feat(agent): support elevated NOW execution

crates/win-api-wrappers/src/process.rs

@@ -29,13 +29,15 @@ use windows::Win32::System::ProcessStatus::K32GetMappedFileNameW;
 use windows::Win32::System::RemoteDesktop::ProcessIdToSessionId;
 use windows::Win32::System::Threading::{
     CREATE_UNICODE_ENVIRONMENT, CreateProcessAsUserW, CreateRemoteThread, EXTENDED_STARTUPINFO_PRESENT,
-    GetCurrentProcess, GetCurrentProcessId, GetExitCodeProcess, GetProcessTimes, INFINITE,
+    GetCurrentProcess, GetCurrentProcessId, GetExitCodeProcess, GetProcessId, GetProcessTimes, INFINITE,
     LPPROC_THREAD_ATTRIBUTE_LIST, LPTHREAD_START_ROUTINE, OpenProcess, OpenProcessToken, PEB, PROCESS_ACCESS_RIGHTS,
     PROCESS_BASIC_INFORMATION, PROCESS_CREATION_FLAGS, PROCESS_INFORMATION, PROCESS_NAME_WIN32, PROCESS_SYNCHRONIZE,
     PROCESS_TERMINATE, QueryFullProcessImageNameW, STARTUPINFOEXW, STARTUPINFOW, STARTUPINFOW_FLAGS, TerminateProcess,
     WaitForSingleObject,
 };
-use windows::Win32::UI::Shell::{SEE_MASK_NOCLOSEPROCESS, SHELLEXECUTEINFOW, ShellExecuteExW};
+use windows::Win32::UI::Shell::{
+    SEE_MASK_FLAG_NO_UI, SEE_MASK_NOASYNC, SEE_MASK_NOCLOSEPROCESS, SHELLEXECUTEINFOW, ShellExecuteExW,
+};
 use windows::Win32::UI::WindowsAndMessaging::{
     EnumWindows, GetWindowThreadProcessId, PostThreadMessageW, SHOW_WINDOW_CMD,
 };
@@ -316,6 +318,17 @@ impl Process {
         Ok(exit_code)
     }
 
+    pub fn process_id(&self) -> Result<u32> {
+        // SAFETY: The process handle is valid for this call.
+        let process_id = unsafe { GetProcessId(self.handle.raw()) };
+
+        if process_id == 0 {
+            bail!(Error::last_error());
+        }
+
+        Ok(process_id)
+    }
+
     pub fn query_basic_information(&self) -> Result<PROCESS_BASIC_INFORMATION> {
         let mut basic_info = PROCESS_BASIC_INFORMATION::default();
 
@@ -431,19 +444,25 @@ impl HandleWrapper for Process {
 
 pub fn shell_execute(
     path: &Path,
-    command_line: &CommandLine,
+    command_line: &str,
     working_directory: &Path,
     verb: &str,
     show_cmd: SHOW_WINDOW_CMD,
 ) -> Result<Process> {
     let path = WideString::from(path);
-    let command_line = WideString::from(command_line.to_command_line());
-    let working_directory = WideString::from(working_directory);
+    let command_line = WideString::from(command_line);
+    let working_directory = if working_directory.as_os_str().is_empty() {
+        WideString::default()
+    } else {
+        WideString::from(working_directory)
+    };
     let verb = WideString::from(verb);
 
     let mut exec_info = SHELLEXECUTEINFOW {
         cbSize: u32size_of::<SHELLEXECUTEINFOW>(),
-        fMask: SEE_MASK_NOCLOSEPROCESS,
+        // UNTESTED: Launch errors must return without modal dialogs while UAC security prompts remain enabled.
+        // Verify both on an interactive Windows desktop when changing these flags.
+        fMask: SEE_MASK_NOCLOSEPROCESS | SEE_MASK_NOASYNC | SEE_MASK_FLAG_NO_UI,
         lpFile: path.as_pcwstr(),
         lpParameters: command_line.as_pcwstr(),
         lpDirectory: working_directory.as_pcwstr(),
@@ -1124,12 +1143,16 @@ pub fn post_message_for_pid(pid: u32, msg: u32, wparam: WPARAM, lparam: LPARAM)
         )
     }?;
 
+    if windows_enum_ctx.threads.is_empty() {
+        return Err(windows::core::Error::from(windows::Win32::Foundation::ERROR_NOT_FOUND).into());
+    }
+
     // Send message to all threads.
-    if !windows_enum_ctx.threads.is_empty() {
-        for thread in windows_enum_ctx.threads {
-            // SAFETY: No outstanding preconditions.
-            let _ = unsafe { PostThreadMessageW(thread, msg, wparam, lparam) };
-        }
+    windows_enum_ctx.threads.sort_unstable();
+    windows_enum_ctx.threads.dedup();
+    for thread in windows_enum_ctx.threads {
+        // SAFETY: No outstanding preconditions.
+        unsafe { PostThreadMessageW(thread, msg, wparam, lparam) }?;
     }
 
     Ok(())

devolutions-session/Cargo.toml

@@ -42,7 +42,7 @@ win-api-wrappers = { path = "../crates/win-api-wrappers", optional = true }
 
 [dependencies.now-proto-pdu]
 optional = true
-version = "0.4.3"
+version = "0.5.0"
 features = ["std"]
 
 [dev-dependencies]

devolutions-session/src/dvc/encoding.rs

@@ -1,9 +1,7 @@
 //! Console encoding transcoding for IO redirection.
 //!
-//! When IO redirection is enabled, the child process writes its stdout/stderr using
-//! the console's OEM codepage (e.g., `cmd.exe`, `powershell.exe`, `pwsh.exe`). This module
-//! provides transcoding between the process's native encoding and UTF-8, which is
-//! the encoding used on the wire (NowProto).
+//! Transcodes OEM console streams to and from UTF-8 when requested by NOW execution flags.
+//! Raw mode preserves bytes for UTF-8 applications such as `pwsh.exe` and for callers managing their own encoding.
 
 use std::borrow::Cow;
 
@@ -25,9 +23,6 @@ const CP_UTF8: u32 = 65001;
 
 impl DataEncoding {
     /// Determine the OEM codepage encoding for the current system.
-    ///
-    /// Console applications (`cmd.exe`, `powershell.exe` 5.x, `pwsh.exe`) use the OEM
-    /// codepage for piped/redirected output.
     pub fn from_oem_codepage() -> Self {
         // SAFETY: FFI call without outstanding preconditions.
         let cp = unsafe { windows::Win32::Globalization::GetOEMCP() };

devolutions-session/src/dvc/now_message_dissector.rs

@@ -1,6 +1,6 @@
 use anyhow::Context;
 use now_proto_pdu::NowMessage;
-use now_proto_pdu::ironrdp_core::{Decode, DecodeError, DecodeErrorKind, IntoOwned, ReadCursor, WriteBuf};
+use now_proto_pdu::ironrdp_core::{Decode, DecodeErrorKind, IntoOwned, ReadCursor, WriteBuf};
 
 /// Reconstructs Now messages from a stream of bytes.
 #[derive(Default)]
@@ -38,10 +38,7 @@ impl NowMessageDissector {
                     // Remove the read bytes from the buffer
                     self.start_pos += pos;
                 }
-                Err(DecodeError {
-                    kind: DecodeErrorKind::NotEnoughBytes { .. },
-                    ..
-                }) => {
+                Err(err) if matches!(err.kind(), DecodeErrorKind::NotEnoughBytes { .. }) => {
                     // Need more data to read the message
                     break;
                 }