Use SystemTime for the certificate's time

Also don't use mem::forget() for the updater, because who knows, Rust
optimizations may be too aggressive.

Maybe
Fixes #13

src/anonymized_dns.rs

@@ -1,5 +1,5 @@
-use crate::*;
 use crate::errors::*;
+use crate::*;
 
 use byteorder::{BigEndian, ByteOrder};
 use siphasher::sip128::Hasher128;

src/dnscrypt_certs.rs

@@ -6,17 +6,20 @@ use crate::globals::*;
 
 use byteorder::{BigEndian, ByteOrder};
 use clockpro_cache::ClockProCache;
-use coarsetime::Clock;
 use parking_lot::Mutex;
 use std::mem;
 use std::slice;
 use std::sync::Arc;
+use std::time::SystemTime;
 
 pub const DNSCRYPT_CERTS_TTL: u32 = 86400;
 pub const DNSCRYPT_CERTS_RENEWAL: u32 = 28800;
 
 fn now() -> u32 {
-    Clock::recent_since_epoch().as_secs() as u32
+    SystemTime::now()
+        .duration_since(SystemTime::UNIX_EPOCH)
+        .expect("The clock is completely off")
+        .as_secs() as _
 }
 
 #[derive(Debug, Default, Clone, Serialize, Deserialize)]

src/main.rs

@@ -65,7 +65,6 @@ use std::collections::vec_deque::VecDeque;
 use std::convert::TryFrom;
 use std::fs::File;
 use std::io::prelude::*;
-use std::mem;
 use std::net::SocketAddr;
 use std::path::Path;
 use std::sync::atomic::{AtomicU32, Ordering};
@@ -461,9 +460,7 @@ fn main() -> Result<(), Error> {
         .init();
 
     crypto::init()?;
-    let updater = coarsetime::Updater::new(1000).start()?;
-    mem::forget(updater);
-
+    let time_updater = coarsetime::Updater::new(1000).start()?;
     let matches = app_from_crate!()
         .arg(
             Arg::with_name("config")
@@ -694,5 +691,6 @@ fn main() -> Result<(), Error> {
             .map(|_| ()),
     );
     runtime.block_on(updater.run());
+    time_updater.stop()?;
     Ok(())
 }