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]>

internal/imq/frame_test.go

@@ -0,0 +1,65 @@
+package imq
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+// frame encodes a frame as the client does: field 1 the type, field 2 the data.
+func frame(t uint64, data []byte) []byte {
+	b := append([]byte{0x08}, uvarint(t)...)
+	b = append(b, 0x12)
+	b = append(b, uvarint(uint64(len(data)))...)
+	return append(b, data...)
+}
+
+func uvarint(v uint64) []byte {
+	var b []byte
+	for v >= 0x80 {
+		b = append(b, byte(v)|0x80)
+		v >>= 7
+	}
+	return append(b, byte(v))
+}
+
+func TestReaderSplitsFrames(t *testing.T) {
+	stream := append(frame(1302, []byte("hello")), frame(3103, bytes.Repeat([]byte{1}, 300))...)
+	stream = append(stream, frame(1301, nil)...)
+	// Fed a byte at a time, the frames still come out whole and in order.
+	var r Reader
+	var got []Frame
+	for i := range stream {
+		frames, err := r.Write(stream[i : i+1])
+		if err != nil {
+			t.Fatal(err)
+		}
+		got = append(got, frames...)
+	}
+	want := []Frame{{1302, 5}, {3103, 300}, {1301, 0}}
+	if len(got) != len(want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("got %v, want %v", got, want)
+		}
+	}
+}
+
+func TestReaderRejectsOtherStreams(t *testing.T) {
+	var r Reader
+	// A TLS ClientHello isn't IMQ.
+	if _, err := r.Write([]byte{0x16, 0x03, 0x01, 0x00, 0xa5}); !errors.Is(err, ErrMalformed) {
+		t.Fatalf("got %v, want ErrMalformed", err)
+	}
+	if _, err := r.Write(frame(1301, nil)); !errors.Is(err, ErrMalformed) {
+		t.Fatal("a reader keeps failing after a malformed frame")
+	}
+}
+
+func TestTypeName(t *testing.T) {
+	if TypeName(3104) != "G2cSendMessage" || TypeName(7) != "type 7" {
+		t.Fatal(TypeName(3104), TypeName(7))
+	}
+}