Adding upstream version 1.9.15p5.upstream/1.9.15p5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 466 insertions, 0 deletions

diff --git a/src/tgetpass.c b/src/tgetpass.c
new file mode 100644
index 0000000..c9bc644
--- /dev/null
+++ b/src/tgetpass.c
@@ -0,0 +1,466 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 1996, 1998-2005, 2007-2021
+ *	Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#ifdef __TANDEM
+# include <floss.h>
+#endif
+
+#include <config.h>
+
+#include <sys/wait.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <fcntl.h>
+
+#include <sudo.h>
+#include <sudo_plugin.h>
+
+enum tgetpass_errval {
+    TGP_ERRVAL_NOERROR,
+    TGP_ERRVAL_TIMEOUT,
+    TGP_ERRVAL_NOPASSWORD,
+    TGP_ERRVAL_READERROR
+};
+
+static volatile sig_atomic_t signo[NSIG];
+
+static void tgetpass_handler(int);
+static char *getln(int, char *, size_t, bool, enum tgetpass_errval *);
+static char *sudo_askpass(const char *, const char *);
+
+static int
+suspend(int sig, struct sudo_conv_callback *callback)
+{
+    int ret = 0;
+    debug_decl(suspend, SUDO_DEBUG_CONV);
+
+    if (callback != NULL && SUDO_API_VERSION_GET_MAJOR(callback->version) != SUDO_CONV_CALLBACK_VERSION_MAJOR) {
+	sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO,
+	    "callback major version mismatch, expected %u, got %u",
+	    SUDO_CONV_CALLBACK_VERSION_MAJOR,
+	    SUDO_API_VERSION_GET_MAJOR(callback->version));
+	callback = NULL;
+    }
+
+    if (callback != NULL && callback->on_suspend != NULL) {
+	if (callback->on_suspend(sig, callback->closure) == -1)
+	    ret = -1;
+    }
+    kill(getpid(), sig);
+    if (callback != NULL && callback->on_resume != NULL) {
+	if (callback->on_resume(sig, callback->closure) == -1)
+	    ret = -1;
+    }
+    debug_return_int(ret);
+}
+
+static void
+tgetpass_display_error(enum tgetpass_errval errval)
+{
+    debug_decl(tgetpass_display_error, SUDO_DEBUG_CONV);
+
+    switch (errval) {
+    case TGP_ERRVAL_NOERROR:
+	break;
+    case TGP_ERRVAL_TIMEOUT:
+	sudo_warnx("%s", U_("timed out reading password"));
+	break;
+    case TGP_ERRVAL_NOPASSWORD:
+	sudo_warnx("%s", U_("no password was provided"));
+	break;
+    case TGP_ERRVAL_READERROR:
+	sudo_warn("%s", U_("unable to read password"));
+	break;
+    }
+    debug_return;
+}
+
+/*
+ * Like getpass(3) but with timeout and echo flags.
+ */
+char *
+tgetpass(const char *prompt, int timeout, unsigned int flags,
+    struct sudo_conv_callback *callback)
+{
+    struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
+    struct sigaction savetstp, savettin, savettou;
+    char *pass;
+    static const char *askpass;
+    static char buf[SUDO_CONV_REPL_MAX + 1];
+    int i, input, output, save_errno, ttyfd;
+    bool feedback, need_restart, neednl;
+    enum tgetpass_errval errval;
+    debug_decl(tgetpass, SUDO_DEBUG_CONV);
+
+    (void) fflush(stdout);
+
+    if (askpass == NULL) {
+	askpass = getenv_unhooked("SUDO_ASKPASS");
+	if (askpass == NULL || *askpass == '\0')
+	    askpass = sudo_conf_askpass_path();
+    }
+
+restart:
+    /* Try to open /dev/tty if we are going to be using it for I/O. */
+    ttyfd = -1;
+    if (!ISSET(flags, TGP_STDIN|TGP_ASKPASS)) {
+	/* If no tty present and we need to disable echo, try askpass. */
+	ttyfd = open(_PATH_TTY, O_RDWR);
+	if (ttyfd == -1 && !ISSET(flags, TGP_ECHO|TGP_NOECHO_TRY)) {
+	    if (askpass == NULL || getenv_unhooked("DISPLAY") == NULL) {
+		sudo_warnx("%s",
+		    U_("a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper"));
+		debug_return_str(NULL);
+	    }
+	    SET(flags, TGP_ASKPASS);
+	}
+    }
+
+    /* If using a helper program to get the password, run it instead. */
+    if (ISSET(flags, TGP_ASKPASS)) {
+	if (askpass == NULL || *askpass == '\0')
+	    sudo_fatalx("%s",
+		U_("no askpass program specified, try setting SUDO_ASKPASS"));
+	debug_return_str_masked(sudo_askpass(askpass, prompt));
+    }
+
+    /* Reset state. */
+    for (i = 0; i < NSIG; i++)
+	signo[i] = 0;
+    pass = NULL;
+    save_errno = 0;
+    neednl = false;
+    need_restart = false;
+    feedback = false;
+
+    /* Use tty for reading/writing if available else use stdin/stderr. */
+    if (ttyfd == -1) {
+	input = STDIN_FILENO;
+	output = STDERR_FILENO;
+	/* Don't try to mask password if /dev/tty is not available. */
+	CLR(flags, TGP_MASK);
+    } else {
+	input = ttyfd;
+	output = ttyfd;
+    }
+
+    /*
+     * If we are using a tty but are not the foreground pgrp this will
+     * return EINTR.  We send ourself SIGTTOU bracketed by callbacks.
+     */
+    if (!ISSET(flags, TGP_ECHO)) {
+	for (;;) {
+	    if (ISSET(flags, TGP_MASK))
+		neednl = feedback = sudo_term_cbreak(input);
+	    else
+		neednl = sudo_term_noecho(input);
+	    if (neednl || errno != EINTR)
+		break;
+	    /* Received SIGTTOU, suspend the process. */
+	    if (suspend(SIGTTOU, callback) == -1) {
+		if (ttyfd != -1)
+		    (void) close(ttyfd);
+		debug_return_ptr(NULL);
+	    }
+	}
+    }
+
+    /*
+     * Catch signals that would otherwise cause the user to end
+     * up with echo turned off in the shell.
+     */
+    memset(&sa, 0, sizeof(sa));
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;	/* don't restart system calls */
+    sa.sa_handler = tgetpass_handler;
+    (void) sigaction(SIGALRM, &sa, &savealrm);
+    (void) sigaction(SIGINT, &sa, &saveint);
+    (void) sigaction(SIGHUP, &sa, &savehup);
+    (void) sigaction(SIGQUIT, &sa, &savequit);
+    (void) sigaction(SIGTERM, &sa, &saveterm);
+    (void) sigaction(SIGTSTP, &sa, &savetstp);
+    (void) sigaction(SIGTTIN, &sa, &savettin);
+    (void) sigaction(SIGTTOU, &sa, &savettou);
+
+    if (ISSET(flags, TGP_BELL) && output != STDERR_FILENO) {
+	/* Ring the bell if requested and there is a tty. */
+	if (write(output, "\a", 1) == -1)
+	    goto restore;
+    }
+    if (prompt) {
+	if (write(output, prompt, strlen(prompt)) == -1)
+	    goto restore;
+    }
+
+    if (timeout > 0)
+	alarm((unsigned int)timeout);
+    pass = getln(input, buf, sizeof(buf), feedback, &errval);
+    alarm(0);
+    save_errno = errno;
+
+    if (neednl || pass == NULL) {
+	if (write(output, "\n", 1) == -1)
+	    goto restore;
+    }
+    tgetpass_display_error(errval);
+
+restore:
+    /* Restore old signal handlers. */
+    (void) sigaction(SIGALRM, &savealrm, NULL);
+    (void) sigaction(SIGINT, &saveint, NULL);
+    (void) sigaction(SIGHUP, &savehup, NULL);
+    (void) sigaction(SIGQUIT, &savequit, NULL);
+    (void) sigaction(SIGTERM, &saveterm, NULL);
+    (void) sigaction(SIGTSTP, &savetstp, NULL);
+    (void) sigaction(SIGTTIN, &savettin, NULL);
+    (void) sigaction(SIGTTOU, &savettou, NULL);
+
+    /* Restore old tty settings. */
+    if (!ISSET(flags, TGP_ECHO)) {
+	/* Restore old tty settings if possible. */
+	if (!sudo_term_restore(input, true))
+	    sudo_warn("%s", U_("unable to restore terminal settings"));
+    }
+    if (ttyfd != -1)
+	(void) close(ttyfd);
+
+    /*
+     * If we were interrupted by a signal, resend it to ourselves
+     * now that we have restored the signal handlers.
+     */
+    for (i = 0; i < NSIG; i++) {
+	if (signo[i]) {
+	    switch (i) {
+		case SIGALRM:
+		    break;
+		case SIGTSTP:
+		case SIGTTIN:
+		case SIGTTOU:
+		    if (suspend(i, callback) == 0)
+			need_restart = true;
+		    break;
+		default:
+		    kill(getpid(), i);
+		    break;
+	    }
+	}
+    }
+    if (need_restart)
+	goto restart;
+
+    if (save_errno)
+	errno = save_errno;
+
+    debug_return_str_masked(pass);
+}
+
+/*
+ * Fork a child and exec sudo-askpass to get the password from the user.
+ */
+static char *
+sudo_askpass(const char *askpass, const char *prompt)
+{
+    static char buf[SUDO_CONV_REPL_MAX + 1], *pass;
+    const struct sudo_cred *cred = sudo_askpass_cred(NULL);
+    sigset_t chldmask;
+    enum tgetpass_errval errval;
+    int pfd[2], status;
+    pid_t child;
+    debug_decl(sudo_askpass, SUDO_DEBUG_CONV);
+
+    /* Block SIGCHLD for the duration since we call waitpid() below. */
+    sigemptyset(&chldmask);
+    sigaddset(&chldmask, SIGCHLD);
+    (void)sigprocmask(SIG_BLOCK, &chldmask, NULL);
+
+    if (pipe2(pfd, O_CLOEXEC) == -1)
+	sudo_fatal("%s", U_("unable to create pipe"));
+
+    child = sudo_debug_fork();
+    if (child == -1)
+	sudo_fatal("%s", U_("unable to fork"));
+
+    if (child == 0) {
+	/* child, set stdout to write side of the pipe */
+	if (dup3(pfd[1], STDOUT_FILENO, 0) == -1) {
+	    sudo_warn("dup3");
+	    _exit(255);
+	}
+	if (setuid(ROOT_UID) == -1)
+	    sudo_warn("setuid(%d)", ROOT_UID);
+	/* Close fds before uid change to prevent prlimit sabotage on Linux. */
+	closefrom(STDERR_FILENO + 1);
+	/* Run the askpass program with the user's original resource limits. */
+	restore_limits();
+	/* But avoid a setuid() failure on Linux due to RLIMIT_NPROC. */
+	unlimit_nproc();
+	if (setgid(cred->gid)) {
+	    sudo_warn(U_("unable to set gid to %u"), (unsigned int)cred->gid);
+	    _exit(255);
+	}
+	if (cred->ngroups != -1) {
+	    if (sudo_setgroups(cred->ngroups, cred->groups) == -1) {
+		sudo_warn("%s", U_("unable to set supplementary group IDs"));
+		_exit(255);
+	    }
+	}
+	if (setuid(cred->uid)) {
+	    sudo_warn(U_("unable to set uid to %u"), (unsigned int)cred->uid);
+	    _exit(255);
+	}
+	restore_nproc();
+	execl(askpass, askpass, prompt, (char *)NULL);
+	sudo_warn(U_("unable to run %s"), askpass);
+	_exit(255);
+    }
+
+    /* Get response from child (askpass). */
+    (void) close(pfd[1]);
+    pass = getln(pfd[0], buf, sizeof(buf), 0, &errval);
+    (void) close(pfd[0]);
+
+    tgetpass_display_error(errval);
+
+    /* Wait for child to exit. */
+    for (;;) {
+	pid_t rv = waitpid(child, &status, 0);
+	if (rv == -1 && errno != EINTR)
+	    break;
+	if (rv != -1 && !WIFSTOPPED(status))
+	    break;
+    }
+
+    if (pass == NULL)
+	errno = EINTR;	/* make cancel button simulate ^C */
+
+    /* Unblock SIGCHLD. */
+    (void)sigprocmask(SIG_UNBLOCK, &chldmask, NULL);
+
+    debug_return_str_masked(pass);
+}
+
+extern int sudo_term_eof, sudo_term_erase, sudo_term_kill;
+
+static char *
+getln(int fd, char *buf, size_t bufsiz, bool feedback,
+    enum tgetpass_errval *errval)
+{
+    size_t left = bufsiz;
+    ssize_t nr = -1;
+    char *cp = buf;
+    char c = '\0';
+    debug_decl(getln, SUDO_DEBUG_CONV);
+
+    *errval = TGP_ERRVAL_NOERROR;
+
+    if (left == 0) {
+	*errval = TGP_ERRVAL_READERROR;
+	errno = EINVAL;
+	debug_return_str(NULL);
+    }
+
+    while (--left) {
+	nr = read(fd, &c, 1);
+	if (nr != 1 || c == '\n' || c == '\r')
+	    break;
+	if (feedback) {
+	    if (c == sudo_term_eof) {
+		nr = 0;
+		break;
+	    } else if (c == sudo_term_kill) {
+		while (cp > buf) {
+		    if (write(fd, "\b \b", 3) == -1)
+			break;
+		    cp--;
+		}
+		cp = buf;
+		left = bufsiz;
+		continue;
+	    } else if (c == sudo_term_erase) {
+		if (cp > buf) {
+		    ignore_result(write(fd, "\b \b", 3));
+		    cp--;
+		    left++;
+		}
+		continue;
+	    }
+	    ignore_result(write(fd, "*", 1));
+	}
+	*cp++ = c;
+    }
+    *cp = '\0';
+    if (feedback) {
+	/* erase stars */
+	while (cp > buf) {
+	    if (write(fd, "\b \b", 3) == -1)
+		break;
+	    --cp;
+	}
+    }
+
+    switch (nr) {
+    case -1:
+	/* Read error */
+	if (errno == EINTR) {
+	    if (signo[SIGALRM] == 1)
+		*errval = TGP_ERRVAL_TIMEOUT;
+	} else {
+	    *errval = TGP_ERRVAL_READERROR;
+	}
+	debug_return_str(NULL);
+    case 0:
+	/* EOF is only an error if no bytes were read. */
+	if (left == bufsiz - 1) {
+	    *errval = TGP_ERRVAL_NOPASSWORD;
+	    debug_return_str(NULL);
+	}
+	FALLTHROUGH;
+    default:
+	debug_return_str_masked(buf);
+    }
+}
+
+static void
+tgetpass_handler(int s)
+{
+    signo[s] = 1;
+}
+
+const struct sudo_cred *
+sudo_askpass_cred(const struct sudo_cred *cred)
+{
+    static const struct sudo_cred *saved_cred;
+
+    if (cred != NULL)
+	saved_cred = cred;
+    return saved_cred;
+}