Unpacked OpenID gem. #699

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2437 e93f8b46-1217-0410-a6f0-8f06a7374b81

vendor/gems/ruby-openid-2.1.4/lib/openid/cryptutil.rb

@@ -0,0 +1,97 @@
+require "openid/util"
+require "digest/sha1"
+require "digest/sha2"
+begin
+  require "digest/hmac"
+rescue LoadError
+  require "hmac/sha1"
+  require "hmac/sha2"
+end
+
+module OpenID
+  # This module contains everything needed to perform low-level
+  # cryptograph and data manipulation tasks.
+  module CryptUtil
+
+    # Generate a random number, doing a little extra work to make it
+    # more likely that it's suitable for cryptography. If your system
+    # doesn't have /dev/urandom then this number is not
+    # cryptographically safe. See
+    # <http://www.cosine.org/2007/08/07/security-ruby-kernel-rand/>
+    # for more information.  max is the largest possible value of such
+    # a random number, where the result will be less than max.
+    def CryptUtil.rand(max)
+      Kernel.srand()
+      return Kernel.rand(max)
+    end
+
+    def CryptUtil.sha1(text)
+      return Digest::SHA1.digest(text)
+    end
+
+    def CryptUtil.hmac_sha1(key, text)
+      if Digest.const_defined? :HMAC      
+        Digest::HMAC.new(key,Digest::SHA1).update(text).digest
+      else
+        return HMAC::SHA1.digest(key, text)
+      end
+    end
+
+    def CryptUtil.sha256(text)
+      return Digest::SHA256.digest(text)
+    end
+
+    def CryptUtil.hmac_sha256(key, text)
+      if Digest.const_defined? :HMAC      
+        Digest::HMAC.new(key,Digest::SHA256).update(text).digest
+      else
+        return HMAC::SHA256.digest(key, text)
+      end
+    end
+
+    # Generate a random string of the given length, composed of the
+    # specified characters.  If chars is nil, generate a string
+    # composed of characters in the range 0..255.
+    def CryptUtil.random_string(length, chars=nil)
+      s = ""
+
+      unless chars.nil?
+        length.times { s << chars[rand(chars.length)] }
+      else
+        length.times { s << rand(256).chr }
+      end
+      return s
+    end
+
+    # Convert a number to its binary representation; return a string
+    # of bytes.
+    def CryptUtil.num_to_binary(n)
+      bits = n.to_s(2)
+      prepend = (8 - bits.length % 8)
+      bits = ('0' * prepend) + bits
+      return [bits].pack('B*')
+    end
+
+    # Convert a string of bytes into a number.
+    def CryptUtil.binary_to_num(s)
+      # taken from openid-ruby 0.0.1
+      s = "\000" * (4 - (s.length % 4)) + s
+      num = 0
+      s.unpack('N*').each do |x|
+        num <<= 32
+        num |= x
+      end
+      return num
+    end
+
+    # Encode a number as a base64-encoded byte string.
+    def CryptUtil.num_to_base64(l)
+      return OpenID::Util.to_base64(num_to_binary(l))
+    end
+
+    # Decode a base64 byte string to a number.
+    def CryptUtil.base64_to_num(s)
+      return binary_to_num(OpenID::Util.from_base64(s))
+    end
+  end
+end