mod_http_files: send valid ETag header

[prosody.git] / plugins / mod_http_files.lua

diff --git a/plugins/mod_http_files.lua b/plugins/mod_http_files.lua
index dd04853beb4ecd8b38466a0a205d7acd4ebfd8bf..40f46c9cf8b9dc524f6c643731b1e2c5e9cf8a60 100644 (file)
--- a/plugins/mod_http_files.lua
+++ b/plugins/mod_http_files.lua
@@ -14,6 +14,7 @@ local os_date = os.date;
 local open = io.open;
 local stat = lfs.attributes;
 local build_path = require"socket.url".build_path;
+local path_sep = package.config:sub(1,1);
 
 local base_path = module:get_option_string("http_files_dir", module:get_option_string("http_path"));
 local dir_indices = module:get_option("http_index_files", { "index.html", "index.htm" });
@@ -48,6 +49,38 @@ if not mime_map then
        end
 end
 
+local forbidden_chars_pattern = "[/%z]";
+if prosody.platform == "windows" then
+       forbidden_chars_pattern = "[/%z\001-\031\127\"*:<>?|]"
+end
+
+local urldecode = require "util.http".urldecode;
+function sanitize_path(path)
+       if not path then return end
+       local out = {};
+
+       local c = 0;
+       for component in path:gmatch("([^/]+)") do
+               component = urldecode(component);
+               if component:find(forbidden_chars_pattern) then
+                       return nil;
+               elseif component == ".." then
+                       if c <= 0 then
+                               return nil;
+                       end
+                       out[c] = nil;
+                       c = c - 1;
+               elseif component ~= "." then
+                       c = c + 1;
+                       out[c] = component;
+               end
+       end
+       if path:sub(-1,-1) == "/" then
+               out[c+1] = "";
+       end
+       return "/"..table.concat(out, "/");
+end
+
 local cache = setmetatable({}, { __mode = "kv" }); -- Let the garbage collector have it if it wants to.
 
 function serve(opts)
@@ -59,9 +92,14 @@ function serve(opts)
        local directory_index = opts.directory_index;
        local function serve_file(event, path)
                local request, response = event.request, event.response;
-               local orig_path = request.path;
-               local full_path = base_path .. (path and "/"..path or "");
-               local attr = stat(full_path);
+               local sanitized_path = sanitize_path(path);
+               if path and not sanitized_path then
+                       return 400;
+               end
+               path = sanitized_path;
+               local orig_path = sanitize_path(request.path);
+               local full_path = base_path .. (path or ""):gsub("/", path_sep);
+               local attr = stat(full_path:match("^.*[^\\/]")); -- Strip trailing path separator because Windows
                if not attr then
                        return 404;
                end
@@ -71,7 +109,7 @@ function serve(opts)
                local last_modified = os_date('!%a, %d %b %Y %H:%M:%S GMT', attr.modification);
                response_headers.last_modified = last_modified;
 
-               local etag = ("%02x-%x-%x-%x"):format(attr.dev or 0, attr.ino or 0, attr.size or 0, attr.modification or 0);
+               local etag = ('"%02x-%x-%x-%x"'):format(attr.dev or 0, attr.ino or 0, attr.size or 0, attr.modification or 0);
                response_headers.etag = etag;
 
                local if_none_match = request_headers.if_none_match