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Edit File : package.rb \| Size : 14.87 KB
# -- coding: utf-8 -- #-- # Copyright (C) 2004 Mauricio Julio Fernández Pradier # See LICENSE.txt for additional licensing information. #++ # # Example using a Gem::Package # # Builds a .gem file given a Gem::Specification. A .gem file is a tarball # which contains a data.tar.gz and metadata.gz, and possibly signatures. # # require 'rubygems' # require 'rubygems/package' # # spec = Gem::Specification.new do \|s\| # s.summary = "Ruby based make-like utility." # s.name = 'rake' # s.version = PKG_VERSION # s.requirements << 'none' # s.files = PKG_FILES # s.description = <<-EOF # Rake is a Make-like program implemented in Ruby. Tasks # and dependencies are specified in standard Ruby syntax. # EOF # end # # Gem::Package.build spec # # Reads a .gem file. # # require 'rubygems' # require 'rubygems/package' # # the_gem = Gem::Package.new(path_to_dot_gem) # the_gem.contents # get the files in the gem # the_gem.extract_files destination_directory # extract the gem into a directory # the_gem.spec # get the spec out of the gem # the_gem.verify # check the gem is OK (contains valid gem specification, contains a not corrupt contents archive) # # #files are the files in the .gem tar file, not the Ruby files in the gem # #extract_files and #contents automatically call #verify require 'rubygems/security' require 'rubygems/specification' require 'rubygems/user_interaction' require 'zlib' class Gem::Package include Gem::UserInteraction class Error < Gem::Exception; end class FormatError < Error attr_reader :path def initialize message, source = nil if source @path = source.path message << " in #{path}" if path end super message end end class PathError < Error def initialize destination, destination_dir super "installing into parent path %s of %s is not allowed" % [destination, destination_dir] end end class NonSeekableIO < Error; end class TooLongFileName < Error; end ## # Raised when a tar file is corrupt class TarInvalidError < Error; end attr_accessor :build_time # :nodoc: ## # Checksums for the contents of the package attr_reader :checksums ## # The files in this package. This is not the contents of the gem, just the # files in the top-level container. attr_reader :files ## # The security policy used for verifying the contents of this package. attr_accessor :security_policy ## # Sets the Gem::Specification to use to build this package. attr_writer :spec def self.build spec, skip_validation=false gem_file = spec.file_name package = new gem_file package.spec = spec package.build skip_validation gem_file end ## # Creates a new Gem::Package for the file at +gem+. +gem+ can also be # provided as an IO object. # # If +gem+ is an existing file in the old format a Gem::Package::Old will be # returned. def self.new gem gem = if gem.is_a?(Gem::Package::Source) gem elsif gem.respond_to? :read Gem::Package::IOSource.new gem else Gem::Package::FileSource.new gem end return super(gem) unless Gem::Package == self return super unless gem.present? return super unless gem.start return super unless gem.start.include? 'MD5SUM =' Gem::Package::Old.new gem end ## # Creates a new package that will read or write to the file +gem+. def initialize gem # :notnew: @gem = gem @build_time = Time.now @checksums = {} @contents = nil @digests = Hash.new { \|h, algorithm\| h[algorithm] = {} } @files = nil @security_policy = nil @signatures = {} @signer = nil @spec = nil end ## # Adds a checksum for each entry in the gem to checksums.yaml.gz. def add_checksums tar Gem.load_yaml checksums_by_algorithm = Hash.new { \|h, algorithm\| h[algorithm] = {} } @checksums.each do \|name, digests\| digests.each do \|algorithm, digest\| checksums_by_algorithm[algorithm][name] = digest.hexdigest end end tar.add_file_signed 'checksums.yaml.gz', 0444, @signer do \|io\| gzip_to io do \|gz_io\| YAML.dump checksums_by_algorithm, gz_io end end end ## # Adds the files listed in the packages's Gem::Specification to data.tar.gz # and adds this file to the +tar+. def add_contents tar # :nodoc: digests = tar.add_file_signed 'data.tar.gz', 0444, @signer do \|io\| gzip_to io do \|gz_io\| Gem::Package::TarWriter.new gz_io do \|data_tar\| add_files data_tar end end end @checksums['data.tar.gz'] = digests end ## # Adds files included the package's Gem::Specification to the +tar+ file def add_files tar # :nodoc: @spec.files.each do \|file\| stat = File.stat file next unless stat.file? tar.add_file_simple file, stat.mode, stat.size do \|dst_io\| open file, 'rb' do \|src_io\| dst_io.write src_io.read 16384 until src_io.eof? end end end end ## # Adds the package's Gem::Specification to the +tar+ file def add_metadata tar # :nodoc: digests = tar.add_file_signed 'metadata.gz', 0444, @signer do \|io\| gzip_to io do \|gz_io\| gz_io.write @spec.to_yaml end end @checksums['metadata.gz'] = digests end ## # Builds this package based on the specification set by #spec= def build skip_validation = false Gem.load_yaml require 'rubygems/security' @spec.mark_version @spec.validate unless skip_validation setup_signer @gem.with_write_io do \|gem_io\| Gem::Package::TarWriter.new gem_io do \|gem\| add_metadata gem add_contents gem add_checksums gem end end say <<-EOM Successfully built RubyGem Name: #{@spec.name} Version: #{@spec.version} File: #{File.basename @spec.cache_file} EOM ensure @signer = nil end ## # A list of file names contained in this gem def contents return @contents if @contents verify unless @spec @contents = [] @gem.with_read_io do \|io\| gem_tar = Gem::Package::TarReader.new io gem_tar.each do \|entry\| next unless entry.full_name == 'data.tar.gz' open_tar_gz entry do \|pkg_tar\| pkg_tar.each do \|contents_entry\| @contents << contents_entry.full_name end end return @contents end end end ## # Creates a digest of the TarEntry +entry+ from the digest algorithm set by # the security policy. def digest entry # :nodoc: algorithms = if @checksums then @checksums.keys else [Gem::Security::DIGEST_NAME].compact end algorithms.each do \|algorithm\| digester = if defined?(OpenSSL::Digest) then OpenSSL::Digest.new algorithm else Digest.const_get(algorithm).new end digester << entry.read(16384) until entry.eof? entry.rewind @digests[algorithm][entry.full_name] = digester end @digests end ## # Extracts the files in this package into +destination_dir+ # # If +pattern+ is specified, only entries matching that glob will be # extracted. def extract_files destination_dir, pattern = "" verify unless @spec FileUtils.mkdir_p destination_dir @gem.with_read_io do \|io\| reader = Gem::Package::TarReader.new io reader.each do \|entry\| next unless entry.full_name == 'data.tar.gz' extract_tar_gz entry, destination_dir, pattern return # ignore further entries end end end ## # Extracts all the files in the gzipped tar archive +io+ into # +destination_dir+. # # If an entry in the archive contains a relative path above # +destination_dir+ or an absolute path is encountered an exception is # raised. # # If +pattern+ is specified, only entries matching that glob will be # extracted. def extract_tar_gz io, destination_dir, pattern = "" # :nodoc: open_tar_gz io do \|tar\| tar.each do \|entry\| next unless File.fnmatch pattern, entry.full_name, File::FNM_DOTMATCH destination = install_location entry.full_name, destination_dir FileUtils.rm_rf destination mkdir_options = {} mkdir_options[:mode] = entry.header.mode if entry.directory? mkdir = if entry.directory? then destination else File.dirname destination end FileUtils.mkdir_p mkdir, mkdir_options open destination, 'wb' do \|out\| out.write entry.read FileUtils.chmod entry.header.mode, destination end if entry.file? verbose destination end end end ## # Gzips content written to +gz_io+ to +io+. #-- # Also sets the gzip modification time to the package build time to ease # testing. def gzip_to io # :yields: gz_io gz_io = Zlib::GzipWriter.new io, Zlib::BEST_COMPRESSION gz_io.mtime = @build_time yield gz_io ensure gz_io.close end ## # Returns the full path for installing +filename+. # # If +filename+ is not inside +destination_dir+ an exception is raised. def install_location filename, destination_dir # :nodoc: raise Gem::Package::PathError.new(filename, destination_dir) if filename.start_with? '/' destination_dir = File.realpath destination_dir if File.respond_to? :realpath destination_dir = File.expand_path destination_dir destination = File.join destination_dir, filename destination = File.expand_path destination raise Gem::Package::PathError.new(destination, destination_dir) unless destination.start_with? destination_dir + '/' destination.untaint destination end ## # Loads a Gem::Specification from the TarEntry +entry+ def load_spec entry # :nodoc: case entry.full_name when 'metadata' then @spec = Gem::Specification.from_yaml entry.read when 'metadata.gz' then args = [entry] args << { :external_encoding => Encoding::UTF_8 } if Object.const_defined?(:Encoding) && Zlib::GzipReader.method(:wrap).arity != 1 Zlib::GzipReader.wrap(args) do \|gzio\| @spec = Gem::Specification.from_yaml gzio.read end end end ## # Opens +io+ as a gzipped tar archive def open_tar_gz io # :nodoc: Zlib::GzipReader.wrap io do \|gzio\| tar = Gem::Package::TarReader.new gzio yield tar end end ## # Reads and loads checksums.yaml.gz from the tar file +gem+ def read_checksums gem Gem.load_yaml @checksums = gem.seek 'checksums.yaml.gz' do \|entry\| Zlib::GzipReader.wrap entry do \|gz_io\| Gem::SafeYAML.safe_load gz_io.read end end end ## # Prepares the gem for signing and checksum generation. If a signing # certificate and key are not present only checksum generation is set up. def setup_signer passphrase = ENV['GEM_PRIVATE_KEY_PASSPHRASE'] if @spec.signing_key then @signer = Gem::Security::Signer.new @spec.signing_key, @spec.cert_chain, passphrase @spec.signing_key = nil @spec.cert_chain = @signer.cert_chain.map { \|cert\| cert.to_s } else @signer = Gem::Security::Signer.new nil, nil, passphrase @spec.cert_chain = @signer.cert_chain.map { \|cert\| cert.to_pem } if @signer.cert_chain end end ## # The spec for this gem. # # If this is a package for a built gem the spec is loaded from the # gem and returned. If this is a package for a gem being built the provided # spec is returned. def spec verify unless @spec @spec end ## # Verifies that this gem: # # Contains a valid gem specification # * Contains a contents archive # * The contents archive is not corrupt # # After verification the gem specification from the gem is available from # #spec def verify @files = [] @spec = nil @gem.with_read_io do \|io\| Gem::Package::TarReader.new io do \|reader\| read_checksums reader verify_files reader end end verify_checksums @digests, @checksums @security_policy.verify_signatures @spec, @digests, @signatures if @security_policy true rescue Gem::Security::Exception @spec = nil @files = [] raise rescue Errno::ENOENT => e raise Gem::Package::FormatError.new e.message rescue Gem::Package::TarInvalidError => e raise Gem::Package::FormatError.new e.message, @gem end ## # Verifies the +checksums+ against the +digests+. This check is not # cryptographically secure. Missing checksums are ignored. def verify_checksums digests, checksums # :nodoc: return unless checksums checksums.sort.each do \|algorithm, gem_digests\| gem_digests.sort.each do \|file_name, gem_hexdigest\| computed_digest = digests[algorithm][file_name] unless computed_digest.hexdigest == gem_hexdigest then raise Gem::Package::FormatError.new \ "#{algorithm} checksum mismatch for #{file_name}", @gem end end end end ## # Verifies +entry+ in a .gem file. def verify_entry entry file_name = entry.full_name @files << file_name case file_name when /\.sig$/ then @signatures[$`] = entry.read if @security_policy return else digest entry end case file_name when /^metadata(.gz)?$/ then load_spec entry when 'data.tar.gz' then verify_gz entry end rescue => e message = "package is corrupt, exception while verifying: " + "#{e.message} (#{e.class})" raise Gem::Package::FormatError.new message, @gem end ## # Verifies the files of the +gem+ def verify_files gem gem.each do \|entry\| verify_entry entry end unless @spec then raise Gem::Package::FormatError.new 'package metadata is missing', @gem end unless @files.include? 'data.tar.gz' then raise Gem::Package::FormatError.new \ 'package content (data.tar.gz) is missing', @gem end if duplicates = @files.group_by {\|f\| f }.select {\|k,v\| v.size > 1 }.map(&:first) and duplicates.any? raise Gem::Security::Exception, "duplicate files in the package: (#{duplicates.map(&:inspect).join(', ')})" end end ## # Verifies that +entry+ is a valid gzipped file. def verify_gz entry # :nodoc: Zlib::GzipReader.wrap entry do \|gzio\| gzio.read 16384 until gzio.eof? # gzip checksum verification end rescue Zlib::GzipFile::Error => e raise Gem::Package::FormatError.new(e.message, entry.full_name) end end require 'rubygems/package/digest_io' require 'rubygems/package/source' require 'rubygems/package/file_source' require 'rubygems/package/io_source' require 'rubygems/package/old' require 'rubygems/package/tar_header' require 'rubygems/package/tar_reader' require 'rubygems/package/tar_reader/entry' require 'rubygems/package/tar_writer' Back

Edit File : package.rb | Size : 14.87 KB

# -*- coding: utf-8 -*-
#--
# Copyright (C) 2004 Mauricio Julio Fernández Pradier
# See LICENSE.txt for additional licensing information.
#++
#
# Example using a Gem::Package
#
# Builds a .gem file given a Gem::Specification. A .gem file is a tarball
# which contains a data.tar.gz and metadata.gz, and possibly signatures.
#
#   require 'rubygems'
#   require 'rubygems/package'
#
#   spec = Gem::Specification.new do |s|
#     s.summary = "Ruby based make-like utility."
#     s.name = 'rake'
#     s.version = PKG_VERSION
#     s.requirements << 'none'
#     s.files = PKG_FILES
#     s.description = <<-EOF
#   Rake is a Make-like program implemented in Ruby. Tasks
#   and dependencies are specified in standard Ruby syntax.
#     EOF
#   end
#
#   Gem::Package.build spec
#
# Reads a .gem file.
#
#   require 'rubygems'
#   require 'rubygems/package'
#
#   the_gem = Gem::Package.new(path_to_dot_gem)
#   the_gem.contents # get the files in the gem
#   the_gem.extract_files destination_directory # extract the gem into a directory
#   the_gem.spec # get the spec out of the gem
#   the_gem.verify # check the gem is OK (contains valid gem specification, contains a not corrupt contents archive)
#
# #files are the files in the .gem tar file, not the Ruby files in the gem
# #extract_files and #contents automatically call #verify

require 'rubygems/security'
require 'rubygems/specification'
require 'rubygems/user_interaction'
require 'zlib'

class Gem::Package

include Gem::UserInteraction

class Error < Gem::Exception; end

class FormatError < Error
    attr_reader :path

def initialize message, source = nil
      if source
        @path = source.path

message << " in #{path}" if path
      end

super message
    end

end

class PathError < Error
    def initialize destination, destination_dir
      super "installing into parent path %s of %s is not allowed" %
              [destination, destination_dir]
    end
  end

class NonSeekableIO < Error; end

class TooLongFileName < Error; end

##
  # Raised when a tar file is corrupt

class TarInvalidError < Error; end

attr_accessor :build_time # :nodoc:

##
  # Checksums for the contents of the package

attr_reader :checksums

##
  # The files in this package.  This is not the contents of the gem, just the
  # files in the top-level container.

attr_reader :files

##
  # The security policy used for verifying the contents of this package.

attr_accessor :security_policy

##
  # Sets the Gem::Specification to use to build this package.

attr_writer :spec

def self.build spec, skip_validation=false
    gem_file = spec.file_name

package = new gem_file
    package.spec = spec
    package.build skip_validation

gem_file
  end

##
  # Creates a new Gem::Package for the file at +gem+. +gem+ can also be
  # provided as an IO object.
  #
  # If +gem+ is an existing file in the old format a Gem::Package::Old will be
  # returned.

def self.new gem
    gem = if gem.is_a?(Gem::Package::Source)
            gem
          elsif gem.respond_to? :read
            Gem::Package::IOSource.new gem
          else
            Gem::Package::FileSource.new gem
          end

return super(gem) unless Gem::Package == self
    return super unless gem.present?

return super unless gem.start
    return super unless gem.start.include? 'MD5SUM ='

Gem::Package::Old.new gem
  end

##
  # Creates a new package that will read or write to the file +gem+.

def initialize gem # :notnew:
    @gem = gem

@build_time      = Time.now
    @checksums       = {}
    @contents        = nil
    @digests         = Hash.new { |h, algorithm| h[algorithm] = {} }
    @files           = nil
    @security_policy = nil
    @signatures      = {}
    @signer          = nil
    @spec            = nil
  end

##
  # Adds a checksum for each entry in the gem to checksums.yaml.gz.

def add_checksums tar
    Gem.load_yaml

checksums_by_algorithm = Hash.new { |h, algorithm| h[algorithm] = {} }

@checksums.each do |name, digests|
      digests.each do |algorithm, digest|
        checksums_by_algorithm[algorithm][name] = digest.hexdigest
      end
    end

tar.add_file_signed 'checksums.yaml.gz', 0444, @signer do |io|
      gzip_to io do |gz_io|
        YAML.dump checksums_by_algorithm, gz_io
      end
    end
  end

##
  # Adds the files listed in the packages's Gem::Specification to data.tar.gz
  # and adds this file to the +tar+.

@checksums['data.tar.gz'] = digests
  end

##
  # Adds files included the package's Gem::Specification to the +tar+ file

def add_files tar # :nodoc:
    @spec.files.each do |file|
      stat = File.stat file

next unless stat.file?

tar.add_file_simple file, stat.mode, stat.size do |dst_io|
        open file, 'rb' do |src_io|
          dst_io.write src_io.read 16384 until src_io.eof?
        end
      end
    end
  end

##
  # Adds the package's Gem::Specification to the +tar+ file

def add_metadata tar # :nodoc:
    digests = tar.add_file_signed 'metadata.gz', 0444, @signer do |io|
      gzip_to io do |gz_io|
        gz_io.write @spec.to_yaml
      end
    end

@checksums['metadata.gz'] = digests
  end

##
  # Builds this package based on the specification set by #spec=

def build skip_validation = false
    Gem.load_yaml
    require 'rubygems/security'

@spec.mark_version
    @spec.validate unless skip_validation

setup_signer

@gem.with_write_io do |gem_io|
      Gem::Package::TarWriter.new gem_io do |gem|
        add_metadata gem
        add_contents gem
        add_checksums gem
      end
    end

say <<-EOM
  Successfully built RubyGem
  Name: #{@spec.name}
  Version: #{@spec.version}
  File: #{File.basename @spec.cache_file}
EOM
  ensure
    @signer = nil
  end

##
  # A list of file names contained in this gem

def contents
    return @contents if @contents

verify unless @spec

@contents = []

@gem.with_read_io do |io|
      gem_tar = Gem::Package::TarReader.new io

gem_tar.each do |entry|
        next unless entry.full_name == 'data.tar.gz'

open_tar_gz entry do |pkg_tar|
          pkg_tar.each do |contents_entry|
            @contents << contents_entry.full_name
          end
        end

return @contents
      end
    end
  end

##
  # Creates a digest of the TarEntry +entry+ from the digest algorithm set by
  # the security policy.

def digest entry # :nodoc:
    algorithms = if @checksums then
                   @checksums.keys
                 else
                   [Gem::Security::DIGEST_NAME].compact
                 end

algorithms.each do |algorithm|
      digester =
        if defined?(OpenSSL::Digest) then
          OpenSSL::Digest.new algorithm
        else
          Digest.const_get(algorithm).new
        end

digester << entry.read(16384) until entry.eof?

entry.rewind

@digests[algorithm][entry.full_name] = digester
    end

@digests
  end

##
  # Extracts the files in this package into +destination_dir+
  #
  # If +pattern+ is specified, only entries matching that glob will be
  # extracted.

def extract_files destination_dir, pattern = "*"
    verify unless @spec

FileUtils.mkdir_p destination_dir

@gem.with_read_io do |io|
      reader = Gem::Package::TarReader.new io

reader.each do |entry|
        next unless entry.full_name == 'data.tar.gz'

extract_tar_gz entry, destination_dir, pattern

return # ignore further entries
      end
    end
  end

##
  # Extracts all the files in the gzipped tar archive +io+ into
  # +destination_dir+.
  #
  # If an entry in the archive contains a relative path above
  # +destination_dir+ or an absolute path is encountered an exception is
  # raised.
  #
  # If +pattern+ is specified, only entries matching that glob will be
  # extracted.

def extract_tar_gz io, destination_dir, pattern = "*" # :nodoc:
    open_tar_gz io do |tar|
      tar.each do |entry|
        next unless File.fnmatch pattern, entry.full_name, File::FNM_DOTMATCH

destination = install_location entry.full_name, destination_dir

FileUtils.rm_rf destination

mkdir_options = {}
        mkdir_options[:mode] = entry.header.mode if entry.directory?
        mkdir =
          if entry.directory? then
            destination
          else
            File.dirname destination
          end

FileUtils.mkdir_p mkdir, mkdir_options

open destination, 'wb' do |out|
          out.write entry.read
          FileUtils.chmod entry.header.mode, destination
        end if entry.file?

verbose destination
      end
    end
  end

##
  # Gzips content written to +gz_io+ to +io+.
  #--
  # Also sets the gzip modification time to the package build time to ease
  # testing.

def gzip_to io # :yields: gz_io
    gz_io = Zlib::GzipWriter.new io, Zlib::BEST_COMPRESSION
    gz_io.mtime = @build_time

yield gz_io
  ensure
    gz_io.close
  end

##
  # Returns the full path for installing +filename+.
  #
  # If +filename+ is not inside +destination_dir+ an exception is raised.

def install_location filename, destination_dir # :nodoc:
    raise Gem::Package::PathError.new(filename, destination_dir) if
      filename.start_with? '/'

destination_dir = File.realpath destination_dir if
      File.respond_to? :realpath
    destination_dir = File.expand_path destination_dir

destination = File.join destination_dir, filename
    destination = File.expand_path destination

raise Gem::Package::PathError.new(destination, destination_dir) unless
      destination.start_with? destination_dir + '/'

destination.untaint
    destination
  end

##
  # Loads a Gem::Specification from the TarEntry +entry+

def load_spec entry # :nodoc:
    case entry.full_name
    when 'metadata' then
      @spec = Gem::Specification.from_yaml entry.read
    when 'metadata.gz' then
      args = [entry]
      args << { :external_encoding => Encoding::UTF_8 } if
        Object.const_defined?(:Encoding) &&
          Zlib::GzipReader.method(:wrap).arity != 1

Zlib::GzipReader.wrap(*args) do |gzio|
        @spec = Gem::Specification.from_yaml gzio.read
      end
    end
  end

##
  # Opens +io+ as a gzipped tar archive

def open_tar_gz io # :nodoc:
    Zlib::GzipReader.wrap io do |gzio|
      tar = Gem::Package::TarReader.new gzio

yield tar
    end
  end

##
  # Reads and loads checksums.yaml.gz from the tar file +gem+

def read_checksums gem
    Gem.load_yaml

@checksums = gem.seek 'checksums.yaml.gz' do |entry|
      Zlib::GzipReader.wrap entry do |gz_io|
        Gem::SafeYAML.safe_load gz_io.read
      end
    end
  end

##
  # Prepares the gem for signing and checksum generation.  If a signing
  # certificate and key are not present only checksum generation is set up.

def setup_signer
    passphrase = ENV['GEM_PRIVATE_KEY_PASSPHRASE']
    if @spec.signing_key then
      @signer = Gem::Security::Signer.new @spec.signing_key, @spec.cert_chain, passphrase
      @spec.signing_key = nil
      @spec.cert_chain = @signer.cert_chain.map { |cert| cert.to_s }
    else
      @signer = Gem::Security::Signer.new nil, nil, passphrase
      @spec.cert_chain = @signer.cert_chain.map { |cert| cert.to_pem } if
        @signer.cert_chain
    end
  end

##
  # The spec for this gem.
  #
  # If this is a package for a built gem the spec is loaded from the
  # gem and returned.  If this is a package for a gem being built the provided
  # spec is returned.

def spec
    verify unless @spec

@spec
  end

##
  # Verifies that this gem:
  #
  # * Contains a valid gem specification
  # * Contains a contents archive
  # * The contents archive is not corrupt
  #
  # After verification the gem specification from the gem is available from
  # #spec

def verify
    @files     = []
    @spec      = nil

@gem.with_read_io do |io|
      Gem::Package::TarReader.new io do |reader|
        read_checksums reader

verify_files reader
      end
    end

verify_checksums @digests, @checksums

@security_policy.verify_signatures @spec, @digests, @signatures if
      @security_policy

true
  rescue Gem::Security::Exception
    @spec = nil
    @files = []
    raise
  rescue Errno::ENOENT => e
    raise Gem::Package::FormatError.new e.message
  rescue Gem::Package::TarInvalidError => e
    raise Gem::Package::FormatError.new e.message, @gem
  end

##
  # Verifies the +checksums+ against the +digests+.  This check is not
  # cryptographically secure.  Missing checksums are ignored.

def verify_checksums digests, checksums # :nodoc:
    return unless checksums

checksums.sort.each do |algorithm, gem_digests|
      gem_digests.sort.each do |file_name, gem_hexdigest|
        computed_digest = digests[algorithm][file_name]

unless computed_digest.hexdigest == gem_hexdigest then
          raise Gem::Package::FormatError.new \
            "#{algorithm} checksum mismatch for #{file_name}", @gem
        end
      end
    end
  end

##
  # Verifies +entry+ in a .gem file.

def verify_entry entry
    file_name = entry.full_name
    @files << file_name

case file_name
    when /\.sig$/ then
      @signatures[$`] = entry.read if @security_policy
      return
    else
      digest entry
    end

case file_name
    when /^metadata(.gz)?$/ then
      load_spec entry
    when 'data.tar.gz' then
      verify_gz entry
    end
  rescue => e
    message = "package is corrupt, exception while verifying: " +
              "#{e.message} (#{e.class})"
    raise Gem::Package::FormatError.new message, @gem
  end

##
  # Verifies the files of the +gem+

def verify_files gem
    gem.each do |entry|
      verify_entry entry
    end

unless @spec then
      raise Gem::Package::FormatError.new 'package metadata is missing', @gem
    end

unless @files.include? 'data.tar.gz' then
      raise Gem::Package::FormatError.new \
              'package content (data.tar.gz) is missing', @gem
    end

if duplicates = @files.group_by {|f| f }.select {|k,v| v.size > 1 }.map(&:first) and duplicates.any?
      raise Gem::Security::Exception, "duplicate files in the package: (#{duplicates.map(&:inspect).join(', ')})"
    end
  end

##
  # Verifies that +entry+ is a valid gzipped file.

def verify_gz entry # :nodoc:
    Zlib::GzipReader.wrap entry do |gzio|
      gzio.read 16384 until gzio.eof? # gzip checksum verification
    end
  rescue Zlib::GzipFile::Error => e
    raise Gem::Package::FormatError.new(e.message, entry.full_name)
  end

end

require 'rubygems/package/digest_io'
require 'rubygems/package/source'
require 'rubygems/package/file_source'
require 'rubygems/package/io_source'
require 'rubygems/package/old'
require 'rubygems/package/tar_header'
require 'rubygems/package/tar_reader'
require 'rubygems/package/tar_reader/entry'
require 'rubygems/package/tar_writer'

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