You can have your hash in a easier way, like in the offical Facebook's documentation.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Add code to print out the key hash
try {
PackageInfo info = getPackageManager().getPackageInfo(
"com.facebook.samples.hellofacebook",
PackageManager.GET_SIGNATURES);
for (Signature signature : info.signatures) {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(signature.toByteArray());
Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
}
} catch (NameNotFoundException e) {
} catch (NoSuchAlgorithmException e) {
}
...
}