Merge pull request #2383 from freifunk-gluon/web-fixes

gluon-web: prohibit cross-origin POST requests

.github/workflows/lint.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install Dependencies
-        run: sudo apt install lua-check
+        run: sudo apt-get -y update && sudo apt-get -y install lua-check
       - name: Install example site
         run: ln -s ./docs/site-example ./site
       - name: Lint Lua code
@@ -22,7 +22,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Install Dependencies
-        run: sudo apt install shellcheck
+        run: sudo apt-get -y update && sudo apt-get -y install shellcheck
       - name: Install example site
         run: ln -s ./docs/site-example ./site
       - name: Lint shell code

package/gluon-web-admin/files/lib/gluon/config-mode/view/admin/upgrade.html

@@ -44,7 +44,6 @@ $Id$
 
 	<div class="gluon-page-actions">
 		<input type="hidden" name="step" value="2" />
-		<input type="hidden" name="token" value="<%=token%>" />
 		<input class="gluon-button gluon-button-submit" type="submit" value="<%:Upload image%>" />
 	</div>
 </form>

package/gluon-web-admin/files/lib/gluon/config-mode/view/admin/upgrade_confirm.html

@@ -49,13 +49,11 @@ You may obtain a copy of the License at
   <form method="post" enctype="multipart/form-data" action="<%|url(request)%>" style="display:inline">
     <input type="hidden" name="step" value="3" />
     <input type="hidden" name="keepcfg" value="<%=keepconfig and "1" or "0"%>" />
-    <input type="hidden" name="token" value="<%=token%>" />
     <input class="gluon-button gluon-button-submit" type="submit" value="<%:Continue%>" />
   </form>
   <form method="post" enctype="multipart/form-data" action="<%|url(request)%>" style="display:inline">
     <input type="hidden" name="step" value="1" />
     <input type="hidden" name="keepcfg" value="<%=keepconfig and "1" or "0"%>" />
-    <input type="hidden" name="token" value="<%=token%>" />
     <input class="gluon-button gluon-button-reset" type="submit" value="<%:Cancel%>" />
   </form>
 </div>

package/gluon-web-model/files/lib/gluon/web/view/model/form.html

 <form method="post" enctype="multipart/form-data" action="<%|url(request)%>" data-update="reset">
-	<input type="hidden" name="token" value="<%=token%>" />
 	<input type="hidden" name="<%=id%>" value="1" />
 
 	<div class="gluon-form" id="form-<%=id%>">

package/gluon-web/luasrc/usr/lib/lua/gluon/web/dispatcher.lua

@@ -184,9 +184,15 @@ local function dispatch(config, http, request)
 		return
 	end
 
-	http:parse_input(node.filehandler)
+	local ok, err = pcall(http.parse_input, http, node.filehandler)
+	if not ok then
+		http:status(400, "Bad request")
+		http:prepare_content("text/plain")
+		http:write(err .. "\r\n")
+		return
+	end
 
-	local ok, err = pcall(node.target)
+	ok, err = pcall(node.target)
 	if not ok then
 		http:status(500, "Internal Server Error")
 		renderer.render_layout("error/500", {
@@ -208,6 +214,6 @@ return function(config, http)
 	if not ok then
 		http:status(500, "Internal Server Error")
 		http:prepare_content("text/plain")
-		http:write(err)
+		http:write(err .. "\r\n")
 	end
 end

package/gluon-web/luasrc/usr/lib/lua/gluon/web/http/protocol.lua

@@ -108,16 +108,11 @@ end
 --  o String value containing a chunk of the file data
 --  o Boolean which indicates whether the current chunk is the last one (eof)
 local function mimedecode_message_body(src, msg, filecb)
-
-	if msg and msg.env.CONTENT_TYPE then
-		msg.mime_boundary = msg.env.CONTENT_TYPE:match("^multipart/form%-data; boundary=(.+)$")
-	end
-
-	if not msg.mime_boundary then
-		return nil, "Invalid Content-Type found"
+	local mime_boundary = (msg.env.CONTENT_TYPE or ''):match("^multipart/form%-data; boundary=(.+)$")
+	if not mime_boundary then
+		error("Invalid Content-Type found")
 	end
 
-
 	local tlen   = 0
 	local inhdr  = false
 	local field  = nil
@@ -188,10 +183,10 @@ local function mimedecode_message_body(src, msg, filecb)
 			local spos, epos, found
 
 			repeat
-				spos, epos = data:find("\r\n--" .. msg.mime_boundary .. "\r\n", 1, true)
+				spos, epos = data:find("\r\n--" .. mime_boundary .. "\r\n", 1, true)
 
 				if not spos then
-					spos, epos = data:find("\r\n--" .. msg.mime_boundary .. "--\r\n", 1, true)
+					spos, epos = data:find("\r\n--" .. mime_boundary .. "--\r\n", 1, true)
 				end
 
 
@@ -250,20 +245,61 @@ local function mimedecode_message_body(src, msg, filecb)
 		return true
 	end
 
-	return pump(src, snk)
+	assert(pump(src, snk))
+end
+
+local function check_post_origin(msg)
+	local default_port = '80'
+	local request_scheme = 'http'
+	if msg.env.HTTPS then
+		default_port = '443'
+		request_scheme = 'https'
+	end
+
+	local request_host = msg.env.HTTP_HOST
+	if not request_host then
+		error('POST request without Host header')
+	end
+	if not request_host:match(':[0-9]+$') then
+		request_host = request_host .. ':' .. default_port
+	end
+
+	local origin = msg.env.HTTP_ORIGIN
+	if not origin then
+		error('POST request without Origin header')
+	end
+	local origin_scheme, origin_host = origin:match('^([^:]*)://(.*)$')
+	if not origin_host then
+		error('POST request with invalid Origin header')
+	end
+	if not origin_host:match(':[0-9]+$') then
+		local origin_port
+		if origin_scheme == 'http' then
+			origin_port = '80'
+		elseif origin_scheme == 'https' then
+			origin_port = '443'
+		else
+			error('POST request with invalid Origin header')
+		end
+		origin_host = origin_host .. ':' .. origin_port
+	end
+
+	if request_scheme ~= origin_scheme or request_host ~= origin_host then
+		error('Invalid cross-origin POST')
+	end
 end
 
 -- This function will examine the Content-Type within the given message object
 -- to select the appropriate content decoder.
 -- Currently only the multipart/form-data mime type is supported.
 function M.parse_message_body(src, msg, filecb)
-	if not (msg.env.REQUEST_METHOD == "POST" and msg.env.CONTENT_TYPE) then
+	if msg.env.REQUEST_METHOD ~= "POST" then
 		return
 	end
 
-	if msg.env.CONTENT_TYPE:match("^multipart/form%-data") then
-		return mimedecode_message_body(src, msg, filecb)
-	end
+	check_post_origin(msg)
+
+	mimedecode_message_body(src, msg, filecb)
 end
 
 return M