1 files changed, 30 insertions, 2 deletions
diff --git a/main.go b/main.go
index 233a26d..ffa9c5c 100644
--- a/main.go
+++ b/main.go
@@ -2,12 +2,21 @@ package main
 
 import (
 	"flag"
+	"fmt"
+	"log"
 	"net/http"
+	"os"
+	"strconv"
 )
 
 const keySize = 2048
 const expiryDays = 28
 
+func errExit(errmsg string) {
+	fmt.Printf("ERROR: %s\n", errmsg)
+	os.Exit(1)
+}
+
 type certHandler struct {
 	cainfo caInfo
 }
@@ -16,15 +25,34 @@ func (ch *certHandler) certResponder(w http.ResponseWriter, r *http.Request) {
 	ch.cainfo.CertWriter(w)
 }
 
+func doFilesSanityCheck(caCrt string, caKey string) {
+	if _, err := os.Stat(caCrt); os.IsNotExist(err) {
+		errExit("cannot find caCrt file")
+	}
+	if _, err := os.Stat(caKey); os.IsNotExist(err) {
+		errExit("cannot find caKey file")
+	}
+}
+
 func main() {
 	var caCrt = flag.String("caCrt", "", "path to the CA public key")
 	var caKey = flag.String("caKey", "", "path to the CA private key")
+	var port = flag.Int("port", 8000, "port where the server will listen")
 
 	flag.Parse()
 
+	if *caCrt == "" {
+		errExit("missing caCrt parameter")
+	}
+	if *caKey == "" {
+		errExit("missing caKey parameter")
+	}
+
+	doFilesSanityCheck(*caCrt, *caKey)
+
 	ci := newCaInfo(*caCrt, *caKey)
 	ch := certHandler{ci}
 
-	http.HandleFunc("/cert", ch.certResponder)
-	http.ListenAndServe(":8000", nil)
+	http.HandleFunc("/1/cert", ch.certResponder)
+	log.Fatal(http.ListenAndServe(":"+strconv.Itoa(*port), nil))
 }