#--
# sha2.rb - defines Digest::SHA2 class which wraps up the SHA256,
# SHA384, and SHA512 classes.
#++
# Copyright (c) 2006 Akinori MUSHA <knu@iDaemons.org>
#
# All rights reserved. You can redistribute and/or modify it under the same
# terms as Ruby.
#
# $Id: sha2.rb 11708 2007-02-12 23:01:19Z shyouhei $
require 'digest'
module Digest
#
# A meta digest provider class for SHA256, SHA384 and SHA512.
#
class SHA2 < Digest::Class
# call-seq:
# Digest::SHA2.new(bitlen = 256) -> digest_obj
#
# Creates a new SHA2 hash object with a given bit length.
def initialize(bitlen = 256)
case bitlen
when 256
@sha2 = Digest::SHA256.new
when 384
@sha2 = Digest::SHA384.new
when 512
@sha2 = Digest::SHA512.new
else
raise ArgumentError, "unsupported bit length: %s" % bitlen.inspect
end
@bitlen = bitlen
end
# :nodoc:
def reset
@sha2.reset
self
end
# :nodoc:
def update(str)
@sha2.update(str)
self
end
alias << update
def finish
@sha2.digest!
end
private :finish
def block_length
@sha2.block_length
end
def digest_length
@sha2.digest_length
end
# :nodoc:
def initialize_copy(other)
@sha2 = other.instance_eval { @sha2.clone }
end
# :nodoc:
def inspect
"#<%s:%d %s>" % [self.class.name, @bitlen, hexdigest]
end
end
end
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