wip: winapi core

src/lib/winapi.rs

@@ -0,0 +1,95 @@
+use windows::core::{PCWSTR, PWSTR};
+use windows::Win32::Foundation::{CloseHandle, HANDLE};
+use windows::Win32::System::RemoteDesktop::{WTSGetActiveConsoleSessionId, WTSQueryUserToken};
+use windows::Win32::System::Threading::{
+    CreateProcessAsUserW, CREATE_NO_WINDOW, CREATE_UNICODE_ENVIRONMENT,
+    PROCESS_INFORMATION, STARTUPINFOW,
+};
+use windows::Win32::System::Environment::{CreateEnvironmentBlock, DestroyEnvironmentBlock};
+use ntapi::ntrtl::RtlAdjustPrivilege;
+
+fn to_wide_vec(s: &str) -> Vec<u16> {
+    s.encode_utf16().collect()
+}
+
+pub fn run_as_user(app: &str, cmd: &str) -> anyhow::Result<()> {
+    // Create vectors for strings.
+    // Note: CreateProcessW requires the CommandLine to be a Mutable buffer (PWSTR),
+    // not a const pointer, as it may modify the string in place.
+    let app_wide = to_wide_vec(app);
+    let mut cmd_wide = to_wide_vec(cmd);
+    let mut desktop_wide = to_wide_vec("winsta0\\default");
+
+    unsafe {
+        // 1. Enable SE_INCREASE_QUOTA_PRIVILEGE (ID 5)
+        let mut useless: u8 = 0;
+        let status = RtlAdjustPrivilege(5, 1, 0, &mut useless);
+        if status != 0 {
+            return Err(tokio::io::Error::new(tokio::io::ErrorKind::PermissionDenied, format!("SE_INCREASE_QUOTA_PRIVILEGE failed: {status}")).into());
+        }
+
+        // 2. Enable SE_ASSIGNPRIMARYTOKEN_PRIVILEGE (ID 3)
+        let mut useless: u8 = 0;
+        let status = RtlAdjustPrivilege(3, 1, 0, &mut useless);
+        if status != 0 {
+            return Err(tokio::io::Error::new(tokio::io::ErrorKind::PermissionDenied, format!("SE_ASSIGNPRIMARYTOKEN_PRIVILEGE failed: {status}")).into());
+        }
+
+        // 3. Get Active Console Session ID
+        // Replaces ntrtl::RtlGetActiveConsoleId with the documented Win32 API
+        let session_id = WTSGetActiveConsoleSessionId();
+        if session_id == 0xFFFFFFFF {
+             return Err(tokio::io::Error::new(tokio::io::ErrorKind::PermissionDenied, format!("WTSGetActiveConsoleSessionId failed: {status}")).into());
+        }
+
+        // 4. Get User Token
+        let mut user_token = HANDLE::default();
+        // Note: WTSQueryUserToken returns BOOL. In windows crate .as_bool() checks it.
+        if let Err(e) = WTSQueryUserToken(session_id, &mut user_token) {
+            return Err(tokio::io::Error::new(tokio::io::ErrorKind::PermissionDenied, format!("WTSQueryUserToken failed: {e}")).into());
+        }
+
+        // 5. Create Environment Block
+        // The windows crate defines the first arg as *mut *mut c_void
+        let mut env_block: *mut std::ffi::c_void = std::ptr::null_mut();
+        
+        if let Err(e) = CreateEnvironmentBlock(&mut env_block, user_token, false) {
+            let _ = CloseHandle(user_token);
+            return Err(tokio::io::Error::new(tokio::io::ErrorKind::PermissionDenied, format!("CreateEnvironmentBlock failed: {e}")).into());
+        }
+
+        // 6. Setup Startup Info
+        let mut si: STARTUPINFOW = std::mem::zeroed();
+        si.cb = std::mem::size_of::<STARTUPINFOW>() as u32;
+        si.lpDesktop = PWSTR(desktop_wide.as_mut_ptr());
+
+        let mut pi: PROCESS_INFORMATION = std::mem::zeroed();
+
+        let creation_flags = CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT;
+
+        // 7. Create Process
+        CreateProcessAsUserW(
+            user_token,
+            PCWSTR(app_wide.as_ptr()),      // Application Name (Const)
+            PWSTR(cmd_wide.as_mut_ptr()),   // Command Line (Mutable!)
+            None,                           // Process Attributes
+            None,                           // Thread Attributes
+            false,                          // Inherit Handles
+            creation_flags,                 // Creation Flags
+            Some(env_block),                // Environment
+            None,                           // Current Directory
+            &si,                            // Startup Info
+            &mut pi,                        // Process Information
+        )?;
+
+        // Cleanup process handles
+        let _ = CloseHandle(pi.hProcess);
+        let _ = CloseHandle(pi.hThread);
+
+        // 8. Cleanup
+        DestroyEnvironmentBlock(env_block)?;
+        let _ = CloseHandle(user_token);
+
+        Ok(())
+    }
+}