffic but provides no authentication, which means it's vulnerable to MITM attack, but is resistent to the sniffing and replay attack. If MITM attack is not one of the concerns, this is more convenient to use.

# Server Side Configuration
[server.transport.noise]
pattern = "Noise_XX_25519_ChaChaPoly_BLAKE2s"

# Client Side Configuration
[client.transport.noise]
pattern = "Noise_XX_25519_ChaChaPoly_BLAKE2s"

Bidirectional Authentication

# Server Side Configuration
[server.transport.noise]
pattern = "Noise_KK_25519_ChaChaPoly_BLAKE2s"
local_private_key = "server-priv-key-here"
remote_public_key = "client-pub-key-here"

# Client Side Configuration
[client.transport.noise]
pattern = "Noise_KK_25519_ChaChaPoly_BLAKE2s"
local_private_key = "client-priv-key-here"
remote_public_key = "server-pub-key-here"

Other Patterns

To find out which pattern to use, refer to:

• 7.5. Interactive handshake patterns (fundamental)
• 8. Protocol names and modifiers

Note that PSKs are not supported currently. Free to open an issue if you need it.