* lib/securerandom.rb: new method SecureRandom#uuid

git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@21868 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/securerandom.rb b/lib/securerandom.rb
index 0de118cb4..0582cee72 100644
--- a/lib/securerandom.rb
+++ b/lib/securerandom.rb
@@ -167,6 +167,16 @@ module SecureRandom
     end
   end
 
+  # SecureRandom.uuid generates a v4 random UUID.
+  def self.uuid
+    str = self.random_bytes(16)
+    str[6] = (str[6] & 0x0f) | 0x40
+    str[8] = (str[8] & 0x3f) | 0x80
+
+    ary = str.unpack("NnnnnN")
+    "%08x-%04x-%04x-%04x-%04x%08x" % ary
+  end
+
   # Following code is based on David Garamond's GUID library for Ruby.
   def self.lastWin32ErrorMessage # :nodoc:
     get_last_error = Win32API.new("kernel32", "GetLastError", '', 'L')