trial: Encrypt and decrypt timestamp

Add functions to encrypt and decrypt a timestamp. We'll be using those
functions to write the encrypted timestamp of the first trial launch
date to a file.

Decided to go for some light encryption instead of just storing a plain
or base64-encoded value. Still need to come up with a key, but that will
be stored as a plain string in the binary.

Need a way to capture the results so we don't end up panicking. Trouble
is, 'magic-crypt' doesn't implement the required `Error` traits, so I
can't just slot it into 'error-chain'. Still trying to work out how to
deal with that.

Also add a function to get the days remaining from now.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 8e23367..27fc7a7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,6 +16,7 @@ extern crate libc;
 
 #[macro_use]
 extern crate log;
+extern crate magic_crypt;
 
 #[macro_use]
 extern crate objc;