/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set noet ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ $OpenBSD: readpassphrase.c,v 1.26 2016/10/18 12:47:18 millert 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 "libc/stdio/readpassphrase.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/calls/termios.h"
#include "libc/errno.h"
#include "libc/paths.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/consts/termios.h"
#include "libc/unistd.h"
__notice(readpassphrase_notice, "\
libbsd readpassphrase (ISC)\n\
Copyright (c) 2000-2002, 2007, 2010 Todd C. Miller <Todd.Miller@courtesan.com>");
// clang-format off
#ifndef TCSASOFT
#define TCSASOFT 0
#endif
#ifndef _NSIG
#if defined(NSIG)
#define _NSIG NSIG
#else
/* The SIGRTMAX define might be set to a function such as sysconf(). */
#define _NSIG (SIGRTMAX + 1)
#endif
#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
(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) {
const int sigttou = signo[SIGTTOU];
/* Ignore SIGTTOU generated when we are not the fg pgrp. */
while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
errno == EINTR && !signo[SIGTTOU])
continue;
signo[SIGTTOU] = sigttou;
}
(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);
if (i == SIGTSTP || i == SIGTTIN || i == 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;
}