T5DE's local proxy for IMVU Classic

The client sends it every HTTP request and its IMQ connection; it makes them with current TLS and
certificates, upgrades IMVU's plain-HTTP hosts to HTTPS, and refuses IMVU's reporting endpoints. CI
tests it and publishes t5de-proxy.exe as nightlies and tagged releases.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

cmd/t5de-proxy/main.go

@@ -0,0 +1,100 @@
+// Command t5de-proxy is T5DE's local proxy for IMVU Classic (see internal/proxy). The client starts one as it
+// starts, and it exits with the client:
+//
+//	t5de-proxy -parent <pid> -ready <file> [-log <file>] [-trace]
+//
+// It listens on a free port of 127.0.0.1 and, once it's listening, writes {"address", "token"} to the ready file
+// (written whole, by renaming), which the client reads.
+package main
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"time"
+
+	"git.t5de.dev/t5de/t5de-proxy/internal/buildinfo"
+	"git.t5de.dev/t5de/t5de-proxy/internal/parent"
+	"git.t5de.dev/t5de/t5de-proxy/internal/proxy"
+)
+
+func main() {
+	listen := flag.String("listen", "127.0.0.1:0", "address to listen on")
+	ready := flag.String("ready", "", "file to write the address and token to once listening")
+	parentPID := flag.Int("parent", 0, "exit when this process exits")
+	logFile := flag.String("log", "", "log file (default: standard error)")
+	trace := flag.Bool("trace", false, "log full URLs and every IMQ frame")
+	version := flag.Bool("version", false, "print the version and exit")
+	flag.Parse()
+	if *version {
+		fmt.Println(buildinfo.Version)
+		return
+	}
+
+	var out io.Writer = os.Stderr
+	if *logFile != "" {
+		f, err := os.Create(*logFile)
+		if err != nil {
+			os.Exit(1)
+		}
+		defer f.Close()
+		out = f
+	}
+	logger := log.New(out, "", log.Ldate|log.Ltime|log.Lmicroseconds)
+	if err := run(logger, *listen, *ready, *parentPID, *trace); err != nil {
+		logger.Printf("t5de-proxy: %v", err)
+		os.Exit(1)
+	}
+}
+
+func run(logger *log.Logger, listen, ready string, parentPID int, trace bool) error {
+	secret := make([]byte, 24)
+	if _, err := rand.Read(secret); err != nil {
+		return err
+	}
+	token := hex.EncodeToString(secret)
+
+	ln, err := net.Listen("tcp", listen)
+	if err != nil {
+		return err
+	}
+	logger.Printf("t5de-proxy %s listening on %s (client process %d)", buildinfo.Version, ln.Addr(), parentPID)
+	if ready != "" {
+		if err := writeReady(ready, ln.Addr().String(), token); err != nil {
+			return err
+		}
+	}
+	if parentPID != 0 {
+		go func() {
+			err := parent.Wait(parentPID)
+			logger.Printf("client process %d exited (%v); exiting", parentPID, err)
+			os.Exit(0)
+		}()
+	}
+	server := &http.Server{
+		Handler:           &proxy.Server{Token: token, Log: logger, Trace: trace},
+		ReadHeaderTimeout: 30 * time.Second,
+		IdleTimeout:       2 * time.Minute,
+		ErrorLog:          logger,
+	}
+	return server.Serve(ln)
+}
+
+func writeReady(path, address, token string) error {
+	data, err := json.Marshal(map[string]string{"address": address, "token": token})
+	if err != nil {
+		return err
+	}
+	tmp := path + ".tmp"
+	if err := os.WriteFile(tmp, data, 0o600); err != nil {
+		return err
+	}
+	return os.Rename(tmp, path)
+}