doing with c language

Encryption / decryption in this software to be realized with C language and extraction, file integrity control methods will be implemented personally, archives / APIs will not be used. The source codes of the implemented Programs will be given with an explanation; a) Implementation of the AES encryption algorithm and its use in encryption / decryption (with test data). b) Using the implemented Shymmetric encryption algorithm, make it possible to perform the tests in CBC and OFB modes. c) A tool that will extract and encrypt a document (.doc / .docx, .pdf, ppt,xls, etc.) with a key known only to the processing person and add it to the end of the file (in section b) use the implementation as the extract function) d) In order to check whether the integrity of the file has changed or not, show the sample tests by implementing the verification tool that compares it with the first extracted value by performing the procedure in c