auth_x11.c File Reference

#include <X11/X.h>
#include <X11/Xlib.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/select.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include "../env_info.h"
#include "../env_settings.h"
#include "../logging.h"
#include "../mlock_page.h"
#include "../util.h"
#include "../wait_pgrp.h"
#include "../wm_properties.h"
#include "../xscreensaver_api.h"
#include "authproto.h"
#include "monitors.h"

Macros
#define	STATIC_ASSERT(state, message)   extern int statically_asserted(int assertion[(state) ? 1 : -1]);
#define	BLINK_INTERVAL   (250 * 1000)
	The blinking interval in microseconds. More...
#define	DISCO_PASSWORD_DANCERS   5
	Number of dancers in the disco password display. More...
#define	PARANOID_PASSWORD_LENGTH   (1 << DISCO_PASSWORD_DANCERS)
	Length of the "paranoid password display". More...
#define	PARANOID_PASSWORD_MIN_CHANGE   4
	Minimum distance the cursor shall move on keypress. More...
#define	WINDOW_BORDER   16
	Border of the window around the text. More...
#define	LINE_SPACING   4
	Draw border rectangle (mainly for debugging). More...
#define	MAIN_WINDOW   0
#define	MAX_WINDOWS   16
#define	NOTE_DS3   156
#define	NOTE_A3   220
#define	NOTE_DS4   311
#define	NOTE_E4   330
#define	NOTE_B4   494
#define	NOTE_E5   659
#define	SOUND_SLEEP_MS   125
#define	SOUND_TONE_MS   100
#define	PWBUF_SIZE   256
	The size of the buffer to store the password in. Not NUL terminated. More...
#define	DISPLAYBUF_SIZE   (PWBUF_SIZE + 2)
	The size of the buffer to use for display, with space for cursor and NUL. More...

Enumerations
enum	PasswordPrompt {   PASSWORD_PROMPT_CURSOR, PASSWORD_PROMPT_ASTERISKS, PASSWORD_PROMPT_HIDDEN, PASSWORD_PROMPT_DISCO,   PASSWORD_PROMPT_EMOJI, PASSWORD_PROMPT_EMOTICON, PASSWORD_PROMPT_KAOMOJI, PASSWORD_PROMPT_COUNT }
	Actual password prompt selected. More...
enum	Sound { SOUND_PROMPT, SOUND_INFO, SOUND_ERROR, SOUND_SUCCESS }

Functions
	STATIC_ASSERT (sizeof(emoji)/sizeof(*emoji)==PARANOID_PASSWORD_LENGTH, "Emoji array size must be equal to PARANOID_PASSWORD_LENGTH")
	STATIC_ASSERT (sizeof(emoticons)/sizeof(*emoticons)==PARANOID_PASSWORD_LENGTH, "Emoticons array size must be equal to PARANOID_PASSWORD_LENGTH")
	STATIC_ASSERT (sizeof(kaomoji)/sizeof(*kaomoji)==PARANOID_PASSWORD_LENGTH, "Kaomoji array size must be equal to PARANOID_PASSWORD_LENGTH")
void	PlaySound (enum Sound snd)
	Play a sound sequence. More...
void	SwitchKeyboardLayout (void)
	Switch to the next keyboard layout. More...
const char *	GetIndicators (int *warning, int *have_multiple_layouts)
	Check which modifiers are active. More...
void	DestroyPerMonitorWindows (size_t keep_windows)
void	CreateOrUpdatePerMonitorWindow (size_t i, const Monitor *monitor, int region_w, int region_h, int x_offset, int y_offset)
void	UpdatePerMonitorWindows (int monitors_changed, int region_w, int region_h, int x_offset, int y_offset)
int	TextAscent (void)
int	TextDescent (void)
int	TextWidth (const char *string, int len)
void	DrawString (int monitor, int x, int y, int is_warning, const char *string, int len)
void	StrAppend (char **output, size_t *output_size, const char *input, size_t input_size)
void	BuildTitle (char *output, size_t output_size, const char *input)
void	DisplayMessage (const char *title, const char *str, int is_warning)
	Display a string in the window. More...
void	WaitForKeypress (int seconds)
void	BumpDisplayMarker (size_t pwlen, size_t *pos, struct timeval *last_keystroke)
	Bump the position for the password "cursor". More...
void	ShowFromArray (const char **array, size_t displaymarker, char *displaybuf, size_t displaybufsize, size_t *displaylen)
int	Prompt (const char *msg, char **response, int echo)
	Ask a question to the user. More...
int	Authenticate ()
	Perform authentication using a helper proxy. More...
enum PasswordPrompt	GetPasswordPromptFromFlags (int paranoid_password_flag, const char *password_prompt_flag)
int	main (int argc_local, char **argv_local)
	The main program. More...

Variables
int	argc
	Number of args. More...
char *const *	argv
	Args. More...
const char *	authproto_executable
	The authproto helper to use. More...
int	prompt_timeout
	The maximum time to wait at a prompt for user input in seconds. More...
const char *	PasswordPromptStrings []
enum PasswordPrompt	password_prompt
const char *	disco_combiner = " ♪ "
const char *	disco_dancers []
const char *	emoji []
const char *	emoticons []
const char *	kaomoji []
int	have_switch_user_command
	If set, we can start a new login session. More...
int	show_username
	If set, the prompt will be fixed by <username>. More...
int	show_hostname
	If set, the prompt will be fixed by <hostname>. If >1, the hostname will be. More...
int	show_datetime
	If set, data and time will be shown. More...
const char *	datetime_format = "%c"
	The date format to display. More...
char	hostname [256]
	The local hostname. More...
char	username [256]
	The username to authenticate as. More...
Display *	display
	The X11 display. More...
Window	main_window
	The X11 window provided by main. Provided from $XSCREENSAVER_WINDOW. More...
Window	parent_window
	main_window's parent. Used to create per-monitor siblings. More...
XFontStruct *	core_font
	The X11 core font for the PAM messages. More...
XColor	xcolor_background
	The background color. More...
XColor	xcolor_foreground
	The foreground color. More...
XColor	xcolor_warning
	The warning color (used as foreground). More...
static const char	cursor [] = "_"
	The cursor character displayed at the end of the masked password input. More...
static int	x_offset = 0
	The x offset to apply to the entire display (to mitigate burn-in). More...
static int	y_offset = 0
	The y offset to apply to the entire display (to mitigate burn-in). More...
static int	burnin_mitigation_max_offset = 0
	Maximum offset value when dynamic changes are enabled. More...
static int	burnin_mitigation_max_offset_change = 0
	How much the offsets are allowed to change dynamically, and if so, how high. More...
static int	auth_sounds = 0
	Whether to play sounds during authentication. More...
static int	auth_cursor_blink = 1
	Whether to blink the cursor in the auth dialog. More...
static int	single_auth_window = 0
	Whether we only want a single auth window. More...
int	per_monitor_windows_dirty = 1
	If set, we need to re-query monitor data and adjust windows. More...
size_t	num_windows = 0
	The number of active X11 per-monitor windows. More...
Window	windows [MAX_WINDOWS]
	The X11 per-monitor windows to draw on. More...
GC	gcs [MAX_WINDOWS]
	The X11 graphics contexts to draw with. More...
GC	gcs_warning [MAX_WINDOWS]
	The X11 graphics contexts to draw warnings with. More...
int	have_xkb_ext
int	sounds [][2]

Macro Definition Documentation

BLINK_INTERVAL

#define BLINK_INTERVAL   (250 * 1000)

The blinking interval in microseconds.

DISCO_PASSWORD_DANCERS

#define DISCO_PASSWORD_DANCERS   5

Number of dancers in the disco password display.

DISPLAYBUF_SIZE

#define DISPLAYBUF_SIZE   (PWBUF_SIZE + 2)

The size of the buffer to use for display, with space for cursor and NUL.

LINE_SPACING

#define LINE_SPACING   4

Draw border rectangle (mainly for debugging).

Extra line spacing.

MAIN_WINDOW

#define MAIN_WINDOW   0

MAX_WINDOWS

#define MAX_WINDOWS   16

NOTE_A3

#define NOTE_A3   220

NOTE_B4

#define NOTE_B4   494

NOTE_DS3

#define NOTE_DS3   156

NOTE_DS4

#define NOTE_DS4   311

NOTE_E4

#define NOTE_E4   330

NOTE_E5

#define NOTE_E5   659

PARANOID_PASSWORD_LENGTH

#define PARANOID_PASSWORD_LENGTH   (1 << DISCO_PASSWORD_DANCERS)

Length of the "paranoid password display".

PARANOID_PASSWORD_MIN_CHANGE

#define PARANOID_PASSWORD_MIN_CHANGE   4

Minimum distance the cursor shall move on keypress.

PWBUF_SIZE

#define PWBUF_SIZE   256

The size of the buffer to store the password in. Not NUL terminated.

SOUND_SLEEP_MS

#define SOUND_SLEEP_MS   125

SOUND_TONE_MS

#define SOUND_TONE_MS   100

STATIC_ASSERT

#define STATIC_ASSERT	(		state,
			message
	)		extern int statically_asserted(int assertion[(state) ? 1 : -1]);

WINDOW_BORDER

#define WINDOW_BORDER   16

Border of the window around the text.

Enumeration Type Documentation

PasswordPrompt

enum PasswordPrompt

Actual password prompt selected.

Enumerator
PASSWORD_PROMPT_CURSOR
PASSWORD_PROMPT_ASTERISKS
PASSWORD_PROMPT_HIDDEN
PASSWORD_PROMPT_DISCO
PASSWORD_PROMPT_EMOJI
PASSWORD_PROMPT_EMOTICON
PASSWORD_PROMPT_KAOMOJI
PASSWORD_PROMPT_COUNT

Sound

enum Sound

Enumerator
SOUND_PROMPT
SOUND_INFO
SOUND_ERROR
SOUND_SUCCESS

Function Documentation

Authenticate()

int Authenticate

(

)

Perform authentication using a helper proxy.

Returns

The authentication status (0 for OK, 1 otherwise).

BuildTitle()

void BuildTitle	(	char *	output,
		size_t	output_size,
		const char *	input
	)

BumpDisplayMarker()

void BumpDisplayMarker	(	size_t	pwlen,
		size_t *	pos,
		struct timeval *	last_keystroke
	)

Bump the position for the password "cursor".

If pwlen > 0: Precondition: pos in 0..PARANOID_PASSWORD_LENGTH-1. Postcondition: pos' in 1..PARANOID_PASSWORD_LENGTH-1. Postcondition: abs(pos' - pos) >= PARANOID_PASSWORD_MIN_CHANGE. Postcondition: pos' is uniformly distributed among all permitted choices. If pwlen == 0: Postcondition: pos' is 0.

Parameters

pwlen	The current password length.
pos	The initial cursor position; will get updated.
last_keystroke	The time of last keystroke; will get updated.

CreateOrUpdatePerMonitorWindow()

void CreateOrUpdatePerMonitorWindow	(	size_t	i,
		const Monitor *	monitor,
		int	region_w,
		int	region_h,
		int	x_offset,
		int	y_offset
	)

DestroyPerMonitorWindows()

void DestroyPerMonitorWindows

(

size_t

keep_windows

)

DisplayMessage()

void DisplayMessage	(	const char *	title,
		const char *	str,
		int	is_warning
	)

Display a string in the window.

The given title and message will be displayed on all screens. In case caps lock is enabled, the string's case will be inverted.

Parameters

title	The title of the message.
str	The message itself.
is_warning	Whether to use the warning style to display the message.

DrawString()

void DrawString	(	int	monitor,
		int	x,
		int	y,
		int	is_warning,
		const char *	string,
		int	len
	)

GetIndicators()

const char* GetIndicators	(	int *	warning,
		int *	have_multiple_layouts
	)

Check which modifiers are active.

Parameters

warning	Will be set to 1 if something's "bad" with the keyboard layout (e.g. Caps Lock).
have_multiple_layouts	Will be set to 1 if more than one keyboard layout is available for switching.

Returns

The current modifier mask as a string.

GetPasswordPromptFromFlags()

enum PasswordPrompt GetPasswordPromptFromFlags	(	int	paranoid_password_flag,
		const char *	password_prompt_flag
	)

main()

int main	(	int	argc_local,
		char **	argv_local
	)

The main program.

Usage: XSCREENSAVER_WINDOW=window_id ./auth_x11; status=$?

Returns

0 if authentication successful, anything else otherwise.

Deprecated flag for setting whether password display should hide the length.
Updated flag for password display choice

PlaySound()

void PlaySound

(

enum Sound

snd

)

Play a sound sequence.

Prompt()

int Prompt	(	const char *	msg,
		char **	response,
		int	echo
	)

Ask a question to the user.

Parameters

msg	The message.
response	The response will be stored in a newly allocated buffer here. The caller is supposed to eventually free() it.
echo	If true, the input will be shown; otherwise it will be hidden (password entry).

Returns

1 if successful, anything else otherwise.

ShowFromArray()

void ShowFromArray	(	const char **	array,
		size_t	displaymarker,
		char *	displaybuf,
		size_t	displaybufsize,
		size_t *	displaylen
	)

STATIC_ASSERT() [1/3]

STATIC_ASSERT	(	sizeof(emoji)/sizeof *	emoji = =PARANOID_PASSWORD_LENGTH,
		"Emoji array size must be equal to PARANOID_PASSWORD_LENGTH"
	)

STATIC_ASSERT() [2/3]

STATIC_ASSERT	(	sizeof(emoticons)/sizeof *	emoticons = =PARANOID_PASSWORD_LENGTH,
		"Emoticons array size must be equal to PARANOID_PASSWORD_LENGTH"
	)

STATIC_ASSERT() [3/3]

STATIC_ASSERT	(	sizeof(kaomoji)/sizeof *	kaomoji = =PARANOID_PASSWORD_LENGTH,
		"Kaomoji array size must be equal to PARANOID_PASSWORD_LENGTH"
	)

StrAppend()

void StrAppend	(	char **	output,
		size_t *	output_size,
		const char *	input,
		size_t	input_size
	)

SwitchKeyboardLayout()

void SwitchKeyboardLayout

(

void

)

Switch to the next keyboard layout.

TextAscent()

int TextAscent

(

void

)

TextDescent()

int TextDescent

(

void

)

TextWidth()

int TextWidth	(	const char *	string,
		int	len
	)

UpdatePerMonitorWindows()

void UpdatePerMonitorWindows	(	int	monitors_changed,
		int	region_w,
		int	region_h,
		int	x_offset,
		int	y_offset
	)

WaitForKeypress()

void WaitForKeypress

(

int

seconds

)

Variable Documentation

argc

int argc

Number of args.

argv

char* const* argv

Args.

auth_cursor_blink

int auth_cursor_blink = 1

static

Whether to blink the cursor in the auth dialog.

auth_sounds

int auth_sounds = 0

static

Whether to play sounds during authentication.

authproto_executable

const char* authproto_executable

The authproto helper to use.

burnin_mitigation_max_offset

int burnin_mitigation_max_offset = 0

static

Maximum offset value when dynamic changes are enabled.

burnin_mitigation_max_offset_change

int burnin_mitigation_max_offset_change = 0

static

How much the offsets are allowed to change dynamically, and if so, how high.

core_font

XFontStruct* core_font

The X11 core font for the PAM messages.

cursor

const char cursor[] = "_"

static

The cursor character displayed at the end of the masked password input.

datetime_format

const char* datetime_format = "%c"

The date format to display.

disco_combiner

const char* disco_combiner = " ♪ "

disco_dancers

const char* disco_dancers[]

Initial value:

= {
    "┏(･o･)┛",
    "┗(･o･)┓",
}

display

Display* display

The X11 display.

emoji

const char* emoji[]

Initial value:

= {
    "_____", "😂", "❤", "♻", "😍", "♥", "😭", "😊", "😒", "💕", "😘",
    "😩",     "☺", "👌", "😔", "😁", "😏", "😉", "👍", "⬅", "😅", "🙏",
    "😌",     "😢", "👀", "💔", "😎", "🎶", "💙", "💜", "🙌", "😳",
}

emoticons

const char* emoticons[]

Initial value:

= {
    ":-)",  ":-p", ":-O", ":-\\", "(-:",  "d-:", "O-:", "/-:",
    "8-)",  "8-p", "8-O", "8-\\", "(-8",  "d-8", "O-8", "/-8",
    "X-)",  "X-p", "X-O", "X-\\", "(-X",  "d-X", "O-X", "/-X",
    ":'-)", ":-S", ":-D", ":-#",  "(-':", "S-:", "D-:", "#-:",
}

gcs

GC gcs[MAX_WINDOWS]

The X11 graphics contexts to draw with.

gcs_warning

GC gcs_warning[MAX_WINDOWS]

The X11 graphics contexts to draw warnings with.

have_switch_user_command

int have_switch_user_command

If set, we can start a new login session.

have_xkb_ext

int have_xkb_ext

hostname

char hostname[256]

The local hostname.

kaomoji

const char* kaomoji[]

Initial value:

= {
    "(͡°͜ʖ͡°)",     "(>_<)",       "O_ם",      "(^_-)",        "o_0",
    "o.O",       "0_o",         "O.o",      "(°o°)",        "^m^",
    "^_^",       "((d[-_-]b))", "┏(･o･)┛",  "┗(･o･)┓",      "（ﾟДﾟ)",
    "(°◇°)",     "\\o/",        "\\o|",     "|o/",          "|o|",
    "(●＾o＾●)", "(＾ｖ＾)",    "(＾ｕ＾)", "(＾◇＾)",      "¯\\_(ツ)_/¯",
    "(^0_0^)",   "(☞ﾟ∀ﾟ)☞",     "(-■_■)",   "(┛ಠ_ಠ)┛彡┻━┻", "┬─┬ノ(º_ºノ)",
    "(˘³˘)♥",    "❤(◍•ᴗ•◍)",
}

main_window

Window main_window

The X11 window provided by main. Provided from $XSCREENSAVER_WINDOW.

num_windows

size_t num_windows = 0

The number of active X11 per-monitor windows.

parent_window

Window parent_window

main_window's parent. Used to create per-monitor siblings.

password_prompt

enum PasswordPrompt password_prompt

PasswordPromptStrings

const char* PasswordPromptStrings[]

Initial value:

= {
     "cursor",
     "asterisks",
     "hidden",
     "disco",
     "emoji",
     "emoticon",
     "kaomoji",




}

per_monitor_windows_dirty

int per_monitor_windows_dirty = 1

If set, we need to re-query monitor data and adjust windows.

prompt_timeout

int prompt_timeout

The maximum time to wait at a prompt for user input in seconds.

show_datetime

int show_datetime

If set, data and time will be shown.

show_hostname

int show_hostname

If set, the prompt will be fixed by <hostname>. If >1, the hostname will be.

show_username

int show_username

If set, the prompt will be fixed by <username>.

single_auth_window

int single_auth_window = 0

static

Whether we only want a single auth window.

sounds

int sounds[][2]

Initial value:

= {
     {NOTE_B4, NOTE_E5},   
     {NOTE_E5, NOTE_E5},   
     {NOTE_A3, NOTE_DS3},  
     {NOTE_DS4, NOTE_E4},  
}

username

char username[256]

The username to authenticate as.

windows

Window windows[MAX_WINDOWS]

The X11 per-monitor windows to draw on.

x_offset

int x_offset = 0

static

The x offset to apply to the entire display (to mitigate burn-in).

xcolor_background

XColor xcolor_background

The background color.

xcolor_foreground

XColor xcolor_foreground

The foreground color.

xcolor_warning

XColor xcolor_warning

The warning color (used as foreground).

y_offset

int y_offset = 0

static

The y offset to apply to the entire display (to mitigate burn-in).