B4R Question MD5 hash for API key

Sub Process_Globals
    Public Serial1 As Serial
    Private MD5Result(16) As Byte
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    Dim b() As Byte = "abcd"
    RunNative("CalcMD5", b)
    For i = 0 To MD5Result.Length - 1
        Log(MD5Result(i))
    Next
    Dim bc As ByteConverter
    Log(bc.HexFromBytes(MD5Result))
End Sub

#if C
#include <MD5Builder.h>
MD5Builder md5;
void CalcMD5(B4R::Object* o) {
    B4R::Array* b = (B4R::Array*)B4R::Object::toPointer(o);
     md5.begin();
     md5.add((uint8_t *)b->data, b->length);
     md5.calculate();
     md5.getBytes((uint8_t *)b4r_main::_md5result->data);
}
#End If