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

module_utils/cert_utils.py

@@ -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
-