metasploit-framework/lib/net/ssh/transport/hmac/abstract.rb

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# -*- coding: binary -*-
require 'openssl'
module Net; module SSH; module Transport; module HMAC
# The base class of all OpenSSL-based HMAC algorithm wrappers.
class Abstract
class <<self
def key_length(*v)
@key_length = nil if !defined?(@key_length)
if v.empty?
@key_length = superclass.key_length if @key_length.nil? && superclass.respond_to?(:key_length)
return @key_length
elsif v.length == 1
@key_length = v.first
else
raise ArgumentError, "wrong number of arguments (#{v.length} for 1)"
end
end
def mac_length(*v)
@mac_length = nil if !defined?(@mac_length)
if v.empty?
@mac_length = superclass.mac_length if @mac_length.nil? && superclass.respond_to?(:mac_length)
return @mac_length
elsif v.length == 1
@mac_length = v.first
else
raise ArgumentError, "wrong number of arguments (#{v.length} for 1)"
end
end
def digest_class(*v)
@digest_class = nil if !defined?(@digest_class)
if v.empty?
@digest_class = superclass.digest_class if @digest_class.nil? && superclass.respond_to?(:digest_class)
return @digest_class
elsif v.length == 1
@digest_class = v.first
else
raise ArgumentError, "wrong number of arguments (#{v.length} for 1)"
end
end
end
def key_length
self.class.key_length
end
def mac_length
self.class.mac_length
end
def digest_class
self.class.digest_class
end
# The key in use for this instance.
attr_reader :key
def initialize(key=nil)
self.key = key
end
# Sets the key to the given value, truncating it so that it is the correct
# length.
def key=(value)
@key = value ? value.to_s[0,key_length] : nil
end
# Compute the HMAC digest for the given data string.
def digest(data)
OpenSSL::HMAC.digest(digest_class.new, key, data)[0,mac_length]
end
end
end; end; end; end