Enhance CertUtils to return the newest matching certificate and add comprehensive unit tests

- Added run_openssl_dates() to extract notBefore/notAfter timestamps.
- Modified mapping logic to store multiple cert entries per SAN with metadata.
- find_cert_for_domain() now selects the newest certificate based on notBefore and mtime.
- Exact SAN matches take precedence over wildcard matches.
- Added new unit tests (test_cert_utils_newest.py) verifying freshness logic, fallback handling, and wildcard behavior.

Reference: https://chatgpt.com/share/68ef4b4c-41d4-800f-9e50-5da4b6be1105
This commit is contained in:
2025-10-15 09:21:00 +02:00
parent e6f4f3a6a4
commit d76e384ae3
2 changed files with 263 additions and 20 deletions

View File

@@ -6,6 +6,7 @@ __metaclass__ = type
import os
import subprocess
import time
from datetime import datetime
class CertUtils:
_domain_cert_mapping = None
@@ -22,6 +23,30 @@ class CertUtils:
except subprocess.CalledProcessError:
return ""
@staticmethod
def run_openssl_dates(cert_path):
"""
Returns (not_before_ts, not_after_ts) as POSIX timestamps or (None, None) on failure.
"""
try:
output = subprocess.check_output(
['openssl', 'x509', '-in', cert_path, '-noout', '-startdate', '-enddate'],
universal_newlines=True
)
nb, na = None, None
for line in output.splitlines():
line = line.strip()
if line.startswith('notBefore='):
nb = line.split('=', 1)[1].strip()
elif line.startswith('notAfter='):
na = line.split('=', 1)[1].strip()
def _parse(openssl_dt):
# OpenSSL format example: "Oct 10 12:34:56 2025 GMT"
return int(datetime.strptime(openssl_dt, "%b %d %H:%M:%S %Y %Z").timestamp())
return (_parse(nb) if nb else None, _parse(na) if na else None)
except Exception:
return (None, None)
@staticmethod
def extract_sans(cert_text):
dns_entries = []
@@ -59,7 +84,6 @@ class CertUtils:
else:
return domain == san
@classmethod
def build_snapshot(cls, cert_base_path):
snapshot = []
@@ -82,6 +106,17 @@ class CertUtils:
@classmethod
def refresh_cert_mapping(cls, cert_base_path, debug=False):
"""
Build mapping: SAN -> list of entries
entry = {
'folder': str,
'cert_path': str,
'mtime': float,
'not_before': int|None,
'not_after': int|None,
'is_wildcard': bool
}
"""
cert_files = cls.list_cert_files(cert_base_path)
mapping = {}
for cert_path in cert_files:
@@ -90,46 +125,82 @@ class CertUtils:
continue
sans = cls.extract_sans(cert_text)
folder = os.path.basename(os.path.dirname(cert_path))
try:
mtime = os.stat(cert_path).st_mtime
except FileNotFoundError:
mtime = 0.0
nb, na = cls.run_openssl_dates(cert_path)
for san in sans:
if san not in mapping:
mapping[san] = folder
entry = {
'folder': folder,
'cert_path': cert_path,
'mtime': mtime,
'not_before': nb,
'not_after': na,
'is_wildcard': san.startswith('*.'),
}
mapping.setdefault(san, []).append(entry)
cls._domain_cert_mapping = mapping
if debug:
print(f"[DEBUG] Refreshed domain-to-cert mapping: {mapping}")
print(f"[DEBUG] Refreshed domain-to-cert mapping (counts): "
f"{ {k: len(v) for k, v in mapping.items()} }")
@classmethod
def ensure_cert_mapping(cls, cert_base_path, debug=False):
if cls._domain_cert_mapping is None or cls.snapshot_changed(cert_base_path):
cls.refresh_cert_mapping(cert_base_path, debug)
@staticmethod
def _score_entry(entry):
"""
Return tuple used for sorting newest-first:
(not_before or -inf, mtime)
"""
nb = entry.get('not_before')
mtime = entry.get('mtime', 0.0)
return (nb if nb is not None else -1, mtime)
@classmethod
def find_cert_for_domain(cls, domain, cert_base_path, debug=False):
cls.ensure_cert_mapping(cert_base_path, debug)
exact_match = None
wildcard_match = None
candidates_exact = []
candidates_wild = []
for san, folder in cls._domain_cert_mapping.items():
for san, entries in cls._domain_cert_mapping.items():
if san == domain:
exact_match = folder
break
if san.startswith('*.'):
candidates_exact.extend(entries)
elif san.startswith('*.'):
base = san[2:]
if domain.count('.') == base.count('.') + 1 and domain.endswith('.' + base):
wildcard_match = folder
candidates_wild.extend(entries)
if exact_match:
if debug:
print(f"[DEBUG] Exact match for {domain} found in {exact_match}")
return exact_match
def _pick_newest(entries):
if not entries:
return None
# newest by (not_before, mtime)
best = max(entries, key=cls._score_entry)
return best
if wildcard_match:
if debug:
print(f"[DEBUG] Wildcard match for {domain} found in {wildcard_match}")
return wildcard_match
best_exact = _pick_newest(candidates_exact)
best_wild = _pick_newest(candidates_wild)
if best_exact and debug:
print(f"[DEBUG] Best exact match for {domain}: {best_exact['folder']} "
f"(not_before={best_exact['not_before']}, mtime={best_exact['mtime']})")
if best_wild and debug:
print(f"[DEBUG] Best wildcard match for {domain}: {best_wild['folder']} "
f"(not_before={best_wild['not_before']}, mtime={best_wild['mtime']})")
# Prefer exact if it exists; otherwise wildcard
chosen = best_exact or best_wild
if chosen:
return chosen['folder']
if debug:
print(f"[DEBUG] No certificate folder found for {domain}")
return None

View File

@@ -0,0 +1,172 @@
#!/usr/bin/env python3
import os
import sys
import unittest
from types import SimpleNamespace
from unittest.mock import patch
# Add the project root/module_utils to the import path
CURRENT_DIR = os.path.dirname(__file__)
PROJECT_ROOT = os.path.abspath(os.path.join(CURRENT_DIR, "../../.."))
sys.path.insert(0, PROJECT_ROOT)
from module_utils.cert_utils import CertUtils
def _san_block(*entries):
"""
Helper: builds a minimal OpenSSL text snippet that contains SAN entries.
Example: _san_block('example.com', '*.example.com')
"""
sans = ", ".join(f"DNS:{e}" for e in entries)
return f"""
Certificate:
Data:
Version: 3 (0x2)
...
X509v3 extensions:
X509v3 Subject Alternative Name:
{sans}
"""
class TestCertUtilsFindNewest(unittest.TestCase):
def setUp(self):
# Reset internal caches before each test
CertUtils._domain_cert_mapping = None
CertUtils._cert_snapshot = None
def _mock_stat_map(self, mtime_map, size_map=None):
size_map = size_map or {}
def _stat_side_effect(path):
return SimpleNamespace(
st_mtime=mtime_map.get(path, 0.0),
st_size=size_map.get(path, 1234),
)
return _stat_side_effect
def test_prefers_newest_by_not_before(self):
"""
Two certs with the same SAN 'www.example.com':
- a/cert.pem: older notBefore
- b/cert.pem: newer notBefore -> should be selected
"""
files = [
"/etc/letsencrypt/live/a/cert.pem",
"/etc/letsencrypt/live/b/cert.pem",
]
san_text = _san_block("www.example.com")
with patch.object(CertUtils, "list_cert_files", return_value=files), \
patch.object(CertUtils, "run_openssl", return_value=san_text), \
patch.object(CertUtils, "run_openssl_dates") as mock_dates, \
patch("os.stat", side_effect=self._mock_stat_map({
files[0]: 1000,
files[1]: 1001,
})):
mock_dates.side_effect = [(10, 100000), (20, 100000)] # older/newer
folder = CertUtils.find_cert_for_domain("www.example.com", "/etc/letsencrypt/live", debug=False)
self.assertEqual(folder, "b", "Should return the folder with the newest notBefore date.")
def test_fallback_to_mtime_when_not_before_missing(self):
"""
When not_before is missing, mtime should be used as a fallback.
"""
files = [
"/etc/letsencrypt/live/a/cert.pem",
"/etc/letsencrypt/live/b/cert.pem",
]
san_text = _san_block("www.example.com")
with patch.object(CertUtils, "list_cert_files", return_value=files), \
patch.object(CertUtils, "run_openssl", return_value=san_text), \
patch.object(CertUtils, "run_openssl_dates", return_value=(None, None)), \
patch("os.stat", side_effect=self._mock_stat_map({
files[0]: 1000,
files[1]: 2000,
})):
folder = CertUtils.find_cert_for_domain("www.example.com", "/etc/letsencrypt/live", debug=False)
self.assertEqual(folder, "b", "Should fall back to mtime and select the newest file.")
def test_exact_beats_wildcard_even_if_wildcard_newer(self):
"""
Exact matches must take precedence over wildcard matches,
even if the wildcard certificate is newer.
"""
files = [
"/etc/letsencrypt/live/exact/cert.pem",
"/etc/letsencrypt/live/wild/cert.pem",
]
text_exact = _san_block("api.example.com")
text_wild = _san_block("*.example.com")
with patch.object(CertUtils, "list_cert_files", return_value=files), \
patch.object(CertUtils, "run_openssl") as mock_text, \
patch.object(CertUtils, "run_openssl_dates") as mock_dates, \
patch("os.stat", side_effect=self._mock_stat_map({
files[0]: 1000, # exact is older
files[1]: 5000, # wildcard is much newer
})):
mock_text.side_effect = [text_exact, text_wild]
mock_dates.side_effect = [(10, 100000), (99, 100000)]
folder = CertUtils.find_cert_for_domain("api.example.com", "/etc/letsencrypt/live", debug=False)
self.assertEqual(
folder, "exact",
"Exact match must win even if the wildcard certificate is newer."
)
def test_wildcard_one_label_only(self):
"""
Wildcards (*.example.com) must only match one additional label.
"""
files = ["/etc/letsencrypt/live/wild/cert.pem"]
text_wild = _san_block("*.example.com")
with patch.object(CertUtils, "list_cert_files", return_value=files), \
patch.object(CertUtils, "run_openssl", return_value=text_wild), \
patch.object(CertUtils, "run_openssl_dates", return_value=(50, 100000)), \
patch("os.stat", side_effect=self._mock_stat_map({files[0]: 1000})):
# should match
self.assertEqual(
CertUtils.find_cert_for_domain("api.example.com", "/etc/letsencrypt/live"),
"wild"
)
# too deep -> should not match
self.assertIsNone(
CertUtils.find_cert_for_domain("deep.api.example.com", "/etc/letsencrypt/live"),
"Wildcard must not match multiple labels."
)
# base domain not covered
self.assertIsNone(
CertUtils.find_cert_for_domain("example.com", "/etc/letsencrypt/live"),
"Base domain is not covered by *.example.com."
)
def test_snapshot_refresh_rebuilds_mapping(self):
"""
ensure_cert_mapping() should rebuild mapping when snapshot changes.
"""
CertUtils._domain_cert_mapping = {"www.example.com": [{"folder": "old", "mtime": 1, "not_before": 1}]}
with patch.object(CertUtils, "snapshot_changed", return_value=True), \
patch.object(CertUtils, "refresh_cert_mapping") as mock_refresh:
def _set_new_mapping(cert_base_path, debug=False):
CertUtils._domain_cert_mapping = {
"www.example.com": [{"folder": "new", "mtime": 999, "not_before": 999}]
}
mock_refresh.side_effect = _set_new_mapping
folder = CertUtils.find_cert_for_domain("www.example.com", "/etc/letsencrypt/live", debug=False)
self.assertEqual(folder, "new", "Mapping must be refreshed when snapshot changes.")
if __name__ == "__main__":
unittest.main()