Foxed versions

Author: k4black

Diff for: pyproject.toml

@@ -1,3 +1,11 @@
+[build-system]
+requires = [
+    "setuptools >= 39.2.0",
+    "wheel >= 0.29.0",
+]
+build-backend = 'setuptools.build_meta'
+
+
 [tool.isort]
 multi_line_output = 3
 include_trailing_comma = true

Diff for: setup.cfg

@@ -29,24 +29,20 @@ classifiers =
     Programming Language :: Python :: Implementation :: PyPy
     Topic :: Utilities
 
+
 [options]
 packages = find:
-# TODO: work this into the extras selection instead.
-setup_requires =
-    pytest-runner
-    setuptools>=39.2.0
 install_requires =
     ecdsa != 0.15
-    rsa
-    pyasn1
+    rsa >=4.0, <5.0, !=4.4, !=4.1.1
+    pyasn1 >=0.4.1, <0.5.0
 
 [options.extras_require]
 test =
     pytest
     pytest-cov
-    pytest-runner
 cryptography =
-    cryptography>=3.4.0
+    cryptography >=3.4.0
 pycrypto =
     pycrypto >=2.6.0, <2.7.0
 pycryptodome =