1) create decrypt_file.cpp (similar to encrypt_file.cpp) that decrypts a given
   file using, a given password [2 points]

2) create a random session key and save it as plaintext to a file
   using CryptGenKey, CryptExportKey (with dwBlobType = PLAINTEXTKEYBLOB)
   [3 points]

3) create a context and generate asymmetric keys for signing and key exchange,
   using CryptAcquireContext (with dwFlags = CRYPT_NEWKEYSET) [2 points]

4) use the generated public key for key exchange to encrypt the session key
   and save it to a file, using:
     - CryptGenKey for creating session key,
     - CryptGetUserKey (with dwKeySpec = AT_KEYEXCHANGE) 
     - CryptExportKey (with dwBlobType = SIMPLEBLOB)
   [3 points]

The deadline is November 15th, maximum is 10 points total.