rename func name

Author: jschlyter

src/cryptojwt/jws.py

@@ -182,7 +182,7 @@ def sign(self, msg, key):
 
     def verify(self, msg, sig, key):
         try:
-            (r,s) = self._split_raw(sig)
+            (r,s) = self._split_raw_signature(sig)
             asn1sig = encode_dss_signature(r, s)
             key.verify(asn1sig, msg, ec.ECDSA(self.hash_algorithm()))
         except InvalidSignature as err:
@@ -191,7 +191,7 @@ def verify(self, msg, sig, key):
             return True
 
     @staticmethod
-    def _split_raw(sig):
+    def _split_raw_signature(sig):
         c_length = len(sig) // 2
         r = int_from_bytes(sig[:c_length], byteorder='big')
         s = int_from_bytes(sig[c_length:], byteorder='big')