/mandos/trunk

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237.1.2 by Teddy Hogeborn
Further steps towards a D-Bus server interface, plus minor syntax
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/*  -*- coding: utf-8 -*- */
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/*
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 * Passprompt - Read a password from a FIFO and output it
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 * 
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 * Copyright © 2008 Teddy Hogeborn
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 * Copyright © 2008 Björn Påhlsson
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 * 
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 * This program is free software: you can redistribute it and/or
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 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation, either version 3 of the
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 * License, or (at your option) any later version.
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 * 
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 * This program is distributed in the hope that it will be useful, but
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 * WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * General Public License for more details.
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 * 
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 * You should have received a copy of the GNU General Public License
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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 <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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214 by Teddy Hogeborn
* Makefile (PLUGINS): Added "plugins.d/askpass-fifo".
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#define _GNU_SOURCE		/* TEMP_FAILURE_RETRY() */
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#include <sys/types.h>		/* ssize_t */
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#include <sys/stat.h>		/* mkfifo(), S_IRUSR, S_IWUSR */
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#include <iso646.h>		/* and */
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#include <errno.h>		/* errno, EEXIST */
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#include <stdio.h>		/* perror() */
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#include <stdlib.h>		/* EXIT_FAILURE, NULL, size_t, free(), 
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				   realloc(), EXIT_SUCCESS */
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#include <fcntl.h>		/* open(), O_RDONLY */
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#include <unistd.h>		/* read(), close(), write(),
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				   STDOUT_FILENO */
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int main(__attribute__((unused))int argc,
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	 __attribute__((unused))char **argv){
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  int ret = 0;
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  ssize_t sret;
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  /* Create FIFO */
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  const char passfifo[] = "/lib/cryptsetup/passfifo";
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  ret = TEMP_FAILURE_RETRY(mkfifo(passfifo, S_IRUSR | S_IWUSR));
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  if(ret == -1 and errno != EEXIST){
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    perror("mkfifo");
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    return EXIT_FAILURE;
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  }
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  /* Open FIFO */
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  int fifo_fd = TEMP_FAILURE_RETRY(open(passfifo, O_RDONLY));
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  if(fifo_fd == -1){
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    perror("open");
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    return EXIT_FAILURE;
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  }
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  /* Read from FIFO */
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  char *buf = NULL;
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  size_t buf_len = 0;
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  {
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    size_t buf_allocated = 0;
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    const size_t blocksize = 1024;
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    do{
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      if(buf_len + blocksize > buf_allocated){
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	char *tmp = realloc(buf, buf_allocated + blocksize);
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	if(tmp == NULL){
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	  perror("realloc");
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	  free(buf);
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	  return EXIT_FAILURE;
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	}
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	buf = tmp;
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	buf_allocated += blocksize;
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      }
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      sret = TEMP_FAILURE_RETRY(read(fifo_fd, buf + buf_len,
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				     buf_allocated - buf_len));
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      if(sret == -1){
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	perror("read");
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	free(buf);
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	return EXIT_FAILURE;
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      }
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      buf_len += (size_t)sret;
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    }while(sret != 0);
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  }
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  /* Close FIFO */
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  TEMP_FAILURE_RETRY(close(fifo_fd));
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  /* Print password to stdout */
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  size_t written = 0;
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  while(written < buf_len){
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    sret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buf + written,
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				    buf_len - written));
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    if(sret == -1){
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      perror("write");
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      free(buf);
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      return EXIT_FAILURE;
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    }
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    written += (size_t)sret;
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  }
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  free(buf);
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  return EXIT_SUCCESS;
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}