telemt/src/tls_front/fetcher.rs

849 lines
27 KiB
Rust

use std::sync::Arc;
use std::time::Duration;
use anyhow::{Result, anyhow};
use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
use tokio::net::TcpStream;
#[cfg(unix)]
use tokio::net::UnixStream;
use tokio::time::timeout;
use tokio_rustls::TlsConnector;
use tokio_rustls::client::TlsStream;
use tracing::{debug, warn};
use rustls::client::ClientConfig;
use rustls::client::danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier};
use rustls::pki_types::{CertificateDer, ServerName, UnixTime};
use rustls::{DigitallySignedStruct, Error as RustlsError};
use x509_parser::certificate::X509Certificate;
use x509_parser::prelude::FromDer;
use crate::crypto::SecureRandom;
use crate::network::dns_overrides::resolve_socket_addr;
use crate::protocol::constants::{
TLS_RECORD_APPLICATION, TLS_RECORD_CHANGE_CIPHER, TLS_RECORD_HANDSHAKE,
};
use crate::tls_front::types::{
ParsedCertificateInfo, ParsedServerHello, TlsBehaviorProfile, TlsCertPayload, TlsExtension,
TlsFetchResult, TlsProfileSource,
};
use crate::transport::UpstreamStream;
use crate::transport::proxy_protocol::{ProxyProtocolV1Builder, ProxyProtocolV2Builder};
/// No-op verifier: accept any certificate (we only need lengths and metadata).
#[derive(Debug)]
struct NoVerify;
impl ServerCertVerifier for NoVerify {
fn verify_server_cert(
&self,
_end_entity: &CertificateDer<'_>,
_intermediates: &[CertificateDer<'_>],
_server_name: &ServerName<'_>,
_ocsp: &[u8],
_now: UnixTime,
) -> Result<ServerCertVerified, RustlsError> {
Ok(ServerCertVerified::assertion())
}
fn verify_tls12_signature(
&self,
_message: &[u8],
_cert: &CertificateDer<'_>,
_dss: &DigitallySignedStruct,
) -> Result<HandshakeSignatureValid, RustlsError> {
Ok(HandshakeSignatureValid::assertion())
}
fn verify_tls13_signature(
&self,
_message: &[u8],
_cert: &CertificateDer<'_>,
_dss: &DigitallySignedStruct,
) -> Result<HandshakeSignatureValid, RustlsError> {
Ok(HandshakeSignatureValid::assertion())
}
fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
use rustls::SignatureScheme::*;
vec![
RSA_PKCS1_SHA256,
RSA_PSS_SHA256,
ECDSA_NISTP256_SHA256,
ECDSA_NISTP384_SHA384,
]
}
}
fn build_client_config() -> Arc<ClientConfig> {
let root = rustls::RootCertStore::empty();
let provider = rustls::crypto::ring::default_provider();
let mut config = ClientConfig::builder_with_provider(Arc::new(provider))
.with_protocol_versions(&[&rustls::version::TLS13, &rustls::version::TLS12])
.expect("protocol versions")
.with_root_certificates(root)
.with_no_client_auth();
config
.dangerous()
.set_certificate_verifier(Arc::new(NoVerify));
Arc::new(config)
}
fn build_client_hello(sni: &str, rng: &SecureRandom) -> Vec<u8> {
// === ClientHello body ===
let mut body = Vec::new();
// Legacy version (TLS 1.0) as in real ClientHello headers
body.extend_from_slice(&[0x03, 0x03]);
// Random
body.extend_from_slice(&rng.bytes(32));
// Session ID: empty
body.push(0);
// Cipher suites (common minimal set, TLS1.3 + a few 1.2 fallbacks)
let cipher_suites: [u8; 10] = [
0x13, 0x01, // TLS_AES_128_GCM_SHA256
0x13, 0x02, // TLS_AES_256_GCM_SHA384
0x13, 0x03, // TLS_CHACHA20_POLY1305_SHA256
0x00, 0x2f, // TLS_RSA_WITH_AES_128_CBC_SHA (legacy)
0x00, 0xff, // RENEGOTIATION_INFO_SCSV
];
body.extend_from_slice(&(cipher_suites.len() as u16).to_be_bytes());
body.extend_from_slice(&cipher_suites);
// Compression methods: null only
body.push(1);
body.push(0);
// === Extensions ===
let mut exts = Vec::new();
// server_name (SNI)
let sni_bytes = sni.as_bytes();
let mut sni_ext = Vec::with_capacity(5 + sni_bytes.len());
sni_ext.extend_from_slice(&(sni_bytes.len() as u16 + 3).to_be_bytes());
sni_ext.push(0); // host_name
sni_ext.extend_from_slice(&(sni_bytes.len() as u16).to_be_bytes());
sni_ext.extend_from_slice(sni_bytes);
exts.extend_from_slice(&0x0000u16.to_be_bytes());
exts.extend_from_slice(&(sni_ext.len() as u16).to_be_bytes());
exts.extend_from_slice(&sni_ext);
// supported_groups
let groups: [u16; 2] = [0x001d, 0x0017]; // x25519, secp256r1
exts.extend_from_slice(&0x000au16.to_be_bytes());
exts.extend_from_slice(&((2 + groups.len() * 2) as u16).to_be_bytes());
exts.extend_from_slice(&(groups.len() as u16 * 2).to_be_bytes());
for g in groups {
exts.extend_from_slice(&g.to_be_bytes());
}
// signature_algorithms
let sig_algs: [u16; 4] = [0x0804, 0x0805, 0x0403, 0x0503]; // rsa_pss_rsae_sha256/384, ecdsa_secp256r1_sha256, rsa_pkcs1_sha256
exts.extend_from_slice(&0x000du16.to_be_bytes());
exts.extend_from_slice(&((2 + sig_algs.len() * 2) as u16).to_be_bytes());
exts.extend_from_slice(&(sig_algs.len() as u16 * 2).to_be_bytes());
for a in sig_algs {
exts.extend_from_slice(&a.to_be_bytes());
}
// supported_versions (TLS1.3 + TLS1.2)
let versions: [u16; 2] = [0x0304, 0x0303];
exts.extend_from_slice(&0x002bu16.to_be_bytes());
exts.extend_from_slice(&((1 + versions.len() * 2) as u16).to_be_bytes());
exts.push((versions.len() * 2) as u8);
for v in versions {
exts.extend_from_slice(&v.to_be_bytes());
}
// key_share (x25519)
let key = gen_key_share(rng);
let mut keyshare = Vec::with_capacity(4 + key.len());
keyshare.extend_from_slice(&0x001du16.to_be_bytes()); // group
keyshare.extend_from_slice(&(key.len() as u16).to_be_bytes());
keyshare.extend_from_slice(&key);
exts.extend_from_slice(&0x0033u16.to_be_bytes());
exts.extend_from_slice(&((2 + keyshare.len()) as u16).to_be_bytes());
exts.extend_from_slice(&(keyshare.len() as u16).to_be_bytes());
exts.extend_from_slice(&keyshare);
// ALPN (http/1.1)
let alpn_proto = b"http/1.1";
exts.extend_from_slice(&0x0010u16.to_be_bytes());
exts.extend_from_slice(&((2 + 1 + alpn_proto.len()) as u16).to_be_bytes());
exts.extend_from_slice(&((1 + alpn_proto.len()) as u16).to_be_bytes());
exts.push(alpn_proto.len() as u8);
exts.extend_from_slice(alpn_proto);
// padding to reduce recognizability and keep length ~500 bytes
const TARGET_EXT_LEN: usize = 180;
if exts.len() < TARGET_EXT_LEN {
let remaining = TARGET_EXT_LEN - exts.len();
if remaining > 4 {
let pad_len = remaining - 4; // minus type+len
exts.extend_from_slice(&0x0015u16.to_be_bytes()); // padding extension
exts.extend_from_slice(&(pad_len as u16).to_be_bytes());
exts.resize(exts.len() + pad_len, 0);
}
}
// Extensions length prefix
body.extend_from_slice(&(exts.len() as u16).to_be_bytes());
body.extend_from_slice(&exts);
// === Handshake wrapper ===
let mut handshake = Vec::new();
handshake.push(0x01); // ClientHello
let len_bytes = (body.len() as u32).to_be_bytes();
handshake.extend_from_slice(&len_bytes[1..4]);
handshake.extend_from_slice(&body);
// === Record ===
let mut record = Vec::new();
record.push(TLS_RECORD_HANDSHAKE);
record.extend_from_slice(&[0x03, 0x01]); // legacy record version
record.extend_from_slice(&(handshake.len() as u16).to_be_bytes());
record.extend_from_slice(&handshake);
record
}
fn gen_key_share(rng: &SecureRandom) -> [u8; 32] {
let mut key = [0u8; 32];
key.copy_from_slice(&rng.bytes(32));
key
}
async fn read_tls_record<S>(stream: &mut S) -> Result<(u8, Vec<u8>)>
where
S: AsyncRead + Unpin,
{
let mut header = [0u8; 5];
stream.read_exact(&mut header).await?;
let len = u16::from_be_bytes([header[3], header[4]]) as usize;
let mut body = vec![0u8; len];
stream.read_exact(&mut body).await?;
Ok((header[0], body))
}
fn parse_server_hello(body: &[u8]) -> Option<ParsedServerHello> {
if body.len() < 4 || body[0] != 0x02 {
return None;
}
let msg_len = u32::from_be_bytes([0, body[1], body[2], body[3]]) as usize;
if msg_len + 4 > body.len() {
return None;
}
let mut pos = 4;
let version = [*body.get(pos)?, *body.get(pos + 1)?];
pos += 2;
let mut random = [0u8; 32];
random.copy_from_slice(body.get(pos..pos + 32)?);
pos += 32;
let session_len = *body.get(pos)? as usize;
pos += 1;
let session_id = body.get(pos..pos + session_len)?.to_vec();
pos += session_len;
let cipher_suite = [*body.get(pos)?, *body.get(pos + 1)?];
pos += 2;
let compression = *body.get(pos)?;
pos += 1;
let ext_len = u16::from_be_bytes([*body.get(pos)?, *body.get(pos + 1)?]) as usize;
pos += 2;
let ext_end = pos.checked_add(ext_len)?;
if ext_end > body.len() {
return None;
}
let mut extensions = Vec::new();
while pos + 4 <= ext_end {
let etype = u16::from_be_bytes([body[pos], body[pos + 1]]);
let elen = u16::from_be_bytes([body[pos + 2], body[pos + 3]]) as usize;
pos += 4;
let data = body.get(pos..pos + elen)?.to_vec();
pos += elen;
extensions.push(TlsExtension {
ext_type: etype,
data,
});
}
Some(ParsedServerHello {
version,
random,
session_id,
cipher_suite,
compression,
extensions,
})
}
fn derive_behavior_profile(records: &[(u8, Vec<u8>)]) -> TlsBehaviorProfile {
let mut change_cipher_spec_count = 0u8;
let mut app_data_record_sizes = Vec::new();
for (record_type, body) in records {
match *record_type {
TLS_RECORD_CHANGE_CIPHER => {
change_cipher_spec_count = change_cipher_spec_count.saturating_add(1);
}
TLS_RECORD_APPLICATION => {
app_data_record_sizes.push(body.len());
}
_ => {}
}
}
let mut ticket_record_sizes = Vec::new();
while app_data_record_sizes
.last()
.is_some_and(|size| *size <= 256 && ticket_record_sizes.len() < 2)
{
if let Some(size) = app_data_record_sizes.pop() {
ticket_record_sizes.push(size);
}
}
ticket_record_sizes.reverse();
TlsBehaviorProfile {
change_cipher_spec_count: change_cipher_spec_count.max(1),
app_data_record_sizes,
ticket_record_sizes,
source: TlsProfileSource::Raw,
}
}
fn parse_cert_info(certs: &[CertificateDer<'static>]) -> Option<ParsedCertificateInfo> {
let first = certs.first()?;
let (_rem, cert) = X509Certificate::from_der(first.as_ref()).ok()?;
let not_before = Some(cert.validity().not_before.to_datetime().unix_timestamp());
let not_after = Some(cert.validity().not_after.to_datetime().unix_timestamp());
let issuer_cn = cert
.issuer()
.iter_common_name()
.next()
.and_then(|cn| cn.as_str().ok())
.map(|s| s.to_string());
let subject_cn = cert
.subject()
.iter_common_name()
.next()
.and_then(|cn| cn.as_str().ok())
.map(|s| s.to_string());
let san_names = cert
.subject_alternative_name()
.ok()
.flatten()
.map(|san| {
san.value
.general_names
.iter()
.filter_map(|gn| match gn {
x509_parser::extensions::GeneralName::DNSName(n) => Some(n.to_string()),
_ => None,
})
.collect::<Vec<_>>()
})
.unwrap_or_default();
Some(ParsedCertificateInfo {
not_after_unix: not_after,
not_before_unix: not_before,
issuer_cn,
subject_cn,
san_names,
})
}
fn u24_bytes(value: usize) -> Option<[u8; 3]> {
if value > 0x00ff_ffff {
return None;
}
Some([
((value >> 16) & 0xff) as u8,
((value >> 8) & 0xff) as u8,
(value & 0xff) as u8,
])
}
async fn connect_with_dns_override(
host: &str,
port: u16,
connect_timeout: Duration,
) -> Result<TcpStream> {
if let Some(addr) = resolve_socket_addr(host, port) {
return Ok(timeout(connect_timeout, TcpStream::connect(addr)).await??);
}
Ok(timeout(connect_timeout, TcpStream::connect((host, port))).await??)
}
async fn connect_tcp_with_upstream(
host: &str,
port: u16,
connect_timeout: Duration,
upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
scope: Option<&str>,
) -> Result<UpstreamStream> {
if let Some(manager) = upstream {
if let Some(addr) = resolve_socket_addr(host, port) {
match manager.connect(addr, None, scope).await {
Ok(stream) => return Ok(stream),
Err(e) => {
warn!(
host = %host,
port = port,
scope = ?scope,
error = %e,
"Upstream connect failed, using direct connect"
);
}
}
} else if let Ok(mut addrs) = tokio::net::lookup_host((host, port)).await
&& let Some(addr) = addrs.find(|a| a.is_ipv4())
{
match manager.connect(addr, None, scope).await {
Ok(stream) => return Ok(stream),
Err(e) => {
warn!(
host = %host,
port = port,
scope = ?scope,
error = %e,
"Upstream connect failed, using direct connect"
);
}
}
}
}
Ok(UpstreamStream::Tcp(
connect_with_dns_override(host, port, connect_timeout).await?,
))
}
fn encode_tls13_certificate_message(cert_chain_der: &[Vec<u8>]) -> Option<Vec<u8>> {
if cert_chain_der.is_empty() {
return None;
}
let mut certificate_list = Vec::new();
for cert in cert_chain_der {
if cert.is_empty() {
return None;
}
certificate_list.extend_from_slice(&u24_bytes(cert.len())?);
certificate_list.extend_from_slice(cert);
certificate_list.extend_from_slice(&0u16.to_be_bytes()); // cert_entry extensions
}
// Certificate = context_len(1) + certificate_list_len(3) + entries
let body_len = 1usize.checked_add(3)?.checked_add(certificate_list.len())?;
let mut message = Vec::with_capacity(4 + body_len);
message.push(0x0b); // HandshakeType::certificate
message.extend_from_slice(&u24_bytes(body_len)?);
message.push(0x00); // certificate_request_context length
message.extend_from_slice(&u24_bytes(certificate_list.len())?);
message.extend_from_slice(&certificate_list);
Some(message)
}
async fn fetch_via_raw_tls_stream<S>(
mut stream: S,
sni: &str,
connect_timeout: Duration,
proxy_protocol: u8,
) -> Result<TlsFetchResult>
where
S: AsyncRead + AsyncWrite + Unpin,
{
let rng = SecureRandom::new();
let client_hello = build_client_hello(sni, &rng);
timeout(connect_timeout, async {
if proxy_protocol > 0 {
let header = match proxy_protocol {
2 => ProxyProtocolV2Builder::new().build(),
_ => ProxyProtocolV1Builder::new().build(),
};
stream.write_all(&header).await?;
}
stream.write_all(&client_hello).await?;
stream.flush().await?;
Ok::<(), std::io::Error>(())
})
.await??;
let mut records = Vec::new();
let mut app_records_seen = 0usize;
// Read a bounded encrypted flight: ServerHello, CCS, certificate-like data,
// and a small number of ticket-like tail records.
for _ in 0..8 {
match timeout(connect_timeout, read_tls_record(&mut stream)).await {
Ok(Ok(rec)) => {
if rec.0 == TLS_RECORD_APPLICATION {
app_records_seen += 1;
}
records.push(rec);
}
Ok(Err(e)) => return Err(e),
Err(_) => break,
}
if app_records_seen >= 4 {
break;
}
}
let mut server_hello = None;
for (t, body) in &records {
if *t == TLS_RECORD_HANDSHAKE && server_hello.is_none() {
server_hello = parse_server_hello(body);
}
}
let parsed = server_hello.ok_or_else(|| anyhow!("ServerHello not received"))?;
let behavior_profile = derive_behavior_profile(&records);
let mut app_sizes = behavior_profile.app_data_record_sizes.clone();
app_sizes.extend_from_slice(&behavior_profile.ticket_record_sizes);
let total_app_data_len = app_sizes.iter().sum::<usize>().max(1024);
let app_data_records_sizes = behavior_profile
.app_data_record_sizes
.first()
.copied()
.or_else(|| behavior_profile.ticket_record_sizes.first().copied())
.map(|size| vec![size])
.unwrap_or_else(|| vec![total_app_data_len]);
Ok(TlsFetchResult {
server_hello_parsed: parsed,
app_data_records_sizes,
total_app_data_len,
behavior_profile,
cert_info: None,
cert_payload: None,
})
}
async fn fetch_via_raw_tls(
host: &str,
port: u16,
sni: &str,
connect_timeout: Duration,
upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
scope: Option<&str>,
proxy_protocol: u8,
unix_sock: Option<&str>,
) -> Result<TlsFetchResult> {
#[cfg(unix)]
if let Some(sock_path) = unix_sock {
match timeout(connect_timeout, UnixStream::connect(sock_path)).await {
Ok(Ok(stream)) => {
debug!(
sni = %sni,
sock = %sock_path,
"Raw TLS fetch using mask unix socket"
);
return fetch_via_raw_tls_stream(stream, sni, connect_timeout, proxy_protocol)
.await;
}
Ok(Err(e)) => {
warn!(
sni = %sni,
sock = %sock_path,
error = %e,
"Raw TLS unix socket connect failed, falling back to TCP"
);
}
Err(_) => {
warn!(
sni = %sni,
sock = %sock_path,
"Raw TLS unix socket connect timed out, falling back to TCP"
);
}
}
}
#[cfg(not(unix))]
let _ = unix_sock;
let stream = connect_tcp_with_upstream(host, port, connect_timeout, upstream, scope).await?;
fetch_via_raw_tls_stream(stream, sni, connect_timeout, proxy_protocol).await
}
async fn fetch_via_rustls_stream<S>(
mut stream: S,
host: &str,
sni: &str,
proxy_protocol: u8,
) -> Result<TlsFetchResult>
where
S: AsyncRead + AsyncWrite + Unpin,
{
// rustls handshake path for certificate and basic negotiated metadata.
if proxy_protocol > 0 {
let header = match proxy_protocol {
2 => ProxyProtocolV2Builder::new().build(),
_ => ProxyProtocolV1Builder::new().build(),
};
stream.write_all(&header).await?;
stream.flush().await?;
}
let config = build_client_config();
let connector = TlsConnector::from(config);
let server_name = ServerName::try_from(sni.to_owned())
.or_else(|_| ServerName::try_from(host.to_owned()))
.map_err(|_| RustlsError::General("invalid SNI".into()))?;
let tls_stream: TlsStream<S> = connector.connect(server_name, stream).await?;
// Extract negotiated parameters and certificates
let (_io, session) = tls_stream.get_ref();
let cipher_suite = session
.negotiated_cipher_suite()
.map(|s| u16::from(s.suite()).to_be_bytes())
.unwrap_or([0x13, 0x01]);
let certs: Vec<CertificateDer<'static>> = session
.peer_certificates()
.map(|slice| slice.to_vec())
.unwrap_or_default();
let cert_chain_der: Vec<Vec<u8>> = certs.iter().map(|c| c.as_ref().to_vec()).collect();
let cert_payload =
encode_tls13_certificate_message(&cert_chain_der).map(|certificate_message| {
TlsCertPayload {
cert_chain_der: cert_chain_der.clone(),
certificate_message,
}
});
let total_cert_len = cert_payload
.as_ref()
.map(|payload| payload.certificate_message.len())
.unwrap_or_else(|| cert_chain_der.iter().map(Vec::len).sum::<usize>())
.max(1024);
let cert_info = parse_cert_info(&certs);
// Heuristic: split across two records if large to mimic real servers a bit.
let app_data_records_sizes = if total_cert_len > 3000 {
vec![total_cert_len / 2, total_cert_len - total_cert_len / 2]
} else {
vec![total_cert_len]
};
let parsed = ParsedServerHello {
version: [0x03, 0x03],
random: [0u8; 32],
session_id: Vec::new(),
cipher_suite,
compression: 0,
extensions: Vec::new(),
};
debug!(
sni = %sni,
len = total_cert_len,
cipher = format!("0x{:04x}", u16::from_be_bytes(cipher_suite)),
has_cert_payload = cert_payload.is_some(),
"Fetched TLS metadata via rustls"
);
Ok(TlsFetchResult {
server_hello_parsed: parsed,
app_data_records_sizes: app_data_records_sizes.clone(),
total_app_data_len: app_data_records_sizes.iter().sum(),
behavior_profile: TlsBehaviorProfile {
change_cipher_spec_count: 1,
app_data_record_sizes: app_data_records_sizes,
ticket_record_sizes: Vec::new(),
source: TlsProfileSource::Rustls,
},
cert_info,
cert_payload,
})
}
async fn fetch_via_rustls(
host: &str,
port: u16,
sni: &str,
connect_timeout: Duration,
upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
scope: Option<&str>,
proxy_protocol: u8,
unix_sock: Option<&str>,
) -> Result<TlsFetchResult> {
#[cfg(unix)]
if let Some(sock_path) = unix_sock {
match timeout(connect_timeout, UnixStream::connect(sock_path)).await {
Ok(Ok(stream)) => {
debug!(
sni = %sni,
sock = %sock_path,
"Rustls fetch using mask unix socket"
);
return fetch_via_rustls_stream(stream, host, sni, proxy_protocol).await;
}
Ok(Err(e)) => {
warn!(
sni = %sni,
sock = %sock_path,
error = %e,
"Rustls unix socket connect failed, falling back to TCP"
);
}
Err(_) => {
warn!(
sni = %sni,
sock = %sock_path,
"Rustls unix socket connect timed out, falling back to TCP"
);
}
}
}
#[cfg(not(unix))]
let _ = unix_sock;
let stream = connect_tcp_with_upstream(host, port, connect_timeout, upstream, scope).await?;
fetch_via_rustls_stream(stream, host, sni, proxy_protocol).await
}
/// Fetch real TLS metadata for the given SNI.
///
/// Strategy:
/// 1) Probe raw TLS for realistic ServerHello and ApplicationData record sizes.
/// 2) Fetch certificate chain via rustls to build cert payload.
/// 3) Merge both when possible; otherwise auto-fallback to whichever succeeded.
pub async fn fetch_real_tls(
host: &str,
port: u16,
sni: &str,
connect_timeout: Duration,
upstream: Option<std::sync::Arc<crate::transport::UpstreamManager>>,
scope: Option<&str>,
proxy_protocol: u8,
unix_sock: Option<&str>,
) -> Result<TlsFetchResult> {
let raw_result = match fetch_via_raw_tls(
host,
port,
sni,
connect_timeout,
upstream.clone(),
scope,
proxy_protocol,
unix_sock,
)
.await
{
Ok(res) => Some(res),
Err(e) => {
warn!(sni = %sni, error = %e, "Raw TLS fetch failed");
None
}
};
match fetch_via_rustls(
host,
port,
sni,
connect_timeout,
upstream,
scope,
proxy_protocol,
unix_sock,
)
.await
{
Ok(rustls_result) => {
if let Some(mut raw) = raw_result {
raw.cert_info = rustls_result.cert_info;
raw.cert_payload = rustls_result.cert_payload;
raw.behavior_profile.source = TlsProfileSource::Merged;
debug!(sni = %sni, "Fetched TLS metadata via raw probe + rustls cert chain");
Ok(raw)
} else {
Ok(rustls_result)
}
}
Err(e) => {
if let Some(raw) = raw_result {
warn!(sni = %sni, error = %e, "Rustls cert fetch failed, using raw TLS metadata only");
Ok(raw)
} else {
Err(e)
}
}
}
}
#[cfg(test)]
mod tests {
use super::{derive_behavior_profile, encode_tls13_certificate_message};
use crate::protocol::constants::{
TLS_RECORD_APPLICATION, TLS_RECORD_CHANGE_CIPHER, TLS_RECORD_HANDSHAKE,
};
use crate::tls_front::types::TlsProfileSource;
fn read_u24(bytes: &[u8]) -> usize {
((bytes[0] as usize) << 16) | ((bytes[1] as usize) << 8) | (bytes[2] as usize)
}
#[test]
fn test_encode_tls13_certificate_message_single_cert() {
let cert = vec![0x30, 0x03, 0x02, 0x01, 0x01];
let message = encode_tls13_certificate_message(&[cert.clone()]).expect("message");
assert_eq!(message[0], 0x0b);
assert_eq!(read_u24(&message[1..4]), message.len() - 4);
assert_eq!(message[4], 0x00);
let cert_list_len = read_u24(&message[5..8]);
assert_eq!(cert_list_len, cert.len() + 5);
let cert_len = read_u24(&message[8..11]);
assert_eq!(cert_len, cert.len());
assert_eq!(&message[11..11 + cert.len()], cert.as_slice());
assert_eq!(&message[11 + cert.len()..13 + cert.len()], &[0x00, 0x00]);
}
#[test]
fn test_encode_tls13_certificate_message_empty_chain() {
assert!(encode_tls13_certificate_message(&[]).is_none());
}
#[test]
fn test_derive_behavior_profile_splits_ticket_like_tail_records() {
let profile = derive_behavior_profile(&[
(TLS_RECORD_HANDSHAKE, vec![0u8; 90]),
(TLS_RECORD_CHANGE_CIPHER, vec![0x01]),
(TLS_RECORD_APPLICATION, vec![0u8; 1400]),
(TLS_RECORD_APPLICATION, vec![0u8; 220]),
(TLS_RECORD_APPLICATION, vec![0u8; 180]),
]);
assert_eq!(profile.change_cipher_spec_count, 1);
assert_eq!(profile.app_data_record_sizes, vec![1400]);
assert_eq!(profile.ticket_record_sizes, vec![220, 180]);
assert_eq!(profile.source, TlsProfileSource::Raw);
}
}