Refactor drop privileges method

This commit is contained in:
Tobias Reisinger 2023-11-27 19:36:53 +01:00
parent 7ed3a9e52d
commit ec461a1a14
Signed by: serguzim
GPG key ID: 13AD60C237A28DFE
7 changed files with 70 additions and 61 deletions

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Cargo.lock generated

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@ -1,7 +1,7 @@
port = 4419
host = "127.0.0.1"
# Set to a user AND a group to drop privileges to after binding to the port
# Set to a user and a group to drop privileges to after binding to the port
#user = "emgauwa"
#group = "emgauwa"

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@ -23,3 +23,4 @@ serde_json = "1.0"
serde_derive = "1.0"
futures = "0.3.29"
libc = "0.2"

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@ -2,14 +2,15 @@ use actix_cors::Cors;
use std::net::TcpListener;
use std::str::FromStr;
use crate::utils::drop_privileges;
use actix_web::middleware::TrailingSlash;
use actix_web::{middleware, web, App, HttpServer};
use emgauwa_lib::handlers;
use emgauwa_lib::utils::drop_privileges;
use log::{trace, LevelFilter};
use simple_logger::SimpleLogger;
mod settings;
mod utils;
#[actix_web::main]
async fn main() -> std::io::Result<()> {
@ -27,23 +28,13 @@ async fn main() -> std::io::Result<()> {
let listener = TcpListener::bind(format!("{}:{}", settings.host, settings.port))
.expect("Error creating listener");
if !settings.user.is_empty() && !settings.group.is_empty() {
log::info!(
"Dropping privileges to {}:{}",
settings.user,
settings.group
);
drop_privileges(&settings.user, &settings.group).expect("Error dropping privileges");
}
drop_privileges(&settings).expect("Error dropping privileges");
let pool = emgauwa_lib::db::init(&settings.database).await;
log::info!("Starting server on {}:{}", settings.host, settings.port);
HttpServer::new(move || {
let cors = Cors::default()
.allow_any_method()
.allow_any_header()
.max_age(3600);
let cors = Cors::default().allow_any_method().allow_any_header();
let origins = settings.origins.clone();
let cors = match settings.origins.is_empty() {

64
emgauwa-core/src/utils.rs Normal file
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@ -0,0 +1,64 @@
use crate::settings::Settings;
use std::ffi::CString;
use std::io::{Error, ErrorKind};
// https://blog.lxsang.me/post/id/28.0
pub fn drop_privileges(settings: &Settings) -> Result<(), Error> {
log::info!(
"Dropping privileges to {}:{}",
settings.user,
settings.group
);
// the group id need to be set first, because, when the user privileges drop,
// we are unable to drop the group privileges
if !settings.group.is_empty() {
drop_privileges_group(&settings.group)?;
}
if !settings.user.is_empty() {
drop_privileges_user(&settings.user)?;
}
Ok(())
}
fn drop_privileges_group(group: &str) -> Result<(), Error> {
// get the gid from username
if let Ok(cstr) = CString::new(group.as_bytes()) {
let p = unsafe { libc::getgrnam(cstr.as_ptr()) };
if p.is_null() {
eprintln!("Unable to getgrnam of group: {}", group);
return Err(Error::last_os_error());
}
if unsafe { libc::setgid((*p).gr_gid) } != 0 {
eprintln!("Unable to setgid of group: {}", group);
return Err(Error::last_os_error());
}
} else {
return Err(Error::new(
ErrorKind::Other,
"Cannot create CString from String (group)!",
));
}
Ok(())
}
fn drop_privileges_user(user: &str) -> Result<(), Error> {
// get the uid from username
if let Ok(cstr) = CString::new(user.as_bytes()) {
let p = unsafe { libc::getpwnam(cstr.as_ptr()) };
if p.is_null() {
eprintln!("Unable to getpwnam of user: {}", user);
return Err(Error::last_os_error());
}
if unsafe { libc::setuid((*p).pw_uid) } != 0 {
eprintln!("Unable to setuid of user: {}", user);
return Err(Error::last_os_error());
}
} else {
return Err(Error::new(
ErrorKind::Other,
"Cannot create CString from String (user)!",
));
}
Ok(())
}

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@ -24,4 +24,3 @@ libsqlite3-sys = { version = "*", features = ["bundled"] }
log = "0.4"
uuid = "1.6"
futures = "0.3"
libc = "0.2"

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@ -1,6 +1,3 @@
use std::ffi::CString;
use std::io::{Error, ErrorKind};
pub fn load_settings<T>(config_name: &str, env_prefix: &str) -> T
where
for<'de> T: serde::Deserialize<'de>,
@ -19,46 +16,3 @@ where
.try_deserialize::<T>()
.expect("Error reading settings")
}
// https://blog.lxsang.me/post/id/28.0
pub fn drop_privileges(user: &str, group: &str) -> Result<(), Error> {
// the group id need to be set first, otherwise,
// when the user privileges drop, it is unable to
// drop the group privileges
// get the gid from username
if let Ok(cstr) = CString::new(group.as_bytes()) {
let p = unsafe { libc::getgrnam(cstr.as_ptr()) };
if p.is_null() {
eprintln!("Unable to getgrnam of group: {}", group);
return Err(Error::last_os_error());
}
if unsafe { libc::setgid((*p).gr_gid) } != 0 {
eprintln!("Unable to setgid of group: {}", group);
return Err(Error::last_os_error());
}
} else {
return Err(Error::new(
ErrorKind::Other,
"Cannot create CString from String (group)!",
));
}
// drop the user privileges
// get the uid from username
if let Ok(cstr) = CString::new(user.as_bytes()) {
let p = unsafe { libc::getpwnam(cstr.as_ptr()) };
if p.is_null() {
eprintln!("Unable to getpwnam of user: {}", user);
return Err(Error::last_os_error());
}
if unsafe { libc::setuid((*p).pw_uid) } != 0 {
eprintln!("Unable to setuid of user: {}", user);
return Err(Error::last_os_error());
}
} else {
return Err(Error::new(
ErrorKind::Other,
"Cannot create CString from String (user)!",
));
}
Ok(())
}