cli: Fix 'certidude list [CA]...' command

certidude/cli.py

@@ -646,7 +646,15 @@ def certidude_list(ca, show_key_type, show_extensions, show_path):
         click.echo(" |    |")
 
     config = load_config()
-    for ca in config.all_authorities():
+
+    wanted_list = None
+    if ca:
+        missing = list(set(ca) - set(config.ca_list))
+        if missing:
+            raise click.NoSuchOption(option_name='', message="Unable to find certificate authority.", possibilities=config.ca_list)
+        wanted_list = ca
+
+    for ca in config.all_authorities(wanted_list):
         click.echo("Certificate authority " + click.style(ca.slug, fg="blue"))
 #        if ca.certificate.email_address:
 #            click.echo("  \u2709 %s" % ca.certificate.email_address)

certidude/wrappers.py

@@ -107,13 +107,28 @@ class CertificateAuthorityConfig(object):
         authority = CertificateAuthority(slug, **dirs)
         return authority
 
-    def all_authorities(self):
-        for section in self._config:
-            if section.startswith("CA_"):
-                try:
-                    yield self.instantiate_authority(section[3:])
-                except FileNotFoundError:
-                    pass
+
+    def all_authorities(self, wanted=None):
+        for ca in self.ca_list:
+            if wanted and ca not in wanted:
+                continue
+            try:
+                yield self.instantiate_authority(ca)
+            except FileNotFoundError:
+                pass
+
+
+    @property
+    def ca_list(self):
+        """
+        Returns sorted list of CA-s defined in the configuration file.
+        """
+        l = [s[3:] for s in self._config if s.startswith("CA_")]
+        # Sanity check for duplicates (although ConfigParser fails earlier)
+        if len(l) != len(set(l)):
+            raise ValueError
+        return sorted(l)
+
 
     def pop_certificate_authority(self):
         def wrapper(func):