require 'digest.so' module Digest def self.const_missing(name) # :nodoc: case name when :SHA256, :SHA384, :SHA512 lib = 'digest/sha2.so' else lib = File.join('digest', name.to_s.downcase) end begin require lib rescue LoadError raise LoadError, "library not found for class Digest::#{name} -- #{lib}", caller(1) end unless Digest.const_defined?(name) raise NameError, "uninitialized constant Digest::#{name}", caller(1) end Digest.const_get(name) end class ::Digest::Class # Creates a digest object and reads a given file, _name_. # Optional arguments are passed to the constructor of the digest # class. # # p Digest::SHA256.file("X11R6.8.2-src.tar.bz2").hexdigest # # => "f02e3c85572dc9ad7cb77c2a638e3be24cc1b5bea9fdbb0b0299c9668475c534" def self.file(name, *args) new(*args).file(name) end # Returns the base64 encoded hash value of a given _string_. The # return value is properly padded with '=' and contains no line # feeds. def self.base64digest(str, *args) [digest(str, *args)].pack('m0') end end module Instance # Updates the digest with the contents of a given file _name_ and # returns self. def file(name) File.open(name, "rb") {|f| buf = "" while f.read(16384, buf) update buf end } self end # If none is given, returns the resulting hash value of the digest # in a base64 encoded form, keeping the digest's state. # # If a +string+ is given, returns the hash value for the given # +string+ in a base64 encoded form, resetting the digest to the # initial state before and after the process. # # In either case, the return value is properly padded with '=' and # contains no line feeds. def base64digest(str = nil) [str ? digest(str) : digest].pack('m0') end # Returns the resulting hash value and resets the digest to the # initial state. def base64digest! [digest!].pack('m0') end end end # call-seq: # Digest(name) -> digest_subclass # # Returns a Digest subclass by +name+. # # require 'digest' # # Digest("MD5") # # => Digest::MD5 # # Digest("Foo") # # => LoadError: library not found for class Digest::Foo -- digest/foo def Digest(name) Digest.const_get(name) end