Adding upstream version 1:9.6p1.upstream/1%9.6p1

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

1 files changed, 332 insertions, 0 deletions

diff --git a/readpass.c b/readpass.c
new file mode 100644
index 0000000..b52f3d6
--- /dev/null
+++ b/readpass.c
@@ -0,0 +1,332 @@
+/* $OpenBSD: readpass.c,v 1.70 2022/05/27 04:27:49 dtucker Exp $ */
+/*
+ * 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
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 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.
+ *
+ * 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"
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#ifdef HAVE_PATHS_H
+# include <paths.h>
+#endif
+#include <signal.h>
+#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"
+
+static char *
+ssh_askpass(char *askpass, const char *msg, const char *env_hint)
+{
+	pid_t pid, ret;
+	size_t len;
+	char *pass;
+	int p[2], status;
+	char buf[1024];
+	void (*osigchld)(int);
+
+	if (fflush(stdout) != 0)
+		error_f("fflush: %s", strerror(errno));
+	if (askpass == NULL)
+		fatal("internal error: askpass undefined");
+	if (pipe(p) == -1) {
+		error_f("pipe: %s", strerror(errno));
+		return NULL;
+	}
+	osigchld = ssh_signal(SIGCHLD, SIG_DFL);
+	if ((pid = fork()) == -1) {
+		error_f("fork: %s", strerror(errno));
+		ssh_signal(SIGCHLD, osigchld);
+		return NULL;
+	}
+	if (pid == 0) {
+		close(p[0]);
+		if (dup2(p[1], STDOUT_FILENO) == -1)
+			fatal_f("dup2: %s", strerror(errno));
+		if (env_hint != NULL)
+			setenv("SSH_ASKPASS_PROMPT", env_hint, 1);
+		execlp(askpass, askpass, msg, (char *)NULL);
+		fatal_f("exec(%s): %s", askpass, strerror(errno));
+	}
+	close(p[1]);
+
+	len = 0;
+	do {
+		ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
+
+		if (r == -1 && errno == EINTR)
+			continue;
+		if (r <= 0)
+			break;
+		len += r;
+	} while (sizeof(buf) - 1 - len > 0);
+	buf[len] = '\0';
+
+	close(p[0]);
+	while ((ret = waitpid(pid, &status, 0)) == -1)
+		if (errno != EINTR)
+			break;
+	ssh_signal(SIGCHLD, osigchld);
+	if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		explicit_bzero(buf, sizeof(buf));
+		return NULL;
+	}
+
+	buf[strcspn(buf, "\r\n")] = '\0';
+	pass = xstrdup(buf);
+	explicit_bzero(buf, sizeof(buf));
+	return pass;
+}
+
+/* private/internal read_passphrase flags */
+#define RP_ASK_PERMISSION	0x8000 /* pass hint to askpass for confirm UI */
+
+/*
+ * 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 or askpass program is available
+ */
+char *
+read_passphrase(const char *prompt, int flags)
+{
+	char cr = '\r', *askpass = NULL, *ret, buf[1024];
+	int rppflags, ttyfd, use_askpass = 0, allow_askpass = 0;
+	const char *askpass_hint = NULL;
+	const char *s;
+
+	if ((s = getenv("DISPLAY")) != NULL)
+		allow_askpass = *s != '\0';
+	if ((s = getenv(SSH_ASKPASS_REQUIRE_ENV)) != NULL) {
+		if (strcasecmp(s, "force") == 0) {
+			use_askpass = 1;
+			allow_askpass = 1;
+		} else if (strcasecmp(s, "prefer") == 0)
+			use_askpass = allow_askpass;
+		else if (strcasecmp(s, "never") == 0)
+			allow_askpass = 0;
+	}
+
+	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
+	if (use_askpass)
+		debug_f("requested to askpass");
+	else if (flags & RP_USE_ASKPASS)
+		use_askpass = 1;
+	else if (flags & RP_ALLOW_STDIN) {
+		if (!isatty(STDIN_FILENO)) {
+			debug_f("stdin is not a tty");
+			use_askpass = 1;
+		}
+	} else {
+		rppflags |= RPP_REQUIRE_TTY;
+		ttyfd = open(_PATH_TTY, O_RDWR);
+		if (ttyfd >= 0) {
+			/*
+			 * If we're on a tty, ensure that show the prompt at
+			 * the beginning of the line. This will hopefully
+			 * clobber any password characters the user has
+			 * optimistically typed before echo is disabled.
+			 */
+			(void)write(ttyfd, &cr, 1);
+			close(ttyfd);
+		} else {
+			debug_f("can't open %s: %s", _PATH_TTY,
+			    strerror(errno));
+			use_askpass = 1;
+		}
+	}
+
+	if ((flags & RP_USE_ASKPASS) && !allow_askpass)
+		return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
+
+	if (use_askpass && allow_askpass) {
+		if (getenv(SSH_ASKPASS_ENV))
+			askpass = getenv(SSH_ASKPASS_ENV);
+		else
+			askpass = _PATH_SSH_ASKPASS_DEFAULT;
+		if ((flags & RP_ASK_PERMISSION) != 0)
+			askpass_hint = "confirm";
+		if ((ret = ssh_askpass(askpass, prompt, askpass_hint)) == NULL)
+			if (!(flags & RP_ALLOW_EOF))
+				return xstrdup("");
+		return ret;
+	}
+
+	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
+		if (flags & RP_ALLOW_EOF)
+			return NULL;
+		return xstrdup("");
+	}
+
+	ret = xstrdup(buf);
+	explicit_bzero(buf, 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|RP_ASK_PERMISSION);
+	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;
+		free(p);
+	}
+
+	return (allowed);
+}
+
+static void
+writemsg(const char *msg)
+{
+	(void)write(STDERR_FILENO, "\r", 1);
+	(void)write(STDERR_FILENO, msg, strlen(msg));
+	(void)write(STDERR_FILENO, "\r\n", 2);
+}
+
+struct notifier_ctx {
+	pid_t pid;
+	void (*osigchld)(int);
+};
+
+struct notifier_ctx *
+notify_start(int force_askpass, const char *fmt, ...)
+{
+	va_list args;
+	char *prompt = NULL;
+	pid_t pid = -1;
+	void (*osigchld)(int) = NULL;
+	const char *askpass, *s;
+	struct notifier_ctx *ret = NULL;
+
+	va_start(args, fmt);
+	xvasprintf(&prompt, fmt, args);
+	va_end(args);
+
+	if (fflush(NULL) != 0)
+		error_f("fflush: %s", strerror(errno));
+	if (!force_askpass && isatty(STDERR_FILENO)) {
+		writemsg(prompt);
+		goto out_ctx;
+	}
+	if ((askpass = getenv("SSH_ASKPASS")) == NULL)
+		askpass = _PATH_SSH_ASKPASS_DEFAULT;
+	if (*askpass == '\0') {
+		debug3_f("cannot notify: no askpass");
+		goto out;
+	}
+	if (getenv("DISPLAY") == NULL &&
+	    ((s = getenv(SSH_ASKPASS_REQUIRE_ENV)) == NULL ||
+	    strcmp(s, "force") != 0)) {
+		debug3_f("cannot notify: no display");
+		goto out;
+	}
+	osigchld = ssh_signal(SIGCHLD, SIG_DFL);
+	if ((pid = fork()) == -1) {
+		error_f("fork: %s", strerror(errno));
+		ssh_signal(SIGCHLD, osigchld);
+		free(prompt);
+		return NULL;
+	}
+	if (pid == 0) {
+		if (stdfd_devnull(1, 1, 0) == -1)
+			fatal_f("stdfd_devnull failed");
+		closefrom(STDERR_FILENO + 1);
+		setenv("SSH_ASKPASS_PROMPT", "none", 1); /* hint to UI */
+		execlp(askpass, askpass, prompt, (char *)NULL);
+		error_f("exec(%s): %s", askpass, strerror(errno));
+		_exit(1);
+		/* NOTREACHED */
+	}
+ out_ctx:
+	if ((ret = calloc(1, sizeof(*ret))) == NULL) {
+		if (pid != -1)
+			kill(pid, SIGTERM);
+		fatal_f("calloc failed");
+	}
+	ret->pid = pid;
+	ret->osigchld = osigchld;
+ out:
+	free(prompt);
+	return ret;
+}
+
+void
+notify_complete(struct notifier_ctx *ctx, const char *fmt, ...)
+{
+	int ret;
+	char *msg = NULL;
+	va_list args;
+
+	if (ctx != NULL && fmt != NULL && ctx->pid == -1) {
+		/*
+		 * notify_start wrote to stderr, so send conclusion message
+		 * there too
+		*/
+		va_start(args, fmt);
+		xvasprintf(&msg, fmt, args);
+		va_end(args);
+		writemsg(msg);
+		free(msg);
+	}
+
+	if (ctx == NULL || ctx->pid <= 0) {
+		free(ctx);
+		return;
+	}
+	kill(ctx->pid, SIGTERM);
+	while ((ret = waitpid(ctx->pid, NULL, 0)) == -1) {
+		if (errno != EINTR)
+			break;
+	}
+	if (ret == -1)
+		fatal_f("waitpid: %s", strerror(errno));
+	ssh_signal(SIGCHLD, ctx->osigchld);
+	free(ctx);
+}