diff --git a/scripts/mbedtls_dev/test_generation.py b/scripts/mbedtls_dev/test_generation.py
new file mode 100644
index 0000000..3abedd0
--- /dev/null
+++ b/scripts/mbedtls_dev/test_generation.py
@@ -0,0 +1,138 @@
+#!/usr/bin/env python3
+"""Common test generation classes and main function.
+
+These are used both by generate_psa_tests.py and generate_bignum_tests.py.
+"""
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import os
+import posixpath
+import re
+from typing import Callable, Dict, Iterable, List, Type, TypeVar
+
+from mbedtls_dev import test_case
+
+T = TypeVar('T') #pylint: disable=invalid-name
+
+
+class BaseTarget:
+    """Base target for test case generation.
+
+    Attributes:
+        count: Counter for test class.
+        desc: Short description of test case.
+        func: Function which the class generates tests for.
+        gen_file: File to write generated tests to.
+        title: Description of the test function/purpose.
+    """
+    count = 0
+    desc = ""
+    func = ""
+    gen_file = ""
+    title = ""
+
+    def __init__(self) -> None:
+        type(self).count += 1
+
+    @property
+    def args(self) -> List[str]:
+        """Create list of arguments for test case."""
+        return []
+
+    @property
+    def description(self) -> str:
+        """Create a numbered test description."""
+        return "{} #{} {}".format(self.title, self.count, self.desc)
+
+    def create_test_case(self) -> test_case.TestCase:
+        """Generate test case from the current object."""
+        tc = test_case.TestCase()
+        tc.set_description(self.description)
+        tc.set_function(self.func)
+        tc.set_arguments(self.args)
+
+        return tc
+
+    @classmethod
+    def generate_tests(cls):
+        """Generate test cases for the target subclasses."""
+        for subclass in sorted(cls.__subclasses__(), key=lambda c: c.__name__):
+            yield from subclass.generate_tests()
+
+
+class TestGenerator:
+    """Generate test data."""
+    def __init__(self, options) -> None:
+        self.test_suite_directory = self.get_option(options, 'directory',
+                                                    'tests/suites')
+
+    @staticmethod
+    def get_option(options, name: str, default: T) -> T:
+        value = getattr(options, name, None)
+        return default if value is None else value
+
+    def filename_for(self, basename: str) -> str:
+        """The location of the data file with the specified base name."""
+        return posixpath.join(self.test_suite_directory, basename + '.data')
+
+    def write_test_data_file(self, basename: str,
+                             test_cases: Iterable[test_case.TestCase]) -> None:
+        """Write the test cases to a .data file.
+
+        The output file is ``basename + '.data'`` in the test suite directory.
+        """
+        filename = self.filename_for(basename)
+        test_case.write_data_file(filename, test_cases)
+
+    # Note that targets whose names contain 'test_format' have their content
+    # validated by `abi_check.py`.
+    TARGETS = {} # type: Dict[str, Callable[..., test_case.TestCase]]
+
+    def generate_target(self, name: str, *target_args) -> None:
+        """Generate cases and write to data file for a target.
+
+        For target callables which require arguments, override this function
+        and pass these arguments using super() (see PSATestGenerator).
+        """
+        test_cases = self.TARGETS[name](*target_args)
+        self.write_test_data_file(name, test_cases)
+
+def main(args, generator_class: Type[TestGenerator] = TestGenerator):
+    """Command line entry point."""
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--list', action='store_true',
+                        help='List available targets and exit')
+    parser.add_argument('targets', nargs='*', metavar='TARGET',
+                        help='Target file to generate (default: all; "-": none)')
+    options = parser.parse_args(args)
+    generator = generator_class(options)
+    if options.list:
+        for name in sorted(generator.TARGETS):
+            print(generator.filename_for(name))
+        return
+    if options.targets:
+        # Allow "-" as a special case so you can run
+        # ``generate_xxx_tests.py - $targets`` and it works uniformly whether
+        # ``$targets`` is empty or not.
+        options.targets = [os.path.basename(re.sub(r'\.data\Z', r'', target))
+                           for target in options.targets
+                           if target != '-']
+    else:
+        options.targets = sorted(generator.TARGETS)
+    for target in options.targets:
+        generator.generate_target(target)