Android Question Can this be a bugg ?

[JTmartins]

I'm reading values from a smart card, using an external lib and JavaObject

When I perform a Warm Reset I get an ATR string.

The values I obtain in the array (defined as object or java object (tested both)) are as following :

3B 7D FFFFFF95 0 0 FFFFFF80 31 FFFFFF80 etc.

The problem is that I know for a fact (documentation from card issuer) that the values should be

3B 7D 95 0 0 80 31 80 etc.

By looking closely the values I'm getting extra " FFFFFF ", but not in all of them (in the picture all the values with this problem show as negative)

If I try the test application from the smart card, the values apear as expected.

Is it me doing something really stupid or is this a bugg ?

 

[thedesolatesoul]

Its not a bug, its just sign extension.
If the 8th bit is set, then you get a negative value i.e. FFFF all the way.

 

[JTmartins]

Many thanks Desolated.

So I guess this wil do...I hope !!!

    For f=0 To bytarray.Length-1
        Private c As int
        c=bytarray(f)
        If c<0 Then
         c=Bit.AND (c,255)
        End If 
    Next

 

[thedesolatesoul]

Yes, infact you do not need to check (if c<0) as the anding the +ve values will have no effect.