Prevent the dcerpc NDR string functions from modifying their argument directly

git-svn-id: file:///home/svn/framework3/trunk@8102 4d416f70-5f16-0410-b530-b9f4589650da

lib/rex/encoder/ndr.rb

@@ -49,7 +49,7 @@ module NDR
 	# use to encode:
 	#       w_char *element_1;
 	def NDR.wstring(string)
-		string << "\x00" # null pad
+		string  = string + "\x00" # null pad
 		return long(string.length) + long(0) + long(string.length) + Rex::Text.to_unicode(string) + align(Rex::Text.to_unicode(string))
 	end
 
@@ -57,7 +57,7 @@ module NDR
 	# use to encode:
 	#       [unique] w_char *element_1;
 	def NDR.uwstring(string)
-		string << "\x00" # null pad
+		string  = string + "\x00" # null pad
 		return long(rand(0xffffffff))+long(string.length) + long(0) + long(string.length) + Rex::Text.to_unicode(string) + align(Rex::Text.to_unicode(string))
 	end
 
@@ -67,7 +67,7 @@ module NDR
 	def NDR.wstring_prebuilt(string)
 		# if the string len is odd, thats bad!
 		if string.length % 2 > 0
-			string << "\x00"
+			string = string + "\x00"
 		end
 		len = string.length / 2;
 		return long(len) + long(0) + long(len) + string + align(string)
@@ -86,3 +86,4 @@ module NDR
 end
 end
 end
+