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putty-source/unix/gtkask.c
Simon Tatham 3214563d8e Convert a lot of 'int' variables to 'bool'. 
My normal habit these days, in new code, is to treat int and bool as
_almost_ completely separate types. I'm still willing to use C's
implicit test for zero on an integer (e.g. 'if (!blob.len)' is fine,
no need to spell it out as blob.len != 0), but generally, if a
variable is going to be conceptually a boolean, I like to declare it
bool and assign to it using 'true' or 'false' rather than 0 or 1.

PuTTY is an exception, because it predates the C99 bool, and I've
stuck to its existing coding style even when adding new code to it.
But it's been annoying me more and more, so now that I've decided C99
bool is an acceptable thing to require from our toolchain in the first
place, here's a quite thorough trawl through the source doing
'boolification'. Many variables and function parameters are now typed
as bool rather than int; many assignments of 0 or 1 to those variables
are now spelled 'true' or 'false'.

I managed this thorough conversion with the help of a custom clang
plugin that I wrote to trawl the AST and apply heuristics to point out
where things might want changing. So I've even managed to do a decent
job on parts of the code I haven't looked at in years!

To make the plugin's work easier, I pushed platform front ends
generally in the direction of using standard 'bool' in preference to
platform-specific boolean types like Windows BOOL or GTK's gboolean;
I've left the platform booleans in places they _have_ to be for the
platform APIs to work right, but variables only used by my own code
have been converted wherever I found them.

In a few places there are int values that look very like booleans in
_most_ of the places they're used, but have a rarely-used third value,
or a distinction between different nonzero values that most users
don't care about. In these cases, I've _removed_ uses of 'true' and
'false' for the return values, to emphasise that there's something
more subtle going on than a simple boolean answer:
 - the 'multisel' field in dialog.h's list box structure, for which
   the GTK front end in particular recognises a difference between 1
   and 2 but nearly everything else treats as boolean
 - the 'urgent' parameter to plug_receive, where 1 vs 2 tells you
   something about the specific location of the urgent pointer, but
   most clients only care about 0 vs 'something nonzero'
 - the return value of wc_match, where -1 indicates a syntax error in
   the wildcard.
 - the return values from SSH-1 RSA-key loading functions, which use
   -1 for 'wrong passphrase' and 0 for all other failures (so any
   caller which already knows it's not loading an _encrypted private_
   key can treat them as boolean)
 - term->esc_query, and the 'query' parameter in toggle_mode in
   terminal.c, which _usually_ hold 0 for ESC[123h or 1 for ESC[?123h,
   but can also hold -1 for some other intervening character that we
   don't support.

In a few places there's an integer that I haven't turned into a bool
even though it really _can_ only take values 0 or 1 (and, as above,
tried to make the call sites consistent in not calling those values
true and false), on the grounds that I thought it would make it more
confusing to imply that the 0 value was in some sense 'negative' or
bad and the 1 positive or good:
 - the return value of plug_accepting uses the POSIXish convention of
   0=success and nonzero=error; I think if I made it bool then I'd
   also want to reverse its sense, and that's a job for a separate
   piece of work.
 - the 'screen' parameter to lineptr() in terminal.c, where 0 and 1
   represent the default and alternate screens. There's no obvious
   reason why one of those should be considered 'true' or 'positive'
   or 'success' - they're just indices - so I've left it as int.

ssh_scp_recv had particularly confusing semantics for its previous int
return value: its call sites used '<= 0' to check for error, but it
never actually returned a negative number, just 0 or 1. Now the
function and its call sites agree that it's a bool.

In a couple of places I've renamed variables called 'ret', because I
don't like that name any more - it's unclear whether it means the
return value (in preparation) for the _containing_ function or the
return value received from a subroutine call, and occasionally I've
accidentally used the same variable for both and introduced a bug. So
where one of those got in my way, I've renamed it to 'toret' or 'retd'
(the latter short for 'returned') in line with my usual modern
practice, but I haven't done a thorough job of finding all of them.

Finally, one amusing side effect of doing this is that I've had to
separate quite a few chained assignments. It used to be perfectly fine
to write 'a = b = c = TRUE' when a,b,c were int and TRUE was just a
the 'true' defined by stdbool.h, that idiom provokes a warning from
gcc: 'suggest parentheses around assignment used as truth value'!
2018-11-03 13:45:00 +00:00

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/*
* GTK implementation of a GUI password/passphrase prompt.
*/
#include <assert.h>
#include <time.h>
#include <stdlib.h>
#include <unistd.h>
#include <gtk/gtk.h>
#include <gdk/gdk.h>
#if !GTK_CHECK_VERSION(3,0,0)
#include <gdk/gdkkeysyms.h>
#endif
#include "defs.h"
#include "gtkfont.h"
#include "gtkcompat.h"
#include "gtkmisc.h"
#include "misc.h"
#define N_DRAWING_AREAS 3
struct drawing_area_ctx {
GtkWidget *area;
#ifndef DRAW_DEFAULT_CAIRO
GdkColor *cols;
#endif
int width, height;
enum { NOT_CURRENT, CURRENT, GREYED_OUT } state;
};
struct askpass_ctx {
GtkWidget *dialog, *promptlabel;
struct drawing_area_ctx drawingareas[N_DRAWING_AREAS];
int active_area;
#if GTK_CHECK_VERSION(2,0,0)
GtkIMContext *imc;
#endif
#ifndef DRAW_DEFAULT_CAIRO
GdkColormap *colmap;
GdkColor cols[3];
#endif
char *error_message; /* if we finish without a passphrase */
char *passphrase; /* if we finish with one */
int passlen, passsize;
#if GTK_CHECK_VERSION(3,20,0)
GdkSeat *seat; /* for gdk_seat_grab */
#elif GTK_CHECK_VERSION(3,0,0)
GdkDevice *keyboard; /* for gdk_device_grab */
#endif
int nattempts;
};
static void visually_acknowledge_keypress(struct askpass_ctx *ctx)
{
int new_active;
new_active = rand() % (N_DRAWING_AREAS - 1);
if (new_active >= ctx->active_area)
new_active++;
ctx->drawingareas[ctx->active_area].state = NOT_CURRENT;
gtk_widget_queue_draw(ctx->drawingareas[ctx->active_area].area);
ctx->drawingareas[new_active].state = CURRENT;
gtk_widget_queue_draw(ctx->drawingareas[new_active].area);
ctx->active_area = new_active;
}
static int last_char_len(struct askpass_ctx *ctx)
{
/*
* GTK always encodes in UTF-8, so we can do this in a fixed way.
*/
int i;
assert(ctx->passlen > 0);
i = ctx->passlen - 1;
while ((unsigned)((unsigned char)ctx->passphrase[i] - 0x80) < 0x40) {
if (i == 0)
break;
i--;
}
return ctx->passlen - i;
}
static void add_text_to_passphrase(struct askpass_ctx *ctx, gchar *str)
{
int len = strlen(str);
if (ctx->passlen + len >= ctx->passsize) {
/* Take some care with buffer expansion, because there are
* pieces of passphrase in the old buffer so we should ensure
* realloc doesn't leave a copy lying around in the address
* space. */
int oldsize = ctx->passsize;
char *newbuf;
ctx->passsize = (ctx->passlen + len) * 5 / 4 + 1024;
newbuf = snewn(ctx->passsize, char);
memcpy(newbuf, ctx->passphrase, oldsize);
smemclr(ctx->passphrase, oldsize);
sfree(ctx->passphrase);
ctx->passphrase = newbuf;
}
strcpy(ctx->passphrase + ctx->passlen, str);
ctx->passlen += len;
visually_acknowledge_keypress(ctx);
}
static gint key_event(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
struct askpass_ctx *ctx = (struct askpass_ctx *)data;
if (event->keyval == GDK_KEY_Return &&
event->type == GDK_KEY_PRESS) {
gtk_main_quit();
} else if (event->keyval == GDK_KEY_Escape &&
event->type == GDK_KEY_PRESS) {
smemclr(ctx->passphrase, ctx->passsize);
ctx->passphrase = NULL;
ctx->error_message = dupstr("passphrase input cancelled");
gtk_main_quit();
} else {
#if GTK_CHECK_VERSION(2,0,0)
if (gtk_im_context_filter_keypress(ctx->imc, event))
return true;
#endif
if (event->type == GDK_KEY_PRESS) {
if (!strcmp(event->string, "\x15")) {
/* Ctrl-U. Wipe out the whole line */
ctx->passlen = 0;
visually_acknowledge_keypress(ctx);
} else if (!strcmp(event->string, "\x17")) {
/* Ctrl-W. Delete back to the last space->nonspace
* boundary. We interpret 'space' in a really simple
* way (mimicking terminal drivers), and don't attempt
* to second-guess exciting Unicode space
* characters. */
while (ctx->passlen > 0) {
char deleted, prior;
ctx->passlen -= last_char_len(ctx);
deleted = ctx->passphrase[ctx->passlen];
prior = (ctx->passlen == 0 ? ' ' :
ctx->passphrase[ctx->passlen-1]);
if (!g_ascii_isspace(deleted) && g_ascii_isspace(prior))
break;
}
visually_acknowledge_keypress(ctx);
} else if (event->keyval == GDK_KEY_BackSpace) {
/* Backspace. Delete one character. */
if (ctx->passlen > 0)
ctx->passlen -= last_char_len(ctx);
visually_acknowledge_keypress(ctx);
#if !GTK_CHECK_VERSION(2,0,0)
} else if (event->string[0]) {
add_text_to_passphrase(ctx, event->string);
#endif
}
}
}
return true;
}
#if GTK_CHECK_VERSION(2,0,0)
static void input_method_commit_event(GtkIMContext *imc, gchar *str,
gpointer data)
{
struct askpass_ctx *ctx = (struct askpass_ctx *)data;
add_text_to_passphrase(ctx, str);
}
#endif
static gint configure_area(GtkWidget *widget, GdkEventConfigure *event,
gpointer data)
{
struct drawing_area_ctx *ctx = (struct drawing_area_ctx *)data;
ctx->width = event->width;
ctx->height = event->height;
gtk_widget_queue_draw(widget);
return true;
}
#ifdef DRAW_DEFAULT_CAIRO
static void askpass_redraw_cairo(cairo_t *cr, struct drawing_area_ctx *ctx)
{
double rgbval = (ctx->state == CURRENT ? 0 :
ctx->state == NOT_CURRENT ? 1 : 0.5);
cairo_set_source_rgb(cr, rgbval, rgbval, rgbval);
cairo_paint(cr);
}
#else
static void askpass_redraw_gdk(GdkWindow *win, struct drawing_area_ctx *ctx)
{
GdkGC *gc = gdk_gc_new(win);
gdk_gc_set_foreground(gc, &ctx->cols[ctx->state]);
gdk_draw_rectangle(win, gc, true, 0, 0, ctx->width, ctx->height);
gdk_gc_unref(gc);
}
#endif
#if GTK_CHECK_VERSION(3,0,0)
static gint draw_area(GtkWidget *widget, cairo_t *cr, gpointer data)
{
struct drawing_area_ctx *ctx = (struct drawing_area_ctx *)data;
askpass_redraw_cairo(cr, ctx);
return true;
}
#else
static gint expose_area(GtkWidget *widget, GdkEventExpose *event,
gpointer data)
{
struct drawing_area_ctx *ctx = (struct drawing_area_ctx *)data;
#ifdef DRAW_DEFAULT_CAIRO
cairo_t *cr = gdk_cairo_create(gtk_widget_get_window(ctx->area));
askpass_redraw_cairo(cr, ctx);
cairo_destroy(cr);
#else
askpass_redraw_gdk(gtk_widget_get_window(ctx->area), ctx);
#endif
return true;
}
#endif
static gboolean try_grab_keyboard(gpointer vctx)
{
struct askpass_ctx *ctx = (struct askpass_ctx *)vctx;
int i, ret;
#if GTK_CHECK_VERSION(3,20,0)
/*
* Grabbing the keyboard in GTK 3.20 requires the new notion of
* GdkSeat.
*/
GdkSeat *seat;
GdkWindow *gdkw = gtk_widget_get_window(ctx->dialog);
if (!GDK_IS_WINDOW(gdkw) || !gdk_window_is_visible(gdkw))
goto fail;
seat = gdk_display_get_default_seat
(gtk_widget_get_display(ctx->dialog));
if (!seat)
goto fail;
ctx->seat = seat;
ret = gdk_seat_grab(seat, gdkw, GDK_SEAT_CAPABILITY_KEYBOARD,
true, NULL, NULL, NULL, NULL);
/*
* For some reason GDK 3.22 hides the GDK window as a side effect
* of a failed grab. I've no idea why. But if we're going to retry
* the grab, then we need to unhide it again or else we'll just
* get GDK_GRAB_NOT_VIEWABLE on every subsequent attempt.
*/
if (ret != GDK_GRAB_SUCCESS)
gdk_window_show(gdkw);
#elif GTK_CHECK_VERSION(3,0,0)
/*
* And it has to be done differently again prior to GTK 3.20.
*/
GdkDeviceManager *dm;
GdkDevice *pointer, *keyboard;
dm = gdk_display_get_device_manager
(gtk_widget_get_display(ctx->dialog));
if (!dm)
goto fail;
pointer = gdk_device_manager_get_client_pointer(dm);
if (!pointer)
goto fail;
keyboard = gdk_device_get_associated_device(pointer);
if (!keyboard)
goto fail;
if (gdk_device_get_source(keyboard) != GDK_SOURCE_KEYBOARD)
goto fail;
ctx->keyboard = keyboard;
ret = gdk_device_grab(ctx->keyboard,
gtk_widget_get_window(ctx->dialog),
GDK_OWNERSHIP_NONE,
true,
GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK,
NULL,
GDK_CURRENT_TIME);
#else
/*
* It's much simpler in GTK 1 and 2!
*/
ret = gdk_keyboard_grab(gtk_widget_get_window(ctx->dialog),
false, GDK_CURRENT_TIME);
#endif
if (ret != GDK_GRAB_SUCCESS)
goto fail;
/*
* Now that we've got the keyboard grab, connect up our keyboard
* handlers.
*/
#if GTK_CHECK_VERSION(2,0,0)
g_signal_connect(G_OBJECT(ctx->imc), "commit",
G_CALLBACK(input_method_commit_event), ctx);
#endif
g_signal_connect(G_OBJECT(ctx->dialog), "key_press_event",
G_CALLBACK(key_event), ctx);
g_signal_connect(G_OBJECT(ctx->dialog), "key_release_event",
G_CALLBACK(key_event), ctx);
#if GTK_CHECK_VERSION(2,0,0)
gtk_im_context_set_client_window(ctx->imc,
gtk_widget_get_window(ctx->dialog));
#endif
/*
* And repaint the key-acknowledgment drawing areas as not greyed
* out.
*/
ctx->active_area = rand() % N_DRAWING_AREAS;
for (i = 0; i < N_DRAWING_AREAS; i++) {
ctx->drawingareas[i].state =
(i == ctx->active_area ? CURRENT : NOT_CURRENT);
gtk_widget_queue_draw(ctx->drawingareas[i].area);
}
return false;
fail:
/*
* If we didn't get the grab, reschedule ourself on a timer to try
* again later.
*
* We have to do this rather than just trying once, because there
* is at least one important situation in which the grab may fail
* the first time: any user who is launching an add-key operation
* off some kind of window manager hotkey will almost by
* definition be running this script with a keyboard grab already
* active, namely the one-key grab that the WM (or whatever) uses
* to detect presses of the hotkey. So at the very least we have
* to give the user time to release that key.
*/
if (++ctx->nattempts >= 4) {
smemclr(ctx->passphrase, ctx->passsize);
ctx->passphrase = NULL;
ctx->error_message = dupstr("unable to grab keyboard after 5 seconds");
gtk_main_quit();
} else {
g_timeout_add(1000/8, try_grab_keyboard, ctx);
}
return false;
}
void realize(GtkWidget *widget, gpointer vctx)
{
struct askpass_ctx *ctx = (struct askpass_ctx *)vctx;
gtk_grab_add(ctx->dialog);
/*
* Schedule the first attempt at the keyboard grab.
*/
ctx->nattempts = 0;
#if GTK_CHECK_VERSION(3,20,0)
ctx->seat = NULL;
#elif GTK_CHECK_VERSION(3,0,0)
ctx->keyboard = NULL;
#endif
g_idle_add(try_grab_keyboard, ctx);
}
static const char *gtk_askpass_setup(struct askpass_ctx *ctx,
const char *window_title,
const char *prompt_text)
{
int i;
GtkBox *action_area;
ctx->passlen = 0;
ctx->passsize = 2048;
ctx->passphrase = snewn(ctx->passsize, char);
/*
* Create widgets.
*/
ctx->dialog = our_dialog_new();
gtk_window_set_title(GTK_WINDOW(ctx->dialog), window_title);
gtk_window_set_position(GTK_WINDOW(ctx->dialog), GTK_WIN_POS_CENTER);
ctx->promptlabel = gtk_label_new(prompt_text);
align_label_left(GTK_LABEL(ctx->promptlabel));
gtk_widget_show(ctx->promptlabel);
gtk_label_set_line_wrap(GTK_LABEL(ctx->promptlabel), true);
#if GTK_CHECK_VERSION(3,0,0)
gtk_label_set_width_chars(GTK_LABEL(ctx->promptlabel), 48);
#endif
our_dialog_add_to_content_area(GTK_WINDOW(ctx->dialog),
ctx->promptlabel, true, true, 0);
#if GTK_CHECK_VERSION(2,0,0)
ctx->imc = gtk_im_multicontext_new();
#endif
#ifndef DRAW_DEFAULT_CAIRO
{
gboolean success[2];
ctx->colmap = gdk_colormap_get_system();
ctx->cols[0].red = ctx->cols[0].green = ctx->cols[0].blue = 0xFFFF;
ctx->cols[1].red = ctx->cols[1].green = ctx->cols[1].blue = 0;
ctx->cols[2].red = ctx->cols[2].green = ctx->cols[2].blue = 0x8000;
gdk_colormap_alloc_colors(ctx->colmap, ctx->cols, 2,
false, true, success);
if (!success[0] || !success[1])
return "unable to allocate colours";
}
#endif
action_area = our_dialog_make_action_hbox(GTK_WINDOW(ctx->dialog));
for (i = 0; i < N_DRAWING_AREAS; i++) {
ctx->drawingareas[i].area = gtk_drawing_area_new();
#ifndef DRAW_DEFAULT_CAIRO
ctx->drawingareas[i].cols = ctx->cols;
#endif
ctx->drawingareas[i].state = GREYED_OUT;
ctx->drawingareas[i].width = ctx->drawingareas[i].height = 0;
/* It would be nice to choose this size in some more
* context-sensitive way, like measuring the size of some
* piece of template text. */
gtk_widget_set_size_request(ctx->drawingareas[i].area, 32, 32);
gtk_box_pack_end(action_area, ctx->drawingareas[i].area,
true, true, 5);
g_signal_connect(G_OBJECT(ctx->drawingareas[i].area),
"configure_event",
G_CALLBACK(configure_area),
&ctx->drawingareas[i]);
#if GTK_CHECK_VERSION(3,0,0)
g_signal_connect(G_OBJECT(ctx->drawingareas[i].area),
"draw",
G_CALLBACK(draw_area),
&ctx->drawingareas[i]);
#else
g_signal_connect(G_OBJECT(ctx->drawingareas[i].area),
"expose_event",
G_CALLBACK(expose_area),
&ctx->drawingareas[i]);
#endif
#if GTK_CHECK_VERSION(3,0,0)
g_object_set(G_OBJECT(ctx->drawingareas[i].area),
"margin-bottom", 8, (const char *)NULL);
#endif
gtk_widget_show(ctx->drawingareas[i].area);
}
ctx->active_area = -1;
/*
* Arrange to receive key events. We don't really need to worry
* from a UI perspective about which widget gets the events, as
* long as we know which it is so we can catch them. So we'll pick
* the prompt label at random, and we'll use gtk_grab_add to
* ensure key events go to it.
*/
gtk_widget_set_sensitive(ctx->dialog, true);
#if GTK_CHECK_VERSION(2,0,0)
gtk_window_set_keep_above(GTK_WINDOW(ctx->dialog), true);
#endif
/*
* Wait for the key-receiving widget to actually be created, in
* order to call gtk_grab_add on it.
*/
g_signal_connect(G_OBJECT(ctx->dialog), "realize",
G_CALLBACK(realize), ctx);
/*
* Show the window.
*/
gtk_widget_show(ctx->dialog);
return NULL;
}
static void gtk_askpass_cleanup(struct askpass_ctx *ctx)
{
#if GTK_CHECK_VERSION(3,20,0)
if (ctx->seat)
gdk_seat_ungrab(ctx->seat);
#elif GTK_CHECK_VERSION(3,0,0)
if (ctx->keyboard)
gdk_device_ungrab(ctx->keyboard, GDK_CURRENT_TIME);
#else
gdk_keyboard_ungrab(GDK_CURRENT_TIME);
#endif
gtk_grab_remove(ctx->promptlabel);
if (ctx->passphrase) {
assert(ctx->passlen < ctx->passsize);
ctx->passphrase[ctx->passlen] = '\0';
}
gtk_widget_destroy(ctx->dialog);
}
static bool setup_gtk(const char *display)
{
static bool gtk_initialised = false;
int argc;
char *real_argv[3];
char **argv = real_argv;
bool ret;
if (gtk_initialised)
return true;
argc = 0;
argv[argc++] = dupstr("dummy");
argv[argc++] = dupprintf("--display=%s", display);
argv[argc] = NULL;
ret = gtk_init_check(&argc, &argv);
while (argc > 0)
sfree(argv[--argc]);
gtk_initialised = ret;
return ret;
}
const bool buildinfo_gtk_relevant = true;
char *gtk_askpass_main(const char *display, const char *wintitle,
const char *prompt, bool *success)
{
struct askpass_ctx actx, *ctx = &actx;
const char *err;
ctx->passphrase = NULL;
ctx->error_message = NULL;
/* In case gtk_init hasn't been called yet by the program */
if (!setup_gtk(display)) {
*success = false;
return dupstr("unable to initialise GTK");
}
if ((err = gtk_askpass_setup(ctx, wintitle, prompt)) != NULL) {
*success = false;
return dupprintf("%s", err);
}
gtk_main();
gtk_askpass_cleanup(ctx);
if (ctx->passphrase) {
*success = true;
return ctx->passphrase;
} else {
*success = false;
return ctx->error_message;
}
}
#ifdef TEST_ASKPASS
void modalfatalbox(const char *p, ...)
{
va_list ap;
fprintf(stderr, "FATAL ERROR: ");
va_start(ap, p);
vfprintf(stderr, p, ap);
va_end(ap);
fputc('\n', stderr);
exit(1);
}
int main(int argc, char **argv)
{
bool success;
int exitcode;
char *ret;
gtk_init(&argc, &argv);
if (argc != 2) {
success = false;
ret = dupprintf("usage: %s <prompt text>", argv[0]);
} else {
srand(time(NULL));
ret = gtk_askpass_main(NULL, "Enter passphrase", argv[1], &success);
}
if (!success) {
fputs(ret, stderr);
fputc('\n', stderr);
exitcode = 1;
} else {
fputs(ret, stdout);
fputc('\n', stdout);
exitcode = 0;
}
smemclr(ret, strlen(ret));
return exitcode;
}
#endif
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