100 lines
2.4 KiB
C
100 lines
2.4 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Ask for a password
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*
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* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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#include "libbb.h"
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/* do nothing signal handler */
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static void askpass_timeout(int UNUSED_PARAM ignore)
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{
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}
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char* FAST_FUNC bb_ask_noecho(int fd, int timeout, const char *prompt)
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{
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#define MAX_LINE 0xfff
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char *ret;
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int i;
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struct sigaction sa, oldsa;
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struct termios tio, oldtio;
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tcflush(fd, TCIFLUSH);
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/* Was buggy: was printing prompt *before* flushing input,
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* which was upsetting "expect" based scripts of some users.
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*/
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fputs(prompt, stdout);
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fflush_all();
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tcgetattr(fd, &oldtio);
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tio = oldtio;
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/* Switch off echo. ECHOxyz meaning:
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* ECHO echo input chars
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* ECHOE echo BS-SP-BS on erase character
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* ECHOK echo kill char specially, not as ^c (ECHOKE controls how exactly)
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* ECHOKE erase all input via BS-SP-BS on kill char (else go to next line)
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* ECHOCTL Echo ctrl chars as ^c (else echo verbatim:
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* e.g. up arrow emits "ESC-something" and thus moves cursor up!)
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* ECHONL Echo NL even if ECHO is not set
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* ECHOPRT On erase, echo erased chars
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* [qwe<BS><BS><BS> input looks like "qwe\ewq/" on screen]
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*/
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tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL);
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tcsetattr(fd, TCSANOW, &tio);
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memset(&sa, 0, sizeof(sa));
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/* sa.sa_flags = 0; - no SA_RESTART! */
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/* SIGINT and SIGALRM will interrupt reads below */
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sa.sa_handler = askpass_timeout;
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sigaction(SIGINT, &sa, &oldsa);
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if (timeout) {
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sigaction_set(SIGALRM, &sa);
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alarm(timeout);
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}
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ret = NULL;
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i = 0;
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while (1) {
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int r;
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/* User input is uber-slow, no need to optimize reallocs.
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* Grow it on every char.
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*/
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ret = xrealloc(ret, i + 2);
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r = read(fd, &ret[i], 1);
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if ((i == 0 && r == 0) /* EOF (^D) with no password */
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|| r < 0 /* read is interrupted by timeout or ^C */
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) {
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ret[i] = '\0'; /* paranoia */
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nuke_str(ret); /* paranoia */
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free(ret);
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ret = NULL;
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break;
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}
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if (r == 0 /* EOF */
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|| ret[i] == '\r' || ret[i] == '\n' /* EOL */
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|| ++i == MAX_LINE /* line limit */
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) {
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ret[i] = '\0';
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break;
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}
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}
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if (timeout) {
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alarm(0);
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}
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sigaction_set(SIGINT, &oldsa);
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tcsetattr(fd, TCSANOW, &oldtio);
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bb_putchar('\n');
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fflush_all();
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return ret;
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}
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char* FAST_FUNC bb_ask_noecho_stdin(const char *prompt)
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{
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return bb_ask_noecho(STDIN_FILENO, 0, prompt);
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}
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