util.is_hex_str: forbid whitespaces

electrum/tests/test_util.py

@@ -125,13 +125,23 @@ class TestUtil(ElectrumTestCase):
 
     def test_is_hex_str(self):
         self.assertTrue(is_hex_str('09a4'))
+        self.assertTrue(is_hex_str('abCD'))
         self.assertTrue(is_hex_str('2A5C3F4062E4F2FCCE7A1C7B4310CB647B327409F580F4ED72CB8FC0B1804DFA'))
         self.assertTrue(is_hex_str('00' * 33))
 
+        self.assertFalse(is_hex_str('0x09a4'))
+        self.assertFalse(is_hex_str('2A 5C3F'))
+        self.assertFalse(is_hex_str(' 2A5C3F'))
+        self.assertFalse(is_hex_str('2A5C3F '))
         self.assertFalse(is_hex_str('000'))
+        self.assertFalse(is_hex_str('123'))
+        self.assertFalse(is_hex_str('0x123'))
         self.assertFalse(is_hex_str('qweqwe'))
+        self.assertFalse(is_hex_str(b'09a4'))
+        self.assertFalse(is_hex_str(b'\x09\xa4'))
         self.assertFalse(is_hex_str(None))
         self.assertFalse(is_hex_str(7))
+        self.assertFalse(is_hex_str(7.2))
 
     def test_is_integer(self):
         self.assertTrue(is_integer(7))

electrum/util.py

@@ -584,9 +584,12 @@ def is_hash256_str(text: Any) -> bool:
 def is_hex_str(text: Any) -> bool:
     if not isinstance(text, str): return False
     try:
-        bytes.fromhex(text)
+        b = bytes.fromhex(text)
     except:
         return False
+    # forbid whitespaces in text:
+    if len(text) != 2 * len(b):
+        return False
     return True