/mandos/trunk : revision 347

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/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */

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/* -*- coding: utf-8 -*- */

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/*

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* Password-prompt - Read a password from the terminal and print it

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*

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@fukt.bsnet.se>.

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* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and

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* <https://www.fukt.bsnet.se/~teddy/>.

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*/

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#define _GNU_SOURCE /* getline() */

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#include <signal.h> /* sig_atomic_t, raise(), struct

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sigaction, sigemptyset(),

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sigaction(), sigaddset(), SIGINT,

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SIGQUIT, SIGHUP, SIGTERM,

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raise() */

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SIGQUIT, SIGHUP, SIGTERM */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <sys/types.h> /* ssize_t */

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#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,

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getenv() */

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getopt_long, getenv() */

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#include <stdio.h> /* fprintf(), stderr, getline(),

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stdin, feof(), perror(), fputc()

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*/

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#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,

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EFAULT, EFBIG, EIO, ENOSPC, EINTR

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*/

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stdin, feof(), perror(), fputc(),

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stdout, getopt_long */

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#include <errno.h> /* errno, EINVAL */

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#include <iso646.h> /* or, not */

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#include <stdbool.h> /* bool, false, true */

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#include <string.h> /* strlen, rindex, strncmp, strcmp */

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argp_parse(), error_t,

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ARGP_KEY_ARG, ARGP_KEY_END,

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ARGP_ERR_UNKNOWN */

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#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,

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EX_UNAVAILABLE, EX_IOERR, EX_OK */

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volatile sig_atomic_t quit_now = 0;

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int signal_received;

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bool debug = false;

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const char *argp_program_version = "password-prompt " VERSION;

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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

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static void termination_handler(int signum){

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if(quit_now){

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return;

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}

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static void termination_handler(__attribute__((unused))int signum){

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quit_now = 1;

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signal_received = signum;

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}

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int main(int argc, char **argv){

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.doc = "Prefix shown before the prompt", .group = 2 },

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{ .name = "debug", .key = 128,

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.doc = "Debug mode", .group = 3 },

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/*

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* These reproduce what we would get without ARGP_NO_HELP

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*/

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{ .name = "help", .key = '?',

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.doc = "Give this help list", .group = -1 },

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{ .name = "usage", .key = -3,

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.doc = "Give a short usage message", .group = -1 },

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{ .name = "version", .key = 'V',

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.doc = "Print program version", .group = -1 },

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{ .name = NULL }

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};

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error_t parse_opt (int key, char *arg, struct argp_state *state){

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errno = 0;

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switch (key){

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case 'p':

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prefix = arg;

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case 128:

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debug = true;

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break;

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/*

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* These reproduce what we would get without ARGP_NO_HELP

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*/

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case '?': /* --help */

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argp_state_help(state, state->out_stream,

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(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

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& ~(unsigned int)ARGP_HELP_EXIT_OK);

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case -3: /* --usage */

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argp_state_help(state, state->out_stream,

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ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

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case 'V': /* --version */

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fprintf(state->out_stream, "%s\n", argp_program_version);

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exit(argp_err_exit_status);

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case ARGP_KEY_ARG:

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argp_usage(state);

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break;

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case ARGP_KEY_END:

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break;

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default:

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return ARGP_ERR_UNKNOWN;

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}

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return errno;

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return 0;

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}

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struct argp argp = { .options = options, .parser = parse_opt,

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.args_doc = "",

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.doc = "Mandos password-prompt -- Read and"

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" output a password" };

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ret = argp_parse(&argp, argc, argv,

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ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);

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switch(ret){

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case 0:

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break;

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case ENOMEM:

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default:

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errno = ret;

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perror("argp_parse");

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return EX_OSERR;

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case EINVAL:

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return EX_USAGE;

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ret = argp_parse(&argp, argc, argv, 0, 0, NULL);

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if(ret == ARGP_ERR_UNKNOWN){

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fprintf(stderr, "Unknown error while parsing arguments\n");

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return EXIT_FAILURE;

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}

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}

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}

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if(tcgetattr(STDIN_FILENO, &t_old) != 0){

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int e = errno;

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perror("tcgetattr");

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switch(e){

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case EBADF:

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case ENOTTY:

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return EX_UNAVAILABLE;

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default:

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return EX_OSERR;

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}

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return EXIT_FAILURE;

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}

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sigemptyset(&new_action.sa_mask);

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ret = sigaddset(&new_action.sa_mask, SIGINT);

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if(ret == -1){

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perror("sigaddset");

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return EX_OSERR;

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}

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ret = sigaddset(&new_action.sa_mask, SIGHUP);

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if(ret == -1){

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perror("sigaddset");

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return EX_OSERR;

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}

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ret = sigaddset(&new_action.sa_mask, SIGTERM);

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if(ret == -1){

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perror("sigaddset");

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return EX_OSERR;

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}

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/* Need to check if the handler is SIG_IGN before handling:

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| [[info:libc:Initial Signal Actions]] |

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| [[info:libc:Basic Signal Handling]] |

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*/

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sigaddset(&new_action.sa_mask, SIGINT);

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sigaddset(&new_action.sa_mask, SIGHUP);

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sigaddset(&new_action.sa_mask, SIGTERM);

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ret = sigaction(SIGINT, NULL, &old_action);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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if(old_action.sa_handler != SIG_IGN){

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ret = sigaction(SIGINT, &new_action, NULL);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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}

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ret = sigaction(SIGHUP, NULL, &old_action);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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if(old_action.sa_handler != SIG_IGN){

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ret = sigaction(SIGHUP, &new_action, NULL);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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}

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ret = sigaction(SIGTERM, NULL, &old_action);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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if(old_action.sa_handler != SIG_IGN){

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ret = sigaction(SIGTERM, &new_action, NULL);

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if(ret == -1){

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perror("sigaction");

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return EX_OSERR;

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return EXIT_FAILURE;

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}

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}

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}

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t_new = t_old;

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t_new.c_lflag &= ~(tcflag_t)ECHO;

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t_new.c_lflag &= ~ECHO;

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if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){

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int e = errno;

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perror("tcsetattr-echo");

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switch(e){

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case EBADF:

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case ENOTTY:

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return EX_UNAVAILABLE;

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case EINVAL:

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default:

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return EX_OSERR;

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}

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return EXIT_FAILURE;

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}

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if(debug){

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fprintf(stderr, "Waiting for input from stdin \n");

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}

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const char *cryptsource = getenv("cryptsource");

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const char *crypttarget = getenv("crypttarget");

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const char *const prompt

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= "Enter passphrase to unlock the disk";

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= "Enter passphrase to unlock the disk";

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if(cryptsource == NULL){

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if(crypttarget == NULL){

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fprintf(stderr, "%s: ", prompt);

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/* Make n = data size instead of allocated buffer size */

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n = (size_t)ret;

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/* Strip final newline */

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if(n > 0 and buffer[n-1] == '\n'){

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if(n>0 and buffer[n-1] == '\n'){

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buffer[n-1] = '\0'; /* not strictly necessary */

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n--;

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}

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while(written < n){

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ret = write(STDOUT_FILENO, buffer + written, n - written);

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if(ret < 0){

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int e = errno;

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perror("write");

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switch(e){

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case EBADF:

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case EFAULT:

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case EINVAL:

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case EFBIG:

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case EIO:

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case ENOSPC:

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default:

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status = EX_IOERR;

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break;

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case EINTR:

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status = EXIT_FAILURE;

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break;

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}

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status = EXIT_FAILURE;

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break;

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}

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written += (size_t)ret;

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}

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ret = close(STDOUT_FILENO);

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if(ret == -1){

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int e = errno;

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perror("close");

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switch(e){

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case EBADF:

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status = EX_OSFILE;

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break;

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case EIO:

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default:

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status = EX_IOERR;

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break;

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}

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}

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break;

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}

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if(ret < 0){

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int e = errno;

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if(errno != EINTR and not feof(stdin)){

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perror("getline");

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switch(e){

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case EBADF:

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status = EX_UNAVAILABLE;

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case EIO:

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case EINVAL:

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default:

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status = EX_IOERR;

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break;

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}

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status = EXIT_FAILURE;

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break;

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}

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}

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/* if(ret == 0), then the only sensible thing to do is to retry to

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read from stdin */

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fputc('\n', stderr);

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if(debug and not quit_now){

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if(debug and quit_now == 0){

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/* If quit_now is nonzero, we were interrupted by a signal, and

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will print that later, so no need to show this too. */

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fprintf(stderr, "getline() returned 0, retrying.\n");

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perror("tcsetattr+echo");

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}

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if(quit_now){

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sigemptyset(&old_action.sa_mask);

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old_action.sa_handler = SIG_DFL;

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ret = sigaction(signal_received, &old_action, NULL);

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if(ret == -1){

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perror("sigaction");

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}

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raise(signal_received);

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}

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if(debug){

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fprintf(stderr, "%s is exiting with status %d\n", argv[0],

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status);

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}

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if(status == EXIT_SUCCESS or status == EX_OK){

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if(status == EXIT_SUCCESS){

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fputc('\n', stderr);

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}

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