Apply string-or-list processing to ssh_config

Now ssh_config also accepts string-or-list options, for serveral
keywords.

openssh/files/ssh_config

@@ -2,6 +2,7 @@
 {%- set ssh_config = salt['pillar.get']('ssh_config', default=default_settings.ssh_config, merge=True) -%}
 {#- present in ssh_config and known in actual file options -#}
 {%- set processed_options = [] -%}
+{%- set string_or_list_options = ['KexAlgorithms', 'Ciphers', 'MACs'] -%}
 
 {%- macro render_raw_option(keyword, value) -%}
   {%- if value is sameas true -%}
@@ -47,8 +48,31 @@
 {{ option_impl(keyword, default, True) }}
 {%- endmacro -%}
 
+{#- macro for collapsing a list into a string -#}
+{%- macro option_collapselist(keyword, sep) -%}
+{%- do processed_options.append(keyword) -%}
+{{keyword}} {{ssh_config.get(keyword)|join(sep)}}
+{%- endmacro -%}
+
+{#- macro for handling an option that can be specified as a list or a string -#}
+{%- macro option_string_or_list(keyword, default, default_commented, sep=',') -%}
+{%- if ssh_config.get(keyword, '') is string -%}
+  {%- if default_commented -%}
+{{ option(keyword, default) }}
+  {%- else -%}
+{{ option_default_uncommented(keyword, default) }}
+  {%- endif -%}
+{%- else -%}
+{{ option_collapselist(keyword, sep) }}
+{%- endif -%}
+{%- endmacro -%}
+
+{%- if ssh_config.get('ConfigBanner', False) -%}
+{{ ssh_config['ConfigBanner'] }}
+{%- else -%}
 # Do not edit this file manually!
 # It will be overwritten by salt!
+{%- endif %}
 
 {%- if 'Hosts' in ssh_config %}
 {%- do processed_options.append('Hosts') %}
@@ -64,8 +88,13 @@ Host {{ host }}
 {%- for keyword in ssh_config.keys() %}
   {#- Matches have to be at the bottom and should be handled differently -#}
   {%- if not keyword in processed_options and keyword != 'matches' -%}
+    {%- if not keyword in string_or_list_options -%}
 {#- send a blank default as it doesn't matter #}
 {{ render_option(keyword, '') }}
+    {%- else -%}
+{#- same as above #}
+{{ option_string_or_list(keyword, '', True) }}
+    {%- endif -%}
   {%- endif -%}
 {%- endfor %}
 
@@ -78,3 +107,6 @@ Match {{ match['type'].keys()[0] }} {{ match['type'].values()[0] }}
     {%- endfor %}
   {%- endfor %}
 {%- endif %}
+
+{#- vim: set ft=jinja : #}
+