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Fix calculation of Security.entity_expansion_text_limit in SAX/pull parsers #195
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test/test_document.rb
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REXML::Security.entity_expansion_text_limit = 90 | ||
doc = REXML::Document.new(xml) | ||
doc.root.children.first.value |
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Can we use assert_equal
here?
doc.root.children.first.value | |
assert_equal(XXX, doc.root.children.first.value.bytesize) |
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OK, I see.
test/test_sax.rb
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XML | ||
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REXML::Security.entity_expansion_text_limit = 90 | ||
REXML::Parsers::SAX2Parser.new(source).parse |
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Can we check the text size here something like the last patch in #194 (comment) ?
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OK, I see.
[Why?] In SAX and PULL, the total value of rv.bytesize was checked, but the summing process was unnecessary. - Add Log ```patch diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb index 28810bf..5cfc089 100644 --- a/lib/rexml/parsers/baseparser.rb +++ b/lib/rexml/parsers/baseparser.rb @@ -556,6 +556,7 @@ module REXML re = Private::DEFAULT_ENTITIES_PATTERNS[entity_reference] || /&#{entity_reference};/ rv.gsub!( re, entity_value ) sum += rv.bytesize +puts " rv.bytesize: #{rv.bytesize} sum: #{sum} > Security.entity_expansion_text_limit: #{Security.entity_expansion_text_limit} : #{rv}" if sum > Security.entity_expansion_text_limit raise "entity expansion has grown too large" end diff --git a/lib/rexml/text.rb b/lib/rexml/text.rb index 7e0befe..cc68dbf 100644 --- a/lib/rexml/text.rb +++ b/lib/rexml/text.rb @@ -415,6 +415,7 @@ module REXML sum = 0 string.gsub( /\r\n?/, "\n" ).gsub( REFERENCE ) { s = Text.expand($&, doctype, filter) +puts " s.bytesize: #{s.bytesize} sum + s.bytesize : #{sum + s.bytesize } > Security.entity_expansion_text_limit: #{Security.entity_expansion_text_limit} : #{s}" if sum + s.bytesize > Security.entity_expansion_text_limit raise "entity expansion has grown too large" else ``` - entity_expansion_text_limit.rb ``` $LOAD_PATH.unshift(File.expand_path("lib")) require 'rexml' require 'rexml/parsers/sax2parser' require 'rexml/parsers/pullparser' def dom_entity_expansion_count_check(xml) doc = REXML::Document.new(xml) doc.root.children.first.value puts "DOM: entity_expansion_count: #{doc.entity_expansion_count}" end def sax_entity_expansion_count_check(xml) sax = REXML::Parsers::SAX2Parser.new(xml) sax.parse puts "SAX: entity_expansion_count: #{sax.entity_expansion_count}" end def pull_entity_expansion_count_check(xml) parser = REXML::Parsers::PullParser.new(xml) while parser.has_next? parser.pull end puts "Pull: entity_expansion_count: #{parser.entity_expansion_count}" end xml = <<XML <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE member [ <!ENTITY a "&b;&b;&b;"> <!ENTITY b "&c;&d;&e;"> <!ENTITY c "xxxxxxxxxx"> <!ENTITY d "yyyyyyyyyy"> <!ENTITY e "zzzzzzzzzz"> ]> <member>&a;</member> XML dom_entity_expansion_count_check(xml) sax_entity_expansion_count_check(xml) pull_entity_expansion_count_check(xml) ``` ``` $ ruby entity_expansion_text_limit.rb s.bytesize: 10 sum + s.bytesize : 10 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx s.bytesize: 10 sum + s.bytesize : 20 > Security.entity_expansion_text_limit: 10240 : yyyyyyyyyy s.bytesize: 10 sum + s.bytesize : 30 > Security.entity_expansion_text_limit: 10240 : zzzzzzzzzz s.bytesize: 30 sum + s.bytesize : 30 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz s.bytesize: 10 sum + s.bytesize : 10 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx s.bytesize: 10 sum + s.bytesize : 20 > Security.entity_expansion_text_limit: 10240 : yyyyyyyyyy s.bytesize: 10 sum + s.bytesize : 30 > Security.entity_expansion_text_limit: 10240 : zzzzzzzzzz s.bytesize: 30 sum + s.bytesize : 60 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz s.bytesize: 10 sum + s.bytesize : 10 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx s.bytesize: 10 sum + s.bytesize : 20 > Security.entity_expansion_text_limit: 10240 : yyyyyyyyyy s.bytesize: 10 sum + s.bytesize : 30 > Security.entity_expansion_text_limit: 10240 : zzzzzzzzzz s.bytesize: 30 sum + s.bytesize : 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz s.bytesize: 90 sum + s.bytesize : 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz DOM: entity_expansion_count: 13 rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 180 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 270 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz SAX: entity_expansion_count: 13 rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 180 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 16 sum: 16 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxx&d;&e; rv.bytesize: 23 sum: 39 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyy&e; rv.bytesize: 30 sum: 69 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 270 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz rv.bytesize: 90 sum: 90 > Security.entity_expansion_text_limit: 10240 : xxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzzxxxxxxxxxxyyyyyyyyyyzzzzzzzzzz Pull: entity_expansion_count: 13 ``` 90 bytes is the expected value, but SAX and Pull exceed 90 bytes due to unnecessary total processing.
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I think this fix looks good! I originally set out to fix the |
GitHub: fix #193
[Why?]
In SAX and pull parsers, the total value of rv.bytesize was checked, but the summing process was unnecessary.
90 bytes is the expected value, but SAX and Pull exceed 90 bytes due to unnecessary total processing.