Moved core extensions to Net::BER. Documented.

lib/net/ber/core_ext/string.rb

@@ -0,0 +1,51 @@
+require 'stringio'
+
+module Net::BER::Extensions::String
+  ##
+  # Converts a string to a BER string. Universal octet-strings are tagged
+  # with 0x04, but other values are possible depending on the context, so we
+  # let the caller give us one.
+  #
+  # User code should call either #to_ber_application_string or
+  # #to_ber_contextspecific.
+  def to_ber(code = 0x04)
+    [code].pack('C') + length.to_ber_length_encoding + self
+  end
+
+  ##
+  # Creates an application-specific BER string encoded value with the
+  # provided syntax code value.
+  def to_ber_application_string(code)
+    to_ber(0x40 + code)
+  end
+
+  ##
+  # Creates a context-specific BER string encoded value with the provided
+  # syntax code value.
+  def to_ber_contextspecific(code)
+    to_ber(0x80 + code)
+  end
+
+  ##
+  # Nondestructively reads a BER object from this string.
+  def read_ber(syntax = nil)
+    StringIO.new(self).read_ber(syntax)
+  end
+
+=begin
+  # 20100319 AZ I've kept this here because I'm not yet sure if it's
+  # necessary.
+
+  ##
+  # Destructively reads a BER object from this string.
+  def read_ber!(syntax = nil)
+    obj, consumed = read_ber_from_string(self, syntax)
+    if consumed
+      self.slice!(0...consumed)
+      obj
+    else
+      nil
+    end
+  end
+=end
+end