Files
telemt/src/stream/tls_stream.rs
Alexey ffe5a6cfb7 Fake TLS Fixes for Async IO
added more comments and schemas
2026-01-02 01:17:56 +03:00

1331 lines
45 KiB
Rust

//! Fake TLS 1.3 stream wrappers
//!
//! This module provides stateful async stream wrappers that handle
//! TLS record framing with proper partial read/write handling.
//!
//! These are "fake" TLS streams - they wrap data in valid TLS 1.3
//! Application Data records but don't perform actual TLS encryption.
//! The actual encryption is handled by the crypto layer underneath.
//!
//! Key design principles:
//! - Explicit state machines for all async operations
//! - Never lose data on partial reads
//! - Atomic TLS record formation for writes
//! - Proper handling of all TLS record types
use bytes::{Bytes, BytesMut, BufMut};
use std::io::{self, Error, ErrorKind, Result};
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::io::{AsyncRead, AsyncWrite, AsyncReadExt, AsyncWriteExt, ReadBuf};
use crate::protocol::constants::{
TLS_VERSION, TLS_RECORD_APPLICATION, TLS_RECORD_CHANGE_CIPHER,
TLS_RECORD_HANDSHAKE, TLS_RECORD_ALERT, MAX_TLS_RECORD_SIZE,
};
use super::state::{StreamState, HeaderBuffer, YieldBuffer, WriteBuffer};
// ============= Constants =============
/// TLS record header size
const TLS_HEADER_SIZE: usize = 5;
/// Maximum TLS record payload size (16KB as per TLS spec)
const MAX_TLS_PAYLOAD: usize = 16384;
/// Maximum pending write buffer
const MAX_PENDING_WRITE: usize = 64 * 1024;
// ============= TLS Record Types =============
/// Parsed TLS record header
#[derive(Debug, Clone, Copy)]
struct TlsRecordHeader {
/// Record type (0x17 = Application Data, 0x14 = Change Cipher, etc.)
record_type: u8,
/// TLS version bytes
version: [u8; 2],
/// Payload length
length: u16,
}
impl TlsRecordHeader {
/// Parse header from 5 bytes
fn parse(header: &[u8; 5]) -> Option<Self> {
let record_type = header[0];
let version = [header[1], header[2]];
let length = u16::from_be_bytes([header[3], header[4]]);
Some(Self {
record_type,
version,
length,
})
}
/// Validate the header
fn validate(&self) -> Result<()> {
// Check version (accept TLS 1.0 for ClientHello, TLS 1.2/1.3 for others)
if self.version != [0x03, 0x01] && self.version != TLS_VERSION {
return Err(Error::new(
ErrorKind::InvalidData,
format!("Invalid TLS version: {:02x?}", self.version),
));
}
// Check length
if self.length as usize > MAX_TLS_RECORD_SIZE {
return Err(Error::new(
ErrorKind::InvalidData,
format!("TLS record too large: {} bytes", self.length),
));
}
Ok(())
}
/// Check if this is an application data record
fn is_application_data(&self) -> bool {
self.record_type == TLS_RECORD_APPLICATION
}
/// Check if this is a change cipher spec record (should be skipped)
fn is_change_cipher_spec(&self) -> bool {
self.record_type == TLS_RECORD_CHANGE_CIPHER
}
/// Build header bytes
fn to_bytes(&self) -> [u8; 5] {
[
self.record_type,
self.version[0],
self.version[1],
(self.length >> 8) as u8,
self.length as u8,
]
}
}
// ============= FakeTlsReader State =============
/// State machine states for FakeTlsReader
#[derive(Debug)]
enum TlsReaderState {
/// Ready to read a new TLS record
Idle,
/// Reading the 5-byte TLS record header
ReadingHeader {
/// Header buffer (5 bytes)
header: HeaderBuffer<TLS_HEADER_SIZE>,
},
/// Reading the TLS record body
ReadingBody {
/// Parsed record type
record_type: u8,
/// Total body length
length: usize,
/// Buffer for body data
buffer: BytesMut,
},
/// Have decrypted data ready to yield to caller
Yielding {
/// Buffer containing data to yield
buffer: YieldBuffer,
},
/// Stream encountered an error and cannot be used
Poisoned {
/// The error that caused poisoning
error: Option<io::Error>,
},
}
impl StreamState for TlsReaderState {
fn is_terminal(&self) -> bool {
matches!(self, Self::Poisoned { .. })
}
fn is_poisoned(&self) -> bool {
matches!(self, Self::Poisoned { .. })
}
fn state_name(&self) -> &'static str {
match self {
Self::Idle => "Idle",
Self::ReadingHeader { .. } => "ReadingHeader",
Self::ReadingBody { .. } => "ReadingBody",
Self::Yielding { .. } => "Yielding",
Self::Poisoned { .. } => "Poisoned",
}
}
}
// ============= FakeTlsReader =============
/// Reader that unwraps TLS 1.3 records with proper state machine
///
/// This reader handles partial reads correctly by maintaining internal state
/// and never losing any data that has been read from upstream.
///
/// # State Machine
///
/// ┌──────────┐ ┌───────────────┐
/// │ Idle │ -----------------> │ ReadingHeader │
/// └──────────┘ └───────┬───────┘
/// ▲ │
/// │ header complete
/// │ │
/// │ │
/// │ ┌───────────────┐
/// │ skip record │ ReadingBody │
/// │ <-------- (CCS) -------- │ │
/// │ └───────┬───────┘
/// │ │
/// │ body complete
/// │ drained │
/// │ <-----------------┐ │
/// │ │ ┌───────────────┐
/// │ └----- │ Yielding │
/// │ └───────────────┘
/// │
/// │ errors /w any state
/// │
/// ┌───────────────────────────────────────────────┐
/// │ Poisoned │
/// └───────────────────────────────────────────────┘
///
pub struct FakeTlsReader<R> {
/// Upstream reader
upstream: R,
/// Current state
state: TlsReaderState,
}
impl<R> FakeTlsReader<R> {
/// Create new fake TLS reader
pub fn new(upstream: R) -> Self {
Self {
upstream,
state: TlsReaderState::Idle,
}
}
/// Get reference to upstream
pub fn get_ref(&self) -> &R {
&self.upstream
}
/// Get mutable reference to upstream
pub fn get_mut(&mut self) -> &mut R {
&mut self.upstream
}
/// Consume and return upstream
pub fn into_inner(self) -> R {
self.upstream
}
/// Check if stream is in poisoned state
pub fn is_poisoned(&self) -> bool {
self.state.is_poisoned()
}
/// Get current state name (for debugging)
pub fn state_name(&self) -> &'static str {
self.state.state_name()
}
/// Transition to poisoned state
fn poison(&mut self, error: io::Error) {
self.state = TlsReaderState::Poisoned { error: Some(error) };
}
/// Take error from poisoned state
fn take_poison_error(&mut self) -> io::Error {
match &mut self.state {
TlsReaderState::Poisoned { error } => {
error.take().unwrap_or_else(|| {
io::Error::new(ErrorKind::Other, "stream previously poisoned")
})
}
_ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
}
}
}
/// Result of polling for header completion
enum HeaderPollResult {
/// Need more data
Pending,
/// EOF at record boundary (clean close)
Eof,
/// Header complete, parsed successfully
Complete(TlsRecordHeader),
/// Error occurred
Error(io::Error),
}
/// Result of polling for body completion
enum BodyPollResult {
/// Need more data
Pending,
/// Body complete
Complete(Bytes),
/// Error occurred
Error(io::Error),
}
impl<R: AsyncRead + Unpin> AsyncRead for FakeTlsReader<R> {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<Result<()>> {
let this = self.get_mut();
loop {
// Take ownership of state to avoid borrow conflicts
let state = std::mem::replace(&mut this.state, TlsReaderState::Idle);
match state {
// Poisoned state - return error
TlsReaderState::Poisoned { error } => {
this.state = TlsReaderState::Poisoned { error: None };
let err = error.unwrap_or_else(|| {
io::Error::new(ErrorKind::Other, "stream previously poisoned")
});
return Poll::Ready(Err(err));
}
// Have buffered data to yield
TlsReaderState::Yielding { mut buffer } => {
if buf.remaining() == 0 {
this.state = TlsReaderState::Yielding { buffer };
return Poll::Ready(Ok(()));
}
// Copy as much as possible to output
let to_copy = buffer.remaining().min(buf.remaining());
let dst = buf.initialize_unfilled_to(to_copy);
let copied = buffer.copy_to(dst);
buf.advance(copied);
// If buffer is drained, transition to Idle
if buffer.is_empty() {
this.state = TlsReaderState::Idle;
} else {
this.state = TlsReaderState::Yielding { buffer };
}
return Poll::Ready(Ok(()));
}
// Ready to read a new TLS record
TlsReaderState::Idle => {
if buf.remaining() == 0 {
this.state = TlsReaderState::Idle;
return Poll::Ready(Ok(()));
}
// Start reading header
this.state = TlsReaderState::ReadingHeader {
header: HeaderBuffer::new(),
};
// Continue to ReadingHeader
}
// Reading TLS record header
TlsReaderState::ReadingHeader { mut header } => {
// Poll to fill header
let result = poll_read_header(&mut this.upstream, cx, &mut header);
match result {
HeaderPollResult::Pending => {
this.state = TlsReaderState::ReadingHeader { header };
return Poll::Pending;
}
HeaderPollResult::Eof => {
this.state = TlsReaderState::Idle;
return Poll::Ready(Ok(()));
}
HeaderPollResult::Error(e) => {
this.poison(Error::new(e.kind(), e.to_string()));
return Poll::Ready(Err(e));
}
HeaderPollResult::Complete(parsed) => {
// Validate header
if let Err(e) = parsed.validate() {
this.poison(Error::new(e.kind(), e.to_string()));
return Poll::Ready(Err(e));
}
let length = parsed.length as usize;
// Transition to reading body
this.state = TlsReaderState::ReadingBody {
record_type: parsed.record_type,
length,
buffer: BytesMut::with_capacity(length),
};
}
}
}
// Reading TLS record body
TlsReaderState::ReadingBody { record_type, length, mut buffer } => {
let result = poll_read_body(&mut this.upstream, cx, &mut buffer, length);
match result {
BodyPollResult::Pending => {
this.state = TlsReaderState::ReadingBody { record_type, length, buffer };
return Poll::Pending;
}
BodyPollResult::Error(e) => {
this.poison(Error::new(e.kind(), e.to_string()));
return Poll::Ready(Err(e));
}
BodyPollResult::Complete(data) => {
// Handle different record types
match record_type {
TLS_RECORD_CHANGE_CIPHER => {
// Skip Change Cipher Spec, read next record
this.state = TlsReaderState::Idle;
continue;
}
TLS_RECORD_APPLICATION => {
// Application data - yield to caller
if data.is_empty() {
this.state = TlsReaderState::Idle;
continue;
}
this.state = TlsReaderState::Yielding {
buffer: YieldBuffer::new(data),
};
// Continue to yield
}
TLS_RECORD_ALERT => {
// TLS Alert - treat as EOF
this.state = TlsReaderState::Idle;
return Poll::Ready(Ok(()));
}
TLS_RECORD_HANDSHAKE => {
let err = Error::new(
ErrorKind::InvalidData,
"unexpected TLS handshake record"
);
this.poison(Error::new(err.kind(), err.to_string()));
return Poll::Ready(Err(err));
}
_ => {
let err = Error::new(
ErrorKind::InvalidData,
format!("unknown TLS record type: 0x{:02x}", record_type)
);
this.poison(Error::new(err.kind(), err.to_string()));
return Poll::Ready(Err(err));
}
}
}
}
}
}
}
}
}
/// Poll to read and fill header buffer (standalone function to avoid borrow issues)
fn poll_read_header<R: AsyncRead + Unpin>(
upstream: &mut R,
cx: &mut Context<'_>,
header: &mut HeaderBuffer<TLS_HEADER_SIZE>,
) -> HeaderPollResult {
while !header.is_complete() {
let unfilled = header.unfilled_mut();
let mut read_buf = ReadBuf::new(unfilled);
match Pin::new(&mut *upstream).poll_read(cx, &mut read_buf) {
Poll::Pending => return HeaderPollResult::Pending,
Poll::Ready(Err(e)) => return HeaderPollResult::Error(e),
Poll::Ready(Ok(())) => {
let n = read_buf.filled().len();
if n == 0 {
// EOF
if header.as_slice().is_empty() {
return HeaderPollResult::Eof;
} else {
return HeaderPollResult::Error(Error::new(
ErrorKind::UnexpectedEof,
format!("unexpected EOF in TLS header (got {} of 5 bytes)",
header.as_slice().len())
));
}
}
header.advance(n);
}
}
}
// Parse header
let header_bytes = *header.as_array();
match TlsRecordHeader::parse(&header_bytes) {
Some(h) => HeaderPollResult::Complete(h),
None => HeaderPollResult::Error(Error::new(
ErrorKind::InvalidData,
"failed to parse TLS header"
)),
}
}
/// Poll to read record body (standalone function to avoid borrow issues)
fn poll_read_body<R: AsyncRead + Unpin>(
upstream: &mut R,
cx: &mut Context<'_>,
buffer: &mut BytesMut,
target_len: usize,
) -> BodyPollResult {
while buffer.len() < target_len {
let remaining = target_len - buffer.len();
// Read into a temporary buffer
let mut temp = vec![0u8; remaining.min(8192)];
let mut read_buf = ReadBuf::new(&mut temp);
match Pin::new(&mut *upstream).poll_read(cx, &mut read_buf) {
Poll::Pending => return BodyPollResult::Pending,
Poll::Ready(Err(e)) => return BodyPollResult::Error(e),
Poll::Ready(Ok(())) => {
let n = read_buf.filled().len();
if n == 0 {
return BodyPollResult::Error(Error::new(
ErrorKind::UnexpectedEof,
format!("unexpected EOF in TLS body (got {} of {} bytes)",
buffer.len(), target_len)
));
}
buffer.extend_from_slice(&temp[..n]);
}
}
}
BodyPollResult::Complete(buffer.split().freeze())
}
impl<R: AsyncRead + Unpin> FakeTlsReader<R> {
/// Read exactly n bytes through TLS layer
///
/// This is a convenience method that accumulates data across
/// multiple TLS records until exactly n bytes are available.
pub async fn read_exact(&mut self, n: usize) -> Result<Bytes> {
if self.is_poisoned() {
return Err(self.take_poison_error());
}
let mut result = BytesMut::with_capacity(n);
while result.len() < n {
let mut buf = vec![0u8; n - result.len()];
let read = AsyncReadExt::read(self, &mut buf).await?;
if read == 0 {
return Err(Error::new(
ErrorKind::UnexpectedEof,
format!("expected {} bytes, got {}", n, result.len())
));
}
result.extend_from_slice(&buf[..read]);
}
Ok(result.freeze())
}
}
// ============= FakeTlsWriter State =============
/// State machine states for FakeTlsWriter
#[derive(Debug)]
enum TlsWriterState {
/// Ready to accept new data
Idle,
/// Writing a complete TLS record
WritingRecord {
/// Complete record (header + body) to write
record: WriteBuffer,
/// Original payload size (for return value calculation)
payload_size: usize,
},
/// Stream encountered an error and cannot be used
Poisoned {
/// The error that caused poisoning
error: Option<io::Error>,
},
}
impl StreamState for TlsWriterState {
fn is_terminal(&self) -> bool {
matches!(self, Self::Poisoned { .. })
}
fn is_poisoned(&self) -> bool {
matches!(self, Self::Poisoned { .. })
}
fn state_name(&self) -> &'static str {
match self {
Self::Idle => "Idle",
Self::WritingRecord { .. } => "WritingRecord",
Self::Poisoned { .. } => "Poisoned",
}
}
}
// ============= FakeTlsWriter =============
/// Writer that wraps data in TLS 1.3 records with proper state machine
///
/// This writer handles partial writes correctly by:
/// - Building complete TLS records before writing
/// - Maintaining internal state for partial record writes
/// - Never splitting a record mid-write to upstream
///
/// # State Machine
///
/// ┌──────────┐ write ┌─────────────────┐
/// │ Idle │ -------------> │ WritingRecord │
/// │ │ <------------- │ │
/// └──────────┘ complete └─────────────────┘
/// │ │
/// │ < errors > │
/// │ │
/// ┌─────────────────────────────────────────────┐
/// │ Poisoned │
/// └─────────────────────────────────────────────┘
///
/// # Record Formation
///
/// Data is chunked into records of at most MAX_TLS_PAYLOAD bytes.
/// Each record has a 5-byte header prepended.
pub struct FakeTlsWriter<W> {
/// Upstream writer
upstream: W,
/// Current state
state: TlsWriterState,
}
impl<W> FakeTlsWriter<W> {
/// Create new fake TLS writer
pub fn new(upstream: W) -> Self {
Self {
upstream,
state: TlsWriterState::Idle,
}
}
/// Get reference to upstream
pub fn get_ref(&self) -> &W {
&self.upstream
}
/// Get mutable reference to upstream
pub fn get_mut(&mut self) -> &mut W {
&mut self.upstream
}
/// Consume and return upstream
pub fn into_inner(self) -> W {
self.upstream
}
/// Check if stream is in poisoned state
pub fn is_poisoned(&self) -> bool {
self.state.is_poisoned()
}
/// Get current state name (for debugging)
pub fn state_name(&self) -> &'static str {
self.state.state_name()
}
/// Check if there's a pending record to write
pub fn has_pending(&self) -> bool {
matches!(&self.state, TlsWriterState::WritingRecord { record, .. } if !record.is_empty())
}
/// Transition to poisoned state
fn poison(&mut self, error: io::Error) {
self.state = TlsWriterState::Poisoned { error: Some(error) };
}
/// Take error from poisoned state
fn take_poison_error(&mut self) -> io::Error {
match &mut self.state {
TlsWriterState::Poisoned { error } => {
error.take().unwrap_or_else(|| {
io::Error::new(ErrorKind::Other, "stream previously poisoned")
})
}
_ => io::Error::new(ErrorKind::Other, "stream not poisoned"),
}
}
/// Build a TLS Application Data record
fn build_record(data: &[u8]) -> BytesMut {
let header = TlsRecordHeader {
record_type: TLS_RECORD_APPLICATION,
version: TLS_VERSION,
length: data.len() as u16,
};
let mut record = BytesMut::with_capacity(TLS_HEADER_SIZE + data.len());
record.extend_from_slice(&header.to_bytes());
record.extend_from_slice(data);
record
}
}
/// Result of flushing pending record
enum FlushResult {
/// All data flushed, returns payload size
Complete(usize),
/// Need to wait for upstream
Pending,
/// Error occurred
Error(io::Error),
}
impl<W: AsyncWrite + Unpin> FakeTlsWriter<W> {
/// Try to flush pending record to upstream (standalone logic)
fn poll_flush_record_inner(
upstream: &mut W,
cx: &mut Context<'_>,
record: &mut WriteBuffer,
) -> FlushResult {
while !record.is_empty() {
let data = record.pending();
match Pin::new(&mut *upstream).poll_write(cx, data) {
Poll::Pending => return FlushResult::Pending,
Poll::Ready(Err(e)) => return FlushResult::Error(e),
Poll::Ready(Ok(0)) => {
return FlushResult::Error(Error::new(
ErrorKind::WriteZero,
"upstream returned 0 bytes written"
));
}
Poll::Ready(Ok(n)) => {
record.advance(n);
}
}
}
FlushResult::Complete(0)
}
}
impl<W: AsyncWrite + Unpin> AsyncWrite for FakeTlsWriter<W> {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<Result<usize>> {
let this = self.get_mut();
// Take ownership of state
let state = std::mem::replace(&mut this.state, TlsWriterState::Idle);
match state {
TlsWriterState::Poisoned { error } => {
this.state = TlsWriterState::Poisoned { error: None };
let err = error.unwrap_or_else(|| {
Error::new(ErrorKind::Other, "stream previously poisoned")
});
return Poll::Ready(Err(err));
}
TlsWriterState::WritingRecord { mut record, payload_size } => {
// Continue flushing existing record
match Self::poll_flush_record_inner(&mut this.upstream, cx, &mut record) {
FlushResult::Pending => {
this.state = TlsWriterState::WritingRecord { record, payload_size };
return Poll::Pending;
}
FlushResult::Error(e) => {
this.poison(Error::new(e.kind(), e.to_string()));
return Poll::Ready(Err(e));
}
FlushResult::Complete(_) => {
this.state = TlsWriterState::Idle;
// Fall through to handle new write
}
}
}
TlsWriterState::Idle => {
this.state = TlsWriterState::Idle;
}
}
// Now in Idle state
if buf.is_empty() {
return Poll::Ready(Ok(0));
}
// Chunk to maximum TLS payload size
let chunk_size = buf.len().min(MAX_TLS_PAYLOAD);
let chunk = &buf[..chunk_size];
// Build the complete record
let record_data = Self::build_record(chunk);
// Try to write directly first
match Pin::new(&mut this.upstream).poll_write(cx, &record_data) {
Poll::Ready(Ok(n)) if n == record_data.len() => {
// Complete record written
Poll::Ready(Ok(chunk_size))
}
Poll::Ready(Ok(n)) => {
// Partial write - buffer the rest
let mut write_buffer = WriteBuffer::with_max_size(MAX_PENDING_WRITE);
let _ = write_buffer.extend(&record_data[n..]);
this.state = TlsWriterState::WritingRecord {
record: write_buffer,
payload_size: chunk_size,
};
// We've accepted chunk_size bytes from caller
Poll::Ready(Ok(chunk_size))
}
Poll::Ready(Err(e)) => {
this.poison(Error::new(e.kind(), e.to_string()));
Poll::Ready(Err(e))
}
Poll::Pending => {
// Buffer the entire record
let mut write_buffer = WriteBuffer::with_max_size(MAX_PENDING_WRITE);
let _ = write_buffer.extend(&record_data);
this.state = TlsWriterState::WritingRecord {
record: write_buffer,
payload_size: chunk_size,
};
// Wake to try again
cx.waker().wake_by_ref();
// We've accepted chunk_size bytes from caller
Poll::Ready(Ok(chunk_size))
}
}
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
let this = self.get_mut();
// Take ownership of state
let state = std::mem::replace(&mut this.state, TlsWriterState::Idle);
match state {
TlsWriterState::Poisoned { error } => {
this.state = TlsWriterState::Poisoned { error: None };
let err = error.unwrap_or_else(|| {
Error::new(ErrorKind::Other, "stream previously poisoned")
});
return Poll::Ready(Err(err));
}
TlsWriterState::WritingRecord { mut record, payload_size } => {
match Self::poll_flush_record_inner(&mut this.upstream, cx, &mut record) {
FlushResult::Pending => {
this.state = TlsWriterState::WritingRecord { record, payload_size };
return Poll::Pending;
}
FlushResult::Error(e) => {
this.poison(Error::new(e.kind(), e.to_string()));
return Poll::Ready(Err(e));
}
FlushResult::Complete(_) => {
this.state = TlsWriterState::Idle;
}
}
}
TlsWriterState::Idle => {
this.state = TlsWriterState::Idle;
}
}
// Flush upstream
Pin::new(&mut this.upstream).poll_flush(cx)
}
fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
let this = self.get_mut();
// Take ownership of state
let state = std::mem::replace(&mut this.state, TlsWriterState::Idle);
match state {
TlsWriterState::WritingRecord { mut record, payload_size } => {
// Try to flush pending (best effort)
match Self::poll_flush_record_inner(&mut this.upstream, cx, &mut record) {
FlushResult::Pending => {
// Can't complete flush, continue with shutdown anyway
this.state = TlsWriterState::Idle;
}
FlushResult::Error(_) => {
// Ignore errors during shutdown
this.state = TlsWriterState::Idle;
}
FlushResult::Complete(_) => {
this.state = TlsWriterState::Idle;
}
}
}
_ => {
this.state = TlsWriterState::Idle;
}
}
// Shutdown upstream
Pin::new(&mut this.upstream).poll_shutdown(cx)
}
}
impl<W: AsyncWrite + Unpin> FakeTlsWriter<W> {
/// Write all data wrapped in TLS records (async method)
///
/// This convenience method handles chunking large data into
/// multiple TLS records automatically.
pub async fn write_all_tls(&mut self, data: &[u8]) -> Result<()> {
let mut written = 0;
while written < data.len() {
let chunk_size = (data.len() - written).min(MAX_TLS_PAYLOAD);
let chunk = &data[written..written + chunk_size];
AsyncWriteExt::write_all(self, chunk).await?;
written += chunk_size;
}
self.flush().await
}
}
// ============= Tests =============
#[cfg(test)]
mod tests {
use super::*;
use std::collections::VecDeque;
use tokio::io::{duplex, AsyncReadExt, AsyncWriteExt};
// ============= Test Helpers =============
/// Build a valid TLS Application Data record
fn build_tls_record(data: &[u8]) -> Vec<u8> {
let mut record = vec![
TLS_RECORD_APPLICATION,
TLS_VERSION[0],
TLS_VERSION[1],
(data.len() >> 8) as u8,
data.len() as u8,
];
record.extend_from_slice(data);
record
}
/// Build a Change Cipher Spec record
fn build_ccs_record() -> Vec<u8> {
vec![
TLS_RECORD_CHANGE_CIPHER,
TLS_VERSION[0],
TLS_VERSION[1],
0x00, 0x01, // length = 1
0x01, // CCS byte
]
}
/// Mock reader that returns data in chunks
struct ChunkedReader {
data: VecDeque<u8>,
chunk_size: usize,
}
impl ChunkedReader {
fn new(data: &[u8], chunk_size: usize) -> Self {
Self {
data: data.iter().copied().collect(),
chunk_size,
}
}
}
impl AsyncRead for ChunkedReader {
fn poll_read(
mut self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<Result<()>> {
if self.data.is_empty() {
return Poll::Ready(Ok(()));
}
let to_read = self.chunk_size.min(self.data.len()).min(buf.remaining());
for _ in 0..to_read {
if let Some(byte) = self.data.pop_front() {
buf.put_slice(&[byte]);
}
}
Poll::Ready(Ok(()))
}
}
// ============= FakeTlsReader Tests =============
#[tokio::test]
async fn test_tls_reader_single_record() {
let payload = b"Hello, TLS!";
let record = build_tls_record(payload);
let reader = ChunkedReader::new(&record, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; payload.len()];
tls_reader.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, payload);
}
#[tokio::test]
async fn test_tls_reader_multiple_records() {
let payload1 = b"First record";
let payload2 = b"Second record";
let mut data = build_tls_record(payload1);
data.extend_from_slice(&build_tls_record(payload2));
let reader = ChunkedReader::new(&data, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf1 = vec![0u8; payload1.len()];
tls_reader.read_exact(&mut buf1).await.unwrap();
assert_eq!(&buf1, payload1);
let mut buf2 = vec![0u8; payload2.len()];
tls_reader.read_exact(&mut buf2).await.unwrap();
assert_eq!(&buf2, payload2);
}
#[tokio::test]
async fn test_tls_reader_partial_header() {
// Read header byte by byte
let payload = b"Test";
let record = build_tls_record(payload);
let reader = ChunkedReader::new(&record, 1); // 1 byte at a time!
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; payload.len()];
tls_reader.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, payload);
}
#[tokio::test]
async fn test_tls_reader_partial_body() {
let payload = b"This is a longer payload that will be read in parts";
let record = build_tls_record(payload);
let reader = ChunkedReader::new(&record, 7); // Awkward chunk size
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; payload.len()];
tls_reader.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, payload);
}
#[tokio::test]
async fn test_tls_reader_skip_ccs() {
// CCS record followed by application data
let mut data = build_ccs_record();
let payload = b"After CCS";
data.extend_from_slice(&build_tls_record(payload));
let reader = ChunkedReader::new(&data, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; payload.len()];
tls_reader.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, payload);
}
#[tokio::test]
async fn test_tls_reader_multiple_ccs() {
// Multiple CCS records
let mut data = build_ccs_record();
data.extend_from_slice(&build_ccs_record());
let payload = b"After multiple CCS";
data.extend_from_slice(&build_tls_record(payload));
let reader = ChunkedReader::new(&data, 3); // Small chunks
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; payload.len()];
tls_reader.read_exact(&mut buf).await.unwrap();
assert_eq!(&buf, payload);
}
#[tokio::test]
async fn test_tls_reader_eof() {
let reader = ChunkedReader::new(&[], 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; 10];
let read = tls_reader.read(&mut buf).await.unwrap();
assert_eq!(read, 0);
}
#[tokio::test]
async fn test_tls_reader_state_names() {
let reader = ChunkedReader::new(&[], 100);
let tls_reader = FakeTlsReader::new(reader);
assert_eq!(tls_reader.state_name(), "Idle");
assert!(!tls_reader.is_poisoned());
}
// ============= FakeTlsWriter Tests =============
#[tokio::test]
async fn test_tls_writer_single_write() {
let (client, mut server) = duplex(4096);
let mut writer = FakeTlsWriter::new(client);
let payload = b"Hello, TLS!";
writer.write_all(payload).await.unwrap();
writer.flush().await.unwrap();
// Read the TLS record from server
let mut header = [0u8; 5];
server.read_exact(&mut header).await.unwrap();
assert_eq!(header[0], TLS_RECORD_APPLICATION);
assert_eq!(&header[1..3], &TLS_VERSION);
let length = u16::from_be_bytes([header[3], header[4]]) as usize;
assert_eq!(length, payload.len());
let mut body = vec![0u8; length];
server.read_exact(&mut body).await.unwrap();
assert_eq!(&body, payload);
}
#[tokio::test]
async fn test_tls_writer_large_data_chunking() {
let (client, mut server) = duplex(65536);
let mut writer = FakeTlsWriter::new(client);
// Write data larger than MAX_TLS_PAYLOAD
let payload: Vec<u8> = (0..20000).map(|i| (i % 256) as u8).collect();
writer.write_all(&payload).await.unwrap();
writer.flush().await.unwrap();
// Read back - should be multiple records
let mut received = Vec::new();
let mut records_count = 0;
while received.len() < payload.len() {
let mut header = [0u8; 5];
if server.read_exact(&mut header).await.is_err() {
break;
}
assert_eq!(header[0], TLS_RECORD_APPLICATION);
records_count += 1;
let length = u16::from_be_bytes([header[3], header[4]]) as usize;
assert!(length <= MAX_TLS_PAYLOAD);
let mut body = vec![0u8; length];
server.read_exact(&mut body).await.unwrap();
received.extend_from_slice(&body);
}
assert_eq!(received, payload);
assert!(records_count >= 2); // Should have multiple records
}
#[tokio::test]
async fn test_tls_stream_roundtrip() {
let (client, server) = duplex(4096);
let mut writer = FakeTlsWriter::new(client);
let mut reader = FakeTlsReader::new(server);
let original = b"Hello, fake TLS!";
writer.write_all_tls(original).await.unwrap();
writer.flush().await.unwrap();
let received = reader.read_exact(original.len()).await.unwrap();
assert_eq!(&received[..], original);
}
#[tokio::test]
async fn test_tls_stream_roundtrip_large() {
let (client, server) = duplex(4096);
let mut writer = FakeTlsWriter::new(client);
let mut reader = FakeTlsReader::new(server);
let original: Vec<u8> = (0..50000).map(|i| (i % 256) as u8).collect();
// Write in background
let write_data = original.clone();
let write_handle = tokio::spawn(async move {
writer.write_all_tls(&write_data).await.unwrap();
writer.shutdown().await.unwrap();
});
// Read
let mut received = Vec::new();
let mut buf = vec![0u8; 1024];
loop {
let n = reader.read(&mut buf).await.unwrap();
if n == 0 {
break;
}
received.extend_from_slice(&buf[..n]);
}
write_handle.await.unwrap();
assert_eq!(received, original);
}
#[tokio::test]
async fn test_tls_writer_state_names() {
let (client, _server) = duplex(4096);
let writer = FakeTlsWriter::new(client);
assert_eq!(writer.state_name(), "Idle");
assert!(!writer.is_poisoned());
assert!(!writer.has_pending());
}
// ============= Error Handling Tests =============
#[tokio::test]
async fn test_tls_reader_invalid_version() {
let invalid_record = vec![
TLS_RECORD_APPLICATION,
0x04, 0x00, // Invalid version
0x00, 0x05, // length = 5
0x01, 0x02, 0x03, 0x04, 0x05,
];
let reader = ChunkedReader::new(&invalid_record, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; 5];
let result = tls_reader.read(&mut buf).await;
assert!(result.is_err());
assert!(tls_reader.is_poisoned());
}
#[tokio::test]
async fn test_tls_reader_unexpected_eof_header() {
// Partial header
let partial = vec![TLS_RECORD_APPLICATION, 0x03];
let reader = ChunkedReader::new(&partial, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; 10];
let result = tls_reader.read(&mut buf).await;
assert!(result.is_err());
}
#[tokio::test]
async fn test_tls_reader_unexpected_eof_body() {
// Valid header but truncated body
let mut record = vec![
TLS_RECORD_APPLICATION,
TLS_VERSION[0], TLS_VERSION[1],
0x00, 0x10, // length = 16
];
record.extend_from_slice(&[0u8; 8]); // Only 8 bytes of body
let reader = ChunkedReader::new(&record, 100);
let mut tls_reader = FakeTlsReader::new(reader);
let mut buf = vec![0u8; 16];
let result = tls_reader.read(&mut buf).await;
assert!(result.is_err());
}
// ============= Header Parsing Tests =============
#[test]
fn test_tls_record_header_parse() {
let header = [0x17, 0x03, 0x03, 0x01, 0x00];
let parsed = TlsRecordHeader::parse(&header).unwrap();
assert_eq!(parsed.record_type, TLS_RECORD_APPLICATION);
assert_eq!(parsed.version, TLS_VERSION);
assert_eq!(parsed.length, 256);
}
#[test]
fn test_tls_record_header_validate() {
let valid = TlsRecordHeader {
record_type: TLS_RECORD_APPLICATION,
version: TLS_VERSION,
length: 100,
};
assert!(valid.validate().is_ok());
let invalid_version = TlsRecordHeader {
record_type: TLS_RECORD_APPLICATION,
version: [0x04, 0x00],
length: 100,
};
assert!(invalid_version.validate().is_err());
let too_large = TlsRecordHeader {
record_type: TLS_RECORD_APPLICATION,
version: TLS_VERSION,
length: 20000,
};
assert!(too_large.validate().is_err());
}
#[test]
fn test_tls_record_header_to_bytes() {
let header = TlsRecordHeader {
record_type: TLS_RECORD_APPLICATION,
version: TLS_VERSION,
length: 0x1234,
};
let bytes = header.to_bytes();
assert_eq!(bytes, [0x17, 0x03, 0x03, 0x12, 0x34]);
}
}