blob: 77c1bcd9566237f3304fad7a8963cb12f3ac3677
| 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * Ask for a password |
| 4 | * I use a static buffer in this function. Plan accordingly. |
| 5 | * |
| 6 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| 7 | * |
| 8 | * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| 9 | */ |
| 10 | |
| 11 | #include "libbb.h" |
| 12 | |
| 13 | /* do nothing signal handler */ |
| 14 | static void askpass_timeout(int UNUSED_PARAM ignore) |
| 15 | { |
| 16 | } |
| 17 | |
| 18 | char* FAST_FUNC bb_ask_stdin(const char *prompt) |
| 19 | { |
| 20 | return bb_ask(STDIN_FILENO, 0, prompt); |
| 21 | } |
| 22 | char* FAST_FUNC bb_ask(const int fd, int timeout, const char *prompt) |
| 23 | { |
| 24 | /* Was static char[BIGNUM] */ |
| 25 | enum { sizeof_passwd = 128 }; |
| 26 | static char *passwd; |
| 27 | |
| 28 | char *ret; |
| 29 | int i; |
| 30 | struct sigaction sa, oldsa; |
| 31 | struct termios tio, oldtio; |
| 32 | |
| 33 | fputs(prompt, stdout); |
| 34 | fflush_all(); |
| 35 | tcflush(fd, TCIFLUSH); |
| 36 | |
| 37 | tcgetattr(fd, &oldtio); |
| 38 | tio = oldtio; |
| 39 | #if 0 |
| 40 | /* Switch off UPPERCASE->lowercase conversion (never used since 198x) |
| 41 | * and XON/XOFF (why we want to mess with this??) |
| 42 | */ |
| 43 | # ifndef IUCLC |
| 44 | # define IUCLC 0 |
| 45 | # endif |
| 46 | tio.c_iflag &= ~(IUCLC|IXON|IXOFF|IXANY); |
| 47 | #endif |
| 48 | /* Switch off echo */ |
| 49 | tio.c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL); |
| 50 | tcsetattr(fd, TCSANOW, &tio); |
| 51 | |
| 52 | memset(&sa, 0, sizeof(sa)); |
| 53 | /* sa.sa_flags = 0; - no SA_RESTART! */ |
| 54 | /* SIGINT and SIGALRM will interrupt reads below */ |
| 55 | sa.sa_handler = askpass_timeout; |
| 56 | sigaction(SIGINT, &sa, &oldsa); |
| 57 | if (timeout) { |
| 58 | sigaction_set(SIGALRM, &sa); |
| 59 | alarm(timeout); |
| 60 | } |
| 61 | |
| 62 | if (!passwd) |
| 63 | passwd = xmalloc(sizeof_passwd); |
| 64 | ret = passwd; |
| 65 | i = 0; |
| 66 | while (1) { |
| 67 | int r = read(fd, &ret[i], 1); |
| 68 | if ((i == 0 && r == 0) /* EOF (^D) with no password */ |
| 69 | || r < 0 |
| 70 | ) { |
| 71 | /* read is interrupted by timeout or ^C */ |
| 72 | ret = NULL; |
| 73 | break; |
| 74 | } |
| 75 | if (r == 0 /* EOF */ |
| 76 | || ret[i] == '\r' || ret[i] == '\n' /* EOL */ |
| 77 | || ++i == sizeof_passwd-1 /* line limit */ |
| 78 | ) { |
| 79 | ret[i] = '\0'; |
| 80 | break; |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | if (timeout) { |
| 85 | alarm(0); |
| 86 | } |
| 87 | sigaction_set(SIGINT, &oldsa); |
| 88 | tcsetattr(fd, TCSANOW, &oldtio); |
| 89 | bb_putchar('\n'); |
| 90 | fflush_all(); |
| 91 | return ret; |
| 92 | } |
| 93 |