Backport of the pre-0.77 demo features to 0.76.

This is a combined cherry-pick of three commits on the 0.77 branch:

896bcd506866d3f "Resurrect the test backends"
9294ee349617632 "Windows PuTTYgen: saw load_key_file in half"
bc7e06c49411a89 "Windows tools: assorted '-demo' options"

Of course, these commits aren't in 0.76 itself, and I don't see any
reason to publish a binary build of 0.76 containing them. This is just
a branch I can build from myself to get a version of PuTTY that will
look exactly like the real 0.76 but permit automated generation of
demo screenshots.

Recipe

@@ -330,7 +330,9 @@ KEYGEN   = sshrsag sshdssg sshecdsag
 # X/GTK Unix app, [U] for command-line Unix app.
 
 putty    : [G] GUITERM NONSSH WINSSH W_BE_ALL WINMISC winx11 putty.res LIBS
+	 + screenshot testback
 puttytel : [G] GUITERM NONSSH W_BE_NOSSH WINMISC puttytel.res nogss LIBS
+	 + screenshot testback
 plink    : [C] winplink wincons console NONSSH WINSSH W_BE_ALL logging WINMISC
          + winx11 plink.res winnojmp sessprep noterm winnohlp winselcli
          + clicons wincliloop console LIBS
@@ -353,6 +355,7 @@ puttygen : [G] winpgen KEYGEN SSHPRIME sshdes ARITH sshmd5 version
          + sshpubk sshaes sshsh256 sshsh512 IMPORT winutils puttygen.res
          + tree234 notiming winhelp winnojmp CONF LIBS wintime sshecc sshprng
          + sshauxcrypt sshhmac winsecur winmiscs sshsha3 sshblake2 sshargon2
+	 + screenshot
 
 pterm    : [X] GTKTERM uxmisc misc ldisc settings uxpty uxsel BE_NONE uxstore
          + uxsignal CHARSET cmdline uxpterm version time xpmpterm xpmptcfg

settings.c

@@ -1302,6 +1302,8 @@ static int sessioncmp(const void *av, const void *bv)
     return strcmp(a, b);               /* otherwise, compare normally */
 }
 
+bool sesslist_demo_mode = false;
+
 void get_sesslist(struct sesslist *list, bool allocate)
 {
     int i;
@@ -1311,12 +1313,18 @@ void get_sesslist(struct sesslist *list, bool allocate)
     if (allocate) {
         strbuf *sb = strbuf_new();
 
-        if ((handle = enum_settings_start()) != NULL) {
+        if (sesslist_demo_mode) {
-            while (enum_settings_next(handle, sb))
+            put_asciz(sb, "demo-server");
-                put_byte(sb, '\0');
+            put_asciz(sb, "demo-server-2");
-            enum_settings_finish(handle);
+        } else {
+            if ((handle = enum_settings_start()) != NULL) {
+                while (enum_settings_next(handle, sb))
+                    put_byte(sb, '\0');
+                enum_settings_finish(handle);
+            }
+            put_byte(sb, '\0');
         }
-        put_byte(sb, '\0');
+
         list->buffer = strbuf_to_str(sb);
 
         /*

testback.c

@@ -32,11 +32,8 @@
 
 #include "putty.h"
 
-static char *null_init(const BackendVtable *, Seat *, Backend **, LogContext *,
-                       Conf *, const char *, int, char **, bool, bool);
 static char *loop_init(const BackendVtable *, Seat *, Backend **, LogContext *,
                        Conf *, const char *, int, char **, bool, bool);
-static void null_free(Backend *);
 static void loop_free(Backend *);
 static void null_reconfig(Backend *, Conf *);
 static size_t null_send(Backend *, const char *, size_t);
@@ -54,8 +51,8 @@ static void null_unthrottle(Backend *, size_t);
 static int null_cfg_info(Backend *);
 
 const BackendVtable null_backend = {
-    .init = null_init,
+    .init = loop_init,
-    .free = null_free,
+    .free = loop_free,
     .reconfig = null_reconfig,
     .send = null_send,
     .sendbuffer = null_sendbuffer,
@@ -102,17 +99,6 @@ struct loop_state {
     Backend backend;
 };
 
-static char *null_init(const BackendVtable *vt, Seat *seat,
-                       Backend **backend_handle, LogContext *logctx,
-                       Conf *conf, const char *host, int port,
-                       char **realhost, bool nodelay, bool keepalive) {
-    /* No local authentication phase in this protocol */
-    seat_set_trust_status(seat, false);
-
-    *backend_handle = NULL;
-    return NULL;
-}
-
 static char *loop_init(const BackendVtable *vt, Seat *seat,
                        Backend **backend_handle, LogContext *logctx,
                        Conf *conf, const char *host, int port,
@@ -123,15 +109,14 @@ static char *loop_init(const BackendVtable *vt, Seat *seat,
     seat_set_trust_status(seat, false);
 
     st->seat = seat;
+    st->backend.vt = vt;
     *backend_handle = &st->backend;
+
+    *realhost = dupstr(host);
+
     return NULL;
 }
 
-static void null_free(Backend *be)
-{
-
-}
-
 static void loop_free(Backend *be)
 {
     struct loop_state *st = container_of(be, struct loop_state, backend);

windows/screenshot.c

@@ -0,0 +1,114 @@
+#include "putty.h"
+
+#include <dwmapi.h>
+
+char *save_screenshot(HWND hwnd, const char *outfile)
+{
+    HDC dcWindow = NULL, dcSave = NULL;
+    HBITMAP bmSave = NULL;
+    uint8_t *buffer = NULL;
+    char *err = NULL;
+
+    static HMODULE dwmapi_module;
+    DECL_WINDOWS_FUNCTION(static, HRESULT, DwmGetWindowAttribute,
+                          (HWND, DWORD, PVOID, DWORD));
+
+    if (!dwmapi_module) {
+        dwmapi_module = load_system32_dll("dwmapi.dll");
+        GET_WINDOWS_FUNCTION(dwmapi_module, DwmGetWindowAttribute);
+    }
+
+    dcWindow = GetDC(NULL);
+    if (!dcWindow) {
+        err = dupprintf("GetDC(window): %s", win_strerror(GetLastError()));
+        goto out;
+    }
+
+    int x, y, w, h;
+    RECT wr;
+
+    /* Use DwmGetWindowAttribute in place of GetWindowRect to exclude
+     * drop shadow, otherwise we get a load of unwanted desktop
+     * background under the shadow */
+    if (p_DwmGetWindowAttribute &&
+        0 <= p_DwmGetWindowAttribute(hwnd, DWMWA_EXTENDED_FRAME_BOUNDS,
+                                     &wr, sizeof(wr))) {
+        x = wr.left;
+        y = wr.top;
+        w = wr.right - wr.left;
+        h = wr.bottom - wr.top;
+    } else {
+        BITMAP bmhdr;
+        memset(&bmhdr, 0, sizeof(bmhdr));
+        GetObject(GetCurrentObject(dcWindow, OBJ_BITMAP),
+                  sizeof(bmhdr), &bmhdr);
+        x = y = 0;
+        w = bmhdr.bmWidth;
+        h = bmhdr.bmHeight;
+    }
+
+    dcSave = CreateCompatibleDC(dcWindow);
+    if (!dcSave) {
+        err = dupprintf("CreateCompatibleDC(desktop window dc): %s",
+                        win_strerror(GetLastError()));
+        goto out;
+    }
+
+    bmSave = CreateCompatibleBitmap(dcWindow, w, h);
+    if (!bmSave) {
+        err = dupprintf("CreateCompatibleBitmap: %s",
+                        win_strerror(GetLastError()));
+        goto out;
+    }
+
+    if (!SelectObject(dcSave, bmSave)) {
+        err = dupprintf("SelectObject: %s", win_strerror(GetLastError()));
+        goto out;
+    }
+
+    if (!BitBlt(dcSave, 0, 0, w, h, dcWindow, x, y, SRCCOPY)) {
+        err = dupprintf("BitBlt: %s", win_strerror(GetLastError()));
+        goto out;
+    }
+
+    BITMAPINFO bmInfo;
+    memset(&bmInfo, 0, sizeof(bmInfo));
+    bmInfo.bmiHeader.biSize = sizeof(bmInfo.bmiHeader);
+    bmInfo.bmiHeader.biWidth = w;
+    bmInfo.bmiHeader.biHeight = h;
+    bmInfo.bmiHeader.biPlanes = 1;
+    bmInfo.bmiHeader.biBitCount = 32;
+    bmInfo.bmiHeader.biCompression = BI_RGB;
+
+    size_t bmPixels = (size_t)w*h, bmBytes = bmPixels * 4;
+    buffer = snewn(bmBytes, uint8_t);
+
+    if (!GetDIBits(dcWindow, bmSave, 0, h, buffer, &bmInfo, DIB_RGB_COLORS))
+        err = dupprintf("GetDIBits (get data): %s",
+                        win_strerror(GetLastError()));
+
+    FILE *fp = fopen(outfile, "wb");
+    if (!fp) {
+        err = dupprintf("'%s': unable to open file", outfile);
+        goto out;
+    }
+
+    BITMAPFILEHEADER bmFileHdr;
+    bmFileHdr.bfType = 'B' | ('M' << 8);
+    bmFileHdr.bfSize = sizeof(bmFileHdr) + sizeof(bmInfo.bmiHeader) + bmBytes;
+    bmFileHdr.bfOffBits = sizeof(bmFileHdr) + sizeof(bmInfo.bmiHeader);
+    fwrite((void *)&bmFileHdr, 1, sizeof(bmFileHdr), fp);
+    fwrite((void *)&bmInfo.bmiHeader, 1, sizeof(bmInfo.bmiHeader), fp);
+    fwrite((void *)buffer, 1, bmBytes, fp);
+    fclose(fp);
+
+  out:
+    if (dcWindow)
+        ReleaseDC(NULL, dcWindow);
+    if (bmSave)
+        DeleteObject(bmSave);
+    if (dcSave)
+        DeleteObject(dcSave);
+    sfree(buffer);
+    return err;
+}

windows/windlg.c

@@ -388,6 +388,8 @@ static void create_controls(HWND hwnd, char *path)
     }
 }
 
+const char *dialog_box_demo_screenshot_filename = NULL;
+
 /*
  * This function is the configuration box.
  * (Being a dialog procedure, in general it returns 0 if the default
@@ -396,6 +398,7 @@ static void create_controls(HWND hwnd, char *path)
 static INT_PTR CALLBACK GenericMainDlgProc(HWND hwnd, UINT msg,
                                            WPARAM wParam, LPARAM lParam)
 {
+    const int DEMO_SCREENSHOT_TIMER_ID = 1230;
     HWND hw, treeview;
     struct treeview_faff tvfaff;
     int ret;
@@ -565,6 +568,21 @@ static INT_PTR CALLBACK GenericMainDlgProc(HWND hwnd, UINT msg,
          * spurious firing during the above setup procedure.
          */
         SetWindowLongPtr(hwnd, GWLP_USERDATA, 1);
+
+        if (dialog_box_demo_screenshot_filename)
+            SetTimer(hwnd, DEMO_SCREENSHOT_TIMER_ID, TICKSPERSEC, NULL);
+        return 0;
+      case WM_TIMER:
+        if (dialog_box_demo_screenshot_filename &&
+            (UINT_PTR)wParam == DEMO_SCREENSHOT_TIMER_ID) {
+            KillTimer(hwnd, DEMO_SCREENSHOT_TIMER_ID);
+            const char *err = save_screenshot(
+                hwnd, dialog_box_demo_screenshot_filename);
+            if (err)
+                MessageBox(hwnd, err, "Demo screenshot failure",
+                           MB_OK | MB_ICONERROR);
+            SaneEndDialog(hwnd, 0);
+        }
         return 0;
       case WM_LBUTTONUP:
         /*

windows/window.c

@@ -231,6 +231,11 @@ static int compose_state = 0;
 
 static UINT wm_mousewheel = WM_MOUSEWHEEL;
 
+extern bool sesslist_demo_mode;
+extern const char *dialog_box_demo_screenshot_filename;
+static strbuf *demo_terminal_data = NULL;
+static const char *terminal_demo_screenshot_filename;
+
 #define IS_HIGH_VARSEL(wch1, wch2) \
     ((wch1) == 0xDB40 && ((wch2) >= 0xDD00 && (wch2) <= 0xDDEF))
 #define IS_LOW_VARSEL(wch) \
@@ -369,7 +374,10 @@ static void start_backend(void)
      * Select protocol. This is farmed out into a table in a
      * separate file to enable an ssh-free variant.
      */
-    vt = backend_vt_from_proto(conf_get_int(conf, CONF_protocol));
+    if (demo_terminal_data)
+        vt = &null_backend;
+    else
+        vt = backend_vt_from_proto(conf_get_int(conf, CONF_protocol));
     if (!vt) {
         char *str = dupprintf("%s Internal Error", appname);
         MessageBox(NULL, "Unsupported protocol number found",
@@ -520,6 +528,7 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
     {
         char *p;
         bool special_launchable_argument = false;
+        bool demo_config_box = false;
 
         settings_set_default_protocol(be_default_protocol);
         /* Find the appropriate default port. */
@@ -646,6 +655,30 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
                 } else if (!strcmp(p, "-pgpfp")) {
                     pgp_fingerprints_msgbox(NULL);
                     exit(1);
+                } else if (!strcmp(p, "-demo-config-box")) {
+                    if (i+1 >= argc) {
+                        cmdline_error("%s expects an output filename", p);
+                    } else {
+                        demo_config_box = true;
+                        dialog_box_demo_screenshot_filename = argv[++i];
+                    }
+                } else if (!strcmp(p, "-demo-terminal")) {
+                    if (i+2 >= argc) {
+                        cmdline_error("%s expects input and output filenames",
+                                      p);
+                    } else {
+                        const char *infile = argv[++i];
+                        terminal_demo_screenshot_filename = argv[++i];
+                        FILE *fp = fopen(infile, "rb");
+                        if (!fp)
+                            cmdline_error("can't open input file '%s'", argv);
+                        demo_terminal_data = strbuf_new();
+                        char buf[4096];
+                        int retd;
+                        while ((retd = fread(buf, 1, sizeof(buf), fp)) > 0)
+                            put_data(demo_terminal_data, buf, retd);
+                        fclose(fp);
+                    }
                 } else if (*p != '-') {
                     cmdline_error("unexpected argument \"%s\"", p);
                 } else {
@@ -656,13 +689,26 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 
         cmdline_run_saved(conf);
 
-        /*
+        if (demo_config_box) {
-         * Bring up the config dialog if the command line hasn't
+            sesslist_demo_mode = true;
-         * (explicitly) specified a launchable configuration.
+            load_open_settings(NULL, conf);
-         */
+            conf_set_str(conf, CONF_host, "demo-server.example.com");
-        if (!(special_launchable_argument || cmdline_host_ok(conf))) {
+            do_config(conf);
-            if (!do_config(conf))
+            cleanup_exit(0);
-                cleanup_exit(0);
+        } else if (demo_terminal_data) {
+            /* Ensure conf will cause an immediate session launch */
+            load_open_settings(NULL, conf);
+            conf_set_str(conf, CONF_host, "demo-server.example.com");
+            conf_set_int(conf, CONF_close_on_exit, FORCE_OFF);
+        } else {
+            /*
+             * Bring up the config dialog if the command line hasn't
+             * (explicitly) specified a launchable configuration.
+             */
+            if (!(special_launchable_argument || cmdline_host_ok(conf))) {
+                if (!do_config(conf))
+                    cleanup_exit(0);
+            }
         }
 
         prepare_session(conf);
@@ -885,6 +931,8 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
     term_set_focus(term, GetForegroundWindow() == wgs.term_hwnd);
     UpdateWindow(wgs.term_hwnd);
 
+    gui_terminal_ready(wgs.term_hwnd, &wgs.seat, backend);
+
     while (1) {
         HANDLE *handles;
         int nhandles, n;
@@ -5858,3 +5906,19 @@ static bool win_seat_get_window_pixel_size(Seat *seat, int *x, int *y)
     *y = r.bottom - r.top;
     return true;
 }
+
+static void demo_terminal_screenshot(void *ctx, unsigned long now)
+{
+    HWND hwnd = (HWND)ctx;
+    save_screenshot(hwnd, terminal_demo_screenshot_filename);
+    cleanup_exit(0);
+}
+
+void gui_terminal_ready(HWND hwnd, Seat *seat, Backend *backend)
+{
+    if (demo_terminal_data) {
+        ptrlen data = ptrlen_from_strbuf(demo_terminal_data);
+        seat_stdout(seat, data.ptr, data.len);
+        schedule_timer(TICKSPERSEC, demo_terminal_screenshot, (void *)hwnd);
+    }
+}

windows/winpgen.c

@@ -27,6 +27,8 @@
 #define DEFAULT_EDCURVE_INDEX 0
 
 static char *cmdline_keyfile = NULL;
+static ptrlen cmdline_demo_keystr;
+static const char *demo_screenshot_filename = NULL;
 
 /*
  * Print a modal (Really Bad) message box and perform a fatal exit.
@@ -966,6 +968,65 @@ void ui_set_fptype(HWND hwnd, struct MainDlgState *state, int option)
     }
 }
 
+static void update_ui_after_load(HWND hwnd, struct MainDlgState *state,
+                                 const char *passphrase, int type,
+                                 RSAKey *newkey1, ssh2_userkey *newkey2)
+{
+    SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT, passphrase);
+    SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT, passphrase);
+
+    if (type == SSH_KEYTYPE_SSH1) {
+        char *fingerprint, *savecomment;
+
+        state->ssh2 = false;
+        state->commentptr = &state->key.comment;
+        state->key = *newkey1;         /* structure copy */
+
+        /*
+         * Set the key fingerprint.
+         */
+        savecomment = state->key.comment;
+        state->key.comment = NULL;
+        fingerprint = rsa_ssh1_fingerprint(&state->key);
+        state->key.comment = savecomment;
+        SetDlgItemText(hwnd, IDC_FINGERPRINT, fingerprint);
+        sfree(fingerprint);
+
+        /*
+         * Construct a decimal representation of the key, for pasting
+         * into .ssh/authorized_keys on a Unix box.
+         */
+        setupbigedit1(hwnd, IDC_KEYDISPLAY, IDC_PKSTATIC, &state->key);
+    } else {
+        char *fp;
+        char *savecomment;
+
+        state->ssh2 = true;
+        state->commentptr = &state->ssh2key.comment;
+        state->ssh2key = *newkey2;      /* structure copy */
+        sfree(newkey2);
+
+        savecomment = state->ssh2key.comment;
+        state->ssh2key.comment = NULL;
+        fp = ssh2_fingerprint(state->ssh2key.key, state->fptype);
+        state->ssh2key.comment = savecomment;
+
+        SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
+        sfree(fp);
+
+        setupbigedit2(hwnd, IDC_KEYDISPLAY,
+                      IDC_PKSTATIC, &state->ssh2key);
+    }
+    SetDlgItemText(hwnd, IDC_COMMENTEDIT,
+                   *state->commentptr);
+
+    /*
+     * Finally, hide the progress bar and show the key data.
+     */
+    ui_set_state(hwnd, state, 2);
+    state->key_exists = true;
+}
+
 void load_key_file(HWND hwnd, struct MainDlgState *state,
                    Filename *filename, bool was_import_cmd)
 {
@@ -1055,65 +1116,7 @@ void load_key_file(HWND hwnd, struct MainDlgState *state,
          * Now update the key controls with all the
          * key data.
          */
-        {
+        update_ui_after_load(hwnd, state, passphrase, type, &newkey1, newkey2);
-            SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
-                           passphrase);
-            SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
-                           passphrase);
-            if (type == SSH_KEYTYPE_SSH1) {
-                char *fingerprint, *savecomment;
-
-                state->ssh2 = false;
-                state->commentptr = &state->key.comment;
-                state->key = newkey1;
-
-                /*
-                 * Set the key fingerprint.
-                 */
-                savecomment = state->key.comment;
-                state->key.comment = NULL;
-                fingerprint = rsa_ssh1_fingerprint(&state->key);
-                state->key.comment = savecomment;
-                SetDlgItemText(hwnd, IDC_FINGERPRINT, fingerprint);
-                sfree(fingerprint);
-
-                /*
-                 * Construct a decimal representation
-                 * of the key, for pasting into
-                 * .ssh/authorized_keys on a Unix box.
-                 */
-                setupbigedit1(hwnd, IDC_KEYDISPLAY,
-                              IDC_PKSTATIC, &state->key);
-            } else {
-                char *fp;
-                char *savecomment;
-
-                state->ssh2 = true;
-                state->commentptr =
-                    &state->ssh2key.comment;
-                state->ssh2key = *newkey2;      /* structure copy */
-                sfree(newkey2);
-
-                savecomment = state->ssh2key.comment;
-                state->ssh2key.comment = NULL;
-                fp = ssh2_fingerprint(state->ssh2key.key, state->fptype);
-                state->ssh2key.comment = savecomment;
-
-                SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
-                sfree(fp);
-
-                setupbigedit2(hwnd, IDC_KEYDISPLAY,
-                              IDC_PKSTATIC, &state->ssh2key);
-            }
-            SetDlgItemText(hwnd, IDC_COMMENTEDIT,
-                           *state->commentptr);
-        }
-        /*
-         * Finally, hide the progress bar and show
-         * the key data.
-         */
-        ui_set_state(hwnd, state, 2);
-        state->key_exists = true;
 
         /*
          * If the user has imported a foreign key
@@ -1179,6 +1182,7 @@ static void start_generating_key(HWND hwnd, struct MainDlgState *state)
 static INT_PTR CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                                 WPARAM wParam, LPARAM lParam)
 {
+    const int DEMO_SCREENSHOT_TIMER_ID = 1230;
     static const char entropy_msg[] =
         "Please generate some randomness by moving the mouse over the blank area.";
     struct MainDlgState *state;
@@ -1402,9 +1406,33 @@ static INT_PTR CALLBACK MainDlgProc(HWND hwnd, UINT msg,
             Filename *fn = filename_from_str(cmdline_keyfile);
             load_key_file(hwnd, state, fn, false);
             filename_free(fn);
+        } else if (cmdline_demo_keystr.ptr) {
+            BinarySource src[1];
+            BinarySource_BARE_INIT_PL(src, cmdline_demo_keystr);
+            const char *errmsg;
+            ssh2_userkey *k = ppk_load_s(src, NULL, &errmsg);
+            assert(!errmsg);
+
+            update_ui_after_load(hwnd, state, "demo passphrase",
+                                 SSH_KEYTYPE_SSH2, NULL, k);
+            /* BODGE for the 0.66 backport */
+            ui_set_key_type(hwnd, state, IDC_KEYSSH2EDDSA);
+            SetDlgItemInt(hwnd, IDC_BITS, 255, false);
+
+            SetTimer(hwnd, DEMO_SCREENSHOT_TIMER_ID, TICKSPERSEC, NULL);
         }
 
         return 1;
+      case WM_TIMER:
+        if ((UINT_PTR)wParam == DEMO_SCREENSHOT_TIMER_ID) {
+            KillTimer(hwnd, DEMO_SCREENSHOT_TIMER_ID);
+            const char *err = save_screenshot(hwnd, demo_screenshot_filename);
+            if (err)
+                MessageBox(hwnd, err, "Demo screenshot failure",
+                           MB_OK | MB_ICONERROR);
+            EndDialog(hwnd, 0);
+        }
+        return 0;
       case WM_MOUSEMOVE:
         state = (struct MainDlgState *) GetWindowLongPtr(hwnd, GWLP_USERDATA);
         if (state->collecting_entropy &&
@@ -2006,6 +2034,21 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
                    !strcmp(argv[i], "-restrict_acl") ||
                    !strcmp(argv[i], "-restrictacl")) {
             restrict_process_acl();
+        } else if (!strcmp(argv[i], "-demo-screenshot")) {
+            demo_screenshot_filename = (i+1 < argc ? argv[++i] :
+                                        "puttygen.bmp");
+            cmdline_demo_keystr = PTRLEN_LITERAL(
+                "PuTTY-User-Key-File-3: ssh-ed25519\n"
+                "Encryption: none\n"
+                "Comment: ed25519-key-20220402\n"
+                "Public-Lines: 2\n"
+                "AAAAC3NzaC1lZDI1NTE5AAAAILzuIFwZ"
+                "8ZhgOlilcSb+9zPuCf/DmKJiloVlmWGy\n"
+                "xa/F\n"
+                "Private-Lines: 1\n"
+                "AAAAIPca6vLwtB2NJhZUpABQISR0gcQH8jjQLta19VyzA3wc\n"
+                "Private-MAC: 1159e9628259b35933b397379bbe8a14"
+                "a1f1d97fe91e446e45a9581a3408b70e\n");
         } else {
             /*
              * Assume the first argument to be a private key file, and

windows/winstuff.h

@@ -701,4 +701,7 @@ void cli_main_loop(cliloop_pre_t pre, cliloop_post_t post, void *ctx);
 bool cliloop_null_pre(void *vctx, const HANDLE **, size_t *);
 bool cliloop_null_post(void *vctx, size_t);
 
+char *save_screenshot(HWND hwnd, const char *outfile);
+void gui_terminal_ready(HWND hwnd, Seat *seat, Backend *backend);
+
 #endif