TLS

An overlay: TLS 1.2 and 1.3 over the layer below. On an outbound it is the client and checks the server's certificate; on an inbound it is the server and presents one.

NOTE

A client sends Chrome's ClientHello by default, through uTLS, because Go's own is easy to single out. REALITY and ECH are not supported yet.

Structure

{
  "type": "tls",
  "settings": {
    "certificates": [
      {
        "certificate_file": "/etc/apranik/cert.pem",
        "key_file": "/etc/apranik/key.pem"
      }
    ],
    "alpn": ["http/1.1"]
  }
}

Outbound fields

server_name

stringDefault: the outbound's server domain

The SNI, checked against the certificate. With an IP server and no name, no SNI is sent and the certificate must list the IP.

fingerprint

stringDefault: chrome

Whose ClientHello to send. The names are Xray's and sing-box's, so a share link's fp= carries over.

Value	Sends
chrome, firefox, safari	the newest version uTLS has (Chrome 133, Firefox 120, Safari 16.0)
ios, android, edge, 360, qq	older presets, warned about
random	one of the above, chosen at start
randomized	a made-up ClientHello, fixed at start
none	Go's own
hellochrome_131 and other uTLS names	that exact version

alpn replaces the preset's ALPN list and nothing else. A server ignores this key.

insecure

booleanDefault: false

Accept any certificate, so anyone on the path can read the traffic. Warned about.

certificate_authorities

list of certificates

Authorities trusted besides the system's, each with a certificate_file path or an inline PEM certificate.

Inbound fields

certificates

list of key pairsRequired

Chains to present, each with its key: certificate_file or inline certificate, and key_file or inline key. The one matching the client's SNI is used. They are read at run, not at check.

Fields for both

alpn

list of strings

Application protocols in preference order. Under ws or httpupgrade, which speak only HTTP/1.1, it must be ["http/1.1"]: otherwise the far end may pick h2 and fail, so check refuses it.

min_version, max_version

stringDefault: 1.2, 1.3

1.0 to 1.3. A client may set them only with "fingerprint": "none".

handshake_timeout

durationDefault: 10s

How long the handshake may take.

A client that fails the TLS handshake is closed, never sent to the inbound's fallback.