Add support for running a helper program to read the password when

no tty is present (or when specified with the -A flag).  TODO: docs.

auth/sudo_auth.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2005 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 1999-2005, 2008 Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -195,7 +195,8 @@ verify_user(pw, prompt)
 		break;
 	}
 
-	pass_warn(stderr);
+	if (!ISSET(tgetpass_flags, TGP_ASKPASS))
+	    pass_warn(stderr);
     }
 
 cleanup:

check.c

@@ -1,5 +1,6 @@
 /*
- * Copyright (c) 1993-1996,1998-2005 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 1993-1996,1998-2005, 2007-2008
+ *	Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -98,7 +99,8 @@ check_user(validated)
     status = timestamp_status(timestampdir, timestampfile, user_name,
 	TS_MAKE_DIRS);
     if (status != TS_CURRENT || ISSET(validated, FLAG_CHECK_USER)) {
-	lecture(status);
+	if (!ISSET(tgetpass_flags, TGP_ASKPASS))
+	    lecture(status);
 
 	/* Expand any escapes in the prompt. */
 	prompt = expand_prompt(user_prompt ? user_prompt : def_passprompt,

configure

@@ -1581,6 +1581,7 @@ Optional Packages:
   --with-secure-path      override the user's path with a built-in one
   --without-interfaces    don't try to read the ip addr of ether interfaces
   --with-stow             properly handle GNU stow packaging
+  --with-askpass=PATH     Fully qualified pathname of sudo-askpass
   --with-selinux          enable SELinux support
   --with-gnu-ld           assume the C compiler uses GNU ld [default=no]
   --with-pic              try to use only PIC/non-PIC objects [default=use
@@ -3740,6 +3741,28 @@ echo "${ECHO_T}no" >&6; }
 fi
 
 
+{ echo "$as_me:$LINENO: checking path to sudo-askpass" >&5
+echo $ECHO_N "checking path to sudo-askpass... $ECHO_C" >&6; }
+
+# Check whether --with-askpass was given.
+if test "${with_askpass+set}" = set; then
+  withval=$with_askpass; case $with_askpass in
+    yes)	with_askpass="$libexecdir/sudo-askpass"
+		;;
+    no)		;;
+    *)		;;
+esac
+else
+  with_askpass="$libexecdir/sudo-askpass"
+fi
+
+{ echo "$as_me:$LINENO: result: $with_askpass" >&5
+echo "${ECHO_T}$with_askpass" >&6; }
+cat >>confdefs.h <<EOF
+#define _PATH_SUDO_ASKPASS "$with_askpass"
+EOF
+
+
 
 { echo "$as_me:$LINENO: checking whether to do user authentication by default" >&5
 echo $ECHO_N "checking whether to do user authentication by default... $ECHO_C" >&6; }
@@ -6180,7 +6203,7 @@ ia64-*-hpux*)
   ;;
 *-*-irix6*)
   # Find out which ABI we are using.
-  echo '#line 6183 "configure"' > conftest.$ac_ext
+  echo '#line 6206 "configure"' > conftest.$ac_ext
   if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
   (eval $ac_compile) 2>&5
   ac_status=$?
@@ -7724,11 +7747,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7727: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7750: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:7731: \$? = $ac_status" >&5
+   echo "$as_me:7754: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -8014,11 +8037,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:8017: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:8040: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>conftest.err)
    ac_status=$?
    cat conftest.err >&5
-   echo "$as_me:8021: \$? = $ac_status" >&5
+   echo "$as_me:8044: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s "$ac_outfile"; then
      # The compiler can only warn and ignore the option if not recognized
      # So say no if there are warnings other than the usual output.
@@ -8118,11 +8141,11 @@ else
    -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
    -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
    -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:8121: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:8144: $lt_compile\"" >&5)
    (eval "$lt_compile" 2>out/conftest.err)
    ac_status=$?
    cat out/conftest.err >&5
-   echo "$as_me:8125: \$? = $ac_status" >&5
+   echo "$as_me:8148: \$? = $ac_status" >&5
    if (exit $ac_status) && test -s out/conftest2.$ac_objext
    then
      # The compiler can only warn and ignore the option if not recognized
@@ -10463,7 +10486,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 10466 "configure"
+#line 10489 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10563,7 +10586,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 10566 "configure"
+#line 10589 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H

configure.in

@@ -1010,6 +1010,17 @@ AC_ARG_WITH(stow, [  --with-stow             properly handle GNU stow packaging]
 		;;
 esac], AC_MSG_RESULT(no))
 
+AC_MSG_CHECKING(path to sudo-askpass)
+AC_ARG_WITH(askpass, [  --with-askpass=PATH     Fully qualified pathname of sudo-askpass],
+[case $with_askpass in
+    yes)	with_askpass="$libexecdir/sudo-askpass"
+		;;
+    no)		;;
+    *)		;;
+esac], [with_askpass="$libexecdir/sudo-askpass"])
+AC_MSG_RESULT($with_askpass)
+SUDO_DEFINE_UNQUOTED(_PATH_SUDO_ASKPASS, "$with_askpass")
+
 dnl
 dnl Options for --enable
 dnl

def_data.c

@@ -282,6 +282,10 @@ struct sudo_defs_types sudo_defs_table[] = {
 	"type", T_STR,
 	"SELinux type to use in the new security context: %s",
 	NULL,
+    }, {
+	"askpass", T_STR|T_PATH,
+	"Path to the askpass helper program: %s",
+	NULL,
     }, {
 	NULL, 0, NULL
     }

def_data.h

@@ -128,6 +128,8 @@
 #define I_ROLE                  63
 #define def_type                (sudo_defs_table[64].sd_un.str)
 #define I_TYPE                  64
+#define def_askpass             (sudo_defs_table[65].sd_un.str)
+#define I_ASKPASS               65
 
 enum def_tupple {
 	never,

def_data.in

@@ -208,3 +208,6 @@ role
 type
 	T_STR
 	"SELinux type to use in the new security context: %s"
+askpass
+	T_STR|T_PATH
+	"Path to the askpass helper program: %s"

defaults.c

@@ -422,6 +422,9 @@ init_defaults()
 #endif
 #ifdef ENV_EDITOR
     def_env_editor = TRUE;
+#endif
+#ifdef _PATH_SUDO_ASKPASS
+    def_askpass = _PATH_SUDO_ASKPASS;
 #endif
     def_env_reset = TRUE;
     def_set_logname = TRUE;

pathnames.h.in

@@ -84,6 +84,10 @@
 #undef _PATH_SUDO_NOEXEC
 #endif /* _PATH_SUDO_NOEXEC */
 
+#ifndef _PATH_SUDO_ASKPASS
+#undef _PATH_SUDO_ASKPASS
+#endif /* _PATH_SUDO_ASKPASS */
+
 #ifndef _PATH_VI
 #undef _PATH_VI
 #endif /* _PATH_VI */

sudo.c

@@ -384,6 +384,15 @@ main(argc, argv, envp)
 	    (void) close(fd);
     }
 
+    /* Use askpass value from sudoers unless specified by the user. */
+    if (def_askpass && !user_askpass)
+	user_askpass = def_askpass;
+
+    /* If no tty is present but DISPLAY is set, use askpass if we have it. */
+    if (user_askpass && !ISSET(tgetpass_flags, TGP_STDIN) &&
+	user_ttypath == NULL && user_display != NULL && *user_display != '\0')
+	SET(tgetpass_flags, TGP_ASKPASS);
+
     /* User may have overriden environment resetting via the -E flag. */
     if (ISSET(sudo_mode, MODE_PRESERVE_ENV) && def_setenv)
 	def_env_reset = FALSE;
@@ -599,7 +608,12 @@ init_vars(sudo_mode, envp)
 	user_tty = "unknown";
 
     for (ep = envp; *ep; ep++) {
+	/* XXX - don't fill in if empty string */
 	switch (**ep) {
+	    case 'D':
+		if (strncmp("DISPLAY=", *ep, 8) == 0)
+		    user_display = *ep + 8;
+		break;
 	    case 'K':
 		if (strncmp("KRB5CCNAME=", *ep, 11) == 0)
 		    user_ccname = *ep + 11;
@@ -615,8 +629,9 @@ init_vars(sudo_mode, envp)
 		    user_prompt = *ep + 12;
 		else if (strncmp("SUDO_USER=", *ep, 10) == 0)
 		    prev_user = *ep + 10;
+		else if (strncmp("SUDO_ASKPASS=", *ep, 13) == 0)
+		    user_askpass = *ep + 13;
 		break;
-
 	    }
     }
 
@@ -810,6 +825,9 @@ parse_args(argc, argv)
 	    }
 
 	    switch (NewArgv[0][1]) {
+		case 'A':
+		    SET(tgetpass_flags, TGP_ASKPASS);
+		    break;
 		case 'p':
 		    /* Must have an associated prompt. */
 		    if (NewArgv[1] == NULL)

sudo.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1993-1996, 1998-2005, 2007
+ * Copyright (c) 1993-1996, 1998-2005, 2007-2008
  *	Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -54,6 +54,8 @@ struct sudo_user {
     char *cmnd_safe;
     char *class_name;
     char *krb5_ccname;
+    char *display;
+    char *askpass;
     int   ngroups;
     GETGROUPS_T *groups;
     struct list_member *env_vars;
@@ -147,6 +149,8 @@ struct sudo_user {
 #define user_host		(sudo_user.host)
 #define user_shost		(sudo_user.shost)
 #define user_ccname		(sudo_user.krb5_ccname)
+#define user_display		(sudo_user.display)
+#define user_askpass		(sudo_user.askpass)
 #define safe_cmnd		(sudo_user.cmnd_safe)
 #define login_class		(sudo_user.class_name)
 #define runas_pw		(sudo_user._runas_pw)
@@ -174,6 +178,7 @@ struct sudo_user {
  */
 #define TGP_ECHO	0x01		/* leave echo on when reading passwd */
 #define TGP_STDIN	0x02		/* read from stdin, not /dev/tty */
+#define TGP_ASKPASS	0x03		/* read from askpass helper program */
 
 struct lbuf;
 struct passwd;

sudo_usage.h.in

@@ -5,9 +5,9 @@
  * Usage strings for sudo.  These are here because we
  * need to be able to substitute values from configure.
  */
-#define SUDO_USAGE1 " -h | -K | -k | -L | -V | -v"
+#define SUDO_USAGE1 " [-A] -h | -K | -k | -L | -V | -v"
-#define SUDO_USAGE2 " -l[l] [-g groupname|#gid] [-U username] [-u username|#uid] [-g groupname|#gid] [command]"
+#define SUDO_USAGE2 " -l[l] [-A] [-g groupname|#gid] [-U username] [-u username|#uid] [-g groupname|#gid] [command]"
-#define SUDO_USAGE3 " [-bEHPS] @BSDAUTH_USAGE@@SELINUX_USAGE@[-C fd] @LOGINCAP_USAGE@[-g groupname|#gid] [-p prompt] [-u username|#uid] [-g groupname|#gid] [VAR=value] [-i|-s] [<command>]"
+#define SUDO_USAGE3 " [-AbEHPS] @BSDAUTH_USAGE@@SELINUX_USAGE@[-C fd] @LOGINCAP_USAGE@[-g groupname|#gid] [-p prompt] [-u username|#uid] [-g groupname|#gid] [VAR=value] [-i|-s] [<command>]"
-#define SUDO_USAGE4 " -e [-S] @BSDAUTH_USAGE@@SELINUX_USAGE@[-C fd] @LOGINCAP_USAGE@[-g groupname|#gid] [-p prompt] [-u username|#uid] file ..."
+#define SUDO_USAGE4 " -e [-AS] @BSDAUTH_USAGE@@SELINUX_USAGE@[-C fd] @LOGINCAP_USAGE@[-g groupname|#gid] [-p prompt] [-u username|#uid] file ..."
 
 #endif /* _SUDO_USAGE_H */

tgetpass.c

@@ -1,5 +1,6 @@
 /*
- * Copyright (c) 1996, 1998-2005 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 1996, 1998-2005, 2007-2008
+ *	Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -122,6 +123,7 @@ static volatile sig_atomic_t signo;
 
 static void handler __P((int));
 static char *getln __P((int, char *, size_t));
+static char *sudo_askpass(const char *);
 
 /*
  * Like getpass(3) but with timeout and echo flags.
@@ -140,6 +142,11 @@ tgetpass(prompt, timeout, flags)
     int input, output, save_errno;
 
     (void) fflush(stdout);
+
+    /* If using a helper program to get the password, run it instead. */
+    if (ISSET(flags, TGP_ASKPASS) && user_askpass)
+	return(sudo_askpass(prompt));
+
 restart:
     signo = 0;
     pass = NULL;
@@ -232,6 +239,49 @@ restart:
     return(pass);
 }
 
+/*
+ * Fork a child and exec sudo-askpass to get the password from the user.
+ */
+static char *
+sudo_askpass(prompt)
+    const char *prompt;
+{
+    static char buf[SUDO_PASS_MAX + 1], *pass;
+    sigaction_t sa, saved_sa_pipe;
+    int pfd[2];
+    pid_t pid;
+
+    if (pipe(pfd) == -1)
+	error(1, "unable to create pipe");
+
+    if ((pid = fork()) == -1)
+	error(1, "unable to fork");
+
+    if (pid == 0) {
+	/* child, point stdout to output side of the pipe and exec askpass */
+	(void) dup2(pfd[1], STDOUT_FILENO);
+	set_perms(PERM_FULL_USER);
+	closefrom(STDERR_FILENO + 1);
+	execl(user_askpass, user_askpass, prompt, (char *)NULL);
+	warning("unable to run %s", user_askpass);
+	_exit(255);
+    }
+
+    /* Ignore SIGPIPE in case child exits prematurely */
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;
+    sa.sa_handler = SIG_IGN;
+    (void) sigaction(SIGPIPE, &sa, &saved_sa_pipe);
+
+    /* Get response from child (askpass) and restore SIGPIPE handler */
+    (void) close(pfd[1]);
+    pass = getln(pfd[0], buf, sizeof(buf));
+    (void) close(pfd[0]);
+    (void) sigaction(SIGPIPE, &saved_sa_pipe, NULL);
+
+    return(pass);
+}
+
 static char *
 getln(fd, buf, bufsiz)
     int fd;