AES encryption on .Net and decrypt in iPhone / iOS sample

We need sample source code for the following use case: 1. Encrypt a string/file on .Net side useing AES 256 bit (server side) 2. Decrypt in iPhone/ iOS side and recover the string/file. (client side) You need to provide workable .Net and XCode project on both side and illustrate the successful encryption and decryption Used code is welcome, the only requirement is to get the job done. This is an urgent project so you have to deliver the code in 24 hours. Other requirements will be provided in further communications