test: add unit test coverage for Python ECDSA implementation

Author: theStack

test/functional/test_framework/key.py

@@ -290,24 +290,33 @@ def sign_schnorr(key, msg, aux=None, flip_p=False, flip_r=False):
 
 
 class TestFrameworkKey(unittest.TestCase):
-    def test_schnorr(self):
-        """Test the Python Schnorr implementation."""
+    def test_ecdsa_and_schnorr(self):
+        """Test the Python ECDSA and Schnorr implementations."""
+        def random_bitflip(sig):
+            sig = list(sig)
+            sig[random.randrange(len(sig))] ^= (1 << (random.randrange(8)))
+            return bytes(sig)
+
         byte_arrays = [generate_privkey() for _ in range(3)] + [v.to_bytes(32, 'big') for v in [0, ORDER - 1, ORDER, 2**256 - 1]]
         keys = {}
-        for privkey in byte_arrays:  # build array of key/pubkey pairs
-            pubkey, _ = compute_xonly_pubkey(privkey)
-            if pubkey is not None:
-                keys[privkey] = pubkey
+        for privkey_bytes in byte_arrays:  # build array of key/pubkey pairs
+            privkey = ECKey()
+            privkey.set(privkey_bytes, compressed=True)
+            if privkey.is_valid:
+                keys[privkey] = privkey.get_pubkey()
         for msg in byte_arrays:  # test every combination of message, signing key, verification key
             for sign_privkey, _ in keys.items():
-                sig = sign_schnorr(sign_privkey, msg)
+                sig_ecdsa = sign_privkey.sign_ecdsa(msg)
+                sig_schnorr = sign_schnorr(sign_privkey.get_bytes(), msg)
                 for verify_privkey, verify_pubkey in keys.items():
+                    verify_xonly_pubkey = verify_pubkey.get_bytes()[1:]
                     if verify_privkey == sign_privkey:
-                        self.assertTrue(verify_schnorr(verify_pubkey, sig, msg))
-                        sig = list(sig)
-                        sig[random.randrange(64)] ^= (1 << (random.randrange(8)))  # damaging signature should break things
-                        sig = bytes(sig)
-                    self.assertFalse(verify_schnorr(verify_pubkey, sig, msg))
+                        self.assertTrue(verify_pubkey.verify_ecdsa(sig_ecdsa, msg))
+                        self.assertTrue(verify_schnorr(verify_xonly_pubkey, sig_schnorr, msg))
+                        sig_ecdsa = random_bitflip(sig_ecdsa)  # damaging signature should break things
+                        sig_schnorr = random_bitflip(sig_schnorr)
+                    self.assertFalse(verify_pubkey.verify_ecdsa(sig_ecdsa, msg))
+                    self.assertFalse(verify_schnorr(verify_xonly_pubkey, sig_schnorr, msg))
 
     def test_schnorr_testvectors(self):
         """Implement the BIP340 test vectors (read from bip340_test_vectors.csv)."""