Update cipher validation to be case-insensitive

lib/openssl/cmac.rb

@@ -26,9 +26,7 @@ class CMAC
     #
     # @return [[String]] supported algorithms
     def self.ciphers
-      l = OpenSSL::Cipher.ciphers.keep_if { |c| c.end_with?('-128-CBC') }
-      l.length.times { |i| l[i] = l[i][0..-9] }
-      l
+      @ciphers ||= OpenSSL::Cipher.ciphers.select { |c| c.match(/-128-CBC$/i) }.map { |e| e[0..-9].upcase }.uniq
     end
 
     # Returns the authentication code as a binary string. The cipher parameter
@@ -56,13 +54,13 @@ def self.digest(cipher, key, data, length = 16)
     #
     # @return [Object] the new CMAC object
     def initialize(cipher, key = '')
-      unless CMAC.ciphers.include?(cipher)
+      unless CMAC.ciphers.include?(cipher.upcase)
         fail CMACError, "unsupported cipher algorithm (#{cipher})"
       end
 
       @keys = []
       @buffer = ''.force_encoding('ASCII-8BIT')
-      @cipher = OpenSSL::Cipher.new("#{cipher}-128-CBC")
+      @cipher = OpenSSL::Cipher.new("#{cipher.upcase}-128-CBC")
 
       self.key = key unless key == ''
     end

test/test_cmac.rb

@@ -87,39 +87,41 @@ def test_cmac_vars
   end
 
   def test_cmac_update
-    # Test with 1 call of update and new CCM object for each test.
-    DATA.length.times do |i|
-      cmac = OpenSSL::CMAC.new('AES', KEY)
-      m = cmac.update(DATA[i]).digest.unpack('H*')[0]
-      assert_equal(MAC[i], m, "Test: 1, Vector: #{i + 1}")
-    end
+    for cipher in ['aes', 'AES']
+      # Test with 1 call of update and new CCM object for each test.
+      DATA.length.times do |i|
+        cmac = OpenSSL::CMAC.new(cipher, KEY)
+        m = cmac.update(DATA[i]).digest.unpack('H*')[0]
+        assert_equal(MAC[i], m, "Test: 1, Vector: #{i + 1}")
+      end
 
-    # Test with 1 call of update and same CCM object for each test.
-    # There is no reset, because it should be possible to calculate
-    # a new mac after digest without reset.
-    cmac = OpenSSL::CMAC.new('AES', KEY)
-    DATA.length.times do |i|
-      m = cmac.update(DATA[i]).digest.unpack('H*')[0]
-      assert_equal(MAC[i], m, "Test: 2, Vector: #{i + 1}")
-    end
+      # Test with 1 call of update and same CCM object for each test.
+      # There is no reset, because it should be possible to calculate
+      # a new mac after digest without reset.
+      cmac = OpenSSL::CMAC.new(cipher, KEY)
+      DATA.length.times do |i|
+        m = cmac.update(DATA[i]).digest.unpack('H*')[0]
+        assert_equal(MAC[i], m, "Test: 2, Vector: #{i + 1}")
+      end
 
-    # Test with multiple calls of update and new CCM object for each test
-    1.upto(DATA.length - 1) do |i|
-      1.upto(17) do |c|
-        cmac = OpenSSL::CMAC.new('AES', KEY)
-        DATA[i].bytes.each_slice(c) { |w| cmac.update(w.pack('C*')) }
-        m = cmac.digest.unpack('H*')[0]
-        assert_equal(MAC[i], m, "Test: 3, Vector: #{i + 1}, Tokenlen: #{c}")
+      # Test with multiple calls of update and new CCM object for each test
+      1.upto(DATA.length - 1) do |i|
+        1.upto(17) do |c|
+          cmac = OpenSSL::CMAC.new(cipher, KEY)
+          DATA[i].bytes.each_slice(c) { |w| cmac.update(w.pack('C*')) }
+          m = cmac.digest.unpack('H*')[0]
+          assert_equal(MAC[i], m, "Test: 3, Vector: #{i + 1}, Tokenlen: #{c}")
+        end
       end
-    end
 
-    # Test with multiple calls of update and same CCM object for each test
-    cmac = OpenSSL::CMAC.new('AES', KEY)
-    1.upto(DATA.length - 1) do |i|
-      1.upto(17) do |c|
-        DATA[i].bytes.each_slice(c) { |w| cmac.update(w.pack('C*')) }
-        m = cmac.digest.unpack('H*')[0]
-        assert_equal(MAC[i], m, "Test: 4, Vector: #{i + 1}, Tokenlen: #{c}")
+      # Test with multiple calls of update and same CCM object for each test
+      cmac = OpenSSL::CMAC.new(cipher, KEY)
+      1.upto(DATA.length - 1) do |i|
+        1.upto(17) do |c|
+          DATA[i].bytes.each_slice(c) { |w| cmac.update(w.pack('C*')) }
+          m = cmac.digest.unpack('H*')[0]
+          assert_equal(MAC[i], m, "Test: 4, Vector: #{i + 1}, Tokenlen: #{c}")
+        end
       end
     end
 
@@ -130,25 +132,27 @@ def test_cmac_update
   end
 
   def test_cmac_digest
-    cmac = OpenSSL::CMAC.new('AES', KEY)
-    m = cmac.update(DATA[3]).digest.unpack('H*')[0]
-    assert_equal(MAC[3], m, 'Digest with no update')
-
-    cmac.update(DATA[3].b[0...20])
-    m = cmac.update(DATA[3].b[20...64]).digest.unpack('H*')[0]
-    assert_equal(MAC[3], m, 'Digest after update')
-
-    cmac.update(DATA[3])
-    m = cmac.update('').digest.unpack('H*')[0]
-    assert_equal(MAC[3], m, 'Empty digest')
-
-    DATA.length.times do |i|
-      m = OpenSSL::CMAC.digest('AES', KEY, DATA[i]).unpack('H*')[0]
-      assert_equal(MAC[i], m, "Vector: #{i + 1}")
-
-      m = OpenSSL::CMAC.digest('AES', KEY, DATA[i], 12).unpack('H*')[0]
-      assert_equal(24, m.length, "Vector: #{i + 1} - length")
-      assert_equal(MAC[i][0...24], m, "Vector: #{i + 1} - 12")
+    for cipher in ['aes', 'AES']
+      cmac = OpenSSL::CMAC.new(cipher, KEY)
+      m = cmac.update(DATA[3]).digest.unpack('H*')[0]
+      assert_equal(MAC[3], m, 'Digest with no update')
+
+      cmac.update(DATA[3].b[0...20])
+      m = cmac.update(DATA[3].b[20...64]).digest.unpack('H*')[0]
+      assert_equal(MAC[3], m, 'Digest after update')
+
+      cmac.update(DATA[3])
+      m = cmac.update('').digest.unpack('H*')[0]
+      assert_equal(MAC[3], m, 'Empty digest')
+
+      DATA.length.times do |i|
+        m = OpenSSL::CMAC.digest(cipher, KEY, DATA[i]).unpack('H*')[0]
+        assert_equal(MAC[i], m, "Vector: #{i + 1}")
+
+        m = OpenSSL::CMAC.digest(cipher, KEY, DATA[i], 12).unpack('H*')[0]
+        assert_equal(24, m.length, "Vector: #{i + 1} - length")
+        assert_equal(MAC[i][0...24], m, "Vector: #{i + 1} - 12")
+      end
     end
   end