error codes

src/main.rs

@@ -8,45 +8,54 @@ use serde_json::Value;
 
 extern crate time;
 
+const ERROR_ARGS:           u8 = 1;
+const ERROR_CONFIG:         u8 = 2;
+const ERROR_NO_USER:        u8 = 3;
+const ERROR_NOT_AUTHORIZED: u8 = 4;
+const ERROR_AUTH_FAILED:    u8 = 5;
+const ERROR_RUN_ROOT:       u8 = 6;
+const SUCCESS:              u8 = 0;
+
+
 fn main() -> ExitCode {
     let args: Vec<String> = env::args().collect();
     if args.len() < 2 {
         eprintln!("Invalid argument count.");
-        return ExitCode::from(0);
+        return ExitCode::from(ERROR_ARGS);
     }
     let config = match config("/etc/crab.conf") {
         Some(data) => data,
-        None => return ExitCode::from(1)
+        None => return ExitCode::from(ERROR_CONFIG)
     };
     let user = match Passwd::current_user() {
         Some(data) => data,
         None => {
             eprintln!("You dont exist.");
-            return ExitCode::from(2);
+            return ExitCode::from(ERROR_NO_USER);
         }
     };
     let persist = match allowed(&config, &user.name) {
         Some(data) => data,
         None => {
             eprintln!("Operation Not Permitted. This incidence will be reported.");
-            return ExitCode::from(3);
+            return ExitCode::from(ERROR_NOT_AUTHORIZED);
         }
     };
 
     if !validate(&user.name, persist) {
         eprintln!("Authentication failed.");
-        return ExitCode::from(4);
+        return ExitCode::from(ERROR_AUTH_FAILED);
     }
 
     if !unistd::setuid(unistd::geteuid()).is_ok() || !unistd::setgid(unistd::getegid()).is_ok() {
         eprintln!("Failed to set root permissions");
-        return ExitCode::from(5);
+        return ExitCode::from(ERROR_RUN_ROOT);
     };
 
     let err = exec::execvp(&args[1], &args[1..]);
     println!("Error: {}", err);
     
-    ExitCode::from(0)
+    ExitCode::from(SUCCESS)
 }
 
 struct Config {
@@ -57,8 +66,14 @@ fn validate(user: &str, persist: bool) -> bool {
     if persist && get_persist(user) {
         return true;
     }
-    let input = rpassword::prompt_password(format!("crab ({}) password: ", user)).unwrap();
-    let mut auth = pam::Authenticator::with_password("crab").unwrap();
+    let input = match rpassword::prompt_password(format!("crab ({}) password: ", user)) {
+        Ok(data) => data,
+        Err(_) => return false
+    };
+    let mut auth = match pam::Authenticator::with_password("crab") {
+        Ok(data) => data,
+        Err(_) => return false
+    };
     auth.get_handler().set_credentials(user.to_owned(), input);
     if !auth.authenticate().is_ok() || !auth.open_session().is_ok() {
         return false;