Avoid mixed content when cgiurl is https but url is not

[ikiwiki.git] / IkiWiki.pm

diff --git a/IkiWiki.pm b/IkiWiki.pm
index d5d11ee857c02b1520fc6a971032cc592df78d23..38b91ae1d373e4c6f38f99a8b4ccb61aed33fcc0 100644 (file)
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -613,12 +613,39 @@ sub checkconfig () {
 
                        $local_cgiurl = $cgiurl->path;
 
-                       if ($cgiurl->scheme ne $baseurl->scheme or
-                               $cgiurl->authority ne $baseurl->authority) {
+                       if ($cgiurl->scheme eq 'https' &&
+                               $baseurl->scheme eq 'http') {
+                               # We assume that the same content is available
+                               # over both http and https, because if it
+                               # wasn't, accessing the static content
+                               # from the CGI would be mixed-content,
+                               # which would be a security flaw.
+
+                               if ($cgiurl->authority ne $baseurl->authority) {
+                                       # use protocol-relative URL for
+                                       # static content
+                                       $local_url = "$config{url}/";
+                                       $local_url =~ s{^http://}{//};
+                               }
+                               # else use host-relative URL for static content
+
+                               # either way, CGI needs to be absolute
+                               $local_cgiurl = $config{cgiurl};
+                       }
+                       elsif ($cgiurl->scheme ne $baseurl->scheme) {
                                # too far apart, fall back to absolute URLs
                                $local_url = "$config{url}/";
                                $local_cgiurl = $config{cgiurl};
                        }
+                       elsif ($cgiurl->authority ne $baseurl->authority) {
+                               # slightly too far apart, fall back to
+                               # protocol-relative URLs
+                               $local_url = "$config{url}/";
+                               $local_url =~ s{^https?://}{//};
+                               $local_cgiurl = $config{cgiurl};
+                               $local_cgiurl =~ s{^https?://}{//};
+                       }
+                       # else keep host-relative URLs
                }
 
                $local_url =~ s{//$}{/};