feat(core): RDP client on IronRDP

clients::rdp connects over any caller-dialled TCP stream (direct, proxy or SSH tunnel), upgrades to TLS and logs on with NLA (CredSSP/NTLM), optionally falling back to TLS-only logon for servers without NLA such as xrdp (credentials are passed so they log straight in). The server certificate is pinned through a caller check on its SHA256 fingerprint before any credentials are sent. The desktop decodes into the VNC client's RGBA framebuffer; input (IronRDP's scancode/Unicode/mouse operations), Display Control resizes and the deactivation-reactivation sequence run on the session thread. IronRDP's releases need three vendored patches (vendor/README.md): picky and sspi with their RustCrypto release-candidate pins relaxed so they share russh's stable versions (their own suites, 402 tests, pass against them), and ironrdp-session with two unreleased upstream bitmap fixes (#1486 stride, #1524 RDP6 orientation) without which xrdp desktops render sheared. Verified live against xrdp (scottyhardy/docker-remote-desktop): logon, full desktop rendering, keyboard and mouse input.
2026-10-12 10:50:24 +01:00
parent 6a4d7381d9
commit 50c0104d57
227 changed files with 66687 additions and 20 deletions
@@ -0,0 +1,70 @@
+use picky_krb::data_types::{KrbResult, ResultExt};
+use picky_krb::messages::{AsRep, KdcReqBody};
+
+use crate::generator::YieldPointLocal;
+use crate::kerberos::client::extractors::extract_salt_from_krb_error;
+use crate::kerberos::client::generators::generate_as_req;
+use crate::kerberos::pa_datas::AsReqPaDataOptions;
+use crate::kerberos::utils::serialize_message;
+use crate::{Error, ErrorKind, Kerberos, Result};
+
+/// Performs AS exchange as specified in [RFC 4210: The Authentication Service Exchange](https://www.rfc-editor.org/rfc/rfc4120#section-3.1).
+pub(crate) async fn as_exchange(
+    client: &mut Kerberos,
+    yield_point: &mut YieldPointLocal,
+    kdc_req_body: &KdcReqBody,
+    mut pa_data_options: AsReqPaDataOptions<'_>,
+) -> Result<AsRep> {
+    pa_data_options.with_pre_auth(false);
+    let pa_datas = pa_data_options.generate()?;
+    let as_req = generate_as_req(pa_datas, kdc_req_body.clone());
+
+    let response = client.send(yield_point, &serialize_message(&as_req)?).await?;
+
+    // first 4 bytes are message len. skipping them
+    {
+        if response.len() < 4 {
+            return Err(Error::new(
+                ErrorKind::InternalError,
+                "the KDC reply message is too small: expected at least 4 bytes",
+            ));
+        }
+
+        let mut d = picky_asn1_der::Deserializer::new_from_bytes(&response[4..]);
+        let as_rep: KrbResult<AsRep> = KrbResult::deserialize(&mut d)?;
+
+        if as_rep.is_ok() {
+            error!("KDC replied with AS_REP to the AS_REQ without the encrypted timestamp. The KRB_ERROR expected.");
+
+            return Err(Error::new(
+                ErrorKind::InvalidToken,
+                "KDC server should not process AS_REQ without the pa-pac data",
+            ));
+        }
+
+        if let Some(correct_salt) = extract_salt_from_krb_error(&as_rep.unwrap_err())? {
+            debug!("salt extracted successfully from the KRB_ERROR");
+
+            pa_data_options.with_salt(correct_salt.into_bytes());
+        }
+    }
+
+    pa_data_options.with_pre_auth(true);
+    let pa_datas = pa_data_options.generate()?;
+
+    let as_req = generate_as_req(pa_datas, kdc_req_body.clone());
+
+    let response = client.send(yield_point, &serialize_message(&as_req)?).await?;
+
+    if response.len() < 4 {
+        return Err(Error::new(
+            ErrorKind::InternalError,
+            "the KDC reply message is too small: expected at least 4 bytes",
+        ));
+    }
+
+    // first 4 bytes are message len. skipping them
+    let mut d = picky_asn1_der::Deserializer::new_from_bytes(&response[4..]);
+
+    Ok(KrbResult::<AsRep>::deserialize(&mut d)?.inspect_err(|err| error!(?err, "AS exchange error"))?)
+}