diff options
Diffstat (limited to 'lib/getpass.c')
| -rw-r--r-- | lib/getpass.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/lib/getpass.c b/lib/getpass.c new file mode 100644 index 0000000..e787e44 --- /dev/null +++ b/lib/getpass.c @@ -0,0 +1,231 @@ +/* Copyright (C) 1992-2001, 2003-2007, 2009-2018 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, see <https://www.gnu.org/licenses/>. */ + +#ifndef _LIBC +# include <config.h> +#endif + +#include "getpass.h" + +#include <stdio.h> + +#if !(defined _WIN32 && !defined __CYGWIN__) + +# include <stdbool.h> + +# if HAVE_DECL___FSETLOCKING && HAVE___FSETLOCKING +# if HAVE_STDIO_EXT_H +# include <stdio_ext.h> +# endif +# else +# define __fsetlocking(stream, type) /* empty */ +# endif + +# if HAVE_TERMIOS_H +# include <termios.h> +# endif + +# if USE_UNLOCKED_IO +# include "unlocked-io.h" +# else +# if !HAVE_DECL_FFLUSH_UNLOCKED +# undef fflush_unlocked +# define fflush_unlocked(x) fflush (x) +# endif +# if !HAVE_DECL_FLOCKFILE +# undef flockfile +# define flockfile(x) ((void) 0) +# endif +# if !HAVE_DECL_FUNLOCKFILE +# undef funlockfile +# define funlockfile(x) ((void) 0) +# endif +# if !HAVE_DECL_FPUTS_UNLOCKED +# undef fputs_unlocked +# define fputs_unlocked(str,stream) fputs (str, stream) +# endif +# if !HAVE_DECL_PUTC_UNLOCKED +# undef putc_unlocked +# define putc_unlocked(c,stream) putc (c, stream) +# endif +# endif + +/* It is desirable to use this bit on systems that have it. + The only bit of terminal state we want to twiddle is echoing, which is + done in software; there is no need to change the state of the terminal + hardware. */ + +# ifndef TCSASOFT +# define TCSASOFT 0 +# endif + +static void +call_fclose (void *arg) +{ + if (arg != NULL) + fclose (arg); +} + +char * +getpass (const char *prompt) +{ + FILE *tty; + FILE *in, *out; +# if HAVE_TCGETATTR + struct termios s, t; +# endif + bool tty_changed = false; + static char *buf; + static size_t bufsize; + ssize_t nread; + + /* Try to write to and read from the terminal if we can. + If we can't open the terminal, use stderr and stdin. */ + + tty = fopen ("/dev/tty", "w+"); + if (tty == NULL) + { + in = stdin; + out = stderr; + } + else + { + /* We do the locking ourselves. */ + __fsetlocking (tty, FSETLOCKING_BYCALLER); + + out = in = tty; + } + + flockfile (out); + + /* Turn echoing off if it is on now. */ +# if HAVE_TCGETATTR + if (tcgetattr (fileno (in), &t) == 0) + { + /* Save the old one. */ + s = t; + /* Tricky, tricky. */ + t.c_lflag &= ~(ECHO | ISIG); + tty_changed = (tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &t) == 0); + } +# endif + + /* Write the prompt. */ + fputs_unlocked (prompt, out); + fflush_unlocked (out); + + /* Read the password. */ + nread = getline (&buf, &bufsize, in); + + /* According to the C standard, input may not be followed by output + on the same stream without an intervening call to a file + positioning function. Suppose in == out; then without this fseek + call, on Solaris, HP-UX, AIX, OSF/1, the previous input gets + echoed, whereas on IRIX, the following newline is not output as + it should be. POSIX imposes similar restrictions if fileno (in) + == fileno (out). The POSIX restrictions are tricky and change + from POSIX version to POSIX version, so play it safe and invoke + fseek even if in != out. */ + fseeko (out, 0, SEEK_CUR); + + if (buf != NULL) + { + if (nread < 0) + buf[0] = '\0'; + else if (buf[nread - 1] == '\n') + { + /* Remove the newline. */ + buf[nread - 1] = '\0'; + if (tty_changed) + { + /* Write the newline that was not echoed. */ + putc_unlocked ('\n', out); + } + } + } + + /* Restore the original setting. */ +# if HAVE_TCSETATTR + if (tty_changed) + tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &s); +# endif + + funlockfile (out); + + call_fclose (tty); + + return buf; +} + +#else /* W32 native */ + +/* Windows implementation by Martin Lambers <marlam@marlam.de>, + improved by Simon Josefsson. */ + +/* For PASS_MAX. */ +# include <limits.h> +/* For _getch(). */ +# include <conio.h> +/* For strdup(). */ +# include <string.h> + +# ifndef PASS_MAX +# define PASS_MAX 512 +# endif + +char * +getpass (const char *prompt) +{ + char getpassbuf[PASS_MAX + 1]; + size_t i = 0; + int c; + + if (prompt) + { + fputs (prompt, stderr); + fflush (stderr); + } + + for (;;) + { + c = _getch (); + if (c == '\r') + { + getpassbuf[i] = '\0'; + break; + } + else if (i < PASS_MAX) + { + getpassbuf[i++] = c; + } + + if (i >= PASS_MAX) + { + getpassbuf[i] = '\0'; + break; + } + } + + if (prompt) + { + fputs ("\r\n", stderr); + fflush (stderr); + } + + return strdup (getpassbuf); +} +#endif |