a60f05ad44
- [client+server] Fernando Arnaboldi from IOActive found that strict filesystem permissions for various fwknop files are not verified. Added warnings whenever permissions are not strict enough, and ensured that files created by the fwknop client and server are only set to user read/write. - [client] Fernando Arnaboldi from IOActive found a local buffer overflow in --last processing with a maliciously constructed ~/.fwknop.run file. This has been fixed with proper validation of .fwknop.run arguments.
136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
/*
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*****************************************************************************
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*
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* File: utils.c
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*
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* Author: Damien S. Stuart
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*
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* Purpose: General/Generic functions for the fwknop client.
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*
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* Copyright 2009-2010 Damien Stuart (dstuart@dstuart.org)
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*
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* License (GNU Public License):
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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
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* as published by the Free Software Foundation; either version 2
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* of the 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,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU 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, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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* USA
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*
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*****************************************************************************
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*/
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#include "utils.h"
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/* Generic hex dump function.
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*/
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void
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hex_dump(const unsigned char *data, const int size)
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{
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int ln, i, j = 0;
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char ascii_str[17] = {0};
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for(i=0; i<size; i++)
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{
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if((i % 16) == 0)
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{
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printf(" %s\n 0x%.4x: ", ascii_str, i);
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memset(ascii_str, 0x0, 17);
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j = 0;
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}
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printf("%.2x ", data[i]);
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ascii_str[j++] = (data[i] < 0x20 || data[i] > 0x7e) ? '.' : data[i];
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if(j == 8)
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printf(" ");
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}
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/* Remainder...
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*/
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ln = strlen(ascii_str);
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if(ln > 0)
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{
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for(i=0; i < 16-ln; i++)
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printf(" ");
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printf(" %s\n\n", ascii_str);
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}
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}
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int
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set_file_perms(const char *file)
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{
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int res = 0;
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res = chmod(file, S_IRUSR | S_IWUSR);
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if(res != 0)
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{
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fprintf(stderr,
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"[-] unable to chmod file %s to user read/write (0600, -rw-------): %s\n",
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file,
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strerror(errno)
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);
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}
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return res;
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}
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int
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verify_file_perms_ownership(const char *file)
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{
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#if HAVE_STAT
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struct stat st;
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/* Every file that the fwknop client deals with should be owned
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* by the user and permissions set to 600 (user read/write)
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*/
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if((stat(file, &st)) != 0)
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{
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fprintf(stderr, "[-] unable to run stat() against file: %s: %s\n",
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file, strerror(errno));
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exit(EXIT_FAILURE);
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}
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/* Make sure it is a regular file or symbolic link
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*/
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if(S_ISREG(st.st_mode) != 1 && S_ISLNK(st.st_mode) != 1)
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{
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fprintf(stderr,
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"[-] file: %s is not a regular file or symbolic link.\n",
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file
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);
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return 0;
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}
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if((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != (S_IRUSR|S_IWUSR))
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{
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fprintf(stderr,
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"[-] file: %s permissions should only be user read/write (0600, -rw-------)\n",
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file
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);
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return 0;
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}
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if(st.st_uid != getuid())
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{
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fprintf(stderr, "[-] file: %s not owned by current effective user id.\n",
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file);
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return 0;
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}
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#endif
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return 1;
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}
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/***EOF***/
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