1) is it possible to recover non-compressed key from compressed one?
for example: given compressed public key ( this one is well-known CHBS )
0378D430274F8C5EC1321338151E9F27F4C676A008BDF8638D07C0B6BE9AB35C71
need to get
0478D430274F8C5EC1321338151E9F27F4C676A008BDF8638D07C0B6BE9AB35C71A1518063243AC D4DFE96B66E3F2EC8013C8E072CD09B3834A19F81F659CC3455

2) is it possible to recover `message digest` from public key and signature (assume it is valid)?