Fix crash #174 by duplicating curl handle

Wrap libcurl to bypass lack of covariance support

attack.go

@@ -32,6 +32,8 @@ func routeAttack(c Curler, camera Stream, route string, timeout time.Duration, e
 		c.Setopt(curl.OPT_WRITEFUNCTION, doNotWrite)
 	}
 
+	// Do not use signals (would break multithreading)
+	c.Setopt(curl.OPT_NOSIGNAL, 1)
 	// Do not send a body in the describe request
 	c.Setopt(curl.OPT_NOBODY, 1)
 	// Send a request to the URL of the camera we want to attack
@@ -82,6 +84,8 @@ func credAttack(c Curler, camera Stream, username string, password string, timeo
 		c.Setopt(curl.OPT_WRITEFUNCTION, doNotWrite)
 	}
 
+	// Do not use signals (would break multithreading)
+	c.Setopt(curl.OPT_NOSIGNAL, 1)
 	// Do not send a body in the describe request
 	c.Setopt(curl.OPT_NOBODY, 1)
 	// Send a request to the URL of the camera we want to attack
@@ -117,7 +121,7 @@ func credAttack(c Curler, camera Stream, username string, password string, timeo
 func attackCameraCredentials(c Curler, target Stream, credentials Credentials, resultsChan chan<- Stream, timeout time.Duration, log bool) {
 	for _, username := range credentials.Usernames {
 		for _, password := range credentials.Passwords {
-			ok := credAttack(c, target, username, password, timeout, log)
+			ok := credAttack(c.Duphandle(), target, username, password, timeout, log)
 			if ok {
 				target.CredentialsFound = true
 				target.Username = username
@@ -133,7 +137,7 @@ func attackCameraCredentials(c Curler, target Stream, credentials Credentials, r
 
 func attackCameraRoute(c Curler, target Stream, routes Routes, resultsChan chan<- Stream, timeout time.Duration, log bool) {
 	for _, route := range routes {
-		ok := routeAttack(c, target, route, timeout, log)
+		ok := routeAttack(c.Duphandle(), target, route, timeout, log)
 		if ok {
 			target.RouteFound = true
 			target.Route = route

attack_test.go

@@ -31,6 +31,10 @@ func (m *CurlerMock) Getinfo(info curl.CurlInfo) (interface{}, error) {
 	return args.Int(0), args.Error(1)
 }
 
+func (m *CurlerMock) Duphandle() Curler {
+	return m
+}
+
 func TestAttackCredentials(t *testing.T) {
 	validStream1 := Stream{
 		Device:  "fakeDevice",

cameradar/cameradar.go

@@ -94,10 +94,11 @@ func main() {
 	w := startSpinner(options.EnableLogs)
 
 	err = curl.GlobalInit(curl.GLOBAL_ALL)
-	c := curl.EasyInit()
-	if err != nil || c == nil {
+	handle := curl.EasyInit()
+	if err != nil || handle == nil {
 		printErr(errors.New("libcurl initialization failed"))
 	}
+	c := &cmrdr.Curl{CURL: handle}
 	defer curl.GlobalCleanup()
 
 	updateSpinner(w, "Loading dictionaries...", options.EnableLogs)

curl.go

@@ -10,4 +10,16 @@ type Curler interface {
 	Setopt(opt int, param interface{}) error
 	Perform() error
 	Getinfo(info curl.CurlInfo) (interface{}, error)
+	Duphandle() Curler
+}
+
+// Curl is a libcurl wrapper used to make the Curler interface work even though
+// golang currently does not support covariance (see https://github.com/golang/go/issues/7512)
+type Curl struct {
+	*curl.CURL
+}
+
+// Duphandle wraps curl.Duphandle
+func (c *Curl) Duphandle() Curler {
+	return &Curl{c.CURL.Duphandle()}
 }