From 93a5adfd189ff8ecd233693dc123b0ef7e11216f Mon Sep 17 00:00:00 2001
From: Neil <git@neilalexander.dev>
Date: Sat, 4 Nov 2023 17:57:15 +0000
Subject: [PATCH] Add `sockstls://` (#1090)

Closes #1087.

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
---
 src/core/link.go       | 34 +++++++++++++++++-----------------
 src/core/link_socks.go | 12 +++++++++++-
 2 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/src/core/link.go b/src/core/link.go
index f3cb431..0b2efc5 100644
--- a/src/core/link.go
+++ b/src/core/link.go
@@ -179,6 +179,22 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
 			}
 			options.password = []byte(p)
 		}
+		// SNI headers must contain hostnames and not IP addresses, so we must make sure
+		// that we do not populate the SNI with an IP literal. We do this by splitting
+		// the host-port combo from the query option and then seeing if it parses to an
+		// IP address successfully or not.
+		if sni := u.Query().Get("sni"); sni != "" {
+			if net.ParseIP(sni) == nil {
+				options.tlsSNI = sni
+			}
+		}
+		// If the SNI is not configured still because the above failed then we'll try
+		// again but this time we'll use the host part of the peering URI instead.
+		if options.tlsSNI == "" {
+			if host, _, err := net.SplitHostPort(u.Host); err == nil && net.ParseIP(host) == nil {
+				options.tlsSNI = host
+			}
+		}
 
 		// If we think we're already connected to this peer, load up
 		// the existing peer state. Try to kick the peer if possible,
@@ -497,24 +513,8 @@ func (l *links) connect(ctx context.Context, u *url.URL, info linkInfo, options
 	case "tcp":
 		dialer = l.tcp
 	case "tls":
-		// SNI headers must contain hostnames and not IP addresses, so we must make sure
-		// that we do not populate the SNI with an IP literal. We do this by splitting
-		// the host-port combo from the query option and then seeing if it parses to an
-		// IP address successfully or not.
-		if sni := u.Query().Get("sni"); sni != "" {
-			if net.ParseIP(sni) == nil {
-				options.tlsSNI = sni
-			}
-		}
-		// If the SNI is not configured still because the above failed then we'll try
-		// again but this time we'll use the host part of the peering URI instead.
-		if options.tlsSNI == "" {
-			if host, _, err := net.SplitHostPort(u.Host); err == nil && net.ParseIP(host) == nil {
-				options.tlsSNI = host
-			}
-		}
 		dialer = l.tls
-	case "socks":
+	case "socks", "sockstls":
 		dialer = l.socks
 	case "unix":
 		dialer = l.unix
diff --git a/src/core/link_socks.go b/src/core/link_socks.go
index 1a038fa..b92374d 100644
--- a/src/core/link_socks.go
+++ b/src/core/link_socks.go
@@ -2,6 +2,7 @@ package core
 
 import (
 	"context"
+	"crypto/tls"
 	"fmt"
 	"net"
 	"net/url"
@@ -34,7 +35,16 @@ func (l *linkSOCKS) dial(_ context.Context, url *url.URL, info linkInfo, options
 		return nil, fmt.Errorf("failed to configure proxy")
 	}
 	pathtokens := strings.Split(strings.Trim(url.Path, "/"), "/")
-	return dialer.Dial("tcp", pathtokens[0])
+	conn, err := dialer.Dial("tcp", pathtokens[0])
+	if err != nil {
+		return nil, fmt.Errorf("failed to dial: %w", err)
+	}
+	if url.Scheme == "sockstls" {
+		tlsconfig := l.tls.config.Clone()
+		tlsconfig.ServerName = options.tlsSNI
+		conn = tls.Client(conn, tlsconfig)
+	}
+	return conn, nil
 }
 
 func (l *linkSOCKS) listen(ctx context.Context, url *url.URL, _ string) (net.Listener, error) {