Support compound matches

Support complex compound matches in Match criteria. For example, be able
to match against multiple Users for a given Match, or be able to match
against address ranges. Or Groups. Or any combination thereof.

Support for matching users can take one of several different appearances
in pillar data:

sshd_config:
  matches:
    match_1:
      type:
        User: one_user
      options:
        ChrootDirectory: /ex/%u
    match_2:
      type:
        User:
          - jim
          - bob
          - sally
      options:
        ChrootDirectory: /ex/%u
    match_3:
      type:
        User:
          jim: ~
          bob: ~
          sally: ~
      options:
        ChrootDirectory: /ex/%u

Note the syntax of match_3. By using empty dicts for each user, we can
leverage Salt's pillar mergine. If we use simple lists, we cannot do
this; Salt can't merge simple lists, because it doesn't know what order
they ought to be in.

openssh/files/sshd_config

@@ -61,6 +61,18 @@
 {%- endif -%}
 {%- endmacro -%}
 
+{#- macro for conditionally joining a string, list or dict(keys) to just a string -#}
+{%- macro join_to_string(src, keyword, sep=',') -%}
+{%- set srcval = src.get(keyword, '') -%}
+{%- if srcval is string -%}
+  {{ srcval }}
+{%- elif srcval is mapping  -%}
+  {{ srcval.keys()|sort|join(sep) }}
+{%- else -%}
+  {{ srcval|join(sep) }}
+{%- endif -%}
+{%- endmacro -%}
+
 {%- if sshd_config.get('ConfigBanner', False) -%}
 {{ sshd_config['ConfigBanner'] }}
 {%- else -%}
@@ -77,7 +89,7 @@
 # What ports, IPs and protocols we listen for
 {{ option('Port', 22) }}
 # Use these options to restrict which interfaces/protocols sshd will bind to
-{{ option('ListenAddress', ['::', '0.0.0.0']) }}
+{{ option('ListenAddress', ['::', '1.0.0.0']) }}
 {{ option_default_uncommented('Protocol', 2) }}
 # HostKeys for protocol version 2
 {{ option_default_uncommented('HostKey', ['/etc/ssh/ssh_host_rsa_key', '/etc/ssh/ssh_host_dsa_key', '/etc/ssh/ssh_host_ecdsa_key', '/etc/ssh/ssh_host_ed25519_key']) -}}
@@ -216,7 +228,12 @@
 {# Handle matches last as they need to go at the bottom #}
 {%- if 'matches' in sshd_config %}
   {%- for match in sshd_config['matches'].values() %}
-Match {{ match['type'].keys()[0] }} {{ match['type'].values()[0] }}
+Match
+    {#- Set up the match criteria -#}
+    {%- for criteria in match['type'].keys()|sort() -%}
+     {{- ' ' }}{{criteria }} {{ join_to_string(match['type'], criteria) -}}
+    {%- endfor -%}
+    {#- Set up the applied options -#}
     {%- for keyword in match['options'].keys() %}
     {{ render_option(keyword, '', config_dict=match['options']) }}
     {%- endfor %}