# frozen_string_literal: true
#--
# Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
# All rights reserved.
# See LICENSE.txt for permissions.
#++
##
# The format class knows the guts of the ancient .gem file format and provides
# the capability to read such ancient gems.
#
# Please pretend this doesn't exist.
class Gem::Package::Old < Gem::Package
undef_method :spec=
##
# Creates a new old-format package reader for +gem+. Old-format packages
# cannot be written.
def initialize(gem, security_policy)
require "fileutils"
require "zlib"
Gem.load_yaml
@contents = nil
@gem = gem
@security_policy = security_policy
@spec = nil
end
##
# A list of file names contained in this gem
def contents
verify
return @contents if @contents
@gem.with_read_io do |io|
read_until_dashes io # spec
header = file_list io
@contents = header.map {|file| file["path"] }
end
end
##
# Extracts the files in this package into +destination_dir+
def extract_files(destination_dir)
verify
errstr = "Error reading files from gem"
@gem.with_read_io do |io|
read_until_dashes io # spec
header = file_list io
raise Gem::Exception, errstr unless header
header.each do |entry|
full_name = entry["path"]
destination = install_location full_name, destination_dir
file_data = String.new
read_until_dashes io do |line|
file_data << line
end
file_data = file_data.strip.unpack1("m")
file_data = Zlib::Inflate.inflate file_data
raise Gem::Package::FormatError, "#{full_name} in #{@gem} is corrupt" if
file_data.length != entry["size"].to_i
FileUtils.rm_rf destination
FileUtils.mkdir_p File.dirname(destination), mode: dir_mode && 0o755
File.open destination, "wb", file_mode(entry["mode"]) do |out|
out.write file_data
end
verbose destination
end
end
rescue Zlib::DataError
raise Gem::Exception, errstr
end
##
# Reads the file list section from the old-format gem +io+
def file_list(io) # :nodoc:
header = String.new
read_until_dashes io do |line|
header << line
end
Gem::SafeYAML.safe_load header
end
##
# Reads lines until a "---" separator is found
def read_until_dashes(io) # :nodoc:
while (line = io.gets) && line.chomp.strip != "---" do
yield line if block_given?
end
end
##
# Skips the Ruby self-install header in +io+.
def skip_ruby(io) # :nodoc:
loop do
line = io.gets
return if line.chomp == "__END__"
break unless line
end
raise Gem::Exception, "Failed to find end of Ruby script while reading gem"
end
##
# The specification for this gem
def spec
verify
return @spec if @spec
yaml = String.new
@gem.with_read_io do |io|
skip_ruby io
read_until_dashes io do |line|
yaml << line
end
end
begin
@spec = Gem::Specification.from_yaml yaml
rescue Psych::SyntaxError
raise Gem::Exception, "Failed to parse gem specification out of gem file"
end
rescue ArgumentError
raise Gem::Exception, "Failed to parse gem specification out of gem file"
end
##
# Raises an exception if a security policy that verifies data is active.
# Old format gems cannot be verified as signed.
def verify
return true unless @security_policy
raise Gem::Security::Exception,
"old format gems do not contain signatures and cannot be verified" if
@security_policy.verify_data
true
end
end
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