The certificates.py module#

Summary#

CertificateGenerator

Certificate generator for creating self-signed certificates for testing.

parse_server_spec

Parse a server specification string into primary hostname and SAN list.

generate_test_certificates

Generate a complete set of test certificates for gRPC mutual TLS.

Description#

Certificate generation utilities for gRPC mutual TLS testing.

This module provides utilities for generating self-signed certificates suitable for testing gRPC applications with mutual TLS authentication, including support for HPC deployments with multiple servers.

Examples#

Generate certificates for a single server:

>>> from ansys.tools.common.utils import generate_test_certificates
>>> files = generate_test_certificates(output_dir="certs")

Generate certificates for multiple servers (HPC deployment):

>>> files = generate_test_certificates(servers=["node01,192.0.2.1", "node02,192.0.2.2"], output_dir="certs")

Use in pytest fixtures:

>>> import pytest
>>> from pathlib import Path
>>> from ansys.tools.common.utils import generate_test_certificates
>>>
>>> @pytest.fixture(scope="session")
... def tls_certificates(tmp_path_factory):
...     cert_dir = tmp_path_factory.mktemp("certs")
...     files = generate_test_certificates(output_dir=cert_dir)
...     return {
...         "ca_cert": cert_dir / "ca.crt",
...         "server_cert": cert_dir / "server.crt",
...         "server_key": cert_dir / "server.key",
...         "client_cert": cert_dir / "client.crt",
...         "client_key": cert_dir / "client.key",
...     }

Module detail#

certificates.parse_server_spec(server_spec: str) → tuple[str, list[str]]#

Parse a server specification string into primary hostname and SAN list.

Parameters#

server_specstr

A comma-separated string like “node01,192.0.2.1” or just “node01”

Returns#

tuple[str, list[str]]

Tuple containing (primary_hostname, [additional_san_names])

Raises#

ValueError

If the server specification is empty or invalid

certificates.generate_test_certificates(servers: list[str] | None = None, client_name: str = 'Test Client', validity_days: int = 1, output_dir: pathlib.Path | None = None, key_size: int = 4096) → list[pathlib.Path]#

Generate a complete set of test certificates for gRPC mutual TLS.

This is a convenience function that generates all necessary certificates (CA, server(s), and client) and saves them to the specified directory. Perfect for pytest fixtures and test setup.

Parameters#

serverslist[str], optional

List of server specifications in format “hostname[,san1,san2,…]”. If None, defaults to [“localhost,127.0.0.1”]

client_namestr, optional

Common name for the client certificate, by default “Test Client”

validity_daysint, optional

Number of days the certificates should be valid, by default 1 (24 hours)

output_dirPath, optional

Output directory for certificates. If None, uses current directory.

key_sizeint, optional

Size of the RSA keys in bits, by default 4096

Returns#

list[Path]

List of paths to all generated certificate files

Examples#

Basic usage:

>>> from ansys.tools.common.utils import generate_test_certificates
>>> files = generate_test_certificates(output_dir=Path("certs"))
>>> print(files)
[Path('certs/ca.key'), Path('certs/ca.crt'), ...]

HPC deployment with multiple servers:

>>> files = generate_test_certificates(servers=["node01,192.0.2.1", "node02,192.0.2.2"], output_dir=Path("certs"))

Use in pytest:

>>> @pytest.fixture(scope="session")
... def tls_certs(tmp_path_factory):
...     cert_dir = tmp_path_factory.mktemp("certs")
...     generate_test_certificates(output_dir=cert_dir)
...     return cert_dir