title: How to do an aes encryption WITH a user password?
body: <p>When softwares such as ecryptfs use AES, it asks for a user password (such as "password123").</p>
  
  <p>The AES algorithm by itself does not call for a user password. So where does the "password123" get thrown into the math?</p>
  
  <p>I'm working to make a C function that encrypts some data using a password. I know the typical way of doing it with OpenSSL and an aes key, but I don't know how to get a user password integrated.</p>