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-rw-r--r--lib/util/getgrouplist.c529
1 files changed, 529 insertions, 0 deletions
diff --git a/lib/util/getgrouplist.c b/lib/util/getgrouplist.c
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--- /dev/null
+++ b/lib/util/getgrouplist.c
@@ -0,0 +1,529 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2010, 2011, 2013-2021
+ * Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <grp.h>
+#include <limits.h>
+#include <unistd.h>
+#ifdef HAVE_NSS_SEARCH
+# include <errno.h>
+# include <limits.h>
+# include <nsswitch.h>
+# ifdef HAVE_NSS_DBDEFS_H
+# include <nss_dbdefs.h>
+# else
+# include "compat/nss_dbdefs.h"
+# endif
+#endif
+
+#include "sudo_compat.h"
+#include "sudo_debug.h"
+#include "sudo_util.h"
+
+#ifndef HAVE_GETGROUPLIST
+int
+sudo_getgrouplist(const char *name, GETGROUPS_T basegid, GETGROUPS_T *groups,
+ int *ngroupsp)
+{
+ return sudo_getgrouplist2(name, basegid, &groups, ngroupsp);
+}
+#endif /* HAVE_GETGROUPLIST */
+
+#if defined(HAVE_GETGROUPLIST)
+
+#if defined(HAVE_GETGROUPLIST_2) && !HAVE_DECL_GETGROUPLIST_2
+int getgrouplist_2(const char *name, GETGROUPS_T basegid, GETGROUPS_T **groups);
+#endif /* HAVE_GETGROUPLIST_2 && !HAVE_DECL_GETGROUPLIST_2 */
+
+/*
+ * Extended getgrouplist(3) using getgrouplist(3) and getgrouplist_2(3)
+ */
+int
+sudo_getgrouplist2_v1(const char *name, GETGROUPS_T basegid,
+ GETGROUPS_T **groupsp, int *ngroupsp)
+{
+#ifdef __APPLE__
+ int *groups = (int *)*groupsp;
+#else
+ GETGROUPS_T *groups = *groupsp;
+#endif
+ int ngroups;
+#ifndef HAVE_GETGROUPLIST_2
+ int grpsize, tries;
+#endif
+ debug_decl(sudo_getgrouplist2, SUDO_DEBUG_UTIL);
+
+ /* For static group vector, just use getgrouplist(3). */
+ if (groups != NULL)
+ debug_return_int(getgrouplist(name, basegid, groups, ngroupsp));
+
+#ifdef HAVE_GETGROUPLIST_2
+ if ((ngroups = getgrouplist_2(name, basegid, groupsp)) == -1)
+ debug_return_int(-1);
+ *ngroupsp = ngroups;
+ debug_return_int(0);
+#else
+ grpsize = (int)sysconf(_SC_NGROUPS_MAX);
+ if (grpsize < 0)
+ grpsize = NGROUPS_MAX;
+ grpsize++; /* include space for the primary gid */
+ /*
+ * It is possible to belong to more groups in the group database
+ * than NGROUPS_MAX.
+ */
+ for (tries = 0; tries < 10; tries++) {
+ free(groups);
+ groups = reallocarray(NULL, grpsize, sizeof(*groups));
+ if (groups == NULL)
+ debug_return_int(-1);
+ ngroups = grpsize;
+ if (getgrouplist(name, basegid, groups, &ngroups) != -1) {
+ *groupsp = groups;
+ *ngroupsp = ngroups;
+ debug_return_int(0);
+ }
+ if (ngroups == grpsize) {
+ /* Failed for some reason other than ngroups too small. */
+ break;
+ }
+ /* getgrouplist(3) set ngroups to the required length, use it. */
+ grpsize = ngroups;
+ }
+ free(groups);
+ debug_return_int(-1);
+#endif /* HAVE_GETGROUPLIST_2 */
+}
+
+#elif defined(HAVE_GETGRSET)
+
+/*
+ * Extended getgrouplist(3) using AIX getgrset(3)
+ */
+int
+sudo_getgrouplist2_v1(const char *name, GETGROUPS_T basegid,
+ GETGROUPS_T **groupsp, int *ngroupsp)
+{
+ GETGROUPS_T *groups = *groupsp;
+ char *cp, *last, *grset = NULL;
+ const char *errstr;
+ int ngroups = 1;
+ int grpsize = *ngroupsp;
+ int ret = -1;
+ gid_t gid;
+ debug_decl(sudo_getgrouplist2, SUDO_DEBUG_UTIL);
+
+#ifdef HAVE_SETAUTHDB
+ aix_setauthdb((char *) name, NULL);
+#endif
+ if ((grset = getgrset(name)) == NULL)
+ goto done;
+
+ if (groups == NULL) {
+ /* Dynamically-sized group vector, count groups and alloc. */
+ grpsize = 1; /* reserve one for basegid */
+ if (*grset != '\0') {
+ grpsize++; /* at least one supplementary group */
+ for (cp = grset; *cp != '\0'; cp++) {
+ if (*cp == ',')
+ grpsize++;
+ }
+ }
+ groups = reallocarray(NULL, grpsize, sizeof(*groups));
+ if (groups == NULL)
+ debug_return_int(-1);
+ } else {
+ /* Static group vector. */
+ if (grpsize < 1)
+ debug_return_int(-1);
+ }
+
+ /* We support BSD semantics where the first element is the base gid */
+ groups[0] = basegid;
+
+ for (cp = strtok_r(grset, ",", &last); cp != NULL; cp = strtok_r(NULL, ",", &last)) {
+ gid = sudo_strtoid(cp, &errstr);
+ if (errstr == NULL && gid != basegid) {
+ if (ngroups == grpsize)
+ goto done;
+ groups[ngroups++] = gid;
+ }
+ }
+ ret = 0;
+
+done:
+ free(grset);
+#ifdef HAVE_SETAUTHDB
+ aix_restoreauthdb();
+#endif
+ *groupsp = groups;
+ *ngroupsp = ngroups;
+
+ debug_return_int(ret);
+}
+
+#elif defined(HAVE_NSS_SEARCH)
+
+#ifndef ALIGNBYTES
+# define ALIGNBYTES (sizeof(long) - 1L)
+#endif
+#ifndef ALIGN
+# define ALIGN(p) (((unsigned long)(p) + ALIGNBYTES) & ~ALIGNBYTES)
+#endif
+
+#if defined(HAVE__NSS_INITF_GROUP) || defined(HAVE___NSS_INITF_GROUP)
+extern void _nss_initf_group(nss_db_params_t *params);
+#else
+static void
+_nss_initf_group(nss_db_params_t *params)
+{
+ params->name = NSS_DBNAM_GROUP;
+ params->default_config = NSS_DEFCONF_GROUP;
+}
+#endif
+
+/*
+ * Convert a groups file string (instr) to a struct group (ent) using
+ * buf for storage.
+ */
+static int
+str2grp(const char *instr, int inlen, void *ent, char *buf, int buflen)
+{
+ struct group *grp = ent;
+ char *cp, *fieldsep = buf;
+ char **gr_mem, **gr_end;
+ const char *errstr;
+ int yp = 0;
+ id_t id;
+ debug_decl(str2grp, SUDO_DEBUG_UTIL);
+
+ /* Must at least have space to copy instr -> buf. */
+ if (inlen >= buflen)
+ debug_return_int(NSS_STR_PARSE_ERANGE);
+
+ /* Paranoia: buf and instr should be distinct. */
+ if (buf != instr) {
+ memmove(buf, instr, inlen);
+ buf[inlen] = '\0';
+ }
+
+ if ((fieldsep = strchr(cp = fieldsep, ':')) == NULL)
+ debug_return_int(NSS_STR_PARSE_PARSE);
+ *fieldsep++ = '\0';
+ grp->gr_name = cp;
+
+ /* Check for YP inclusion/exclusion entries. */
+ if (*cp == '+' || *cp == '-') {
+ /* Only the name is required for YP inclusion/exclusion entries. */
+ grp->gr_passwd = (char *)"";
+ grp->gr_gid = 0;
+ grp->gr_mem = NULL;
+ yp = 1;
+ }
+
+ if ((fieldsep = strchr(cp = fieldsep, ':')) == NULL)
+ debug_return_int(yp ? NSS_STR_PARSE_SUCCESS : NSS_STR_PARSE_PARSE);
+ *fieldsep++ = '\0';
+ grp->gr_passwd = cp;
+
+ if ((fieldsep = strchr(cp = fieldsep, ':')) == NULL)
+ debug_return_int(yp ? NSS_STR_PARSE_SUCCESS : NSS_STR_PARSE_PARSE);
+ *fieldsep++ = '\0';
+ id = sudo_strtoid(cp, &errstr);
+ if (errstr != NULL) {
+ /*
+ * A range error is always a fatal error, but ignore garbage
+ * at the end of YP entries since it has no meaning.
+ */
+ if (errno == ERANGE)
+ debug_return_int(NSS_STR_PARSE_ERANGE);
+ debug_return_int(yp ? NSS_STR_PARSE_SUCCESS : NSS_STR_PARSE_PARSE);
+ }
+#ifdef GID_NOBODY
+ /* Negative gids get mapped to nobody on Solaris. */
+ if (*cp == '-' && id != 0)
+ grp->gr_gid = GID_NOBODY;
+ else
+#endif
+ grp->gr_gid = (gid_t)id;
+
+ /* Store group members, taking care to use proper alignment. */
+ grp->gr_mem = NULL;
+ if (*fieldsep != '\0') {
+ grp->gr_mem = gr_mem = (char **)ALIGN(buf + inlen + 1);
+ gr_end = (char **)((unsigned long)(buf + buflen) & ~ALIGNBYTES) - 1;
+ for (;;) {
+ if (gr_mem >= gr_end)
+ debug_return_int(NSS_STR_PARSE_ERANGE); /* out of space! */
+ *gr_mem++ = cp;
+ if (fieldsep == NULL)
+ break;
+ if ((fieldsep = strchr(cp = fieldsep, ',')) != NULL)
+ *fieldsep++ = '\0';
+ }
+ *gr_mem = NULL;
+ }
+ debug_return_int(NSS_STR_PARSE_SUCCESS);
+}
+
+static nss_status_t
+process_cstr(const char *instr, int inlen, struct nss_groupsbymem *gbm,
+ int dynamic)
+{
+ const char *user = gbm->username;
+ nss_status_t ret = NSS_NOTFOUND;
+ nss_XbyY_buf_t *buf;
+ struct group *grp;
+ char **gr_mem;
+ int error, i;
+ debug_decl(process_cstr, SUDO_DEBUG_UTIL);
+
+ sudo_debug_printf(SUDO_DEBUG_INFO, "%s: parsing %.*s", __func__,
+ inlen, instr);
+
+ /* Hack to let us check whether the query was handled by nscd or us. */
+ if (gbm->force_slow_way != 0)
+ gbm->force_slow_way = 2;
+
+ buf = _nss_XbyY_buf_alloc(sizeof(struct group), NSS_BUFLEN_GROUP);
+ if (buf == NULL)
+ debug_return_int(NSS_UNAVAIL);
+
+ /* Parse groups file string -> struct group. */
+ grp = buf->result;
+ error = (*gbm->str2ent)(instr, inlen, grp, buf->buffer, buf->buflen);
+ if (error != NSS_STR_PARSE_SUCCESS || grp->gr_mem == NULL)
+ goto done;
+
+ for (gr_mem = grp->gr_mem; *gr_mem != NULL; gr_mem++) {
+ if (strcmp(*gr_mem, user) == 0) {
+ const int numgids = MIN(gbm->numgids, gbm->maxgids);
+
+ /* Append to gid_array unless gr_gid is a dupe. */
+ for (i = 0; i < numgids; i++) {
+ if (gbm->gid_array[i] == grp->gr_gid)
+ goto done; /* already present */
+ }
+ if (i == gbm->maxgids && dynamic) {
+ GETGROUPS_T *tmp = reallocarray(gbm->gid_array, gbm->maxgids,
+ 2 * sizeof(GETGROUPS_T));
+ if (tmp == NULL) {
+ /* Out of memory, just return what we have. */
+ dynamic = 0;
+ } else {
+ gbm->gid_array = tmp;
+ gbm->maxgids <<= 1;
+ }
+ }
+ /* Store gid if there is space. */
+ if (i < gbm->maxgids)
+ gbm->gid_array[i] = grp->gr_gid;
+ /* Always increment numgids so we can detect when out of space. */
+ gbm->numgids++;
+ goto done;
+ }
+ }
+done:
+ _nss_XbyY_buf_free(buf);
+ debug_return_int(ret);
+}
+
+static nss_status_t
+process_cstr_static(const char *instr, int inlen, struct nss_groupsbymem *gbm)
+{
+ return process_cstr(instr, inlen, gbm, 0);
+}
+
+static nss_status_t
+process_cstr_dynamic(const char *instr, int inlen, struct nss_groupsbymem *gbm)
+{
+ return process_cstr(instr, inlen, gbm, 1);
+}
+
+/*
+ * Extended getgrouplist(3) using nss_search(3)
+ */
+int
+sudo_getgrouplist2_v1(const char *name, GETGROUPS_T basegid,
+ GETGROUPS_T **groupsp, int *ngroupsp)
+{
+ struct nss_groupsbymem gbm;
+ static DEFINE_NSS_DB_ROOT(db_root);
+ debug_decl(sudo_getgrouplist2, SUDO_DEBUG_UTIL);
+
+ memset(&gbm, 0, sizeof(gbm));
+ gbm.username = name;
+ gbm.gid_array = *groupsp;
+ gbm.maxgids = *ngroupsp;
+ gbm.numgids = 1; /* for basegid */
+ gbm.force_slow_way = 1;
+ gbm.str2ent = str2grp;
+
+ if (gbm.gid_array == NULL) {
+ /* Dynamically-sized group vector. */
+ gbm.maxgids = (int)sysconf(_SC_NGROUPS_MAX);
+ if (gbm.maxgids < 0)
+ gbm.maxgids = NGROUPS_MAX;
+ gbm.gid_array = reallocarray(NULL, gbm.maxgids, 4 * sizeof(GETGROUPS_T));
+ if (gbm.gid_array == NULL)
+ debug_return_int(-1);
+ gbm.maxgids <<= 2;
+ gbm.process_cstr = process_cstr_dynamic;
+ } else {
+ /* Static group vector. */
+ if (gbm.maxgids <= 0)
+ debug_return_int(-1);
+ gbm.process_cstr = process_cstr_static;
+ }
+
+ /* We support BSD semantics where the first element is the base gid */
+ gbm.gid_array[0] = basegid;
+
+ /*
+ * Can't use nss_search return value since it may return NSS_UNAVAIL
+ * when no nsswitch.conf entry (e.g. compat mode).
+ */
+ for (;;) {
+ GETGROUPS_T *tmp;
+
+ (void)nss_search(&db_root, _nss_initf_group, NSS_DBOP_GROUP_BYMEMBER,
+ &gbm);
+
+ /*
+ * If this was a statically-sized group vector or nscd was not used
+ * we are done.
+ */
+ if (gbm.process_cstr != process_cstr_dynamic || gbm.force_slow_way == 2)
+ break;
+
+ /*
+ * If gid_array is full and the query was handled by nscd, there
+ * may be more data, so double gid_array and try again.
+ */
+ if (gbm.numgids != gbm.maxgids)
+ break;
+
+ tmp = reallocarray(gbm.gid_array, gbm.maxgids, 2 * sizeof(GETGROUPS_T));
+ if (tmp == NULL) {
+ free(gbm.gid_array);
+ debug_return_int(-1);
+ }
+ gbm.gid_array = tmp;
+ gbm.maxgids <<= 1;
+ }
+
+ /* Note: we can only detect a too-small group list if nscd is not used. */
+ *groupsp = gbm.gid_array;
+ if (gbm.numgids <= gbm.maxgids) {
+ *ngroupsp = gbm.numgids;
+ debug_return_int(0);
+ }
+ *ngroupsp = gbm.maxgids;
+ debug_return_int(-1);
+}
+
+#else /* !HAVE_GETGROUPLIST && !HAVE_GETGRSET && !HAVE__GETGROUPSBYMEMBER */
+
+/*
+ * Extended getgrouplist(3) using getgrent(3)
+ */
+int
+sudo_getgrouplist2_v1(const char *name, GETGROUPS_T basegid,
+ GETGROUPS_T **groupsp, int *ngroupsp)
+{
+ GETGROUPS_T *groups = *groupsp;
+ int grpsize = *ngroupsp;
+ int i, ngroups = 1;
+ int ret = -1;
+ struct group *grp;
+ debug_decl(sudo_getgrouplist2, SUDO_DEBUG_UTIL);
+
+ if (groups == NULL) {
+ /* Dynamically-sized group vector. */
+ grpsize = (int)sysconf(_SC_NGROUPS_MAX);
+ if (grpsize < 0)
+ grpsize = NGROUPS_MAX;
+ groups = reallocarray(NULL, grpsize, 4 * sizeof(*groups));
+ if (groups == NULL)
+ debug_return_int(-1);
+ grpsize <<= 2;
+ } else {
+ /* Static group vector. */
+ if (grpsize < 1)
+ debug_return_int(-1);
+ }
+
+ /* We support BSD semantics where the first element is the base gid */
+ groups[0] = basegid;
+
+ setgrent();
+ while ((grp = getgrent()) != NULL) {
+ if (grp->gr_gid == basegid || grp->gr_mem == NULL)
+ continue;
+
+ for (i = 0; grp->gr_mem[i] != NULL; i++) {
+ if (strcmp(name, grp->gr_mem[i]) == 0)
+ break;
+ }
+ if (grp->gr_mem[i] == NULL)
+ continue; /* user not found */
+
+ /* Only add if it is not the same as an existing gid */
+ for (i = 0; i < ngroups; i++) {
+ if (grp->gr_gid == groups[i])
+ break;
+ }
+ if (i == ngroups) {
+ if (ngroups == grpsize) {
+ GETGROUPS_T *tmp;
+
+ if (*groupsp != NULL) {
+ /* Static group vector. */
+ goto done;
+ }
+ tmp = reallocarray(groups, grpsize, 2 * sizeof(*groups));
+ if (tmp == NULL) {
+ free(groups);
+ groups = NULL;
+ ngroups = 0;
+ goto done;
+ }
+ groups = tmp;
+ grpsize <<= 1;
+ }
+ groups[ngroups++] = grp->gr_gid;
+ }
+ }
+ ret = 0;
+
+done:
+ endgrent();
+ *groupsp = groups;
+ *ngroupsp = ngroups;
+
+ debug_return_int(ret);
+}
+#endif /* !HAVE_GETGROUPLIST && !HAVE_GETGRSET && !HAVE__GETGROUPSBYMEMBER */
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