* ext/digest/lib/digest/hmac.rb: Add digest/hmac, which implements

HMAC keyed-hashing algorithm.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@11126 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/digest/lib/digest/hmac.rb

@@ -0,0 +1,263 @@
+# = digest/hmac.rb
+#
+# An implementation of HMAC keyed-hashing algorithm
+#
+# == Overview 
+# 
+# This library adds a method named hmac() to Digest classes, which
+# creates a Digest class for calculating HMAC digests.
+#
+# == Examples
+#
+#   require 'digest/hmac'
+#
+#   # one-liner example
+#   puts Digest::SHA1.hmac("hash key").hexdigest("data")
+#
+#   # rather longer one
+#   hmac = Digest::RMD160.hmac("foo").new
+#
+#   buf = ""
+#   while stream.read(16384, buf)
+#     hmac.update(buf)
+#   end
+#
+#   puts hmac.bubblebabble
+#
+# == License
+#
+# Copyright (c) 2006 Akinori MUSHA <knu@iDaemons.org>
+#
+# Documentation by Akinori MUSHA
+#
+# All rights reserved.  You can redistribute and/or modify it under
+# the same terms as Ruby.
+#
+#   $Id$
+#
+
+require 'digest'
+
+module Digest
+  class Base
+    def self.hmac(key)
+      algo = self
+      key = digest(key) if key.length > algo::BLOCK_LENGTH
+
+      (@digest_hmac_class_cache ||= {})[key] ||= Class.new(algo) {
+        const_set(:DIGEST_LENGTH, algo::DIGEST_LENGTH)
+        const_set(:BLOCK_LENGTH,  algo::BLOCK_LENGTH)
+        const_set(:KEY, key)
+        @@algo = superclass
+
+        def initialize(text = nil)
+          ipad = Array.new(BLOCK_LENGTH).fill(0x36)
+          opad = Array.new(BLOCK_LENGTH).fill(0x5c)
+
+          i = 0
+          KEY.each_byte { |c|
+            ipad[i] ^= c
+            opad[i] ^= c
+            i += 1
+          }
+          #KEY.bytes.each_with_index { |c, i|
+          #  ipad[i] ^= c
+          #  opad[i] ^= c
+          #}
+
+          @ipad = ipad.inject('') { |s, c| s << c.chr }
+          @opad = opad.inject('') { |s, c| s << c.chr }
+
+          @md = @@algo.new
+
+          update(text) unless text.nil?
+        end
+
+        def update(text)
+          @md = @@algo.new(@opad + @@algo.digest(@ipad + text))
+
+          self
+        end
+
+        def digest
+          @md.digest
+        end
+
+        def self.inspect
+          sprintf('#<%s.hmac(%s)>', @@algo.name, KEY.inspect);
+        end
+
+        def inspect
+          sprintf('#<%s.hmac(%s): %s>', @@algo.name, KEY.inspect, hexdigest());
+        end
+      }
+    end
+  end
+end
+
+if $0 == __FILE__
+  eval DATA.read, nil, $0, __LINE__+4
+end
+
+__END__
+
+require 'test/unit'
+
+module TM_HMAC
+  def test_s_hexdigest
+    cases.each { |h|
+      hmac_class = digest_class.hmac(h[:key])
+
+      assert_equal(h[:hexdigest], hmac_class.hexdigest(h[:data]))
+    }
+  end
+
+  def test_hexdigest
+    cases.each { |h|
+      hmac = digest_class.hmac(h[:key]).new
+      hmac.update(h[:data])
+
+      assert_equal(h[:hexdigest], hmac.hexdigest)
+    }
+  end
+
+  def test_reset
+    cases.each { |h|
+      hmac = digest_class.hmac(h[:key]).new
+      hmac.update("test")
+      hmac.reset
+      hmac.update(h[:data])
+
+      assert_equal(h[:hexdigest], hmac.hexdigest)
+    }
+  end
+end  
+
+class TC_HMAC_MD5 < Test::Unit::TestCase
+  include TM_HMAC
+
+  def digest_class
+    Digest::MD5
+  end
+
+  # Taken from RFC 2202: Test Cases for HMAC-MD5 and HMAC-SHA-1
+  def cases
+    [
+     {
+       :key		=> "\x0b" * 16,
+       :data		=> "Hi There",
+       :hexdigest	=> "9294727a3638bb1c13f48ef8158bfc9d",
+     }, {
+       :key		=> "Jefe",
+       :data		=> "what do ya want for nothing?",
+       :hexdigest	=> "750c783e6ab0b503eaa86e310a5db738",
+     }, {
+       :key		=> "\xaa" * 16,
+       :data		=> "\xdd" * 50,
+       :hexdigest	=> "56be34521d144c88dbb8c733f0e8b3f6",
+     }, {
+       :key		=> "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19",
+       :data		=> "\xcd" * 50,
+       :hexdigest	=> "697eaf0aca3a3aea3a75164746ffaa79",
+     }, {
+       :key		=> "\x0c" * 16,
+       :data		=> "Test With Truncation",
+       :hexdigest	=> "56461ef2342edc00f9bab995690efd4c",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key - Hash Key First",
+       :hexdigest	=> "6b1ab7fe4bd7bf8f0b62e6ce61b9d0cd",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data",
+       :hexdigest	=> "6f630fad67cda0ee1fb1f562db3aa53e",
+     }
+    ]
+  end
+end
+
+class TC_HMAC_SHA1 < Test::Unit::TestCase
+  include TM_HMAC
+
+  def digest_class
+    Digest::SHA1
+  end
+
+  # Taken from RFC 2202: Test Cases for HMAC-MD5 and HMAC-SHA-1
+  def cases
+    [
+     {
+       :key		=> "\x0b" * 20,
+       :data		=> "Hi There",
+       :hexdigest	=> "b617318655057264e28bc0b6fb378c8ef146be00",
+     }, {
+       :key		=> "Jefe",
+       :data		=> "what do ya want for nothing?",
+       :hexdigest	=> "effcdf6ae5eb2fa2d27416d5f184df9c259a7c79",
+     }, {
+       :key		=> "\xaa" * 20,
+       :data		=> "\xdd" * 50,
+       :hexdigest	=> "125d7342b9ac11cd91a39af48aa17b4f63f175d3",
+     }, {
+       :key		=> "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19",
+       :data		=> "\xcd" * 50,
+       :hexdigest	=> "4c9007f4026250c6bc8414f9bf50c86c2d7235da",
+     }, {
+       :key		=> "\x0c" * 20,
+       :data		=> "Test With Truncation",
+       :hexdigest	=> "4c1a03424b55e07fe7f27be1d58bb9324a9a5a04",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key - Hash Key First",
+       :hexdigest	=> "aa4ae5e15272d00e95705637ce8a3b55ed402112",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data",
+       :hexdigest	=> "e8e99d0f45237d786d6bbaa7965c7808bbff1a91",
+     }
+    ]
+  end
+end
+
+class TC_HMAC_RMD160 < Test::Unit::TestCase
+  include TM_HMAC
+
+  def digest_class
+    Digest::RMD160
+  end
+
+  # Taken from RFC 2286: Test Cases for HMAC-RIPEMD160 and HMAC-RIPEMD128
+  def cases
+    [
+     {
+       :key		=> "\x0b" * 20,
+       :data		=> "Hi There",
+       :hexdigest	=> "24cb4bd67d20fc1a5d2ed7732dcc39377f0a5668",
+     }, {
+       :key		=> "Jefe",
+       :data		=> "what do ya want for nothing?",
+       :hexdigest	=> "dda6c0213a485a9e24f4742064a7f033b43c4069",
+     }, {
+       :key		=> "\xaa" * 20,
+       :data		=> "\xdd" * 50,
+       :hexdigest	=> "b0b105360de759960ab4f35298e116e295d8e7c1",
+     }, {
+       :key		=> "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19",
+       :data		=> "\xcd" * 50,
+       :hexdigest	=> "d5ca862f4d21d5e610e18b4cf1beb97a4365ecf4",
+     }, {
+       :key		=> "\x0c" * 20,
+       :data		=> "Test With Truncation",
+       :hexdigest	=> "7619693978f91d90539ae786500ff3d8e0518e39",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key - Hash Key First",
+       :hexdigest	=> "6466ca07ac5eac29e1bd523e5ada7605b791fd8b",
+     }, {
+       :key		=> "\xaa" * 80,
+       :data		=> "Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data",
+       :hexdigest	=> "69ea60798d71616cce5fd0871e23754cd75d5a0a",
+     }
+    ]
+  end
+end