Land #6398, content length header

lands wei's content length header pr

lib/rex/proto/http/client_request.rb

@@ -393,7 +393,17 @@ class ClientRequest
   # Return the content length header
   #
   def set_content_len_header(clen)
-    return "" if clen == 0 || opts['chunked_size'] > 0 || (opts['headers'] && opts['headers']['Content-Length'])
+    if opts['method'] == 'GET' && (clen == 0 || opts['chunked_size'] > 0)
+      # This condition only applies to GET because of the specs.
+      # RFC-7230:
+      # A Content-Length header field is normally sent in a POST
+      # request even when the value is 0 (indicating an empty payload body)
+      return ''
+    elsif opts['headers'] && opts['headers']['Content-Length']
+      # If the module has a modified content-length header, respect that by
+      # not setting another one.
+      return ''
+    end
     set_formatted_header("Content-Length", clen)
   end
 

spec/lib/rex/proto/http/client_request_spec.rb

@@ -170,6 +170,16 @@ RSpec.describe Rex::Proto::Http::ClientRequest do
         :set_content_len_header => { args: 1024, result: "Content-Length: 1024\r\n"}
       }
     ],
+
+    [
+      "with a POST request and no payload body",
+      default_options.merge({
+        'method' => 'POST'
+      }),
+      {
+        :set_content_len_header => { args: 0, result: "Content-Length: 0\r\n"}
+      }
+    ],
   
   ].each do |c, opts, expectations|
     context c do