X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/700318f39b6ee399768d0ed0ee2b2935410c8b0b..d89322b8b73f64b1c6692a7e2f205caf86385278:/openssh/readpass.c

diff --git a/openssh/readpass.c b/openssh/readpass.c
index 96b7e84..bd144c2 100644
--- a/openssh/readpass.c
+++ b/openssh/readpass.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: readpass.c,v 1.47 2006/08/03 03:34:42 deraadt Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -23,13 +24,27 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: readpass.c,v 1.27 2002/03/26 15:58:46 markus Exp $");
+
+#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 "readpass.h"
+#include "misc.h"
 #include "pathnames.h"
 #include "log.h"
 #include "ssh.h"
+#include "uidswap.h"
 
 static char *
 ssh_askpass(char *askpass, const char *msg)
@@ -46,15 +61,14 @@ ssh_askpass(char *askpass, const char *msg)
 		fatal("internal error: askpass undefined");
 	if (pipe(p) < 0) {
 		error("ssh_askpass: pipe: %s", strerror(errno));
-		return xstrdup("");
+		return NULL;
 	}
 	if ((pid = fork()) < 0) {
 		error("ssh_askpass: fork: %s", strerror(errno));
-		return xstrdup("");
+		return NULL;
 	}
 	if (pid == 0) {
-		seteuid(getuid());
-		setuid(getuid());
+		permanently_drop_suid(getuid());
 		close(p[0]);
 		if (dup2(p[1], STDOUT_FILENO) < 0)
 			fatal("ssh_askpass: dup2: %s", strerror(errno));
@@ -79,6 +93,11 @@ ssh_askpass(char *askpass, const char *msg)
 		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));
@@ -98,24 +117,37 @@ read_passphrase(const char *prompt, int flags)
 	int rppflags, use_askpass = 0, ttyfd;
 
 	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
-	if (flags & RP_ALLOW_STDIN) {
-		if (!isatty(STDIN_FILENO))
+	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
+		else {
+			debug("read_passphrase: can't open %s: %s", _PATH_TTY,
+			    strerror(errno));
 			use_askpass = 1;
+		}
 	}
 
+	if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
+		return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
+
 	if (use_askpass && getenv("DISPLAY")) {
 		if (getenv(SSH_ASKPASS_ENV))
 			askpass = getenv(SSH_ASKPASS_ENV);
 		else
 			askpass = _PATH_SSH_ASKPASS_DEFAULT;
-		return ssh_askpass(askpass, prompt);
+		if ((ret = ssh_askpass(askpass, prompt)) == NULL)
+			if (!(flags & RP_ALLOW_EOF))
+				return xstrdup("");
+		return ret;
 	}
 
 	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
@@ -128,3 +160,29 @@ read_passphrase(const char *prompt, int flags)
 	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);
+}