mdw@git.distorted.org.uk Git - checkpath/blob - chkpath.c

   1 /* -*-c-*-
   2  *
   3  * $Id: chkpath.c,v 1.3 2003/01/25 23:58:44 mdw Exp $
   4  *
   5  * Check a user's file search path
   6  *
   7  * (c) 1999 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of chkpath.
  13  *
  14  * chkpath is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * chkpath is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with chkpath; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: chkpath.c,v $
  32  * Revision 1.3  2003/01/25 23:58:44  mdw
  33  * Make guts into official library.
  34  *
  35  * Revision 1.2  2001/01/25 22:16:02  mdw
  36  * Make flags be unsigned.
  37  *
  38  * Revision 1.1.1.1  1999/04/06 20:12:07  mdw
  39  * Import new project.
  40  *
  41  */
  42
  43 /*----- Header files ------------------------------------------------------*/
  44
  45 #include <errno.h>
  46 #include <limits.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 #include <mLib/alloc.h>
  52 #include <mLib/mdwopt.h>
  53 #include <mLib/quis.h>
  54 #include <mLib/report.h>
  55
  56 #include "checkpath.h"
  57
  58 /*----- Main code ---------------------------------------------------------*/
  59
  60 static void report(unsigned what, int verbose,
  61                    const char *p, const char *msg,
  62                    void *arg)
  63 {
  64   moan("%s", msg);
  65 }
  66
  67 /* --- @usage@ --- */
  68
  69 static void usage(FILE *fp)
  70 {
  71   fprintf(fp, "Usage: %s [-vqstp] [PATH...]\n", QUIS);
  72 }
  73
  74 /* --- @version@ --- */
  75
  76 static void version(FILE *fp)
  77 {
  78   fprintf(fp, "%s version %s\n", QUIS, VERSION);
  79 }
  80
  81 /* --- @help@ --- */
  82
  83 static void help(FILE *fp)
  84 {
  85   version(fp);
  86   putc('\n', fp);
  87   usage(fp);
  88   fputs("\n\
  89 Checks a path string (by default the PATH variable) for security.  It\n\
  90 ensures that only `root' or the calling user can write to all the parent\n\
  91 directories of the path elements, so nobody can maliciously replace the\n\
  92 binaries unexpectedly.\n\
  93 \n\
  94 Options provided are:\n\
  95 \n\
  96 -h, --help              Display this help message.\n\
  97 -V, --version           Display the program's version number.\n\
  98 -u, --usage             Show a terse usage summary.\n\
  99 \n\
 100 -v, --verbose           Be verbose about the search progress (cumulative).\n\
 101 -q, --quiet             Be quiet about the search progress (cumulative).\n\
 102 -s, --sticky            Consider sticky directories secure against\n\
 103                         modification by world and group (not recommended).\n\
 104 -t, --trust-group       Consider other members of your group trustworthy.\n\
 105 -p, --print             Write the secure path elements to standard output.\n\
 106 ",
 107         fp);
 108 }
 109
 110 int main(int argc, char *argv[])
 111 {
 112   unsigned bad = 0;
 113   int i;
 114   char *p, *q, *path;
 115   struct checkpath cp;
 116   int f = 0;
 117
 118 #define f_print 1u
 119 #define f_colon 2u
 120
 121   /* --- Initialize the world --- */
 122
 123   ego(argv[0]);
 124
 125   /* --- Set up path scanning defaults --- */
 126
 127   cp.cp_verbose = 1;
 128   cp.cp_what = CP_PROBLEMS | CP_REPORT | CP_SYMLINK;
 129   cp.cp_report = report;
 130   cp.cp_arg = 0;
 131   checkpath_setids(&cp);
 132
 133   /* --- Parse the options --- */
 134
 135   for (;;) {
 136     static struct option opts[] = {
 137       { "help",         0,              0,      'h' },
 138       { "version",      0,              0,      'V' },
 139       { "usage",        0,              0,      'u' },
 140       { "verbose",      0,              0,      'v' },
 141       { "quiet",        0,              0,      'q' },
 142       { "sticky",       0,              0,      's' },
 143       { "trust-group",  0,              0,      't' },
 144       { "print",        0,              0,      'p' },
 145       { 0,              0,              0,      0 }
 146     };
 147     int i = mdwopt(argc, argv, "hVu vqstp", opts, 0, 0, 0);
 148
 149     if (i < 0)
 150       break;
 151     switch (i) {
 152       case 'h':
 153         help(stdout);
 154         exit(0);
 155       case 'V':
 156         version(stdout);
 157         exit(0);
 158       case 'u':
 159         usage(stdout);
 160         exit(0);
 161       case 'v':
 162         cp.cp_verbose++;
 163         break;
 164       case 'q':
 165         if (cp.cp_verbose)
 166           cp.cp_verbose--;
 167         break;
 168       case 's':
 169         cp.cp_what |= CP_STICKYOK;
 170         break;
 171       case 't':
 172         cp.cp_what = (cp.cp_what & ~CP_WRGRP) | CP_WROTHGRP;
 173         break;
 174       case 'p':
 175         f |= f_print;
 176         break;
 177       default:
 178         bad = 1;
 179         break;
 180     }
 181   }
 182
 183   if (bad) {
 184     usage(stderr);
 185     exit(1);
 186   }
 187
 188   /* --- Sort out what needs doing --- */
 189
 190   if (optind == argc) {
 191     path = getenv("PATH");
 192     argv = &path;
 193     argc = 1;
 194     optind = 0;
 195   }
 196
 197   for (i = optind; i < argc; i++) {
 198     p = xstrdup(argv[i]);
 199     q = strtok(p, ":");
 200     while (q) {
 201       unsigned b = checkpath(q, &cp);
 202       if (!b && (f & f_print)) {
 203         if (f & f_colon)
 204           putchar(':');
 205         fputs(q, stdout);
 206         f |= f_colon;
 207       }
 208       bad |= b;
 209       q = strtok(0, ":");
 210     }
 211     free(p);
 212   }
 213
 214   if (f & f_colon)
 215     putchar('\n');
 216
 217   return (bad);
 218 }
 219
 220 /*----- That's all, folks -------------------------------------------------*/