--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compat/readpassphrase.c	Thu Jan 19 22:39:51 2017 +0100
@@ -0,0 +1,209 @@
+/*	$OpenBSD: readpassphrase.c,v 1.24 2013/11/24 23:51:29 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2000-2002, 2007, 2010
+ *	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
+ * 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.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#ifdef	HAVE_PATHS_H
+#include <paths.h>
+#endif /* HAVE_PATHS_H */
+#include <pwd.h>
+#include <signal.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include "readpassphrase.h"
+
+#ifndef TCSASOFT
+#define TCSASOFT 0
+#endif /* !TCSASOFT */
+
+#ifndef	_NSIG
+#ifdef NSIG
+#define	_NSIG NSIG
+#else /* NSIG */
+#define	_NSIG 128
+#endif /* NSIG */
+#endif /* !_NSIG */
+
+#ifndef	_PATH_TTY
+#define	_PATH_TTY	"/dev/tty"
+#endif
+
+static volatile sig_atomic_t signo[_NSIG];
+
+static void handler(int);
+
+char *
+readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
+{
+	ssize_t nr;
+	int input, output, save_errno, i, need_restart;
+	char ch, *p, *end;
+	struct termios term, oterm;
+	struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
+	struct sigaction savetstp, savettin, savettou, savepipe;
+
+	/* I suppose we could alloc on demand in this case (XXX). */
+	if (bufsiz == 0) {
+		errno = EINVAL;
+		return(NULL);
+	}
+
+restart:
+	for (i = 0; i < _NSIG; i++)
+		signo[i] = 0;
+	nr = -1;
+	save_errno = 0;
+	need_restart = 0;
+	/*
+	 * Read and write to /dev/tty if available.  If not, read from
+	 * stdin and write to stderr unless a tty is required.
+	 */
+	if ((flags & RPP_STDIN) ||
+	    (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
+		if (flags & RPP_REQUIRE_TTY) {
+			errno = ENOTTY;
+			return(NULL);
+		}
+		input = STDIN_FILENO;
+		output = STDERR_FILENO;
+	}
+
+	/*
+	 * Turn off echo if possible.
+	 * If we are using a tty but are not the foreground pgrp this will
+	 * generate SIGTTOU, so do it *before* installing the signal handlers.
+	 */
+	if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
+		memcpy(&term, &oterm, sizeof(term));
+		if (!(flags & RPP_ECHO_ON))
+			term.c_lflag &= ~(ECHO | ECHONL);
+#ifdef VSTATUS
+		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
+			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
+#endif /* VSTATUS */
+		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
+	} else {
+		memset(&term, 0, sizeof(term));
+		term.c_lflag |= ECHO;
+		memset(&oterm, 0, sizeof(oterm));
+		oterm.c_lflag |= ECHO;
+	}
+
+	/*
+	 * Catch signals that would otherwise cause the user to end
+	 * up with echo turned off in the shell.  Don't worry about
+	 * things like SIGXCPU and SIGVTALRM for now.
+	 */
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = 0;		/* don't restart system calls */
+	sa.sa_handler = handler;
+	(void)sigaction(SIGALRM, &sa, &savealrm);
+	(void)sigaction(SIGHUP, &sa, &savehup);
+	(void)sigaction(SIGINT, &sa, &saveint);
+	(void)sigaction(SIGPIPE, &sa, &savepipe);
+	(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 (!(flags & RPP_STDIN))
+		(void)write(output, prompt, strlen(prompt));
+	end = buf + bufsiz - 1;
+	p = buf;
+	while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
+		if (p < end) {
+			if ((flags & RPP_SEVENBIT))
+				ch &= 0x7f;
+			if (isalpha((unsigned char)ch)) {
+				if ((flags & RPP_FORCELOWER))
+					ch = (char)tolower((unsigned char)ch);
+				if ((flags & RPP_FORCEUPPER))
+					ch = (char)toupper((unsigned char)ch);
+			}
+			*p++ = ch;
+		}
+	}
+	*p = '\0';
+	save_errno = errno;
+	if (!(term.c_lflag & ECHO))
+		(void)write(output, "\n", 1);
+
+	/* Restore old terminal settings and signals. */
+	if (memcmp(&term, &oterm, sizeof(term)) != 0) {
+		while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
+		    errno == EINTR && !signo[SIGTTOU])
+			continue;
+	}
+	(void)sigaction(SIGALRM, &savealrm, NULL);
+	(void)sigaction(SIGHUP, &savehup, NULL);
+	(void)sigaction(SIGINT, &saveint, NULL);
+	(void)sigaction(SIGQUIT, &savequit, NULL);
+	(void)sigaction(SIGPIPE, &savepipe, NULL);
+	(void)sigaction(SIGTERM, &saveterm, NULL);
+	(void)sigaction(SIGTSTP, &savetstp, NULL);
+	(void)sigaction(SIGTTIN, &savettin, NULL);
+	(void)sigaction(SIGTTOU, &savettou, NULL);
+	if (input != STDIN_FILENO)
+		(void)close(input);
+
+	/*
+	 * 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]) {
+			kill(getpid(), i);
+			switch (i) {
+			case SIGTSTP:
+			case SIGTTIN:
+			case SIGTTOU:
+				need_restart = 1;
+			}
+		}
+	}
+	if (need_restart)
+		goto restart;
+
+	if (save_errno)
+		errno = save_errno;
+	return(nr == -1 ? NULL : buf);
+}
+
+#if 0
+char *
+getpass(const char *prompt)
+{
+	static char buf[_PASSWORD_LEN + 1];
+
+	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
+}
+#endif
+
+static void handler(int s)
+{
+
+	signo[s] = 1;
+}