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|
use std::env;
use std::process::ExitCode;
use pwd::Passwd;
use nix::unistd;
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;
mod persist;
mod flags;
mod help;
fn main() -> ExitCode {
let args: Vec<String> = env::args().collect();
let flags = match flags::parse(&args[1..]) {
Some(data) => data,
None => {
help::help();
return ExitCode::from(ERROR_ARGS);
}
};
if flags.version {
println!("crab version 0.0.4");
return ExitCode::SUCCESS;
}
if flags.help {
help::help();
return ExitCode::SUCCESS;
}
if args.len() - flags.arg_count < 2 {
println!("usage: crab [-d] command [args]");
return ExitCode::SUCCESS;
}
let config = match config("/etc/crab.conf") {
Some(data) => data,
None => return ExitCode::from(ERROR_CONFIG)
};
let user = match Passwd::current_user() {
Some(data) => data,
None => {
eprintln!("You dont exist.");
return ExitCode::from(ERROR_NO_USER);
}
};
let persist = match allowed(&config, &user.name) {
Some(data) => data && !flags.dont_persist,
None => {
eprintln!("Operation Not Permitted.");
return ExitCode::from(ERROR_NOT_AUTHORIZED);
}
};
if !validate(&user.name, persist) {
eprintln!("Authentication failed.");
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(ERROR_RUN_ROOT);
};
let start = 1 + flags.arg_count;
let err = exec::execvp(&args[start], &args[start..]);
eprintln!("{}", err);
ExitCode::SUCCESS
}
struct Config {
users: Vec<(String, bool)>
}
fn validate(user: &str, persist: bool) -> bool {
if persist && persist::get_persist(user) {
return true;
}
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;
}
if persist {
persist::set_persist(user);
}
return true;
}
fn allowed(config: &Config, user: &str) -> Option<bool> {
for (name, persist) in &config.users {
if name == user {
return Some(persist.clone());
}
}
None
}
fn config(path: &str) -> Option<Config> {
let file = match std::fs::read_to_string(path) {
Err(e) => {
eprintln!("{}: {}", &path, e);
return None
},
Ok(data) => data
};
let mut users = vec![];
for (line_num, line) in file.split("\n").enumerate() {
let args: Vec<&str> = line.split(" ").collect();
if line.trim() == "" {
continue;
}
if args.len() < 2 {
eprintln!("Error in config at line {}: Not enough arguments", line_num);
continue;
}
let user: String = args[0].to_string();
let persist: bool = match args[1].parse() {
Err(e) => {
eprintln!("Error in config at line {}: {}", line_num, e);
continue;
},
Ok(data) => data
};
users.push((user, persist));
}
Some(Config{users})
}
|
