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// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
#![allow(clippy::missing_safety_doc)] // TODO add safety docs
use crate::{
callbacks::*,
cert_chain::CertificateChain,
config::Config,
enums::*,
error::{Error, Fallible, Pollable},
security,
};
use core::{
convert::TryInto,
fmt,
mem::{self, ManuallyDrop, MaybeUninit},
pin::Pin,
ptr::NonNull,
task::{Poll, Waker},
time::Duration,
};
use libc::c_void;
use s2n_tls_sys::*;
use std::ffi::CStr;
mod builder;
pub use builder::*;
macro_rules! static_const_str {
($c_chars:expr) => {
unsafe { CStr::from_ptr($c_chars) }
.to_str()
.map_err(|_| Error::INVALID_INPUT)
};
}
pub struct Connection {
connection: NonNull<s2n_connection>,
}
impl fmt::Debug for Connection {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut debug = f.debug_struct("Connection");
if let Ok(handshake) = self.handshake_type() {
debug.field("handshake_type", &handshake);
}
if let Ok(cipher) = self.cipher_suite() {
debug.field("cipher_suite", &cipher);
}
if let Ok(version) = self.actual_protocol_version() {
debug.field("actual_protocol_version", &version);
}
if let Ok(curve) = self.selected_curve() {
debug.field("selected_curve", &curve);
}
debug.finish_non_exhaustive()
}
}
/// # Safety
///
/// s2n_connection objects can be sent across threads
unsafe impl Send for Connection {}
/// # Sync
///
/// Although NonNull isn't Sync and allows access to mutable pointers even from
/// immutable references, the Connection interface enforces that all mutating
/// methods correctly require &mut self.
///
/// Developers and reviewers MUST ensure that new methods correctly use
/// either &self or &mut self depending on their behavior. No mechanism enforces this.
///
/// Note: Although non-mutating methods like getters should be thread-safe by definition,
/// technically the only thread safety guarantee provided by the underlying C library
/// is that s2n_send and s2n_recv can be called concurrently.
///
unsafe impl Sync for Connection {}
impl Connection {
pub fn new(mode: Mode) -> Self {
crate::init::init();
let connection = unsafe { s2n_connection_new(mode.into()).into_result() }.unwrap();
unsafe {
debug_assert! {
s2n_connection_get_config(connection.as_ptr(), &mut core::ptr::null_mut())
.into_result()
.is_err()
}
}
let mut connection = Self { connection };
connection.init_context(mode);
connection
}
fn init_context(&mut self, mode: Mode) {
let context = Box::new(Context::new(mode));
let context = Box::into_raw(context) as *mut c_void;
// allocate a new context object
unsafe {
// There should never be an existing context
debug_assert!(s2n_connection_get_ctx(self.connection.as_ptr())
.into_result()
.is_err());
s2n_connection_set_ctx(self.connection.as_ptr(), context)
.into_result()
.unwrap();
}
}
pub fn new_client() -> Self {
Self::new(Mode::Client)
}
pub fn new_server() -> Self {
Self::new(Mode::Server)
}
pub(crate) fn as_ptr(&mut self) -> *mut s2n_connection {
self.connection.as_ptr()
}
/// # Safety
///
/// Caller must ensure s2n_connection is a valid reference to a [`s2n_connection`] object
pub(crate) unsafe fn from_raw(connection: NonNull<s2n_connection>) -> Self {
Self { connection }
}
pub(crate) fn mode(&self) -> Mode {
self.context().mode
}
/// can be used to configure s2n to either use built-in blinding (set blinding
/// to Blinding::BuiltIn) or self-service blinding (set blinding to
/// Blinding::SelfService).
pub fn set_blinding(&mut self, blinding: Blinding) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_blinding(self.connection.as_ptr(), blinding.into()).into_result()
}?;
Ok(self)
}
/// Reports the remaining nanoseconds before the connection may be gracefully shutdown.
///
/// This method is expected to succeed, but could fail if the
/// [underlying C call](`s2n_connection_get_delay`) encounters errors.
/// Failure indicates that calls to [`Self::poll_shutdown`] will also fail and
/// that a graceful two-way shutdown of the connection will not be possible.
pub fn remaining_blinding_delay(&self) -> Result<Duration, Error> {
let nanos = unsafe { s2n_connection_get_delay(self.connection.as_ptr()).into_result() }?;
Ok(Duration::from_nanos(nanos))
}
/// Sets whether or not a Client Certificate should be required to complete the TLS Connection.
///
/// If this is set to ClientAuthType::Optional the server will request a client certificate
/// but allow the client to not provide one. Rejecting a client certificate when using
/// ClientAuthType::Optional will terminate the handshake.
pub fn set_client_auth_type(
&mut self,
client_auth_type: ClientAuthType,
) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_client_auth_type(self.connection.as_ptr(), client_auth_type.into())
.into_result()
}?;
Ok(self)
}
/// Attempts to drop the config on the connection.
///
/// # Safety
///
/// The caller must ensure the config associated with the connection was created
/// with a [`config::Builder`].
unsafe fn drop_config(&mut self) -> Result<(), Error> {
let mut prev_config = core::ptr::null_mut();
// A valid non-null pointer is returned only if the application previously called
// [`Self::set_config()`].
if s2n_connection_get_config(self.connection.as_ptr(), &mut prev_config)
.into_result()
.is_ok()
{
let prev_config = NonNull::new(prev_config).expect(
"config should exist since the call to s2n_connection_get_config was successful",
);
drop(Config::from_raw(prev_config));
}
Ok(())
}
/// Associates a configuration object with a connection.
pub fn set_config(&mut self, mut config: Config) -> Result<&mut Self, Error> {
unsafe {
// attempt to drop the currently set config
self.drop_config()?;
s2n_connection_set_config(self.connection.as_ptr(), config.as_mut_ptr())
.into_result()?;
debug_assert! {
s2n_connection_get_config(self.connection.as_ptr(), &mut core::ptr::null_mut()).into_result().is_ok(),
"s2n_connection_set_config was successful"
};
// Setting the config on the connection creates one additional reference to the config
// so do not drop so prevent Rust from calling `drop()` at the end of this function.
mem::forget(config);
}
Ok(self)
}
pub(crate) fn config(&self) -> Option<Config> {
let mut raw = core::ptr::null_mut();
let config = unsafe {
s2n_connection_get_config(self.connection.as_ptr(), &mut raw)
.into_result()
.ok()?;
let raw = NonNull::new(raw)?;
Config::from_raw(raw)
};
// Because the config pointer is still set on the connection, this is a copy,
// not the original config. This is fine -- Configs are immutable.
let _ = ManuallyDrop::new(config.clone());
Some(config)
}
pub fn set_security_policy(&mut self, policy: &security::Policy) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_cipher_preferences(
self.connection.as_ptr(),
policy.as_cstr().as_ptr(),
)
.into_result()
}?;
Ok(self)
}
/// provides a smooth transition from s2n_connection_prefer_low_latency to s2n_connection_prefer_throughput.
///
/// s2n_send uses small TLS records that fit into a single TCP segment for the resize_threshold
/// bytes (cap to 8M) of data and reset record size back to a single segment after timeout_threshold
/// seconds of inactivity.
pub fn set_dynamic_record_threshold(
&mut self,
resize_threshold: u32,
timeout_threshold: u16,
) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_dynamic_record_threshold(
self.connection.as_ptr(),
resize_threshold,
timeout_threshold,
)
.into_result()
}?;
Ok(self)
}
/// sets the application protocol preferences on an s2n_connection object.
///
/// protocols is a list in order of preference, with most preferred protocol first, and of
/// length protocol_count. When acting as a client the protocol list is included in the
/// Client Hello message as the ALPN extension. As a server, the list is used to negotiate
/// a mutual application protocol with the client. After the negotiation for the connection has
/// completed, the agreed upon protocol can be retrieved with s2n_get_application_protocol
pub fn set_application_protocol_preference<P: IntoIterator<Item = I>, I: AsRef<[u8]>>(
&mut self,
protocols: P,
) -> Result<&mut Self, Error> {
// reset the list
unsafe {
s2n_connection_set_protocol_preferences(self.connection.as_ptr(), core::ptr::null(), 0)
.into_result()
}?;
for protocol in protocols {
self.append_application_protocol_preference(protocol.as_ref())?;
}
Ok(self)
}
pub fn append_application_protocol_preference(
&mut self,
protocol: &[u8],
) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_append_protocol_preference(
self.connection.as_ptr(),
protocol.as_ptr(),
protocol
.len()
.try_into()
.map_err(|_| Error::INVALID_INPUT)?,
)
.into_result()
}?;
Ok(self)
}
/// may be used to receive data with callbacks defined by the user.
pub fn set_receive_callback(&mut self, callback: s2n_recv_fn) -> Result<&mut Self, Error> {
unsafe { s2n_connection_set_recv_cb(self.connection.as_ptr(), callback).into_result() }?;
Ok(self)
}
/// # Safety
///
/// The `context` pointer must live at least as long as the connection
pub unsafe fn set_receive_context(&mut self, context: *mut c_void) -> Result<&mut Self, Error> {
s2n_connection_set_recv_ctx(self.connection.as_ptr(), context).into_result()?;
Ok(self)
}
/// may be used to receive data with callbacks defined by the user.
pub fn set_send_callback(&mut self, callback: s2n_send_fn) -> Result<&mut Self, Error> {
unsafe { s2n_connection_set_send_cb(self.connection.as_ptr(), callback).into_result() }?;
Ok(self)
}
/// Sets the callback to use for verifying that a hostname from an X.509 certificate is
/// trusted.
///
/// The callback may be called more than once during certificate validation as each SAN on
/// the certificate will be checked.
///
/// Corresponds to the underlying C API
/// [s2n_connection_set_verify_host_callback](https://aws.github.io/s2n-tls/doxygen/s2n_8h.html).
pub fn set_verify_host_callback<T: 'static + VerifyHostNameCallback>(
&mut self,
handler: T,
) -> Result<&mut Self, Error> {
unsafe extern "C" fn verify_host_cb_fn(
host_name: *const ::libc::c_char,
host_name_len: usize,
context: *mut ::libc::c_void,
) -> u8 {
let context = &mut *(context as *mut Context);
let handler = context.verify_host_callback.as_mut().unwrap();
verify_host(host_name, host_name_len, handler)
}
self.context_mut().verify_host_callback = Some(Box::new(handler));
unsafe {
s2n_connection_set_verify_host_callback(
self.connection.as_ptr(),
Some(verify_host_cb_fn),
self.context_mut() as *mut Context as *mut c_void,
)
.into_result()
}?;
Ok(self)
}
/// # Safety
///
/// The `context` pointer must live at least as long as the connection
pub unsafe fn set_send_context(&mut self, context: *mut c_void) -> Result<&mut Self, Error> {
s2n_connection_set_send_ctx(self.connection.as_ptr(), context).into_result()?;
Ok(self)
}
/// Connections prefering low latency will be encrypted using small record sizes that
/// can be decrypted sooner by the recipient.
pub fn prefer_low_latency(&mut self) -> Result<&mut Self, Error> {
unsafe { s2n_connection_prefer_low_latency(self.connection.as_ptr()).into_result() }?;
Ok(self)
}
/// Connections prefering throughput will use large record sizes that minimize overhead.
pub fn prefer_throughput(&mut self) -> Result<&mut Self, Error> {
unsafe { s2n_connection_prefer_throughput(self.connection.as_ptr()).into_result() }?;
Ok(self)
}
/// wipes and free the in and out buffers associated with a connection.
///
/// This function may be called when a connection is in keep-alive or idle state to
/// reduce memory overhead of long lived connections.
pub fn release_buffers(&mut self) -> Result<&mut Self, Error> {
unsafe { s2n_connection_release_buffers(self.connection.as_ptr()).into_result() }?;
Ok(self)
}
pub fn use_corked_io(&mut self) -> Result<&mut Self, Error> {
unsafe { s2n_connection_use_corked_io(self.connection.as_ptr()).into_result() }?;
Ok(self)
}
/// wipes an existing connection and allows it to be reused.
///
/// This method erases all data associated with a connection including pending reads.
/// This function should be called after all I/O is completed and s2n_shutdown has been
/// called. Reusing the same connection handle(s) is more performant than repeatedly
/// calling s2n_connection_new and s2n_connection_free
pub fn wipe(&mut self) -> Result<&mut Self, Error> {
let mode = self.mode();
unsafe {
// Wiping the connection will wipe the pointer to the context,
// so retrieve and drop that memory first.
let ctx = self.context_mut();
drop(Box::from_raw(ctx));
s2n_connection_wipe(self.connection.as_ptr()).into_result()
}?;
self.init_context(mode);
Ok(self)
}
/// Performs the TLS handshake to completion
///
/// Multiple callbacks can be configured for a connection and config, but
/// [`Self::poll_negotiate()`] can only execute and block on one callback at a time.
/// The handshake is sequential, not concurrent, and stops execution when
/// it encounters an async callback.
///
/// The handshake does not continue execution (and therefore can't call
/// any other callbacks) until the blocking async task reports completion.
pub fn poll_negotiate(&mut self) -> Poll<Result<&mut Self, Error>> {
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
if !core::mem::replace(&mut self.context_mut().connection_initialized, true) {
if let Some(config) = self.config() {
if let Some(callback) = config.context().connection_initializer.as_ref() {
let future = callback.initialize_connection(self);
AsyncCallback::trigger(future, self);
}
}
}
loop {
// check if an async task exists and poll it to completion
if let Some(fut) = self.poll_async_task() {
match fut {
Poll::Ready(Ok(())) => {
// happy case:
// continue and call s2n_negotiate to make progress on the handshake
}
Poll::Ready(Err(err)) => {
// error case:
// if the callback returned an error then abort the handshake
return Poll::Ready(Err(err));
}
Poll::Pending => return Poll::Pending,
}
}
let res = unsafe { s2n_negotiate(self.connection.as_ptr(), &mut blocked).into_poll() };
match res {
Poll::Ready(res) => {
let res = res.map(|_| self);
return Poll::Ready(res);
}
Poll::Pending => {
// if there is no connection_future then return, otherwise continue
// looping and polling the future
if self.context_mut().async_callback.is_none() {
return Poll::Pending;
}
}
}
}
}
// Poll the connection future if it exists.
//
// If the future returns Pending, then re-set it back on the Connection.
fn poll_async_task(&mut self) -> Option<Poll<Result<(), Error>>> {
self.take_async_callback().map(|mut callback| {
let waker = self.waker().ok_or(Error::MISSING_WAKER)?.clone();
let mut ctx = core::task::Context::from_waker(&waker);
match Pin::new(&mut callback).poll(self, &mut ctx) {
Poll::Ready(result) => Poll::Ready(result),
Poll::Pending => {
// replace the future if it hasn't completed yet
self.set_async_callback(callback);
Poll::Pending
}
}
})
}
/// Encrypts and sends data on a connection where
/// [negotiate](`Self::poll_negotiate`) has succeeded.
///
/// Returns the number of bytes written, and may indicate a partial write.
pub fn poll_send(&mut self, buf: &[u8]) -> Poll<Result<usize, Error>> {
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
let buf_len: isize = buf.len().try_into().map_err(|_| Error::INVALID_INPUT)?;
let buf_ptr = buf.as_ptr() as *const ::libc::c_void;
unsafe { s2n_send(self.connection.as_ptr(), buf_ptr, buf_len, &mut blocked).into_poll() }
}
/// Reads and decrypts data from a connection where
/// [negotiate](`Self::poll_negotiate`) has succeeded.
///
/// Returns the number of bytes read, and may indicate a partial read.
/// 0 bytes returned indicates EOF due to connection closure.
pub fn poll_recv(&mut self, buf: &mut [u8]) -> Poll<Result<usize, Error>> {
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
let buf_len: isize = buf.len().try_into().map_err(|_| Error::INVALID_INPUT)?;
let buf_ptr = buf.as_ptr() as *mut ::libc::c_void;
unsafe { s2n_recv(self.connection.as_ptr(), buf_ptr, buf_len, &mut blocked).into_poll() }
}
/// Reads and decrypts data from a connection where
/// [negotiate](`Self::poll_negotiate`) has succeeded
/// to a uninitialized buffer.
///
/// Returns the number of bytes read, and may indicate a partial read.
/// 0 bytes returned indicates EOF due to connection closure.
///
/// Safety: this function is always safe to call, and additionally:
/// 1. It will never deinitialize any bytes in `buf`.
/// 2. If it returns `Ok(n)`, then the first `n` bytes of `buf`
/// will have been initialized by this function.
pub fn poll_recv_uninitialized(
&mut self,
buf: &mut [MaybeUninit<u8>],
) -> Poll<Result<usize, Error>> {
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
let buf_len: isize = buf.len().try_into().map_err(|_| Error::INVALID_INPUT)?;
let buf_ptr = buf.as_ptr() as *mut ::libc::c_void;
// Safety:
// 1. s2n_recv never writes uninitialized garbage to `buf`.
// 2. if s2n_recv returns `+n`, it guarantees that the first
// `n` bytes of `buf` have been initialized, which allows this
// function to return `Ok(n)`
unsafe { s2n_recv(self.connection.as_ptr(), buf_ptr, buf_len, &mut blocked).into_poll() }
}
/// Attempts to flush any data previously buffered by a call to [send](`Self::poll_send`).
pub fn poll_flush(&mut self) -> Poll<Result<&mut Self, Error>> {
self.poll_send(&[0; 0]).map_ok(|_| self)
}
/// Gets the number of bytes that are currently available in the buffer to be read.
pub fn peek_len(&self) -> usize {
unsafe { s2n_peek(self.connection.as_ptr()) as usize }
}
/// Attempts a graceful shutdown of the TLS connection.
///
/// The shutdown is not complete until the necessary shutdown messages
/// have been successfully sent and received. If the peer does not respond
/// correctly, the graceful shutdown may fail.
pub fn poll_shutdown(&mut self) -> Poll<Result<&mut Self, Error>> {
if !self.remaining_blinding_delay()?.is_zero() {
return Poll::Pending;
}
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
unsafe {
s2n_shutdown(self.connection.as_ptr(), &mut blocked)
.into_poll()
.map_ok(|_| self)
}
}
/// Attempts a graceful shutdown of the write side of a TLS connection.
///
/// Unlike Self::poll_shutdown, no reponse from the peer is necessary.
/// If using TLS1.3, the connection can continue to be used for reading afterwards.
pub fn poll_shutdown_send(&mut self) -> Poll<Result<&mut Self, Error>> {
if !self.remaining_blinding_delay()?.is_zero() {
return Poll::Pending;
}
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
unsafe {
s2n_shutdown_send(self.connection.as_ptr(), &mut blocked)
.into_poll()
.map_ok(|_| self)
}
}
/// Returns the TLS alert code, if any
pub fn alert(&self) -> Option<u8> {
let alert =
unsafe { s2n_connection_get_alert(self.connection.as_ptr()).into_result() }.ok()?;
Some(alert as u8)
}
/// Sets the server name value for the connection
pub fn set_server_name(&mut self, server_name: &str) -> Result<&mut Self, Error> {
let server_name = std::ffi::CString::new(server_name).map_err(|_| Error::INVALID_INPUT)?;
unsafe {
s2n_set_server_name(self.connection.as_ptr(), server_name.as_ptr()).into_result()
}?;
Ok(self)
}
/// Get the server name associated with the connection client hello.
pub fn server_name(&self) -> Option<&str> {
unsafe {
let server_name = s2n_get_server_name(self.connection.as_ptr());
match server_name.into_result() {
Ok(server_name) => CStr::from_ptr(server_name).to_str().ok(),
Err(_) => None,
}
}
}
/// Adds a session ticket from a previous TLS connection to create a resumed session
pub fn set_session_ticket(&mut self, session: &[u8]) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_session(self.connection.as_ptr(), session.as_ptr(), session.len())
.into_result()
}?;
Ok(self)
}
/// Sets a Waker on the connection context or clears it if `None` is passed.
pub fn set_waker(&mut self, waker: Option<&Waker>) -> Result<&mut Self, Error> {
let ctx = self.context_mut();
if let Some(waker) = waker {
if let Some(prev_waker) = ctx.waker.as_mut() {
// only replace the Waker if they dont reference the same task
if !prev_waker.will_wake(waker) {
*prev_waker = waker.clone();
}
} else {
ctx.waker = Some(waker.clone());
}
} else {
ctx.waker = None;
}
Ok(self)
}
/// Returns the Waker set on the connection context.
pub fn waker(&self) -> Option<&Waker> {
let ctx = self.context();
ctx.waker.as_ref()
}
/// Takes the [`Option::take`] the connection_future stored on the
/// connection context.
///
/// If the Future returns `Poll::Pending` and has not completed, then it
/// should be re-set using [`Self::set_connection_future()`]
fn take_async_callback(&mut self) -> Option<AsyncCallback> {
let ctx = self.context_mut();
ctx.async_callback.take()
}
/// Sets a `connection_future` on the connection context.
pub(crate) fn set_async_callback(&mut self, callback: AsyncCallback) {
let ctx = self.context_mut();
debug_assert!(ctx.async_callback.is_none());
ctx.async_callback = Some(callback);
}
/// Retrieve a mutable reference to the [`Context`] stored on the connection.
fn context_mut(&mut self) -> &mut Context {
unsafe {
let ctx = s2n_connection_get_ctx(self.connection.as_ptr())
.into_result()
.unwrap();
&mut *(ctx.as_ptr() as *mut Context)
}
}
/// Retrieve a reference to the [`Context`] stored on the connection.
fn context(&self) -> &Context {
unsafe {
let ctx = s2n_connection_get_ctx(self.connection.as_ptr())
.into_result()
.unwrap();
&*(ctx.as_ptr() as *mut Context)
}
}
/// Mark that the server_name extension was used to configure the connection.
pub fn server_name_extension_used(&mut self) {
// TODO: requiring the application to call this method is a pretty sharp edge.
// Figure out if its possible to automatically call this from the Rust bindings.
unsafe {
s2n_connection_server_name_extension_used(self.connection.as_ptr())
.into_result()
.unwrap();
}
}
/// Check if client auth was used for a connection.
///
/// This is only relevant if [`ClientAuthType::Optional] was used.
pub fn client_cert_used(&self) -> bool {
unsafe { s2n_connection_client_cert_used(self.connection.as_ptr()) == 1 }
}
/// Retrieves the raw bytes of the client cert chain received from the peer, if present.
pub fn client_cert_chain_bytes(&self) -> Result<Option<&[u8]>, Error> {
if !self.client_cert_used() {
return Ok(None);
}
let mut chain = std::ptr::null_mut();
let mut len = 0;
unsafe {
s2n_connection_get_client_cert_chain(self.connection.as_ptr(), &mut chain, &mut len)
.into_result()?;
}
if chain.is_null() || len == 0 {
return Ok(None);
}
unsafe { Ok(Some(std::slice::from_raw_parts(chain, len as usize))) }
}
// The memory backing the ClientHello is owned by the Connection, so we
// tie the ClientHello to the lifetime of the Connection. This is validated
// with a doc test that ensures the ClientHello is invalid once the
// connection has gone out of scope.
//
/// Returns a reference to the ClientHello associated with the connection.
/// ```compile_fail
/// use s2n_tls::client_hello::{ClientHello, FingerprintType};
/// use s2n_tls::connection::Connection;
/// use s2n_tls::enums::Mode;
///
/// let mut conn = Connection::new(Mode::Server);
/// let mut client_hello: &ClientHello = conn.client_hello().unwrap();
/// let mut hash = Vec::new();
/// drop(conn);
/// client_hello.fingerprint_hash(FingerprintType::JA3, &mut hash);
/// ```
///
/// The compilation could be failing for a variety of reasons, so make sure
/// that the test case is actually good.
/// ```no_run
/// use s2n_tls::client_hello::{ClientHello, FingerprintType};
/// use s2n_tls::connection::Connection;
/// use s2n_tls::enums::Mode;
///
/// let mut conn = Connection::new(Mode::Server);
/// let mut client_hello: &ClientHello = conn.client_hello().unwrap();
/// let mut hash = Vec::new();
/// client_hello.fingerprint_hash(FingerprintType::JA3, &mut hash);
/// drop(conn);
/// ```
pub fn client_hello(&self) -> Result<&crate::client_hello::ClientHello, Error> {
let mut handle =
unsafe { s2n_connection_get_client_hello(self.connection.as_ptr()).into_result()? };
Ok(crate::client_hello::ClientHello::from_ptr(unsafe {
handle.as_mut()
}))
}
pub(crate) fn mark_client_hello_cb_done(&mut self) -> Result<(), Error> {
unsafe {
s2n_client_hello_cb_done(self.connection.as_ptr()).into_result()?;
}
Ok(())
}
pub fn actual_protocol_version(&self) -> Result<Version, Error> {
let version = unsafe {
s2n_connection_get_actual_protocol_version(self.connection.as_ptr()).into_result()?
};
version.try_into()
}
pub fn handshake_type(&self) -> Result<&str, Error> {
let handshake = unsafe {
s2n_connection_get_handshake_type_name(self.connection.as_ptr()).into_result()?
};
// The strings returned by s2n_connection_get_handshake_type_name
// are static and immutable after they are first calculated
static_const_str!(handshake)
}
pub fn cipher_suite(&self) -> Result<&str, Error> {
let cipher = unsafe { s2n_connection_get_cipher(self.connection.as_ptr()).into_result()? };
// The strings returned by s2n_connection_get_cipher
// are static and immutable since they are const fields on static const structs
static_const_str!(cipher)
}
pub fn selected_curve(&self) -> Result<&str, Error> {
let curve = unsafe { s2n_connection_get_curve(self.connection.as_ptr()).into_result()? };
static_const_str!(curve)
}
pub fn selected_signature_algorithm(&self) -> Result<SignatureAlgorithm, Error> {
let mut sig_alg = s2n_tls_signature_algorithm::ANONYMOUS;
unsafe {
s2n_connection_get_selected_signature_algorithm(self.connection.as_ptr(), &mut sig_alg)
.into_result()?;
}
sig_alg.try_into()
}
pub fn selected_hash_algorithm(&self) -> Result<HashAlgorithm, Error> {
let mut hash_alg = s2n_tls_hash_algorithm::NONE;
unsafe {
s2n_connection_get_selected_digest_algorithm(self.connection.as_ptr(), &mut hash_alg)
.into_result()?;
}
hash_alg.try_into()
}
pub fn selected_client_signature_algorithm(&self) -> Result<Option<SignatureAlgorithm>, Error> {
let mut sig_alg = s2n_tls_signature_algorithm::ANONYMOUS;
unsafe {
s2n_connection_get_selected_client_cert_signature_algorithm(
self.connection.as_ptr(),
&mut sig_alg,
)
.into_result()?;
}
Ok(match sig_alg {
s2n_tls_signature_algorithm::ANONYMOUS => None,
sig_alg => Some(sig_alg.try_into()?),
})
}
pub fn selected_client_hash_algorithm(&self) -> Result<Option<HashAlgorithm>, Error> {
let mut hash_alg = s2n_tls_hash_algorithm::NONE;
unsafe {
s2n_connection_get_selected_client_cert_digest_algorithm(
self.connection.as_ptr(),
&mut hash_alg,
)
.into_result()?;
}
Ok(match hash_alg {
s2n_tls_hash_algorithm::NONE => None,
hash_alg => Some(hash_alg.try_into()?),
})
}
/// Provides access to the TLS-Exporter functionality.
///
/// See https://datatracker.ietf.org/doc/html/rfc5705 and https://www.rfc-editor.org/rfc/rfc8446.
///
/// This is currently only available with TLS 1.3 connections which have finished a handshake.
pub fn tls_exporter(
&self,
label: &[u8],
context: &[u8],
output: &mut [u8],
) -> Result<(), Error> {
unsafe {
s2n_connection_tls_exporter(
self.connection.as_ptr(),
label.as_ptr(),
label.len().try_into().map_err(|_| Error::INVALID_INPUT)?,
context.as_ptr(),
context.len().try_into().map_err(|_| Error::INVALID_INPUT)?,
output.as_mut_ptr(),
output.len().try_into().map_err(|_| Error::INVALID_INPUT)?,
)
.into_result()
.map(|_| ())
}
}
/// Returns the validated peer certificate chain.
// 'static lifetime is because this copies the certificate chain from the connection into a new
// chain, so the lifetime is independent of the connection.
pub fn peer_cert_chain(&self) -> Result<CertificateChain<'static>, Error> {
unsafe {
let mut chain = CertificateChain::new()?;
s2n_connection_get_peer_cert_chain(
self.connection.as_ptr(),
chain.as_mut_ptr().as_ptr(),
)
.into_result()
.map(|_| ())?;
Ok(chain)
}
}
/// Get the certificate used during the TLS handshake
///
/// - If `self` is a server connection, the certificate selected will depend on the
/// ServerName sent by the client and supported ciphers.
/// - If `self` is a client connection, the certificate sent in response to a CertificateRequest
/// message is returned. Currently s2n-tls supports loading only one certificate in client mode. Note that
/// not all TLS endpoints will request a certificate.
pub fn selected_cert(&self) -> Option<CertificateChain<'_>> {
unsafe {
// The API only returns null, no error is actually set.
// Clippy doesn't realize from_ptr_reference is unsafe.
#[allow(clippy::manual_map)]
if let Some(ptr) =
NonNull::new(s2n_connection_get_selected_cert(self.connection.as_ptr()))
{
Some(CertificateChain::from_ptr_reference(ptr))
} else {
None
}
}
}
pub fn master_secret(&self) -> Result<Vec<u8>, Error> {
// TLS1.2 master secrets are always 48 bytes
let mut secret = vec![0; 48];
unsafe {
s2n_connection_get_master_secret(
self.connection.as_ptr(),
secret.as_mut_ptr(),
secret.len(),
)
.into_result()?;
}
Ok(secret)
}
}
struct Context {
mode: Mode,
waker: Option<Waker>,
async_callback: Option<AsyncCallback>,
verify_host_callback: Option<Box<dyn VerifyHostNameCallback>>,
connection_initialized: bool,
}
impl Context {
fn new(mode: Mode) -> Self {
Context {
mode,
waker: None,
async_callback: None,
verify_host_callback: None,
connection_initialized: false,
}
}
}
#[cfg(feature = "quic")]
impl Connection {
pub fn enable_quic(&mut self) -> Result<&mut Self, Error> {
unsafe { s2n_connection_enable_quic(self.connection.as_ptr()).into_result() }?;
Ok(self)
}
pub fn set_quic_transport_parameters(&mut self, buffer: &[u8]) -> Result<&mut Self, Error> {
unsafe {
s2n_connection_set_quic_transport_parameters(
self.connection.as_ptr(),
buffer.as_ptr(),
buffer.len().try_into().map_err(|_| Error::INVALID_INPUT)?,
)
.into_result()
}?;
Ok(self)
}
pub fn quic_transport_parameters(&mut self) -> Result<&[u8], Error> {
let mut ptr = core::ptr::null();
let mut len = 0;
unsafe {
s2n_connection_get_quic_transport_parameters(
self.connection.as_ptr(),
&mut ptr,
&mut len,
)
.into_result()
}?;
let buffer = unsafe { core::slice::from_raw_parts(ptr, len as _) };
Ok(buffer)
}
/// # Safety
///
/// The `context` pointer must live at least as long as the connection
pub unsafe fn set_secret_callback(
&mut self,
callback: s2n_secret_cb,
context: *mut c_void,
) -> Result<&mut Self, Error> {
s2n_connection_set_secret_callback(self.connection.as_ptr(), callback, context)
.into_result()?;
Ok(self)
}
pub fn quic_process_post_handshake_message(&mut self) -> Result<&mut Self, Error> {
let mut blocked = s2n_blocked_status::NOT_BLOCKED;
unsafe {
s2n_recv_quic_post_handshake_message(self.connection.as_ptr(), &mut blocked)
.into_result()
}?;
Ok(self)
}
/// Allows the quic library to check if session tickets are expected
pub fn are_session_tickets_enabled(&self) -> bool {
unsafe { s2n_connection_are_session_tickets_enabled(self.connection.as_ptr()) }
}
}
impl AsRef<Connection> for Connection {
fn as_ref(&self) -> &Connection {
self
}
}
impl AsMut<Connection> for Connection {
fn as_mut(&mut self) -> &mut Connection {
self
}
}
impl Drop for Connection {
fn drop(&mut self) {
// ignore failures since there's not much we can do about it
unsafe {
// clean up context
let prev_ctx = self.context_mut();
drop(Box::from_raw(prev_ctx));
let _ = s2n_connection_set_ctx(self.connection.as_ptr(), core::ptr::null_mut())
.into_result();
// cleanup config
let _ = self.drop_config();
// cleanup connection
let _ = s2n_connection_free(self.connection.as_ptr()).into_result();
}
}
}
#[cfg(test)]
mod tests {
use super::*;
// ensure the connection context is send
#[test]
fn context_send_test() {
fn assert_send<T: 'static + Send>() {}
assert_send::<Context>();
}
// ensure the connection context is sync
#[test]
fn context_sync_test() {
fn assert_sync<T: 'static + Sync>() {}
assert_sync::<Context>();
}
}