From eaf26765c12efe5519fb2af72557dc0ee8286bcd Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Fri, 7 Oct 2016 10:42:00 -0600
Subject: [PATCH] Add su

---
 Cargo.toml       |  4 +++
 src/bin/login.rs |  4 ---
 src/bin/su.rs    | 84 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 4 deletions(-)
 create mode 100644 src/bin/su.rs

diff --git a/Cargo.toml b/Cargo.toml
index 9287729090..fbbef1a662 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,10 @@ path = "src/bin/id.rs"
 name = "login"
 path = "src/bin/login.rs"
 
+[[bin]]
+name = "su"
+path = "src/bin/su.rs"
+
 [[bin]]
 name = "sudo"
 path = "src/bin/sudo.rs"
diff --git a/src/bin/login.rs b/src/bin/login.rs
index 9806a14de1..ba2e9d1d7d 100644
--- a/src/bin/login.rs
+++ b/src/bin/login.rs
@@ -52,10 +52,6 @@ pub fn main() {
 
                     let password_hash = Passwd::encode(&password);
 
-                    if let Ok(mut debug) = File::open("debug:") {
-                        let _  = write!(debug, "{};{}\n", user, password_hash);
-                    }
-
                     for line in passwd_string.lines() {
                         if let Ok(passwd) = Passwd::parse(line) {
                             if user == passwd.user && password_hash == passwd.hash {
diff --git a/src/bin/su.rs b/src/bin/su.rs
new file mode 100644
index 0000000000..7c57000d00
--- /dev/null
+++ b/src/bin/su.rs
@@ -0,0 +1,84 @@
+#![feature(question_mark)]
+
+extern crate syscall;
+extern crate termion;
+extern crate userutils;
+
+use std::env;
+use std::fs::File;
+use std::io::{self, Read, Write};
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+use std::str;
+
+use termion::input::TermRead;
+use userutils::Passwd;
+
+pub fn main() {
+    let stdin = io::stdin();
+    let mut stdin = stdin.lock();
+    let stdout = io::stdout();
+    let mut stdout = stdout.lock();
+
+    let mut user = env::args().nth(1).unwrap_or(String::new());
+    if user.is_empty() {
+        user = String::from("root");
+    }
+
+    let uid = syscall::getuid().unwrap();
+
+    let mut passwd_string = String::new();
+    File::open("file:etc/passwd").unwrap().read_to_string(&mut passwd_string).unwrap();
+
+    let mut passwd_option = None;
+    for line in passwd_string.lines() {
+        if let Ok(passwd) = Passwd::parse(line) {
+            if user == passwd.user && ("" == passwd.hash || uid == 0) {
+                passwd_option = Some(passwd);
+                break;
+            }
+        }
+    }
+
+    if passwd_option.is_none() {
+        stdout.write_all(b"password: ").unwrap();
+        let _ = stdout.flush();
+
+        if let Some(password) = stdin.read_passwd(&mut stdout).unwrap() {
+            stdout.write(b"\n").unwrap();
+            let _ = stdout.flush();
+
+            let password_hash = Passwd::encode(&password);
+
+            for line in passwd_string.lines() {
+                if let Ok(passwd) = Passwd::parse(line) {
+                    if user == passwd.user && password_hash == passwd.hash {
+                        passwd_option = Some(passwd);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    if let Some(passwd) = passwd_option  {
+        let mut command = Command::new(passwd.shell);
+
+        command.uid(passwd.uid);
+        command.gid(passwd.gid);
+
+        command.env("USER", &user);
+        command.env("HOME", passwd.home);
+
+        match command.spawn() {
+            Ok(mut child) => match child.wait() {
+                Ok(_status) => (), //println!("login: waited for {}: {:?}", sh, status.code()),
+                Err(err) => panic!("su: failed to wait for '{}': {}", passwd.shell, err)
+            },
+            Err(err) => panic!("su: failed to execute '{}': {}", passwd.shell, err)
+        }
+    } else {
+        stdout.write(b"su: authentication failed\n").unwrap();
+        let _ = stdout.flush();
+    }
+}