feat(proxy): support HTTP/2 CONNECT

Author: hightemp

Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 
-FROM golang:1.26.5-alpine AS builder
+FROM golang:1.26.7-alpine AS builder
 WORKDIR /src
 COPY go.mod go.sum* ./
 RUN go mod download

README.md

@@ -15,6 +15,7 @@ A secure HTTP/HTTPS proxy server in Go with Basic authentication, TLS support, a
 ## Features
 
 - HTTP and HTTPS proxy modes
+- HTTP/2 CONNECT multiplexing in HTTPS mode with HTTP/1.1 fallback
 - Basic authentication
 - TLS with configurable certificates
 - Upstream proxy chaining (proxy chain support)
@@ -25,7 +26,7 @@ A secure HTTP/HTTPS proxy server in Go with Basic authentication, TLS support, a
 - Bounded dial, TLS handshake, and response-header timeouts
 - Configurable via YAML file
 - Systemd service support
-- Graceful shutdown of HTTP requests and hijacked CONNECT tunnels
+- Graceful shutdown of HTTP requests and HTTP/1.1 or HTTP/2 CONNECT tunnels
 
 ## Installation
 
@@ -121,6 +122,8 @@ The bundled [docker-compose.yml](docker-compose.yml) starts an HTTP proxy, an HT
 
 Certbot checks for renewals every 12 hours. On new TLS handshakes, the HTTPS proxy checks the mounted certificate files at most once per `PROXY_TLS_RELOAD_INTERVAL` (one minute by default). A valid replacement is loaded without restarting the container or interrupting existing connections. If Certbot is temporarily updating the certificate/key pair or the new files are invalid, the proxy keeps the last valid certificate and retries later.
 
+HTTPS mode advertises HTTP/2 and HTTP/1.1 through ALPN. Browsers that support an HTTP/2 secure web proxy multiplex CONNECT tunnels as independent streams on one TLS connection; other clients continue to use the HTTP/1.1 CONNECT path.
+
 ### Build from source
 
 1. Clone the repository:
@@ -143,7 +146,7 @@ cmd/https_proxy/  application entry point
 internal/config/  configuration loading and validation
 internal/auth/    proxy authentication
 internal/proxy/   HTTP forwarding, upstream chaining, and server lifecycle
-internal/tunnel/  CONNECT tunnel tracking and bidirectional relay
+internal/tunnel/  HTTP/1.1 and HTTP/2 CONNECT tracking and bidirectional relay
 ```
 
 ## Configuration

VERSION

@@ -1 +1 @@
-0.4.0
+0.5.0

go.mod

@@ -1,5 +1,5 @@
 module github.com/hightemp/https_proxy
 
-go 1.26.5
+go 1.26.7
 
 require gopkg.in/yaml.v3 v3.0.1