1 /* $OpenBSD: groupaccess.c,v 1.17 2019/03/06 22:14:23 dtucker Exp $ */ 2 /* 3 * Copyright (c) 2001 Kevin Steves. 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "includes.h" 27 28 #include <sys/types.h> 29 30 #include <grp.h> 31 #include <unistd.h> 32 #include <stdarg.h> 33 #include <stdlib.h> 34 #include <string.h> 35 #include <limits.h> 36 37 #include "xmalloc.h" 38 #include "groupaccess.h" 39 #include "match.h" 40 #include "log.h" 41 42 static int ngroups; 43 static char **groups_byname; 44 45 /* 46 * Initialize group access list for user with primary (base) and 47 * supplementary groups. Return the number of groups in the list. 48 */ 49 int 50 ga_init(const char *user, gid_t base) 51 { 52 gid_t *groups_bygid; 53 int i, j, retry = 0; 54 struct group *gr; 55 56 if (ngroups > 0) 57 ga_free(); 58 59 ngroups = NGROUPS_MAX; 60 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX) 61 ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX)); 62 #endif 63 64 groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid)); 65 while (getgrouplist(user, base, groups_bygid, &ngroups) == -1) { 66 if (retry++ > 0) 67 fatal("getgrouplist: groups list too small"); 68 groups_bygid = xreallocarray(groups_bygid, ngroups, 69 sizeof(*groups_bygid)); 70 } 71 groups_byname = xcalloc(ngroups, sizeof(*groups_byname)); 72 73 for (i = 0, j = 0; i < ngroups; i++) 74 if ((gr = getgrgid(groups_bygid[i])) != NULL) 75 groups_byname[j++] = xstrdup(gr->gr_name); 76 free(groups_bygid); 77 return (ngroups = j); 78 } 79 80 /* 81 * Return 1 if one of user's groups is contained in groups. 82 * Return 0 otherwise. Use match_pattern() for string comparison. 83 */ 84 int 85 ga_match(char * const *groups, int n) 86 { 87 int i, j; 88 89 for (i = 0; i < ngroups; i++) 90 for (j = 0; j < n; j++) 91 if (match_pattern(groups_byname[i], groups[j])) 92 return 1; 93 return 0; 94 } 95 96 /* 97 * Return 1 if one of user's groups matches group_pattern list. 98 * Return 0 on negated or no match. 99 */ 100 int 101 ga_match_pattern_list(const char *group_pattern) 102 { 103 int i, found = 0; 104 105 for (i = 0; i < ngroups; i++) { 106 switch (match_usergroup_pattern_list(groups_byname[i], 107 group_pattern)) { 108 case -1: 109 return 0; /* Negated match wins */ 110 case 0: 111 continue; 112 case 1: 113 found = 1; 114 } 115 } 116 return found; 117 } 118 119 /* 120 * Free memory allocated for group access list. 121 */ 122 void 123 ga_free(void) 124 { 125 int i; 126 127 if (ngroups > 0) { 128 for (i = 0; i < ngroups; i++) 129 free(groups_byname[i]); 130 ngroups = 0; 131 free(groups_byname); 132 groups_byname = NULL; 133 } 134 } 135