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 } 288