Merge branch 'onionscan-0.2' of github.com:s-rah/onionscan into onion…

…scan-0.2

main.go

@@ -8,6 +8,7 @@ import (
  "github.com/s-rah/onionscan/deanonymization"
  "github.com/s-rah/onionscan/onionscan"
  "github.com/s-rah/onionscan/report"
+ "github.com/s-rah/onionscan/utils"
  "golang.org/x/crypto/ssh/terminal"
  "io/ioutil"
  "log"
@@ -49,6 +50,11 @@ func main() {
  log.Fatalf("You must set one of --simpleReport or --jsonReport or --jsonSimpleReport")
  }
 
+ proxyStatus := utils.CheckTorProxy(*torProxyAddress)
+ if proxyStatus != utils.ProxyStatusOK {
+ log.Fatalf("%s, is the --torProxyAddress setting correct?", utils.ProxyStatusMessage(proxyStatus))
+ }
+
  onionsToScan := []string{}
  if *list == "" {
  onionsToScan = append(onionsToScan, flag.Args()[0])

utils/proxycheck.go

@@ -0,0 +1,62 @@
+package utils
+
+import (
+ "net"
+ "net/http"
+ "net/url"
+ "strings"
+ "time"
+)
+
+type ProxyStatus int
+
+const (
+ ProxyStatusOK ProxyStatus = iota
+ ProxyStatusWrongType
+ ProxyStatusCannotConnect
+ ProxyStatusTimeout
+)
+
+// Detect whether a proxy is connectable and is a Tor proxy
+func CheckTorProxy(proxyAddress string) ProxyStatus {
+ // A trick to do this without making an outward connection is,
+ // paradoxically, to try to open it as http.
+ // This is documented in section 4 here: https://github.com/torproject/torspec/blob/master/socks-extensions.txt
+ client := &http.Client{Timeout: 2 * time.Second}
+ response, err := client.Get("http://" + proxyAddress + "/")
+ if err != nil {
+ switch t := err.(type) {
+ case *url.Error:
+ switch t.Err.(type) {
+ case *net.OpError: // Network-level error. Will in turn contain a os.SyscallError
+ return ProxyStatusCannotConnect
+ default:
+ // http.error unfortunately not exported, need to match on string
+ // net/http: request canceled
+ if strings.Index(t.Err.Error(), "request canceled") != -1 {
+ return ProxyStatusTimeout
+ }
+ }
+ }
+ // Protocol-level errors mean that http failed, so it's not Tor
+ return ProxyStatusWrongType
+ }
+ defer response.Body.Close()
+ if response.Status != "501 Tor is not an HTTP Proxy" {
+ return ProxyStatusWrongType
+ }
+ return ProxyStatusOK
+}
+
+func ProxyStatusMessage(status ProxyStatus) string {
+ switch status {
+ case ProxyStatusWrongType:
+ return "Proxy specified is not a Tor proxy"
+ case ProxyStatusCannotConnect:
+ return "Cannot connect to Tor proxy"
+ case ProxyStatusTimeout:
+ return "Proxy timeout"
+ default:
+ return "Unknown proxy error"
+ }
+}