# frozen_string_literal: false
require 'digest.so'
module Digest
# A mutex for Digest().
REQUIRE_MUTEX = Thread::Mutex.new
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+ in a thread-safe manner even
# when on-demand loading is involved.
#
# require 'digest'
#
# Digest("MD5")
# # => Digest::MD5
#
# Digest(:SHA256)
# # => Digest::SHA256
#
# Digest(:Foo)
# # => LoadError: library not found for class Digest::Foo -- digest/foo
def Digest(name)
const = name.to_sym
Digest::REQUIRE_MUTEX.synchronize {
# Ignore autoload's because it is void when we have #const_missing
Digest.const_missing(const)
}
rescue LoadError
# Constants do not necessarily rely on digest/*.
if Digest.const_defined?(const)
Digest.const_get(const)
else
raise
end
end
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