120 lines
3.0 KiB
C
120 lines
3.0 KiB
C
/*
|
|
*
|
|
* readpass.c
|
|
*
|
|
* Author: Tatu Ylonen <ylo@cs.hut.fi>
|
|
*
|
|
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
|
|
* All rights reserved
|
|
*
|
|
* Created: Mon Jul 10 22:08:59 1995 ylo
|
|
*
|
|
* Functions for reading passphrases and passwords.
|
|
*
|
|
*/
|
|
|
|
#include "includes.h"
|
|
RCSID("$Id: readpass.c,v 1.3 1999/11/25 00:54:59 damien Exp $");
|
|
|
|
#include "xmalloc.h"
|
|
#include "ssh.h"
|
|
|
|
/* Saved old terminal mode for read_passphrase. */
|
|
static struct termios saved_tio;
|
|
|
|
/* Old interrupt signal handler for read_passphrase. */
|
|
static void (*old_handler) (int sig) = NULL;
|
|
|
|
/* Interrupt signal handler for read_passphrase. */
|
|
|
|
void
|
|
intr_handler(int sig)
|
|
{
|
|
/* Restore terminal modes. */
|
|
tcsetattr(fileno(stdin), TCSANOW, &saved_tio);
|
|
/* Restore the old signal handler. */
|
|
signal(sig, old_handler);
|
|
/* Resend the signal, with the old handler. */
|
|
kill(getpid(), sig);
|
|
}
|
|
|
|
/*
|
|
* Reads a passphrase from /dev/tty with echo turned off. Returns the
|
|
* passphrase (allocated with xmalloc). Exits if EOF is encountered. The
|
|
* passphrase if read from stdin if from_stdin is true (as is the case with
|
|
* ssh-keygen).
|
|
*/
|
|
|
|
char *
|
|
read_passphrase(const char *prompt, int from_stdin)
|
|
{
|
|
char buf[1024], *cp;
|
|
struct termios tio;
|
|
FILE *f;
|
|
|
|
if (from_stdin)
|
|
f = stdin;
|
|
else {
|
|
/*
|
|
* Read the passphrase from /dev/tty to make it possible to
|
|
* ask it even when stdin has been redirected.
|
|
*/
|
|
f = fopen("/dev/tty", "r");
|
|
if (!f) {
|
|
/* No controlling terminal and no DISPLAY. Nowhere to read. */
|
|
fprintf(stderr, "You have no controlling tty and no DISPLAY. Cannot read passphrase.\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
/* Display the prompt (on stderr because stdout might be redirected). */
|
|
fflush(stdout);
|
|
fprintf(stderr, "%s", prompt);
|
|
fflush(stderr);
|
|
|
|
/* Get terminal modes. */
|
|
tcgetattr(fileno(f), &tio);
|
|
saved_tio = tio;
|
|
/* Save signal handler and set the new handler. */
|
|
old_handler = signal(SIGINT, intr_handler);
|
|
|
|
/* Set new terminal modes disabling all echo. */
|
|
tio.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
|
|
tcsetattr(fileno(f), TCSANOW, &tio);
|
|
|
|
/* Read the passphrase from the terminal. */
|
|
if (fgets(buf, sizeof(buf), f) == NULL) {
|
|
/* Got EOF. Just exit. */
|
|
/* Restore terminal modes. */
|
|
tcsetattr(fileno(f), TCSANOW, &saved_tio);
|
|
/* Restore the signal handler. */
|
|
signal(SIGINT, old_handler);
|
|
/* Print a newline (the prompt probably didn\'t have one). */
|
|
fprintf(stderr, "\n");
|
|
/* Close the file. */
|
|
if (f != stdin)
|
|
fclose(f);
|
|
exit(1);
|
|
}
|
|
/* Restore terminal modes. */
|
|
tcsetattr(fileno(f), TCSANOW, &saved_tio);
|
|
/* Restore the signal handler. */
|
|
(void) signal(SIGINT, old_handler);
|
|
/* Remove newline from the passphrase. */
|
|
if (strchr(buf, '\n'))
|
|
*strchr(buf, '\n') = 0;
|
|
/* Allocate a copy of the passphrase. */
|
|
cp = xstrdup(buf);
|
|
/*
|
|
* Clear the buffer so we don\'t leave copies of the passphrase
|
|
* laying around.
|
|
*/
|
|
memset(buf, 0, sizeof(buf));
|
|
/* Print a newline since the prompt probably didn\'t have one. */
|
|
fprintf(stderr, "\n");
|
|
/* Close the file. */
|
|
if (f != stdin)
|
|
fclose(f);
|
|
return cp;
|
|
}
|