+/* $OpenBSD: readpass.c,v 1.47 2006/08/03 03:34:42 deraadt Exp $ */
/*
- * Copyright (c) 1988, 1993
- * The Regents of the University of California. All rights reserved.
+ * Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
*
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
-RCSID("$Id$");
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#ifdef HAVE_PATHS_H
+# include <paths.h>
+#endif
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
#include "xmalloc.h"
+#include "misc.h"
+#include "pathnames.h"
+#include "log.h"
#include "ssh.h"
+#include "uidswap.h"
-volatile int intr;
-
-void
-intcatch()
+static char *
+ssh_askpass(char *askpass, const char *msg)
{
- intr = 1;
+ pid_t pid;
+ size_t len;
+ char *pass;
+ int p[2], status, ret;
+ char buf[1024];
+
+ if (fflush(stdout) != 0)
+ error("ssh_askpass: fflush: %s", strerror(errno));
+ if (askpass == NULL)
+ fatal("internal error: askpass undefined");
+ if (pipe(p) < 0) {
+ error("ssh_askpass: pipe: %s", strerror(errno));
+ return NULL;
+ }
+ if ((pid = fork()) < 0) {
+ error("ssh_askpass: fork: %s", strerror(errno));
+ return NULL;
+ }
+ if (pid == 0) {
+ permanently_drop_suid(getuid());
+ close(p[0]);
+ if (dup2(p[1], STDOUT_FILENO) < 0)
+ fatal("ssh_askpass: dup2: %s", strerror(errno));
+ execlp(askpass, askpass, msg, (char *) 0);
+ fatal("ssh_askpass: exec(%s): %s", askpass, strerror(errno));
+ }
+ close(p[1]);
+
+ len = ret = 0;
+ do {
+ ret = read(p[0], buf + len, sizeof(buf) - 1 - len);
+ if (ret == -1 && errno == EINTR)
+ continue;
+ if (ret <= 0)
+ break;
+ len += ret;
+ } while (sizeof(buf) - 1 - len > 0);
+ buf[len] = '\0';
+
+ close(p[0]);
+ while (waitpid(pid, &status, 0) < 0)
+ if (errno != EINTR)
+ break;
+
+ if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+ memset(buf, 0, sizeof(buf));
+ return NULL;
+ }
+
+ buf[strcspn(buf, "\r\n")] = '\0';
+ pass = xstrdup(buf);
+ memset(buf, 0, sizeof(buf));
+ return pass;
}
/*
- * Reads a passphrase from /dev/tty with echo turned off. Returns the
- * passphrase (allocated with xmalloc), being very careful to ensure that
- * no other userland buffer is storing the password.
+ * Reads a passphrase from /dev/tty with echo turned off/on. Returns the
+ * passphrase (allocated with xmalloc). Exits if EOF is encountered. If
+ * RP_ALLOW_STDIN is set, the passphrase will be read from stdin if no
+ * tty is available
*/
char *
-read_passphrase(const char *prompt, int from_stdin)
+read_passphrase(const char *prompt, int flags)
{
- char buf[1024], *p, ch;
- struct termios tio, saved_tio;
- sigset_t oset, nset;
- struct sigaction sa, osa;
- int input, output, echo = 0;
-
- if (from_stdin) {
- input = STDIN_FILENO;
- output = STDERR_FILENO;
- } else
- input = output = open("/dev/tty", O_RDWR);
-
- if (input == -1)
- fatal("You have no controlling tty. Cannot read passphrase.\n");
-
- /* block signals, get terminal modes and turn off echo */
- sigemptyset(&nset);
- sigaddset(&nset, SIGTSTP);
- (void) sigprocmask(SIG_BLOCK, &nset, &oset);
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = intcatch;
- (void) sigaction(SIGINT, &sa, &osa);
-
- intr = 0;
-
- if (tcgetattr(input, &saved_tio) == 0 && (saved_tio.c_lflag & ECHO)) {
- echo = 1;
- tio = saved_tio;
- tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
- (void) tcsetattr(input, TCSANOW, &tio);
+ char *askpass = NULL, *ret, buf[1024];
+ int rppflags, use_askpass = 0, ttyfd;
+
+ rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
+ if (flags & RP_USE_ASKPASS)
+ use_askpass = 1;
+ else if (flags & RP_ALLOW_STDIN) {
+ if (!isatty(STDIN_FILENO)) {
+ debug("read_passphrase: stdin is not a tty");
+ use_askpass = 1;
+ }
+ } else {
+ rppflags |= RPP_REQUIRE_TTY;
+ ttyfd = open(_PATH_TTY, O_RDWR);
+ if (ttyfd >= 0)
+ close(ttyfd);
+ else {
+ debug("read_passphrase: can't open %s: %s", _PATH_TTY,
+ strerror(errno));
+ use_askpass = 1;
+ }
}
- fflush(stdout);
+ if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
+ return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
- (void)write(output, prompt, strlen(prompt));
- for (p = buf; read(input, &ch, 1) == 1 && ch != '\n';) {
- if (intr)
- break;
- if (p < buf + sizeof(buf) - 1)
- *p++ = ch;
+ if (use_askpass && getenv("DISPLAY")) {
+ if (getenv(SSH_ASKPASS_ENV))
+ askpass = getenv(SSH_ASKPASS_ENV);
+ else
+ askpass = _PATH_SSH_ASKPASS_DEFAULT;
+ if ((ret = ssh_askpass(askpass, prompt)) == NULL)
+ if (!(flags & RP_ALLOW_EOF))
+ return xstrdup("");
+ return ret;
}
- *p = '\0';
- if (!intr)
- (void)write(output, "\n", 1);
-
- /* restore terminal modes and allow signals */
- if (echo)
- tcsetattr(input, TCSANOW, &saved_tio);
- (void) sigprocmask(SIG_SETMASK, &oset, NULL);
- (void) sigaction(SIGINT, &osa, NULL);
-
- if (intr) {
- kill(getpid(), SIGINT);
- sigemptyset(&nset);
- /* XXX tty has not neccessarily drained by now? */
- sigsuspend(&nset);
+
+ if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
+ if (flags & RP_ALLOW_EOF)
+ return NULL;
+ return xstrdup("");
}
- if (!from_stdin)
- (void)close(input);
- p = xstrdup(buf);
- memset(buf, 0, sizeof(buf));
- return (p);
+ ret = xstrdup(buf);
+ memset(buf, 'x', sizeof buf);
+ return ret;
+}
+
+int
+ask_permission(const char *fmt, ...)
+{
+ va_list args;
+ char *p, prompt[1024];
+ int allowed = 0;
+
+ va_start(args, fmt);
+ vsnprintf(prompt, sizeof(prompt), fmt, args);
+ va_end(args);
+
+ p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
+ if (p != NULL) {
+ /*
+ * Accept empty responses and responses consisting
+ * of the word "yes" as affirmative.
+ */
+ if (*p == '\0' || *p == '\n' ||
+ strcasecmp(p, "yes") == 0)
+ allowed = 1;
+ xfree(p);
+ }
+
+ return (allowed);
}
andersk / openssh.git / blobdiff