deprecate digest_integer() and related methods

Author: tomato42

src/ecdsa/ecdsa.py

@@ -64,6 +64,7 @@
 modified as part of the python-ecdsa package.
 """
 
+import warnings
 from six import int2byte, b
 from . import ellipticcurve
 from . import numbertheory
@@ -269,8 +270,14 @@ def sign(self, hash, random_k):
         return Signature(r, s)
 
 
-def int_to_string(x):
+def int_to_string(x):  # pragma: no cover
     """Convert integer x into a string of bytes, as per X9.62."""
+    # deprecated in 0.19
+    warnings.warn(
+        "Function is unused in library code. If you use this code, "
+        "change to util.string_to_number.",
+        DeprecationWarning,
+    )
     assert x >= 0
     if x == 0:
         return b("\0")
@@ -284,8 +291,14 @@ def int_to_string(x):
     return b("").join(result)
 
 
-def string_to_int(s):
+def string_to_int(s):  # pragma: no cover
     """Convert a string of bytes into an integer, as per X9.62."""
+    # deprecated in 0.19
+    warnings.warn(
+        "Function is unused in library code. If you use this code, "
+        "change to util.number_to_string.",
+        DeprecationWarning,
+    )
     result = 0
     for c in s:
         if not isinstance(c, int):
@@ -294,9 +307,16 @@ def string_to_int(s):
     return result
 
 
-def digest_integer(m):
+def digest_integer(m):  # pragma: no cover
     """Convert an integer into a string of bytes, compute
     its SHA-1 hash, and convert the result to an integer."""
+    # deprecated in 0.19
+    warnings.warn(
+        "Function is unused in library code. If you use this code, "
+        "change to a one-liner with util.number_to_string and "
+        "util.string_to_number methods.",
+        DeprecationWarning,
+    )
     #
     # I don't expect this function to be used much. I wrote
     # it in order to be able to duplicate the examples

src/ecdsa/test_ecdsa.py

@@ -598,7 +598,13 @@ def test_signature_validity(gen, msg, qx, qy, r, s, expected):
     elliptic curve of `gen`, `r` and `s` are the signature, and
     `expected` is True iff the signature is expected to be valid."""
     pubk = Public_key(gen, ellipticcurve.Point(gen.curve(), qx, qy))
-    assert expected == pubk.verifies(digest_integer(msg), Signature(r, s))
+    with pytest.warns(DeprecationWarning) as warns:
+        msg_dgst = digest_integer(msg)
+    assert len(warns) == 3
+    assert "unused" in warns[0].message.args[0]
+    assert "unused" in warns[1].message.args[0]
+    assert "unused" in warns[2].message.args[0]
+    assert expected == pubk.verifies(msg_dgst, Signature(r, s))
 
 
 @pytest.mark.parametrize(
@@ -607,7 +613,13 @@ def test_signature_validity(gen, msg, qx, qy, r, s, expected):
 def test_pk_recovery(gen, msg, r, s, qx, qy, expected):
     del expected
     sign = Signature(r, s)
-    pks = sign.recover_public_keys(digest_integer(msg), gen)
+    with pytest.warns(DeprecationWarning) as warns:
+        msg_dgst = digest_integer(msg)
+    assert len(warns) == 3
+    assert "unused" in warns[0].message.args[0]
+    assert "unused" in warns[1].message.args[0]
+    assert "unused" in warns[2].message.args[0]
+    pks = sign.recover_public_keys(msg_dgst, gen)
 
     assert pks
 
@@ -675,4 +687,8 @@ def test_sig_verify(args):
 
 
 def test_int_to_string_with_zero():
-    assert int_to_string(0) == b"\x00"
+    with pytest.warns(DeprecationWarning) as warns:
+        assert int_to_string(0) == b"\x00"
+
+    assert len(warns) == 1
+    assert "unused" in warns[0].message.args[0]