| 1 | /* Copyright (C) 1992-2001, 2003-2007, 2009-2016 Free Software Foundation, Inc. |
| 2 | |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 2, or (at your option) |
| 8 | any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License along |
| 16 | with this program; if not, see <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | /*#ifndef _LIBC |
| 19 | # include <config.h> |
| 20 | #endifi*/ |
| 21 | |
| 22 | #include "getpass.h" |
| 23 | |
| 24 | |
| 25 | #include <stdio.h> |
| 26 | |
| 27 | #if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) |
| 28 | |
| 29 | # include <stdbool.h> |
| 30 | |
| 31 | # if HAVE_DECL___FSETLOCKING && HAVE___FSETLOCKING |
| 32 | # if HAVE_STDIO_EXT_H |
| 33 | # include <stdio_ext.h> |
| 34 | # endif |
| 35 | # else |
| 36 | # define __fsetlocking(stream, type) /* empty */ |
| 37 | # endif |
| 38 | |
| 39 | # if HAVE_TERMIOS_H |
| 40 | # include <termios.h> |
| 41 | # endif |
| 42 | |
| 43 | # if USE_UNLOCKED_IO |
| 44 | # include "unlocked-io.h" |
| 45 | # else |
| 46 | # if !HAVE_DECL_FFLUSH_UNLOCKED |
| 47 | # undef fflush_unlocked |
| 48 | # define fflush_unlocked(x) fflush (x) |
| 49 | # endif |
| 50 | # if !HAVE_DECL_FLOCKFILE |
| 51 | # undef flockfile |
| 52 | # define flockfile(x) ((void) 0) |
| 53 | # endif |
| 54 | # if !HAVE_DECL_FUNLOCKFILE |
| 55 | # undef funlockfile |
| 56 | # define funlockfile(x) ((void) 0) |
| 57 | # endif |
| 58 | # if !HAVE_DECL_FPUTS_UNLOCKED |
| 59 | # undef fputs_unlocked |
| 60 | # define fputs_unlocked(str,stream) fputs (str, stream) |
| 61 | # endif |
| 62 | # if !HAVE_DECL_PUTC_UNLOCKED |
| 63 | # undef putc_unlocked |
| 64 | # define putc_unlocked(c,stream) putc (c, stream) |
| 65 | # endif |
| 66 | # endif |
| 67 | |
| 68 | /* It is desirable to use this bit on systems that have it. |
| 69 | The only bit of terminal state we want to twiddle is echoing, which is |
| 70 | done in software; there is no need to change the state of the terminal |
| 71 | hardware. */ |
| 72 | |
| 73 | # ifndef TCSASOFT |
| 74 | # define TCSASOFT 0 |
| 75 | # endif |
| 76 | |
| 77 | static void |
| 78 | call_fclose (void *arg) |
| 79 | { |
| 80 | if (arg != NULL) |
| 81 | fclose (arg); |
| 82 | } |
| 83 | |
| 84 | char * |
| 85 | getpass (const char *prompt) |
| 86 | { |
| 87 | FILE *tty; |
| 88 | FILE *in, *out; |
| 89 | # if HAVE_TCGETATTR |
| 90 | struct termios s, t; |
| 91 | # endif |
| 92 | bool tty_changed = false; |
| 93 | static char *buf; |
| 94 | static size_t bufsize; |
| 95 | ssize_t nread; |
| 96 | |
| 97 | /* Try to write to and read from the terminal if we can. |
| 98 | If we can't open the terminal, use stderr and stdin. */ |
| 99 | |
| 100 | tty = fopen ("/dev/tty", "w+"); |
| 101 | if (tty == NULL) |
| 102 | { |
| 103 | in = stdin; |
| 104 | out = stderr; |
| 105 | } |
| 106 | else |
| 107 | { |
| 108 | /* We do the locking ourselves. */ |
| 109 | __fsetlocking (tty, FSETLOCKING_BYCALLER); |
| 110 | |
| 111 | out = in = tty; |
| 112 | } |
| 113 | |
| 114 | flockfile (out); |
| 115 | |
| 116 | /* Turn echoing off if it is on now. */ |
| 117 | # if HAVE_TCGETATTR |
| 118 | if (tcgetattr (fileno (in), &t) == 0) |
| 119 | { |
| 120 | /* Save the old one. */ |
| 121 | s = t; |
| 122 | /* Tricky, tricky. */ |
| 123 | t.c_lflag &= ~(ECHO | ISIG); |
| 124 | tty_changed = (tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &t) == 0); |
| 125 | } |
| 126 | # endif |
| 127 | |
| 128 | /* Write the prompt. */ |
| 129 | fputs_unlocked (prompt, out); |
| 130 | fflush_unlocked (out); |
| 131 | |
| 132 | /* Read the password. */ |
| 133 | nread = getline (&buf, &bufsize, in); |
| 134 | |
| 135 | /* According to the C standard, input may not be followed by output |
| 136 | on the same stream without an intervening call to a file |
| 137 | positioning function. Suppose in == out; then without this fseek |
| 138 | call, on Solaris, HP-UX, AIX, OSF/1, the previous input gets |
| 139 | echoed, whereas on IRIX, the following newline is not output as |
| 140 | it should be. POSIX imposes similar restrictions if fileno (in) |
| 141 | == fileno (out). The POSIX restrictions are tricky and change |
| 142 | from POSIX version to POSIX version, so play it safe and invoke |
| 143 | fseek even if in != out. */ |
| 144 | fseeko (out, 0, SEEK_CUR); |
| 145 | |
| 146 | if (buf != NULL) |
| 147 | { |
| 148 | if (nread < 0) |
| 149 | buf[0] = '\0'; |
| 150 | else if (buf[nread - 1] == '\n') |
| 151 | { |
| 152 | /* Remove the newline. */ |
| 153 | buf[nread - 1] = '\0'; |
| 154 | if (tty_changed) |
| 155 | { |
| 156 | /* Write the newline that was not echoed. */ |
| 157 | putc_unlocked ('\n', out); |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /* Restore the original setting. */ |
| 163 | # if HAVE_TCSETATTR |
| 164 | if (tty_changed) |
| 165 | tcsetattr (fileno (in), TCSAFLUSH | TCSASOFT, &s); |
| 166 | # endif |
| 167 | |
| 168 | funlockfile (out); |
| 169 | |
| 170 | call_fclose (tty); |
| 171 | |
| 172 | return buf; |
| 173 | } |
| 174 | |
| 175 | #else /* W32 native */ |
| 176 | |
| 177 | /* Windows implementation by Martin Lambers <marlam@marlam.de>, |
| 178 | improved by Simon Josefsson. */ |
| 179 | |
| 180 | /* For PASS_MAX. */ |
| 181 | # include <limits.h> |
| 182 | /* For _getch(). */ |
| 183 | # include <conio.h> |
| 184 | /* For strdup(). */ |
| 185 | # include <string.h> |
| 186 | |
| 187 | # ifndef PASS_MAX |
| 188 | # define PASS_MAX 512 |
| 189 | # endif |
| 190 | |
| 191 | char * |
| 192 | getpass (const char *prompt) |
| 193 | { |
| 194 | char getpassbuf[PASS_MAX + 1]; |
| 195 | size_t i = 0; |
| 196 | int c; |
| 197 | |
| 198 | if (prompt) |
| 199 | { |
| 200 | fputs (prompt, stderr); |
| 201 | fflush (stderr); |
| 202 | } |
| 203 | |
| 204 | for (;;) |
| 205 | { |
| 206 | c = _getch (); |
| 207 | if (c == '\r') |
| 208 | { |
| 209 | getpassbuf[i] = '\0'; |
| 210 | break; |
| 211 | } |
| 212 | else if (i < PASS_MAX) |
| 213 | { |
| 214 | getpassbuf[i++] = c; |
| 215 | } |
| 216 | |
| 217 | if (i >= PASS_MAX) |
| 218 | { |
| 219 | getpassbuf[i] = '\0'; |
| 220 | break; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | if (prompt) |
| 225 | { |
| 226 | fputs ("\r\n", stderr); |
| 227 | fflush (stderr); |
| 228 | } |
| 229 | |
| 230 | return strdup (getpassbuf); |
| 231 | } |
| 232 | #endif |