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/*
* For license terms, see the file COPYING in this directory.
*/
/***********************************************************************
module: getpass.c
project: fetchmail
programmer: Carl Harris, ceharris@mal.com
description: getpass() replacement which allows for long passwords.
This version hacked by Wilfred Teiken, allowing the
password to be piped to fetchmail.
***********************************************************************/
#include "config.h"
#include "fetchmail.h"
#include <errno.h>
#include <stdio.h>
#include <signal.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include "i18n.h"
#define INPUT_BUF_SIZE PASSWORDLEN
#include <termios.h>
static int ttyfd;
static struct termios termb;
static tcflag_t flags;
static void save_tty_state(void);
static void disable_tty_echo(void);
static void restore_tty_state(void);
static void sigint_handler(int);
static char pbuf[INPUT_BUF_SIZE];
void fm_clearpassword(void)
{
fm_safe_clearmem(pbuf, sizeof(pbuf));
}
char *fm_getpassword(const char *prompt)
{
char *p;
FILE *fi = NULL;
SIGHANDLERTYPE sig = 0; /* initialization pacifies -Wall */
int istty = isatty(0);
ttyfd = STDIN_FILENO;
/* get the file descriptor for the actual input device if it's a tty */
if (istty)
{
fi = fopen("/dev/tty", "r+");
if (fi) {
setbuf(fi, (char *)NULL);
/* store descriptor for the controlling tty */
ttyfd = fileno(fi);
} else {
report(stderr, "fm_getpassword: fopen(\"/dev/tty\", \"r+\"): %s\n", strerror(errno));
}
/* preserve tty state before turning off echo */
save_tty_state();
/* now that we have the current tty state, we can catch SIGINT and
exit gracefully */
sig = set_signal_handler(SIGINT, sigint_handler);
/* turn off echo on the tty */
disable_tty_echo();
/* display the prompt and get the input string */
fputs(prompt, stderr);
}
/* regardless of if the input is a TTY or not, read characters
* until we have a LF or an EOF, truncating if we reach full
* buffer size */
FILE *readstream = fi ? fi : stdin;
clearerr(readstream);
p = fgets(pbuf, sizeof(pbuf), readstream);
int save_errno = errno;
if (!p && !ferror(readstream)) {
// fgets() returns NULL if EOF happens early,
// so don't report error in that case
p = pbuf;
}
// Zap LF:
(void)strtok(pbuf, "\n");
if (istty)
{
/* write a newline so cursor won't appear to hang */
fprintf(stderr, "\n");
/* restore previous state of the tty */
restore_tty_state();
/* restore previous state of SIGINT */
set_signal_handler(SIGINT, sig);
if (fi) {
(void)fclose(fi); /* not checking should be safe, file mode was "r" */
}
}
errno = save_errno;
return p;
}
static void save_tty_state (void)
{
tcgetattr(ttyfd, &termb);
flags = termb.c_lflag;
}
static void disable_tty_echo(void)
{
/* turn off echo on the tty */
termb.c_lflag &= ~ECHO;
tcsetattr(ttyfd, TCSAFLUSH, &termb);
}
static void restore_tty_state(void)
{
/* restore previous tty echo state */
termb.c_lflag = flags;
tcsetattr(ttyfd, TCSAFLUSH, &termb);
}
static void sigint_handler(int signum)
{
(void)signum;
fm_clearpassword();
restore_tty_state();
report(stderr, GT_("\nCaught SIGINT... bailing out.\n"));
exit(1);
}
/* getpass.c ends here */
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