test: increase test coverage across multiple packages

Add comprehensive tests for:
- network: CryptConn encryption connection tests
- signserver: character and member struct validation
- entranceserver: encryption roundtrip, server config tests
- channelserver: stage creation, object IDs, quest membership

All tests pass with race detector enabled.

network/crypt_conn_test.go

@@ -0,0 +1,179 @@
+package network
+
+import (
+	"testing"
+)
+
+func TestNewCryptConn(t *testing.T) {
+	// NewCryptConn with nil should not panic
+	cc := NewCryptConn(nil)
+
+	if cc == nil {
+		t.Fatal("NewCryptConn() returned nil")
+	}
+
+	// Verify default key rotation values
+	if cc.readKeyRot != 995117 {
+		t.Errorf("readKeyRot = %d, want 995117", cc.readKeyRot)
+	}
+	if cc.sendKeyRot != 995117 {
+		t.Errorf("sendKeyRot = %d, want 995117", cc.sendKeyRot)
+	}
+	if cc.sentPackets != 0 {
+		t.Errorf("sentPackets = %d, want 0", cc.sentPackets)
+	}
+	if cc.prevRecvPacketCombinedCheck != 0 {
+		t.Errorf("prevRecvPacketCombinedCheck = %d, want 0", cc.prevRecvPacketCombinedCheck)
+	}
+	if cc.prevSendPacketCombinedCheck != 0 {
+		t.Errorf("prevSendPacketCombinedCheck = %d, want 0", cc.prevSendPacketCombinedCheck)
+	}
+}
+
+func TestCryptConnInitialState(t *testing.T) {
+	cc := &CryptConn{}
+
+	// Zero value should have all zeros
+	if cc.readKeyRot != 0 {
+		t.Errorf("zero value readKeyRot = %d, want 0", cc.readKeyRot)
+	}
+	if cc.sendKeyRot != 0 {
+		t.Errorf("zero value sendKeyRot = %d, want 0", cc.sendKeyRot)
+	}
+	if cc.conn != nil {
+		t.Error("zero value conn should be nil")
+	}
+}
+
+func TestCryptConnDefaultKeyRotation(t *testing.T) {
+	// The magic number 995117 is the default key rotation value
+	const defaultKeyRot = 995117
+
+	cc := NewCryptConn(nil)
+
+	if cc.readKeyRot != defaultKeyRot {
+		t.Errorf("default readKeyRot = %d, want %d", cc.readKeyRot, defaultKeyRot)
+	}
+	if cc.sendKeyRot != defaultKeyRot {
+		t.Errorf("default sendKeyRot = %d, want %d", cc.sendKeyRot, defaultKeyRot)
+	}
+}
+
+func TestCryptConnStructFields(t *testing.T) {
+	cc := &CryptConn{
+		readKeyRot:                  123456,
+		sendKeyRot:                  654321,
+		sentPackets:                 10,
+		prevRecvPacketCombinedCheck: 0x1234,
+		prevSendPacketCombinedCheck: 0x5678,
+	}
+
+	if cc.readKeyRot != 123456 {
+		t.Errorf("readKeyRot = %d, want 123456", cc.readKeyRot)
+	}
+	if cc.sendKeyRot != 654321 {
+		t.Errorf("sendKeyRot = %d, want 654321", cc.sendKeyRot)
+	}
+	if cc.sentPackets != 10 {
+		t.Errorf("sentPackets = %d, want 10", cc.sentPackets)
+	}
+	if cc.prevRecvPacketCombinedCheck != 0x1234 {
+		t.Errorf("prevRecvPacketCombinedCheck = 0x%X, want 0x1234", cc.prevRecvPacketCombinedCheck)
+	}
+	if cc.prevSendPacketCombinedCheck != 0x5678 {
+		t.Errorf("prevSendPacketCombinedCheck = 0x%X, want 0x5678", cc.prevSendPacketCombinedCheck)
+	}
+}
+
+func TestCryptConnKeyRotationType(t *testing.T) {
+	// Verify key rotation uses uint32
+	cc := NewCryptConn(nil)
+
+	// Simulate key rotation
+	keyRotDelta := byte(3)
+	cc.sendKeyRot = (uint32(keyRotDelta) * (cc.sendKeyRot + 1))
+
+	// Should not overflow or behave unexpectedly
+	if cc.sendKeyRot == 0 {
+		t.Error("sendKeyRot should not be 0 after rotation")
+	}
+}
+
+func TestCryptConnSentPacketsCounter(t *testing.T) {
+	cc := NewCryptConn(nil)
+
+	if cc.sentPackets != 0 {
+		t.Errorf("initial sentPackets = %d, want 0", cc.sentPackets)
+	}
+
+	// Simulate incrementing sent packets
+	cc.sentPackets++
+	if cc.sentPackets != 1 {
+		t.Errorf("sentPackets after increment = %d, want 1", cc.sentPackets)
+	}
+
+	// Verify it's int32
+	cc.sentPackets = 0x7FFFFFFF // Max int32
+	if cc.sentPackets != 0x7FFFFFFF {
+		t.Errorf("sentPackets max value = %d, want %d", cc.sentPackets, 0x7FFFFFFF)
+	}
+}
+
+func TestCryptConnCombinedCheckStorage(t *testing.T) {
+	cc := NewCryptConn(nil)
+
+	// Test combined check storage
+	cc.prevRecvPacketCombinedCheck = 0xABCD
+	cc.prevSendPacketCombinedCheck = 0xDCBA
+
+	if cc.prevRecvPacketCombinedCheck != 0xABCD {
+		t.Errorf("prevRecvPacketCombinedCheck = 0x%X, want 0xABCD", cc.prevRecvPacketCombinedCheck)
+	}
+	if cc.prevSendPacketCombinedCheck != 0xDCBA {
+		t.Errorf("prevSendPacketCombinedCheck = 0x%X, want 0xDCBA", cc.prevSendPacketCombinedCheck)
+	}
+}
+
+func TestCryptConnKeyRotationFormula(t *testing.T) {
+	// Test the key rotation formula: (keyRotDelta * (keyRot + 1))
+	tests := []struct {
+		name        string
+		initialKey  uint32
+		keyRotDelta byte
+		expectedKey uint32
+	}{
+		{"delta 1", 995117, 1, 995118},
+		{"delta 3 default", 995117, 3, 2985354},
+		{"delta 0", 995117, 0, 0},
+		{"zero initial", 0, 3, 3},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			newKey := uint32(tt.keyRotDelta) * (tt.initialKey + 1)
+			if newKey != tt.expectedKey {
+				t.Errorf("key rotation = %d, want %d", newKey, tt.expectedKey)
+			}
+		})
+	}
+}
+
+func TestCryptPacketHeaderLengthConstant(t *testing.T) {
+	// CryptPacketHeaderLength should always be 14
+	if CryptPacketHeaderLength != 14 {
+		t.Errorf("CryptPacketHeaderLength = %d, want 14", CryptPacketHeaderLength)
+	}
+}
+
+func TestMultipleCryptConnInstances(t *testing.T) {
+	// Multiple instances should be independent
+	cc1 := NewCryptConn(nil)
+	cc2 := NewCryptConn(nil)
+
+	cc1.sendKeyRot = 12345
+	cc2.sendKeyRot = 54321
+
+	if cc1.sendKeyRot == cc2.sendKeyRot {
+		t.Error("CryptConn instances should be independent")
+	}
+}