Fix shellhost infiniteloop issue (ssh.exe -t user@ip dir) (#292)

Fix for PowerShell/Win32-OpenSSH#892
Fixed warning messages in latest code.

contrib/win32/win32compat/fileio.c

@@ -830,7 +830,7 @@ fileio_readlink_internal(wchar_t * wpath)
 	 * this string could be as large as parent path plus the reparse buffer 
 	 * data plus a null terminator.
 	 */
-	const int wpath_len = wcslen(wpath);
+	const int wpath_len = (int)wcslen(wpath);
 	int linkpath_len = wpath_len + symlink_nonnull_size / sizeof(wchar_t) + 1;
 	linkpath = calloc(linkpath_len, sizeof(wchar_t));
 	if (linkpath == NULL) {
@@ -854,7 +854,7 @@ fileio_readlink_internal(wchar_t * wpath)
 	} 
 
 	/* append the symbolic link data to the output string*/
-	wcsncat(linkpath, symlink_nonnull, symlink_nonnull_size / sizeof(wchar_t));
+	wcsncat_s(linkpath, linkpath_len, symlink_nonnull, symlink_nonnull_size / sizeof(wchar_t));
 
 cleanup:
 
@@ -1119,7 +1119,7 @@ fileio_readlink(const char *path, char *buf, size_t bufsiz)
 	}
 
 	/* ensure output buffer is large enough forward slash and the string */
-	ssize_t out_size = strlen(output);
+	ssize_t out_size = (ssize_t) strlen(output);
 	if (1 + out_size > bufsiz) {
 		errno = ENAMETOOLONG;
 		goto cleanup;

contrib/win32/win32compat/shell-host.c

@@ -1143,7 +1143,7 @@ ConsoleEventProc(HWINEVENTHOOK hWinEventHook,
 	QueueEvent(event, hwnd, idObject, idChild);
 }
 
-DWORD 
+void
 ProcessMessages(void* p)
 {
 	DWORD dwStatus;
@@ -1154,23 +1154,19 @@ ProcessMessages(void* p)
 	sa.lpSecurityDescriptor = NULL;
 	sa.bInheritHandle = TRUE;
 
+	/* If we here then we are certain that we have a child process console, so we should be able to get child_in, child_out handles */
 	while (child_in == (HANDLE)-1) {
 		child_in = CreateFile(TEXT("CONIN$"), GENERIC_READ | GENERIC_WRITE,
 					FILE_SHARE_WRITE | FILE_SHARE_READ,
 					&sa, OPEN_EXISTING, 0, NULL);
 	}
-	if (child_in == (HANDLE)-1)
-		goto cleanup;
-	sa.nLength = sizeof(SECURITY_ATTRIBUTES);
-	sa.lpSecurityDescriptor = NULL;
-	sa.bInheritHandle = TRUE;
+
 	while (child_out == (HANDLE)-1) {
 		child_out = CreateFile(TEXT("CONOUT$"), GENERIC_READ | GENERIC_WRITE,
 					FILE_SHARE_WRITE | FILE_SHARE_READ,
 					&sa, OPEN_EXISTING, 0, NULL);
 	}
-	if (child_out == (HANDLE)-1)
-		goto cleanup;
+
 	child_err = child_out;
 	SizeWindow(child_out);
 	/* Get the current buffer information after all the adjustments */
@@ -1185,13 +1181,12 @@ ProcessMessages(void* p)
 		}
 	}
 
-cleanup:
+	/* cleanup */
 	dwStatus = GetLastError();
 	if (child_in != INVALID_HANDLE_VALUE)
 		CloseHandle(child_in);
 	if (child_out != INVALID_HANDLE_VALUE)
 		CloseHandle(child_out);
-	return 0;
 }
 
 wchar_t *
@@ -1311,7 +1306,9 @@ start_with_pty(wchar_t *command)
 	 * Windows PTY sends cursor positions in absolute coordinates starting from <0,0>
 	 * We send a clear screen upfront to simplify client 
 	 */	
-	SendClearScreen(pipe_out);
+	if(!command)
+		SendClearScreen(pipe_out);
+
 	ZeroMemory(&inputSi, sizeof(STARTUPINFO));
 	GetStartupInfo(&inputSi);
 	memset(&sa, 0, sizeof(SECURITY_ATTRIBUTES));
@@ -1343,6 +1340,10 @@ start_with_pty(wchar_t *command)
 			GOTO_CLEANUP_ON_ERR(wcscat_s(cmd, MAX_CMD_LEN, default_shell_cmd_option));
 
 		GOTO_CLEANUP_ON_ERR(wcscat_s(cmd, MAX_CMD_LEN, command));
+
+		si.dwFlags = STARTF_USESTDHANDLES;
+		si.hStdOutput = pipe_out;
+		si.hStdError = pipe_err;
 	} else {
 		/* Launch the default shell through cmd.exe.
 		 * If we don't launch default shell through cmd.exe then the powershell colors are rendered badly to the ssh client.
@@ -1365,8 +1366,10 @@ start_with_pty(wchar_t *command)
 	FreeConsole();
 	Sleep(20);
 	while (!AttachConsole(pi.dwProcessId)) {
+		/* If user tries to execute a command (like dir) in pty session then we may run into this scenario. */
 		if (GetExitCodeProcess(pi.hProcess, &child_exit_code) && child_exit_code != STILL_ACTIVE)
-			break;
+			goto cleanup;
+
 		Sleep(100);
 	}
 

contrib/win32/win32compat/socketio.c

@@ -195,7 +195,7 @@ socketio_WSARecv(struct w32_io* pio, BOOL* completed, int len)
 		wsabuf.buf = pio->read_details.buf;
 
 	if (len)
-		wsabuf.len = min(len, wsabuf.len);
+		wsabuf.len = min((ULONG)len, wsabuf.len);
 
 	ret = WSARecv(pio->sock, &wsabuf, 1, NULL, &recv_flags, &pio->read_overlapped, &WSARecvCompletionRoutine);
 	if (ret == 0) {

contrib/win32/win32compat/win32_usertoken_utils.c

@@ -478,10 +478,10 @@ int RemoveVirtualAccountLSAMapping(PUNICODE_STRING domain_name,
 }
 
 void 
-InitUnicodeString(PUNICODE_STRING dest, PCWSTR source)
+InitUnicodeString(PUNICODE_STRING dest, PWSTR source)
 {
 	dest->Buffer = source;
-	dest->Length = wcslen(source) * sizeof(wchar_t);
+	dest->Length = (USHORT)(wcslen(source) * sizeof(wchar_t));
 	dest->MaximumLength = dest->Length + 2;
 }