binctl: show fingerprint for BinImage (hash of header - signature)

tools/binctl

@@ -50,6 +50,7 @@ class BinImage(object):
         assert self.reserved2 == 415 * b'\x00'
         self.code = data[self.hdrlen:]
         assert len(self.code) == self.codelen
+        self.fingerprint = pyblake2.blake2s(data[:IMAGE_HEADER_SIZE - 65]).hexdigest()
 
     def print(self):
         if self.magic == b'TRZF':
@@ -71,6 +72,7 @@ class BinImage(object):
         print('  * sigmask :', format_sigmask(self.sigmask))
         print('  * sig     :', binascii.hexlify(self.sig).decode())
         print('  * total   : %d bytes' % total_len)
+        print('  * fngprnt :', self.fingerprint)
         print()
 
     def compute_hashes(self):