crypto/heimdal-0.6.3/lib/roken/iruserok.c

   1 /*
   2  * Copyright (c) 1983, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 RCSID("$Id: iruserok.c,v 1.23 1999/12/05 13:27:05 assar Exp $");
  37 #endif
  38
  39 #include <stdio.h>
  40 #include <ctype.h>
  41 #ifdef HAVE_SYS_TYPES_H
  42 #include <sys/types.h>
  43 #endif
  44 #ifdef HAVE_NETINET_IN_H
  45 #include <netinet/in.h>
  46 #endif
  47 #ifdef HAVE_NETINET_IN6_H
  48 #include <netinet/in6.h>
  49 #endif
  50 #ifdef HAVE_NETINET6_IN6_H
  51 #include <netinet6/in6.h>
  52 #endif
  53 #ifdef HAVE_RPCSVC_YPCLNT_H
  54 #include <rpcsvc/ypclnt.h>
  55 #endif
  56
  57 #include "roken.h"
  58
  59 int     __check_rhosts_file = 1;
  60 char    *__rcmd_errstr = 0;
  61
  62 /*
  63  * Returns "true" if match, 0 if no match.
  64  */
  65 static
  66 int
  67 __icheckhost(unsigned raddr, const char *lhost)
  68 {
  69         struct hostent *hp;
  70         u_long laddr;
  71         char **pp;
  72
  73         /* Try for raw ip address first. */
  74         if (isdigit((unsigned char)*lhost)
  75             && (long)(laddr = inet_addr(lhost)) != -1)
  76                 return (raddr == laddr);
  77
  78         /* Better be a hostname. */
  79         if ((hp = gethostbyname(lhost)) == NULL)
  80                 return (0);
  81
  82         /* Spin through ip addresses. */
  83         for (pp = hp->h_addr_list; *pp; ++pp)
  84                 if (memcmp(&raddr, *pp, sizeof(u_long)) == 0)
  85                         return (1);
  86
  87         /* No match. */
  88         return (0);
  89 }
  90
  91 /*
  92  * Returns 0 if ok, -1 if not ok.
  93  */
  94 static
  95 int
  96 __ivaliduser(FILE *hostf, unsigned raddr, const char *luser,
  97              const char *ruser)
  98 {
  99         char *user, *p;
 100         int ch;
 101         char buf[MaxHostNameLen + 128];         /* host + login */
 102         char hname[MaxHostNameLen];
 103         struct hostent *hp;
 104         /* Presumed guilty until proven innocent. */
 105         int userok = 0, hostok = 0;
 106 #ifdef HAVE_YP_GET_DEFAULT_DOMAIN
 107         char *ypdomain;
 108
 109         if (yp_get_default_domain(&ypdomain))
 110                 ypdomain = NULL;
 111 #else
 112 #define ypdomain NULL
 113 #endif
 114         /* We need to get the damn hostname back for netgroup matching. */
 115         if ((hp = gethostbyaddr((char *)&raddr,
 116                                 sizeof(u_long),
 117                                 AF_INET)) == NULL)
 118                 return (-1);
 119         strlcpy(hname, hp->h_name, sizeof(hname));
 120
 121         while (fgets(buf, sizeof(buf), hostf)) {
 122                 p = buf;
 123                 /* Skip lines that are too long. */
 124                 if (strchr(p, '\n') == NULL) {
 125                         while ((ch = getc(hostf)) != '\n' && ch != EOF);
 126                         continue;
 127                 }
 128                 if (*p == '\n' || *p == '#') {
 129                         /* comment... */
 130                         continue;
 131                 }
 132                 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
 133                         if (isupper((unsigned char)*p))
 134                             *p = tolower((unsigned char)*p);
 135                         p++;
 136                 }
 137                 if (*p == ' ' || *p == '\t') {
 138                         *p++ = '\0';
 139                         while (*p == ' ' || *p == '\t')
 140                                 p++;
 141                         user = p;
 142                         while (*p != '\n' && *p != ' ' &&
 143                             *p != '\t' && *p != '\0')
 144                                 p++;
 145                 } else
 146                         user = p;
 147                 *p = '\0';
 148                 /*
 149                  * Do +/- and +@/-@ checking. This looks really nasty,
 150                  * but it matches SunOS's behavior so far as I can tell.
 151                  */
 152                 switch(buf[0]) {
 153                 case '+':
 154                         if (!buf[1]) {     /* '+' matches all hosts */
 155                                 hostok = 1;
 156                                 break;
 157                         }
 158                         if (buf[1] == '@')  /* match a host by netgroup */
 159                                 hostok = innetgr((char *)&buf[2],
 160                                         (char *)&hname, NULL, ypdomain);
 161                         else            /* match a host by addr */
 162                                 hostok = __icheckhost(raddr,(char *)&buf[1]);
 163                         break;
 164                 case '-':     /* reject '-' hosts and all their users */
 165                         if (buf[1] == '@') {
 166                                 if (innetgr((char *)&buf[2],
 167                                               (char *)&hname, NULL, ypdomain))
 168                                         return(-1);
 169                         } else {
 170                                 if (__icheckhost(raddr,(char *)&buf[1]))
 171                                         return(-1);
 172                         }
 173                         break;
 174                 default:  /* if no '+' or '-', do a simple match */
 175                         hostok = __icheckhost(raddr, buf);
 176                         break;
 177                 }
 178                 switch(*user) {
 179                 case '+':
 180                         if (!*(user+1)) {      /* '+' matches all users */
 181                                 userok = 1;
 182                                 break;
 183                         }
 184                         if (*(user+1) == '@')  /* match a user by netgroup */
 185                                 userok = innetgr(user+2, NULL, (char *)ruser,
 186                                                  ypdomain);
 187                         else       /* match a user by direct specification */
 188                                 userok = !(strcmp(ruser, user+1));
 189                         break;
 190                 case '-':               /* if we matched a hostname, */
 191                         if (hostok) {   /* check for user field rejections */
 192                                 if (!*(user+1))
 193                                         return(-1);
 194                                 if (*(user+1) == '@') {
 195                                         if (innetgr(user+2, NULL,
 196                                                     (char *)ruser, ypdomain))
 197                                                 return(-1);
 198                                 } else {
 199                                         if (!strcmp(ruser, user+1))
 200                                                 return(-1);
 201                                 }
 202                         }
 203                         break;
 204                 default:        /* no rejections: try to match the user */
 205                         if (hostok)
 206                                 userok = !(strcmp(ruser,*user ? user : luser));
 207                         break;
 208                 }
 209                 if (hostok && userok)
 210                         return(0);
 211         }
 212         return (-1);
 213 }
 214
 215 /*
 216  * New .rhosts strategy: We are passed an ip address. We spin through
 217  * hosts.equiv and .rhosts looking for a match. When the .rhosts only
 218  * has ip addresses, we don't have to trust a nameserver.  When it
 219  * contains hostnames, we spin through the list of addresses the nameserver
 220  * gives us and look for a match.
 221  *
 222  * Returns 0 if ok, -1 if not ok.
 223  */
 224 int
 225 iruserok(unsigned raddr, int superuser, const char *ruser, const char *luser)
 226 {
 227         char *cp;
 228         struct stat sbuf;
 229         struct passwd *pwd;
 230         FILE *hostf;
 231         uid_t uid;
 232         int first;
 233         char pbuf[MaxPathLen];
 234
 235         first = 1;
 236         hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
 237 again:
 238         if (hostf) {
 239                 if (__ivaliduser(hostf, raddr, luser, ruser) == 0) {
 240                         fclose(hostf);
 241                         return (0);
 242                 }
 243                 fclose(hostf);
 244         }
 245         if (first == 1 && (__check_rhosts_file || superuser)) {
 246                 first = 0;
 247                 if ((pwd = k_getpwnam((char*)luser)) == NULL)
 248                         return (-1);
 249                 snprintf (pbuf, sizeof(pbuf), "%s/.rhosts", pwd->pw_dir);
 250
 251                 /*
 252                  * Change effective uid while opening .rhosts.  If root and
 253                  * reading an NFS mounted file system, can't read files that
 254                  * are protected read/write owner only.
 255                  */
 256                 uid = geteuid();
 257                 seteuid(pwd->pw_uid);
 258                 hostf = fopen(pbuf, "r");
 259                 seteuid(uid);
 260
 261                 if (hostf == NULL)
 262                         return (-1);
 263                 /*
 264                  * If not a regular file, or is owned by someone other than
 265                  * user or root or if writeable by anyone but the owner, quit.
 266                  */
 267                 cp = NULL;
 268                 if (lstat(pbuf, &sbuf) < 0)
 269                         cp = ".rhosts lstat failed";
 270                 else if (!S_ISREG(sbuf.st_mode))
 271                         cp = ".rhosts not regular file";
 272                 else if (fstat(fileno(hostf), &sbuf) < 0)
 273                         cp = ".rhosts fstat failed";
 274                 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
 275                         cp = "bad .rhosts owner";
 276                 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
 277                         cp = ".rhosts writeable by other than owner";
 278                 /* If there were any problems, quit. */
 279                 if (cp) {
 280                         __rcmd_errstr = cp;
 281                         fclose(hostf);
 282                         return (-1);
 283                 }
 284                 goto again;
 285         }
 286         return (-1);
 287 }