diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/xml.lua | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/util/xml.lua b/util/xml.lua index dac3f6fe..700da1d4 100644 --- a/util/xml.lua +++ b/util/xml.lua @@ -3,6 +3,7 @@ local st = require "util.stanza"; local lxp = require "lxp"; local t_insert = table.insert; local t_remove = table.remove; +local error = error; local _ENV = nil; -- luacheck: std none @@ -13,7 +14,7 @@ local parse_xml = (function() }; local ns_separator = "\1"; local ns_pattern = "^([^"..ns_separator.."]*)"..ns_separator.."?(.*)$"; - return function(xml) + return function(xml, options) --luacheck: ignore 212/self local handler = {}; local stanza = st.stanza("root"); @@ -64,7 +65,27 @@ local parse_xml = (function() function handler:EndElement() stanza:up(); end - local parser = lxp.new(handler, "\1"); + local parser; + -- SECURITY: These two handlers, especially the Doctype one, are required to prevent exploits such as Billion Laughs. + function handler:StartDoctypeDecl() + if not parser.stop or not parser:stop() then + error("Failed to abort parsing"); + end + end + function handler:ProcessingInstruction() + if not parser.stop or not parser:stop() then + error("Failed to abort parsing"); + end + end + if not options or not options.allow_comments then + -- NOTE: comments are generally harmless and can be useful when parsing configuration files or other data, even user-provided data + function handler:Comment() + if not parser.stop or not parser:stop() then + error("Failed to abort parsing"); + end + end + end + parser = lxp.new(handler, ns_separator); local ok, err, line, col = parser:parse(xml); if ok then ok, err, line, col = parser:parse(); end --parser:close(); |