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Diffstat (limited to '')
| -rw-r--r-- | src/newgrp.c | 879 |
1 files changed, 879 insertions, 0 deletions
diff --git a/src/newgrp.c b/src/newgrp.c new file mode 100644 index 0000000..e3c44e1 --- /dev/null +++ b/src/newgrp.c @@ -0,0 +1,879 @@ +/* + * Copyright (c) 1990 - 1994, Julianne Frances Haugh + * Copyright (c) 1996 - 2000, Marek Michałkiewicz + * Copyright (c) 2001 - 2006, Tomasz Kłoczko + * Copyright (c) 2007 - 2008, Nicolas François + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#ident "$Id$" + +#include <errno.h> +#include <grp.h> +#include <pwd.h> +#include <stdio.h> +#include <assert.h> +#include "defines.h" +#include "getdef.h" +#include "prototypes.h" +/*@-exitarg@*/ +#include "exitcodes.h" + +/* + * Global variables + */ +const char *Prog; + +extern char **newenvp; +extern char **environ; + +#ifdef HAVE_SETGROUPS +static int ngroups; +static /*@null@*/ /*@only@*/GETGROUPS_T *grouplist; +#endif + +static bool is_newgrp; + +#ifdef WITH_AUDIT +static char audit_buf[80]; +#endif + +/* local function prototypes */ +static void usage (void); +static void check_perms (const struct group *grp, + struct passwd *pwd, + const char *groupname); +static void syslog_sg (const char *name, const char *group); + +/* + * usage - print command usage message + */ +static void usage (void) +{ + if (is_newgrp) { + (void) fputs (_("Usage: newgrp [-] [group]\n"), stderr); + } else { + (void) fputs (_("Usage: sg group [[-c] command]\n"), stderr); + } +} + +static bool ingroup(const char *name, struct group *gr) +{ + char **look; + bool notfound = true; + + look = gr->gr_mem; + while (*look && notfound) + notfound = strcmp (*look++, name); + + return !notfound; +} + +/* + * find_matching_group - search all groups of a gr's group id for + * membership of a given username + * but check gr itself first + */ +static /*@null@*/struct group *find_matching_group (const char *name, struct group *gr) +{ + gid_t gid = gr->gr_gid; + + if (ingroup(name, gr)) + return gr; + + setgrent (); + while ((gr = getgrent ()) != NULL) { + if (gr->gr_gid != gid) { + continue; + } + + /* + * A group with matching GID was found. + * Test for membership of 'name'. + */ + if (ingroup(name, gr)) + break; + } + endgrent (); + return gr; +} + +/* + * check_perms - check if the user is allowed to switch to this group + * + * If needed, the user will be authenticated. + * + * It will not return if the user could not be authenticated. + */ +static void check_perms (const struct group *grp, + struct passwd *pwd, + const char *groupname) +{ + bool needspasswd = false; + struct spwd *spwd; + char *cp; + const char *cpasswd; + + /* + * see if she is a member of this group (i.e. in the list of + * members of the group, or if the group is her primary group). + * + * If she isn't a member, she needs to provide the group password. + * If there is no group password, she will be denied access + * anyway. + * + */ + if ( (grp->gr_gid != pwd->pw_gid) + && !is_on_list (grp->gr_mem, pwd->pw_name)) { + needspasswd = true; + } + + /* + * If she does not have either a shadowed password, or a regular + * password, and the group has a password, she needs to give the + * group password. + */ + spwd = xgetspnam (pwd->pw_name); + if (NULL != spwd) { + pwd->pw_passwd = spwd->sp_pwdp; + } + + if ((pwd->pw_passwd[0] == '\0') && (grp->gr_passwd[0] != '\0')) { + needspasswd = true; + } + + /* + * Now I see about letting her into the group she requested. If she + * is the root user, I'll let her in without having to prompt for + * the password. Otherwise I ask for a password if she flunked one + * of the tests above. + */ + if ((getuid () != 0) && needspasswd) { + /* + * get the password from her, and set the salt for + * the decryption from the group file. + */ + cp = getpass (_("Password: ")); + if (NULL == cp) { + goto failure; + } + + /* + * encrypt the key she gave us using the salt from the + * password in the group file. The result of this encryption + * must match the previously encrypted value in the file. + */ + cpasswd = pw_encrypt (cp, grp->gr_passwd); + strzero (cp); + + if (NULL == cpasswd) { + fprintf (stderr, + _("%s: failed to crypt password with previous salt: %s\n"), + Prog, strerror (errno)); + SYSLOG ((LOG_INFO, + "Failed to crypt password with previous salt of group '%s'", + groupname)); + goto failure; + } + + if (grp->gr_passwd[0] == '\0' || + strcmp (cpasswd, grp->gr_passwd) != 0) { +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), + "authentication new-gid=%lu", + (unsigned long) grp->gr_gid); + audit_logger (AUDIT_GRP_AUTH, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); +#endif + SYSLOG ((LOG_INFO, + "Invalid password for group '%s' from '%s'", + groupname, pwd->pw_name)); + (void) sleep (1); + (void) fputs (_("Invalid password.\n"), stderr); + goto failure; + } +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), + "authentication new-gid=%lu", + (unsigned long) grp->gr_gid); + audit_logger (AUDIT_GRP_AUTH, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 1); +#endif + } + + return; + +failure: + /* The closelog is probably unnecessary, but it does no + * harm. -- JWP + */ + closelog (); +#ifdef WITH_AUDIT + if (groupname) { + snprintf (audit_buf, sizeof(audit_buf), + "changing new-group=%s", groupname); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); + } else { + audit_logger (AUDIT_CHGRP_ID, Prog, + "changing", NULL, + (unsigned int) getuid (), 0); + } +#endif + exit (EXIT_FAILURE); +} + +#ifdef USE_SYSLOG +/* + * syslog_sg - log the change of group to syslog + * + * The logout will also be logged when the user will quit the + * sg/newgrp session. + */ +static void syslog_sg (const char *name, const char *group) +{ + const char *loginname = getlogin (); + const char *tty = ttyname (0); + char *free_login = NULL, *free_tty = NULL; + + if (loginname != NULL) { + free_login = xstrdup (loginname); + loginname = free_login; + } + if (tty != NULL) { + free_tty = xstrdup (tty); + tty = free_tty; + } + + if (loginname == NULL) { + loginname = "???"; + } + if (tty == NULL) { + tty = "???"; + } else if (strncmp (tty, "/dev/", 5) == 0) { + tty += 5; + } + SYSLOG ((LOG_INFO, + "user '%s' (login '%s' on %s) switched to group '%s'", + name, loginname, tty, group)); +#ifdef USE_PAM + /* + * We want to fork and exec the new shell in the child, leaving the + * parent waiting to log the session close. + * + * The parent must ignore signals generated from the console + * (SIGINT, SIGQUIT, SIGHUP) which might make the parent terminate + * before its child. When bash is exec'ed as the subshell, it + * generates a new process group id for itself, and consequently + * only SIGHUP, which is sent to all process groups in the session, + * can reach the parent. However, since arbitrary programs can be + * specified as login shells, there is no such guarantee in general. + * For the same reason, we must also ignore stop signals generated + * from the console (SIGTSTP, SIGTTIN, and SIGTTOU) in order to + * avoid any possibility of the parent being stopped when it + * receives SIGCHLD from the terminating subshell. -- JWP + */ + { + pid_t child; + + /* Ignore these signals. The signal handlers will later be + * restored to the default handlers. */ + (void) signal (SIGINT, SIG_IGN); + (void) signal (SIGQUIT, SIG_IGN); + (void) signal (SIGHUP, SIG_IGN); + (void) signal (SIGTSTP, SIG_IGN); + (void) signal (SIGTTIN, SIG_IGN); + (void) signal (SIGTTOU, SIG_IGN); + child = fork (); + if ((pid_t)-1 == child) { + /* error in fork() */ + fprintf (stderr, _("%s: failure forking: %s\n"), + is_newgrp ? "newgrp" : "sg", strerror (errno)); +#ifdef WITH_AUDIT + if (group) { + snprintf (audit_buf, sizeof(audit_buf), + "changing new-group=%s", group); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); + } else { + audit_logger (AUDIT_CHGRP_ID, Prog, + "changing", NULL, + (unsigned int) getuid (), 0); + } +#endif + exit (EXIT_FAILURE); + } else if (child != 0) { + /* parent - wait for child to finish, then log session close */ + int cst = 0; + gid_t gid = getgid(); + struct group *grp = getgrgid (gid); + pid_t pid; + + do { + errno = 0; + pid = waitpid (child, &cst, WUNTRACED); + if ((pid == child) && (WIFSTOPPED (cst) != 0)) { + /* The child (shell) was suspended. + * Suspend sg/newgrp. */ + kill (getpid (), SIGSTOP); + /* wake child when resumed */ + kill (child, SIGCONT); + } + } while ( ((pid == child) && (WIFSTOPPED (cst) != 0)) + || ((pid != child) && (errno == EINTR))); + /* local, no need for xgetgrgid */ + if (NULL != grp) { + SYSLOG ((LOG_INFO, + "user '%s' (login '%s' on %s) returned to group '%s'", + name, loginname, tty, grp->gr_name)); + } else { + SYSLOG ((LOG_INFO, + "user '%s' (login '%s' on %s) returned to group '%lu'", + name, loginname, tty, + (unsigned long) gid)); + /* Either the user's passwd entry has a + * GID that does not match with any group, + * or the group was deleted while the user + * was in a newgrp session.*/ + SYSLOG ((LOG_WARN, + "unknown GID '%lu' used by user '%s'", + (unsigned long) gid, name)); + } + closelog (); + exit ((0 != WIFEXITED (cst)) ? WEXITSTATUS (cst) + : WTERMSIG (cst) + 128); + } + + /* child - restore signals to their default state */ + (void) signal (SIGINT, SIG_DFL); + (void) signal (SIGQUIT, SIG_DFL); + (void) signal (SIGHUP, SIG_DFL); + (void) signal (SIGTSTP, SIG_DFL); + (void) signal (SIGTTIN, SIG_DFL); + (void) signal (SIGTTOU, SIG_DFL); + } +#endif /* USE_PAM */ + free(free_login); + free(free_tty); +} +#endif /* USE_SYSLOG */ + +/* + * newgrp - change the invokers current real and effective group id + */ +int main (int argc, char **argv) +{ + bool initflag = false; + int i; + bool is_member = false; + bool cflag = false; + int err = 0; + gid_t gid; + char *cp; + char *progbase; + const char *name, *prog; + char *group = NULL; + char *command = NULL; + char **envp = environ; + struct passwd *pwd; + /*@null@*/struct group *grp; + +#ifdef SHADOWGRP + struct sgrp *sgrp; +#endif + +#ifdef WITH_AUDIT + audit_help_open (); +#endif + (void) setlocale (LC_ALL, ""); + (void) bindtextdomain (PACKAGE, LOCALEDIR); + (void) textdomain (PACKAGE); + + /* + * Save my name for error messages and save my real gid incase of + * errors. If there is an error i have to exec a new login shell for + * the user since her old shell won't have fork'd to create the + * process. Skip over the program name to the next command line + * argument. + * + * This historical comment, and the code itself, suggest that the + * behavior of the system/shell on which it was written differed + * significantly from the one I am using. If this process was + * started from a shell (including the login shell), it was fork'ed + * and exec'ed as a child by that shell. In order to get the user + * back to that shell, it is only necessary to exit from this + * process which terminates the child of the fork. The parent shell, + * which is blocked waiting for a signal, will then receive a + * SIGCHLD and will continue; any changes made to the process + * persona or the environment after the fork never occurred in the + * parent process. + * + * Bottom line: we want to save the name and real gid for messages, + * but we do not need to restore the previous process persona and we + * don't need to re-exec anything. -- JWP + */ + Prog = Basename (argv[0]); + is_newgrp = (strcmp (Prog, "newgrp") == 0); + OPENLOG (is_newgrp ? "newgrp" : "sg"); + gid = getgid (); + argc--; + argv++; + + initenv (); + + pwd = get_my_pwent (); + if (NULL == pwd) { + fprintf (stderr, _("%s: Cannot determine your user name.\n"), + Prog); +#ifdef WITH_AUDIT + audit_logger (AUDIT_CHGRP_ID, Prog, + "changing", NULL, + (unsigned int) getuid (), 0); +#endif + SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)", + (unsigned long) getuid ())); + closelog (); + exit (EXIT_FAILURE); + } + name = pwd->pw_name; + + /* + * Parse the command line. There are two accepted flags. The first + * is "-", which for newgrp means to re-create the entire + * environment as though a login had been performed, and "-c", which + * for sg causes a command string to be executed. + * + * The next argument, if present, must be the new group name. Any + * remaining remaining arguments will be used to execute a command + * as the named group. If the group name isn't present, I just use + * the login group ID of the current user. + * + * The valid syntax are + * newgrp [-] [groupid] + * newgrp [-l] [groupid] + * sg [-] + * sg [-] groupid [[-c command] + */ + if ( (argc > 0) + && ( (strcmp (argv[0], "-") == 0) + || (strcmp (argv[0], "-l") == 0))) { + argc--; + argv++; + initflag = true; + } + if (!is_newgrp) { + /* + * Do the command line for everything that is + * not "newgrp". + */ + if ((argc > 0) && (argv[0][0] != '-')) { + group = argv[0]; + argc--; + argv++; + } else { + usage (); + closelog (); + exit (EXIT_FAILURE); + } + if (argc > 0) { + + /* + * skip -c if specified so both forms work: + * "sg group -c command" (as in the man page) or + * "sg group command" (as in the usage message). + */ + if ((argc > 1) && (strcmp (argv[0], "-c") == 0)) { + command = argv[1]; + } else { + command = argv[0]; + } + cflag = true; + } + } else { + /* + * Do the command line for "newgrp". It's just making sure + * there aren't any flags and getting the new group name. + */ + if ((argc > 0) && (argv[0][0] == '-')) { + usage (); + goto failure; + } else if (argv[0] != (char *) 0) { + group = argv[0]; + } else { + /* + * get the group file entry for her login group id. + * the entry must exist, simply to be annoying. + * + * Perhaps in the past, but the default behavior now depends on the + * group entry, so it had better exist. -- JWP + */ + grp = xgetgrgid (pwd->pw_gid); + if (NULL == grp) { + fprintf (stderr, + _("%s: GID '%lu' does not exist\n"), + Prog, (unsigned long) pwd->pw_gid); + SYSLOG ((LOG_CRIT, "GID '%lu' does not exist", + (unsigned long) pwd->pw_gid)); + goto failure; + } else { + group = grp->gr_name; + } + } + } + +#ifdef HAVE_SETGROUPS + /* + * get the current users groupset. The new group will be added to + * the concurrent groupset if there is room, otherwise you get a + * nasty message but at least your real and effective group id's are + * set. + */ + /* don't use getgroups(0, 0) - it doesn't work on some systems */ + i = 16; + for (;;) { + grouplist = (GETGROUPS_T *) xmalloc (i * sizeof (GETGROUPS_T)); + ngroups = getgroups (i, grouplist); + if (i > ngroups && !(ngroups == -1 && errno == EINVAL)) { + break; + } + /* not enough room, so try allocating a larger buffer */ + free (grouplist); + i *= 2; + } + if (ngroups < 0) { + perror ("getgroups"); +#ifdef WITH_AUDIT + if (group) { + snprintf (audit_buf, sizeof(audit_buf), + "changing new-group=%s", group); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); + } else { + audit_logger (AUDIT_CHGRP_ID, Prog, + "changing", NULL, + (unsigned int) getuid (), 0); + } +#endif + exit (EXIT_FAILURE); + } +#endif /* HAVE_SETGROUPS */ + + /* + * now we put her in the new group. The password file entry for her + * current user id has been gotten. If there was no optional group + * argument she will have her real and effective group id set to the + * set to the value from her password file entry. + * + * If run as newgrp, or as sg with no command, this process exec's + * an interactive subshell with the effective GID of the new group. + * If run as sg with a command, that command is exec'ed in this + * subshell. When this process terminates, either because the user + * exits, or the command completes, the parent of this process + * resumes with the current GID. + * + * If a group is explicitly specified on the command line, the + * interactive shell or command is run with that effective GID. + * Access will be denied if no entry for that group can be found in + * /etc/group. If the current user name appears in the members list + * for that group, access will be granted immediately; if not, the + * user will be challenged for that group's password. If the + * password response is incorrect, if the specified group does not + * have a password, or if that group has been locked by gpasswd -R, + * access will be denied. This is true even if the group specified + * has the user's login GID (as shown in /etc/passwd). If no group + * is explicitly specified on the command line, the effect is + * exactly the same as if a group name matching the user's login GID + * had been explicitly specified. Root, however, is never + * challenged for passwords, and is always allowed access. + * + * The previous behavior was to allow access to the login group if + * no explicit group was specified, irrespective of the group + * control file(s). This behavior is usually not desirable. A user + * wishing to return to the login group has only to exit back to the + * login shell. Generating yet more shell levels in order to + * provide a convenient "return" to the default group has the + * undesirable side effects of confusing the user, scrambling the + * history file, and consuming system resources. The default now is + * to lock out such behavior. A sys admin can allow it by explicitly + * including the user's name in the member list of the user's login + * group. -- JWP + */ + grp = getgrnam (group); /* local, no need for xgetgrnam */ + if (NULL == grp) { + fprintf (stderr, _("%s: group '%s' does not exist\n"), Prog, group); + goto failure; + } + +#ifdef HAVE_SETGROUPS + /* when using pam_group, she will not be listed in the groups + * database. However getgroups() will return the group. So + * if she is listed there already it is ok to grant membership. + */ + for (i = 0; i < ngroups; i++) { + if (grp->gr_gid == grouplist[i]) { + is_member = true; + break; + } + } +#endif /* HAVE_SETGROUPS */ + /* + * For splitted groups (due to limitations of NIS), check all + * groups of the same GID like the requested group for + * membership of the current user. + */ + if (!is_member) { + grp = find_matching_group (name, grp); + if (NULL == grp) { + /* + * No matching group found. As we already know that + * the group exists, this happens only in the case + * of a requested group where the user is not member. + * + * Re-read the group entry for further processing. + */ + grp = xgetgrnam (group); + assert (NULL != grp); + } + } +#ifdef SHADOWGRP + sgrp = getsgnam (group); + if (NULL != sgrp) { + grp->gr_passwd = sgrp->sg_passwd; + grp->gr_mem = sgrp->sg_mem; + } +#endif + + /* + * Check if the user is allowed to access this group. + */ + if (!is_member) { + check_perms (grp, pwd, group); + } + + /* + * all successful validations pass through this point. The group id + * will be set, and the group added to the concurrent groupset. + */ +#ifdef USE_SYSLOG + if (getdef_bool ("SYSLOG_SG_ENAB")) { + syslog_sg (name, group); + } +#endif /* USE_SYSLOG */ + + gid = grp->gr_gid; + +#ifdef HAVE_SETGROUPS + /* + * I am going to try to add her new group id to her concurrent group + * set. If the group id is already present i'll just skip this part. + * If the group doesn't fit, i'll complain loudly and skip this + * part. + */ + for (i = 0; i < ngroups; i++) { + if (gid == grouplist[i]) { + break; + } + } + if (i == ngroups) { + if (ngroups >= sysconf (_SC_NGROUPS_MAX)) { + (void) fputs (_("too many groups\n"), stderr); + } else { + grouplist[ngroups++] = gid; + if (setgroups (ngroups, grouplist) != 0) { + perror ("setgroups"); + } + } + } +#endif + + /* + * Close all files before changing the user/group IDs. + * + * The needed structure should have been copied before, or + * permission to read the database will be required. + */ + endspent (); +#ifdef SHADOWGRP + endsgent (); +#endif + endpwent (); + endgrent (); + + /* + * Set the effective GID to the new group id and the effective UID + * to the real UID. For root, this also sets the real GID to the + * new group id. + */ + if (setgid (gid) != 0) { + perror ("setgid"); +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), + "changing new-gid=%lu", (unsigned long) gid); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); +#endif + exit (EXIT_FAILURE); + } + + if (setuid (getuid ()) != 0) { + perror ("setuid"); +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), + "changing new-gid=%lu", (unsigned long) gid); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); +#endif + exit (EXIT_FAILURE); + } + + /* + * See if the "-c" flag was used. If it was, i just create a shell + * command for her using the argument that followed the "-c" flag. + */ + if (cflag) { + closelog (); + execl (SHELL, "sh", "-c", command, (char *) 0); +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), + "changing new-gid=%lu", (unsigned long) gid); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); +#endif + perror (SHELL); + exit ((errno == ENOENT) ? E_CMD_NOTFOUND : E_CMD_NOEXEC); + } + + /* + * I have to get the pathname of her login shell. As a favor, i'll + * try her environment for a $SHELL value first, and then try the + * password file entry. Obviously this shouldn't be in the + * restricted command directory since it could be used to leave the + * restricted environment. + * + * Note that the following assumes this user's entry in /etc/passwd + * does not have a chroot * prefix. If it does, the * will be copied + * verbatim into the exec path. This is probably not an issue + * because if this user is operating in a chroot jail, her entry in + * the version of /etc/passwd that is accessible here should + * probably never have a chroot shell entry (but entries for other + * users might). If I have missed something, and this causes you a + * problem, try using $SHELL as a workaround; also please notify me + * at jparmele@wildbear.com -- JWP + */ + cp = getenv ("SHELL"); + if (!initflag && (NULL != cp)) { + prog = cp; + } else if ((NULL != pwd->pw_shell) && ('\0' != pwd->pw_shell[0])) { + prog = pwd->pw_shell; + } else { + prog = SHELL; + } + + /* + * Now I try to find the basename of the login shell. This will + * become argv[0] of the spawned command. + */ + progbase = (char *) Basename ((char *) prog); + + /* + * Switch back to her home directory if i am doing login + * initialization. + */ + if (initflag) { + if (chdir (pwd->pw_dir) != 0) { + perror ("chdir"); + } + + while (NULL != *envp) { + if (strncmp (*envp, "PATH=", 5) == 0 || + strncmp (*envp, "HOME=", 5) == 0 || + strncmp (*envp, "SHELL=", 6) == 0 || + strncmp (*envp, "TERM=", 5) == 0) + addenv (*envp, NULL); + + envp++; + } + } else { + while (NULL != *envp) { + addenv (*envp, NULL); + envp++; + } + } + +#ifdef WITH_AUDIT + snprintf (audit_buf, sizeof(audit_buf), "changing new-gid=%lu", + (unsigned long) gid); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 1); +#endif + /* + * Exec the login shell and go away. We are trying to get back to + * the previous environment which should be the user's login shell. + */ + err = shell (prog, initflag ? (char *) 0 : progbase, newenvp); + exit ((err == ENOENT) ? E_CMD_NOTFOUND : E_CMD_NOEXEC); + /*@notreached@*/ + failure: + + /* + * The previous code, when run as newgrp, re-exec'ed the shell in + * the current process with the original gid on error conditions. + * See the comment above. This historical behavior now has the + * effect of creating unlogged extraneous shell layers when the + * command line has an error or there is an authentication failure. + * We now just want to exit with error status back to the parent + * process. The closelog is probably unnecessary, but it does no + * harm. -- JWP + */ + closelog (); +#ifdef WITH_AUDIT + if (NULL != group) { + snprintf (audit_buf, sizeof(audit_buf), + "changing new-group=%s", group); + audit_logger (AUDIT_CHGRP_ID, Prog, + audit_buf, NULL, + (unsigned int) getuid (), 0); + } else { + audit_logger (AUDIT_CHGRP_ID, Prog, + "changing", NULL, + (unsigned int) getuid (), 0); + } +#endif + exit (EXIT_FAILURE); +} + |