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-rw-r--r--libpam/pam_modutil_ingroup.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/libpam/pam_modutil_ingroup.c b/libpam/pam_modutil_ingroup.c
new file mode 100644
index 0000000..356302e
--- /dev/null
+++ b/libpam/pam_modutil_ingroup.c
@@ -0,0 +1,130 @@
+/*
+ * $Id$
+ *
+ * This function provides common methods for checking if a user is in a
+ * specified group.
+ */
+
+#include "pam_modutil_private.h"
+
+#include <stdlib.h>
+#include <pwd.h>
+#include <grp.h>
+
+#ifdef HAVE_GETGROUPLIST
+
+#define NGROUPS_MIN 100
+#define NGROUPS_MAX 65536
+
+static int checkgrouplist(const char *user, gid_t primary, gid_t target)
+{
+ int ngroups, pgroups, i;
+
+ ngroups = NGROUPS_MIN;
+ do {
+ gid_t *grouplist;
+
+ pgroups = ngroups;
+ grouplist = malloc(sizeof(gid_t) * ngroups);
+ if (grouplist == NULL) {
+ return 0;
+ }
+ i = getgrouplist(user, primary, grouplist, &ngroups);
+ if (i >= 0) {
+ for (i = 0; i < ngroups; i++) {
+ if (grouplist[i] == target) {
+ free(grouplist);
+ return 1;
+ }
+ }
+ }
+ free(grouplist);
+ } while (i < 0 && ngroups > 0 && ngroups != pgroups && ngroups <= NGROUPS_MAX);
+ return 0;
+}
+#endif
+
+static int
+pam_modutil_user_in_group_common(pam_handle_t *pamh UNUSED,
+ struct passwd *pwd,
+ struct group *grp)
+{
+ int i;
+
+ if (pwd == NULL) {
+ return 0;
+ }
+ if (grp == NULL) {
+ return 0;
+ }
+
+ if (pwd->pw_gid == grp->gr_gid) {
+ return 1;
+ }
+
+ for (i = 0; (grp->gr_mem != NULL) && (grp->gr_mem[i] != NULL); i++) {
+ if (strcmp(pwd->pw_name, grp->gr_mem[i]) == 0) {
+ return 1;
+ }
+ }
+
+#ifdef HAVE_GETGROUPLIST
+ if (checkgrouplist(pwd->pw_name, pwd->pw_gid, grp->gr_gid)) {
+ return 1;
+ }
+#endif
+
+ return 0;
+}
+
+int
+pam_modutil_user_in_group_nam_nam(pam_handle_t *pamh,
+ const char *user, const char *group)
+{
+ struct passwd *pwd;
+ struct group *grp;
+
+ pwd = pam_modutil_getpwnam(pamh, user);
+ grp = pam_modutil_getgrnam(pamh, group);
+
+ return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_nam_gid(pam_handle_t *pamh,
+ const char *user, gid_t group)
+{
+ struct passwd *pwd;
+ struct group *grp;
+
+ pwd = pam_modutil_getpwnam(pamh, user);
+ grp = pam_modutil_getgrgid(pamh, group);
+
+ return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_uid_nam(pam_handle_t *pamh,
+ uid_t user, const char *group)
+{
+ struct passwd *pwd;
+ struct group *grp;
+
+ pwd = pam_modutil_getpwuid(pamh, user);
+ grp = pam_modutil_getgrnam(pamh, group);
+
+ return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_uid_gid(pam_handle_t *pamh,
+ uid_t user, gid_t group)
+{
+ struct passwd *pwd;
+ struct group *grp;
+
+ pwd = pam_modutil_getpwuid(pamh, user);
+ grp = pam_modutil_getgrgid(pamh, group);
+
+ return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}