diff --git a/src/runner.go b/src/runner.go
index 955a6ac..418217d 100644
--- a/src/runner.go
+++ b/src/runner.go
@@ -21,14 +21,18 @@ const (
 )
 
 // Helpers for byte convertion
+// ------------------------------
+
+// cBytes must be initialized to proper size
 func convBytesGoToC(goBytes []byte, cBytes []C.uchar) {
     for i,v:=range(goBytes) {
         cBytes[i] = C.uchar(v)
     }
 }
 
+// goBytes must be initialized to proper size
 func convBytesCToGo(cBytes []C.uchar, goBytes []byte) {
-    goBytes=C.GoBytes(unsafe.Pointer(&cBytes[0]), GSKsz)
+    copy(goBytes, C.GoBytes(unsafe.Pointer(&cBytes[0]), C.int(len(cBytes))))
 }
 
 // Helpers for key generation
@@ -154,9 +158,6 @@ func test_cfK_msrE_cfD() {
 
     for i,_:=range(gSS) {
         if gSS[i] != byte(cSS[i]) {
-            fmt.Printf("LEN=%d %X\n", len(gSS), gSS)
-            fmt.Printf("LEN=%d %X\n", len(cSS), cSS)
-            fmt.Printf("LEN=%d %X\n", len(gCT), gCT)
             fmt.Println("ERR: shared secrets differ")
             break
         }