initial parsing of shadow file

Cargo.lock

@@ -4,6 +4,7 @@
 name = "adduser"
 version = "0.1.0"
 dependencies = [
+ "chrono",
  "lazy_static",
  "log",
  "regex",

Cargo.toml

@@ -11,3 +11,4 @@ regex = "1"
 lazy_static = "1.4"
 log = "0.4"
 simplelog = "0.8"
+chrono = "0.4"

src/lib.rs

@@ -4,5 +4,6 @@ extern crate lazy_static;
 extern crate log;
 
 pub mod passwd;
+pub mod shadow;
 pub mod userlib_error;
-pub use passwd::{Gecos, Gid, HomeDir, Password, ShellPath, Uid, Username};
+pub use passwd::{Gecos, Gid, HomeDir, Passwd, Password, ShellPath, Uid, Username};

src/shadow.rs

@@ -0,0 +1,92 @@
+#![warn(
+    clippy::all,
+/*    clippy::restriction,*/
+    clippy::pedantic,
+    clippy::nursery,
+    clippy::cargo
+)]
+#![allow(clippy::non_ascii_literal)]
+
+use log::warn;
+use regex::Regex;
+
+use crate::passwd;
+use crate::userlib_error::UserLibError;
+use chrono;
+use std::cmp::Eq;
+use std::convert::TryFrom;
+use std::fmt::{self, Display};
+
+/// A record(line) in the user database `/etc/shadow` found in most linux systems.
+#[derive(Debug, PartialEq, Eq)]
+pub struct Shadow<'a> {
+    username: passwd::Username<'a>,                 /* Username.  */
+    password: passwd::Password<'a>,                 /* Hashed passphrase */
+    last_change: Option<chrono::NaiveDateTime>,     /* User ID.  */
+    earliest_change: Option<chrono::NaiveDateTime>, /* Group ID.  */
+    lateste_change: Option<chrono::NaiveDateTime>,  /* Real name.  */
+    warn_period: Option<chrono::Duration>,          /* Home directory.  */
+    deactivated: Option<chrono::Duration>,          /* Shell program.  */
+    deactivated_since: Option<chrono::Duration>,    /* Shell program.  */
+    extensions: Option<u64>,                        /* Shell program.  */
+}
+
+impl<'a> Shadow<'a> {
+    /// Parse a line formatted like one in `/etc/shadow` and construct a matching `Shadow` instance
+    ///
+    /// # Example
+    /// ```
+    /// let pwd = adduser::shadow::Shadow::new_from_string(
+    ///     ""
+    /// ).unwrap();
+    /// //assert_eq!(pwd.get_username(), "testuser");
+    /// ```
+    ///
+    /// # Errors
+    /// When parsing fails this function returns a `UserLibError::Message` containing some information as to why the function failed.
+    pub fn new_from_string(line: &'a str) -> Result<Self, UserLibError> {
+        let elements: Vec<&str> = line.split(':').collect();
+        if elements.len() == 9 {
+            Ok(Shadow {
+                username: passwd::Username::try_from(*elements.get(0).unwrap())?,
+                password: passwd::Password::try_from(*elements.get(1).unwrap())?,
+                last_change: date_since_epoch(elements.get(2).unwrap()),
+                earliest_change: date_since_epoch(elements.get(3).unwrap()),
+                lateste_change: date_since_epoch(elements.get(4).unwrap()),
+                warn_period: duration_for_days(elements.get(5).unwrap()),
+                deactivated: duration_for_days(elements.get(6).unwrap()),
+                deactivated_since: duration_for_days(elements.get(7).unwrap()),
+                extensions: Some(0),
+            })
+        } else {
+            Err("Failed to parse: not enough elements".into())
+        }
+    }
+}
+
+const SECONDS_PER_DAY: i64 = 86400;
+fn date_since_epoch(days_since_epoch: &str) -> Option<chrono::NaiveDateTime> {
+    if days_since_epoch.is_empty() {
+        None
+    } else {
+        let days: i64 = days_since_epoch.parse::<i64>().unwrap();
+        let seconds = days * SECONDS_PER_DAY;
+        Some(chrono::NaiveDateTime::from_timestamp(seconds, 0))
+    }
+}
+fn duration_for_days(days_source: &str) -> Option<chrono::Duration> {
+    if days_source.is_empty() {
+        None
+    } else {
+        let days: i64 = days_source.parse::<i64>().unwrap();
+        Some(chrono::Duration::days(days))
+    }
+}
+
+#[test]
+fn test_since_epoch() {
+    panic!(format!(
+        "{:?}",
+        Shadow::new_from_string("dietrich:$6$SCJjPV7$SZ7XgOdEMiqZ3v5n9Q2AR2yJKN0PLbSHlrdiZcp/NcB41JEtT12Ke3Zy6XThfiFemJheC0IrM3..JVCAagqxg.:18110:0:99999:7:::")
+    ));
+}