diff options
author | des <des@FreeBSD.org> | 2002-01-30 19:10:21 +0000 |
---|---|---|
committer | des <des@FreeBSD.org> | 2002-01-30 19:10:21 +0000 |
commit | 55cd9bb2e33a3623fd62ff11ae442a44dc29c0fa (patch) | |
tree | 3bcc0f2228325e3d9f4de6703239dbcb5750bbce /usr.bin/login/login.c | |
parent | 1caa7bdd9eceeecfb676b36880fa12a25d1da85e (diff) | |
download | FreeBSD-src-55cd9bb2e33a3623fd62ff11ae442a44dc29c0fa.zip FreeBSD-src-55cd9bb2e33a3623fd62ff11ae442a44dc29c0fa.tar.gz |
Still with asbestos longjohns on, completely PAMify login(1) and remove
code made redundant by various PAM modules (primarily pam_unix(8)).
Sponsored by: DARPA, NAI Labs
Diffstat (limited to 'usr.bin/login/login.c')
-rw-r--r-- | usr.bin/login/login.c | 898 |
1 files changed, 369 insertions, 529 deletions
diff --git a/usr.bin/login/login.c b/usr.bin/login/login.c index d84a274..b6a6c2b 100644 --- a/usr.bin/login/login.c +++ b/usr.bin/login/login.c @@ -56,20 +56,16 @@ __FBSDID("$FreeBSD$"); #include <sys/copyright.h> #include <sys/param.h> #include <sys/file.h> -#include <sys/socket.h> #include <sys/stat.h> #include <sys/time.h> #include <sys/resource.h> #include <sys/wait.h> -#include <netinet/in.h> -#include <arpa/inet.h> #include <err.h> #include <errno.h> #include <grp.h> #include <libutil.h> #include <login_cap.h> -#include <netdb.h> #include <pwd.h> #include <setjmp.h> #include <signal.h> @@ -79,12 +75,9 @@ __FBSDID("$FreeBSD$"); #include <syslog.h> #include <ttyent.h> #include <unistd.h> -#include <utmp.h> -#ifndef NO_PAM #include <security/pam_appl.h> #include <security/pam_misc.h> -#endif #include "login.h" #include "pathnames.h" @@ -94,97 +87,104 @@ __FBSDID("$FreeBSD$"); #define NI_WITHSCOPEID 0 #endif -static int auth_traditional __P((void)); -static void badlogin __P((char *)); -static void dolastlog __P((int)); -static void getloginname __P((void)); -static void motd __P((const char *)); -static void refused __P((const char *,const char *,int)); -static int rootterm __P((char *)); -static void sigint __P((int)); -static void sleepexit __P((int)); -static const char *stypeof __P((char *)); -static void timedout __P((int)); -static void usage __P((void)); - -#ifndef NO_PAM -static int auth_pam __P((void)); -static int export_pam_environment __P((void)); -static int ok_to_export __P((const char *)); - -static pam_handle_t *pamh = NULL; -static char **environ_pam; - -#define PAM_END { \ - if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \ - syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \ - if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \ - syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \ - if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \ - syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \ -} -#endif /* NO_PAM */ +static int auth_pam(void); +static void bail(int, int); +static int export(const char *); +static void export_pam_environment(void); +static int motd(const char *); +static void badlogin(char *); +static char *getloginname(void); +static void pam_syslog(const char *); +static void pam_cleanup(void); +static void refused(const char *, const char *, int); +static const char *stypeof(char *); +static void sigint(int); +static void timedout(int); +static void usage(void); #define TTYGRPNAME "tty" /* group to own ttys */ #define DEFAULT_BACKOFF 3 #define DEFAULT_RETRIES 10 #define DEFAULT_PROMPT "login: " #define DEFAULT_PASSWD_PROMPT "Password:" -#define INVALID_HOST "invalid hostname" -#define UNKNOWN "su" +#define TERM_UNKNOWN "su" #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ -#define NBUFSIZ UT_NAMESIZE + 64 +#define NO_SLEEP_EXIT 0 +#define SLEEP_EXIT 5 /* * This bounds the time given to login. Not a define so it can * be patched on machines where it's too small. */ -u_int timeout = 300; +static u_int timeout = 300; /* Buffer for signal handling of timeout */ -jmp_buf timeout_buf; +static jmp_buf timeout_buf; + +struct passwd *pwd; +static int failures; + +static char *envinit[1]; /* empty environment list */ + +/* + * Command line flags and arguments + */ +static int fflag; /* -f: do not perform authentication */ +static int hflag; /* -h: login from remote host */ +static char *hostname; /* hostname from command line */ +static int pflag; /* -p: preserve environment */ + +/* + * User name + */ +static char *username; /* user name */ +static char *olduser; /* previous user name */ + +/* + * Prompts + */ +static char default_prompt[] = DEFAULT_PROMPT; +static char *prompt; +static char default_passwd_prompt[] = DEFAULT_PASSWD_PROMPT; +static char *passwd_prompt; + +static char *tty; -struct passwd *pwd; -int failures; -char *term, *envinit[1], *hostname, *passwd_prompt, *prompt, *tty, *username; -char full_hostname[MAXHOSTNAMELEN]; +/* + * PAM data + */ +static pam_handle_t *pamh = NULL; +static struct pam_conv pamc = { misc_conv, NULL }; +static int pam_err; +static int pam_silent = PAM_SILENT; +static int pam_cred_established; +static int pam_session_established; int -main(argc, argv) - int argc; - char *argv[]; +main(int argc, char *argv[]) { struct group *gr; struct stat st; - struct timeval tp; - struct utmp utmp; - int rootok, retries, backoff; - int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval; - time_t warntime; + int retries, backoff; + int ask, ch, cnt, quietlog, rootlogin, rval; uid_t uid, euid; gid_t egid; + char *term; char *p, *ttyn; - char tbuf[MAXPATHLEN + 2]; char tname[sizeof(_PATH_TTY) + 10]; - char *shell = NULL; - static char default_prompt[] = DEFAULT_PROMPT; - static char default_passwd_prompt[] = DEFAULT_PASSWD_PROMPT; - static char invalid_host[] = INVALID_HOST; + char *arg0, *shell = NULL; login_cap_t *lc = NULL; -#ifndef NO_PAM pid_t pid; - int e; -#endif /* NO_PAM */ (void)signal(SIGQUIT, SIG_IGN); (void)signal(SIGINT, SIG_IGN); (void)signal(SIGHUP, SIG_IGN); if (setjmp(timeout_buf)) { if (failures) - badlogin(tbuf); + badlogin(username); (void)fprintf(stderr, "Login timed out after %d seconds\n", timeout); - exit(0); + bail(NO_SLEEP_EXIT, 0); } (void)signal(SIGALRM, timedout); (void)alarm(timeout); @@ -192,63 +192,22 @@ main(argc, argv) openlog("login", LOG_ODELAY, LOG_AUTH); - /* - * -p is used by getty to tell login not to destroy the environment - * -f is used to skip a second login authentication - * -h is used by other servers to pass the name of the remote - * host to login so that it may be placed in utmp and wtmp - */ - *full_hostname = '\0'; - term = NULL; - - fflag = hflag = pflag = 0; uid = getuid(); euid = geteuid(); egid = getegid(); + while ((ch = getopt(argc, argv, "fh:p")) != -1) switch (ch) { case 'f': fflag = 1; break; case 'h': - if (uid) + if (uid != 0) errx(1, "-h option: %s", strerror(EPERM)); - hflag = 1; - if (strlcpy(full_hostname, optarg, - sizeof(full_hostname)) >= sizeof(full_hostname)) + if (strlen(optarg) >= MAXHOSTNAMELEN) errx(1, "-h option: %s: exceeds maximum " "hostname size", optarg); - - trimdomain(optarg, UT_HOSTSIZE); - - if (strlen(optarg) > UT_HOSTSIZE) { - struct addrinfo hints, *res; - int ga_err; - - memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_UNSPEC; - ga_err = getaddrinfo(optarg, NULL, &hints, - &res); - if (ga_err == 0) { - char hostbuf[MAXHOSTNAMELEN]; - - getnameinfo(res->ai_addr, - res->ai_addrlen, - hostbuf, - sizeof(hostbuf), NULL, 0, - NI_NUMERICHOST| - NI_WITHSCOPEID); - optarg = strdup(hostbuf); - if (optarg == NULL) { - syslog(LOG_NOTICE, - "strdup(): %m"); - sleepexit(1); - } - } else - optarg = invalid_host; - if (res != NULL) - freeaddrinfo(res); - } + hflag = 1; hostname = optarg; break; case 'p': @@ -256,22 +215,28 @@ main(argc, argv) break; case '?': default: - if (!uid) + if (uid == 0) syslog(LOG_ERR, "invalid flag %c", ch); usage(); } argc -= optind; argv += optind; - if (*argv) { - username = *argv; + if (argc > 0) { + username = strdup(*argv); + if (username == NULL) + err(1, "strdup()"); ask = 0; - } else + } else { ask = 1; + } for (cnt = getdtablesize(); cnt > 2; cnt--) (void)close(cnt); + /* + * Get current TTY + */ ttyn = ttyname(STDIN_FILENO); if (ttyn == NULL || *ttyn == '\0') { (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY); @@ -286,110 +251,96 @@ main(argc, argv) * Get "login-retries" & "login-backoff" from default class */ lc = login_getclass(NULL); - prompt = login_getcapstr(lc, "prompt", default_prompt, default_prompt); + prompt = login_getcapstr(lc, "prompt", + default_prompt, default_prompt); passwd_prompt = login_getcapstr(lc, "passwd_prompt", default_passwd_prompt, default_passwd_prompt); - retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES, - DEFAULT_RETRIES); - backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF, - DEFAULT_BACKOFF); + retries = login_getcapnum(lc, "login-retries", + DEFAULT_RETRIES, DEFAULT_RETRIES); + backoff = login_getcapnum(lc, "login-backoff", + DEFAULT_BACKOFF, DEFAULT_BACKOFF); login_close(lc); lc = NULL; + /* + * Try to authenticate the user until we succeed or time out. + */ for (cnt = 0;; ask = 1) { if (ask) { fflag = 0; - getloginname(); + if (olduser != NULL) + free(olduser); + olduser = username; + username = getloginname(); } rootlogin = 0; - rootok = rootterm(tty); /* Default (auth may change) */ - - if (strlen(username) > UT_NAMESIZE) - username[UT_NAMESIZE] = '\0'; /* * Note if trying multiple user names; log failures for * previous user name, but don't bother logging one failure * for nonexistent name (mistyped username). */ - if (failures && strcmp(tbuf, username)) { + if (failures && strcmp(olduser, username) != 0) { if (failures > (pwd ? 0 : 1)) - badlogin(tbuf); + badlogin(olduser); } - (void)strlcpy(tbuf, username, sizeof(tbuf)); - - pwd = getpwnam(username); + olduser = username; /* - * if we have a valid account name, and it doesn't have a - * password, or the -f option was specified and the caller - * is root or the caller isn't changing their uid, don't - * authenticate. + * Load the PAM policy and set some variables */ - if (pwd != NULL) { - if (pwd->pw_uid == 0) - rootlogin = 1; - - if (fflag && (uid == (uid_t)0 || - uid == (uid_t)pwd->pw_uid)) { - /* already authenticated */ - break; - } else if (pwd->pw_passwd[0] == '\0') { - if (!rootlogin || rootok) { - /* pretend password okay */ - rval = 0; - goto ttycheck; - } - } + pam_err = pam_start("login", username, &pamc, &pamh); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_start()"); + bail(NO_SLEEP_EXIT, 1); } - - fflag = 0; - - (void)setpriority(PRIO_PROCESS, 0, -4); - -#ifndef NO_PAM - /* - * Try to authenticate using PAM. If a PAM system error - * occurs, perhaps because of a botched configuration, - * then fall back to using traditional Unix authentication. - */ - if ((rval = auth_pam()) == -1) -#endif /* NO_PAM */ - rval = auth_traditional(); - - (void)setpriority(PRIO_PROCESS, 0, 0); - - /* - * PAM authentication may have changed "pwd" to the - * entry for the template user. Check again to see if - * this is a root login after all. - */ + pam_err = pam_set_item(pamh, PAM_TTY, tty); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_set_item(PAM_TTY)"); + bail(NO_SLEEP_EXIT, 1); + } + pam_err = pam_set_item(pamh, PAM_RHOST, hostname); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_set_item(PAM_RHOST)"); + bail(NO_SLEEP_EXIT, 1); + } + + pwd = getpwnam(username); if (pwd != NULL && pwd->pw_uid == 0) rootlogin = 1; - ttycheck: /* - * If trying to log in as root without Kerberos, - * but with insecure terminal, refuse the login attempt. + * If the -f option was specified and the caller is + * root or the caller isn't changing their uid, don't + * authenticate. */ - if (pwd && !rval) { - if (rootlogin && !rootok) - refused(NULL, "NOROOT", 0); - else /* valid password & authenticated */ - break; + if (pwd != NULL && fflag && + (uid == (uid_t)0 || uid == (uid_t)pwd->pw_uid)) { + /* already authenticated */ + rval = 0; + } else { + fflag = 0; + (void)setpriority(PRIO_PROCESS, 0, -4); + rval = auth_pam(); + (void)setpriority(PRIO_PROCESS, 0, 0); } + if (pwd && rval == 0) + break; + + pam_cleanup(); + (void)printf("Login incorrect\n"); failures++; /* - * we allow up to 'retry' (10) tries, - * but after 'backoff' (3) we start backing off + * Allow up to 'retry' (10) attempts, but start + * backing off after 'backoff' (3) attempts. */ if (++cnt > backoff) { if (cnt >= retries) { badlogin(username); - sleepexit(1); + bail(SLEEP_EXIT, 1); } sleep((u_int)((cnt - backoff) * 5)); } @@ -407,6 +358,7 @@ main(argc, argv) lc = login_getpwclass(pwd); quietlog = login_getcapbool(lc, "hushlogin", 0); + /* * Switching needed for NFS with root access disabled. * @@ -426,92 +378,28 @@ main(argc, argv) pwd->pw_dir = strdup("/"); if (pwd->pw_dir == NULL) { syslog(LOG_NOTICE, "strdup(): %m"); - sleepexit(1); + bail(SLEEP_EXIT, 1); } } (void)seteuid(euid); (void)setegid(egid); if (!quietlog) quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; - - if (pwd->pw_change || pwd->pw_expire) - (void)gettimeofday(&tp, (struct timezone *)NULL); - - warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN, - DEFAULT_WARN); - - if (pwd->pw_expire) { - if (tp.tv_sec >= pwd->pw_expire) { - refused("Sorry -- your account has expired", "EXPIRED", - 1); - } else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog) - (void)printf("Warning: your account expires on %s", - ctime(&pwd->pw_expire)); - } - - if (lc != NULL) { - if (hostname) { - struct addrinfo hints, *res; - int ga_err; - - memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_UNSPEC; - ga_err = getaddrinfo(full_hostname, NULL, &hints, - &res); - if (ga_err == 0) { - char hostbuf[MAXHOSTNAMELEN]; - - getnameinfo(res->ai_addr, res->ai_addrlen, - hostbuf, sizeof(hostbuf), NULL, 0, - NI_NUMERICHOST|NI_WITHSCOPEID); - if ((optarg = strdup(hostbuf)) == NULL) { - syslog(LOG_NOTICE, "strdup(): %m"); - sleepexit(1); - } - } else - optarg = NULL; - if (res != NULL) - freeaddrinfo(res); - if (!auth_hostok(lc, full_hostname, optarg)) - refused("Permission denied", "HOST", 1); - } - - if (!auth_ttyok(lc, tty)) - refused("Permission denied", "TTY", 1); - - if (!auth_timeok(lc, time(NULL))) - refused("Logins not available right now", "TIME", 1); - } + shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell); if (*pwd->pw_shell == '\0') pwd->pw_shell = strdup(_PATH_BSHELL); if (pwd->pw_shell == NULL) { syslog(LOG_NOTICE, "strdup(): %m"); - sleepexit(1); + bail(SLEEP_EXIT, 1); } if (*shell == '\0') /* Not overridden */ shell = pwd->pw_shell; if ((shell = strdup(shell)) == NULL) { syslog(LOG_NOTICE, "strdup(): %m"); - sleepexit(1); + bail(SLEEP_EXIT, 1); } -#ifdef LOGIN_ACCESS - if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0) - refused("Permission denied", "ACCESS", 1); -#endif /* LOGIN_ACCESS */ - - /* Nothing else left to fail -- really log in. */ - memset((void *)&utmp, 0, sizeof(utmp)); - (void)time(&utmp.ut_time); - (void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name)); - if (hostname) - (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); - (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); - login(&utmp); - - dolastlog(quietlog); - /* * Set device protections, depending on what terminal the * user is logged in. This feature is used on Suns to give @@ -525,126 +413,116 @@ main(argc, argv) * Since it isn't clear that flags are useful on character * devices, we just clear them. */ - if (chflags(ttyn, 0) && errno != EOPNOTSUPP) - syslog(LOG_ERR, "chmod(%s): %m", ttyn); - if (chown(ttyn, pwd->pw_uid, + if (ttyn != tname && chflags(ttyn, 0) && errno != EOPNOTSUPP) + syslog(LOG_ERR, "chflags(%s): %m", ttyn); + if (ttyn != tname && chown(ttyn, pwd->pw_uid, (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid)) syslog(LOG_ERR, "chmod(%s): %m", ttyn); - - /* - * Preserve TERM if it happens to be already set. - */ - if ((term = getenv("TERM")) != NULL) { - if ((term = strdup(term)) == NULL) { - syslog(LOG_NOTICE, - "strdup(): %m"); - sleepexit(1); - } - } - /* * Exclude cons/vt/ptys only, assume dialup otherwise * TODO: Make dialup tty determination a library call * for consistency (finger etc.) */ - if (hostname==NULL && isdialuptty(tty)) + if (hflag && isdialuptty(tty)) syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); #ifdef LOGALL /* - * Syslog each successful login, so we don't have to watch hundreds - * of wtmp or lastlogin files. + * Syslog each successful login, so we don't have to watch + * hundreds of wtmp or lastlogin files. */ - if (hostname) + if (hflag) syslog(LOG_INFO, "login from %s on %s as %s", - full_hostname, tty, pwd->pw_name); + hostname, tty, pwd->pw_name); else syslog(LOG_INFO, "login on %s as %s", tty, pwd->pw_name); #endif /* - * If fflag is on, assume caller/authenticator has logged root login. + * If fflag is on, assume caller/authenticator has logged root + * login. */ - if (rootlogin && fflag == 0) - { - if (hostname) + if (rootlogin && fflag == 0) { + if (hflag) syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", - username, tty, full_hostname); + username, tty, hostname); else syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", username, tty); } /* - * Destroy environment unless user has requested its preservation. - * We need to do this before setusercontext() because that may - * set or reset some environment variables. + * Destroy environment unless user has requested its + * preservation - but preserve TERM in all cases */ + term = getenv("TERM"); if (!pflag) environ = envinit; + if (term != NULL) + setenv("TERM", term, 0); /* * PAM modules might add supplementary groups during pam_setcred(). */ if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { syslog(LOG_ERR, "setusercontext() failed - exiting"); - exit(1); + bail(NO_SLEEP_EXIT, 1); } -#ifndef NO_PAM - if (pamh) { - if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_open_session: %s", - pam_strerror(pamh, e)); - } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) - != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_setcred: %s", - pam_strerror(pamh, e)); - } - - /* - * Add any environmental variables that the - * PAM modules may have set. - * Call *after* opening session! - */ - if (pamh) { - environ_pam = pam_getenvlist(pamh); - if (environ_pam) - export_pam_environment(); - } + pam_err = pam_setcred(pamh, pam_silent|PAM_ESTABLISH_CRED); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_setcred()"); + bail(NO_SLEEP_EXIT, 1); + } + pam_cred_established = 1; + + pam_err = pam_open_session(pamh, pam_silent); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_open_session()"); + bail(NO_SLEEP_EXIT, 1); + } + pam_session_established = 1; + /* + * We must fork() before setuid() because we need to call + * pam_close_session() as root. + */ + pid = fork(); + if (pid < 0) { + err(1, "fork"); + } else if (pid != 0) { /* - * We must fork() before setuid() because we need to call - * pam_close_session() as root. + * Parent: wait for child to finish, then clean up + * session. */ - pid = fork(); - if (pid < 0) { - err(1, "fork"); - PAM_END; - exit(0); - } else if (pid) { - /* parent - wait for child to finish, then cleanup - session */ - wait(NULL); - PAM_END; - exit(0); - } else { - if ((e = pam_end(pamh, PAM_DATA_SILENT)) != PAM_SUCCESS) - syslog(LOG_ERR, "pam_end: %s", - pam_strerror(pamh, e)); - } + wait(NULL); + bail(NO_SLEEP_EXIT, 0); } -#endif /* NO_PAM */ /* - * We don't need to be root anymore, so - * set the user and session context + * NOTICE: We are now in the child process! + */ + + /* + * Add any environment variables the PAM modules may have set. + */ + export_pam_environment(); + + /* + * We're done with PAM now; our parent will deal with the rest. + */ + pam_end(pamh, PAM_DATA_SILENT); + pamh = NULL; + + /* + * We don't need to be root anymore, so set the login name and + * the UID. */ if (setlogin(username) != 0) { syslog(LOG_ERR, "setlogin(%s): %m - exiting", username); - exit(1); + bail(NO_SLEEP_EXIT, 1); } if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) { @@ -654,45 +532,38 @@ main(argc, argv) (void)setenv("SHELL", pwd->pw_shell, 1); (void)setenv("HOME", pwd->pw_dir, 1); - if (term != NULL && *term != '\0') - (void)setenv("TERM", term, 1); /* Preset overrides */ - else { - (void)setenv("TERM", stypeof(tty), 0); /* Fallback doesn't */ - } + (void)setenv("TERM", stypeof(tty), 0); (void)setenv("LOGNAME", username, 1); (void)setenv("USER", username, 1); (void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0); if (!quietlog) { - const char *cw; + char *cw; cw = login_getcapstr(lc, "copyright", NULL, NULL); - if (cw != NULL && access(cw, F_OK) == 0) - motd(cw); - else - (void)printf("%s\n\t%s %s\n", - "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", - "The Regents of the University of California. ", - "All rights reserved."); + if (cw == NULL || motd(cw) == -1) + (void)printf("%s", copyright); (void)printf("\n"); cw = login_getcapstr(lc, "welcome", NULL, NULL); - if (cw == NULL || access(cw, F_OK) != 0) - cw = _PATH_MOTDFILE; - motd(cw); + if (cw != NULL && access(cw, F_OK) == 0) + motd(cw); + else + motd(_PATH_MOTDFILE); if (login_getcapbool(lc, "nocheckmail", 0) == 0) { /* $MAIL may have been set by class. */ cw = getenv("MAIL"); - if (cw != NULL) - strlcpy(tbuf, cw, sizeof(tbuf)); - else - snprintf(tbuf, sizeof(tbuf), "%s/%s", + if (cw == NULL) { + asprintf(&cw, "%s/%s", _PATH_MAILDIR, pwd->pw_name); - if (stat(tbuf, &st) == 0 && st.st_size != 0) + } + if (cw && stat(cw, &st) == 0 && st.st_size != 0) (void)printf("You have %smail.\n", (st.st_mtime > st.st_atime) ? "new " : ""); + if (getenv("MAIL") == NULL) + free(cw); } } @@ -706,45 +577,23 @@ main(argc, argv) /* * Login shells have a leading '-' in front of argv[0] */ - if ((u_int)snprintf(tbuf, sizeof(tbuf), "-%s", - (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell) >= - sizeof(tbuf)) { + p = strrchr(pwd->pw_shell, '/'); + if (asprintf(&arg0, "-%s", p ? p + 1 : pwd->pw_shell) >= MAXPATHLEN) { syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size", username); errx(1, "shell exceeds maximum pathname size"); + } else if (arg0 == NULL) { + err(1, "asprintf()"); } - execlp(shell, tbuf, (char *)0); + execlp(shell, arg0, (char *)0); err(1, "%s", shell); + + /* + * That's it, folks! + */ } -static int -auth_traditional() -{ - int rval; - char *p; - const char *ep; - const char *salt; - - rval = 1; - salt = pwd != NULL ? pwd->pw_passwd : "xx"; - - p = getpass(passwd_prompt); - ep = crypt(p, salt); - - if (pwd) { - if (!p[0] && pwd->pw_passwd[0]) - ep = ":"; - if (strcmp(ep, pwd->pw_passwd) == 0) - rval = 0; - } - - /* clear entered password */ - memset(p, 0, strlen(p)); - return rval; -} - -#ifndef NO_PAM /* * Attempt to authenticate the user using PAM. Returns 0 if the user is * authenticated, or 1 if not authenticated. If some sort of PAM system @@ -753,31 +602,14 @@ auth_traditional() * fall back to a different authentication mechanism. */ static int -auth_pam() +auth_pam(void) { const char *tmpl_user; const void *item; int rval; - int e; - static struct pam_conv conv = { misc_conv, NULL }; - if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e)); - return -1; - } - if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s", - pam_strerror(pamh, e)); - return -1; - } - if (hostname != NULL && - (e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s", - pam_strerror(pamh, e)); - return -1; - } - e = pam_authenticate(pamh, 0); - switch (e) { + pam_err = pam_authenticate(pamh, pam_silent); + switch (pam_err) { case PAM_SUCCESS: /* @@ -797,14 +629,14 @@ auth_pam() * point of view, the template user is always passed * back as a changed value of the PAM_USER item. */ - if ((e = pam_get_item(pamh, PAM_USER, &item)) == - PAM_SUCCESS) { - tmpl_user = (const char *) item; + pam_err = pam_get_item(pamh, PAM_USER, &item); + if (pam_err == PAM_SUCCESS) { + tmpl_user = (const char *)item; if (strcmp(username, tmpl_user) != 0) pwd = getpwnam(tmpl_user); - } else - syslog(LOG_ERR, "Couldn't get PAM_USER: %s", - pam_strerror(pamh, e)); + } else { + pam_syslog("pam_get_item(PAM_USER)"); + } rval = 0; break; @@ -815,57 +647,66 @@ auth_pam() break; default: - syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e)); + pam_syslog("pam_authenticate()"); rval = -1; break; } if (rval == 0) { - e = pam_acct_mgmt(pamh, 0); - if (e == PAM_NEW_AUTHTOK_REQD) { - e = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); - if (e != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_chauthtok: %s", - pam_strerror(pamh, e)); + pam_err = pam_acct_mgmt(pamh, pam_silent); + switch (pam_err) { + case PAM_SUCCESS: + break; + case PAM_NEW_AUTHTOK_REQD: + pam_err = pam_chauthtok(pamh, + pam_silent|PAM_CHANGE_EXPIRED_AUTHTOK); + if (pam_err != PAM_SUCCESS) { + pam_syslog("pam_chauthtok()"); rval = 1; } - } else if (e != PAM_SUCCESS) { + break; + default: + pam_syslog("pam_acct_mgmt()"); rval = 1; + break; } } if (rval != 0) { - if ((e = pam_end(pamh, e)) != PAM_SUCCESS) { - syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); - } + pam_end(pamh, pam_err); pamh = NULL; } - return rval; + return (rval); } -static int +/* + * Export any environment variables PAM modules may have set + */ +static void export_pam_environment() { - char **pp; - - for (pp = environ_pam; *pp != NULL; pp++) { - if (ok_to_export(*pp)) - (void) putenv(*pp); - free(*pp); + char **pam_env; + char **pp; + + pam_env = pam_getenvlist(pamh); + if (pam_env != NULL) { + for (pp = pam_env; *pp != NULL; pp++) { + (void)export(*pp); + free(*pp); + } } - return PAM_SUCCESS; } /* - * Sanity checks on PAM environmental variables: + * Perform sanity checks on an environment variable: * - Make sure there is an '=' in the string. * - Make sure the string doesn't run on too long. * - Do not export certain variables. This list was taken from the * Solaris pam_putenv(3) man page. + * Then export it. */ static int -ok_to_export(s) - const char *s; +export(const char *s) { static const char *noexport[] = { "SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH", @@ -875,17 +716,17 @@ ok_to_export(s) size_t n; if (strlen(s) > 1024 || strchr(s, '=') == NULL) - return 0; + return (0); if (strncmp(s, "LD_", 3) == 0) - return 0; + return (0); for (pp = noexport; *pp != NULL; pp++) { n = strlen(*pp); if (s[n] == '=' && strncmp(s, *pp, n) == 0) - return 0; + return (0); } - return 1; + (void)putenv(s); + return (1); } -#endif /* NO_PAM */ static void usage() @@ -896,135 +737,101 @@ usage() } /* - * Allow for authentication style and/or kerberos instance + * Prompt user and read login name from stdin. */ - -void +static char * getloginname() { + char *nbuf, *p; int ch; - char *p; - static char nbuf[NBUFSIZ]; - for (;;) { + nbuf = malloc(MAXLOGNAME); + if (nbuf == NULL) + err(1, "malloc()"); + do { (void)printf("%s", prompt); for (p = nbuf; (ch = getchar()) != '\n'; ) { if (ch == EOF) { badlogin(username); - exit(0); + bail(NO_SLEEP_EXIT, 0); } - if (p < nbuf + (NBUFSIZ - 1)) + if (p < nbuf + MAXLOGNAME - 1) *p++ = ch; } - if (p > nbuf) { - if (nbuf[0] == '-') - (void)fprintf(stderr, - "login names may not start with '-'.\n"); - else { - *p = '\0'; - username = nbuf; - break; - } - } + } while (p == nbuf); + + *p = '\0'; + if (nbuf[0] == '-') { + pam_silent = 0; + memmove(nbuf, nbuf + 1, strlen(nbuf)); + } else { + pam_silent = PAM_SILENT; } + return nbuf; } -int -rootterm(ttyn) - char *ttyn; -{ - struct ttyent *t; - - return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE); -} - -volatile int motdinterrupt; - -void -sigint(signo) - int signo __unused; +/* + * SIGINT handler for motd(). + */ +static volatile int motdinterrupt; +static void +sigint(int signo __unused) { motdinterrupt = 1; } -void -motd(motdfile) - const char *motdfile; +/* + * Display the contents of a file (such as /etc/motd). + */ +static int +motd(const char *motdfile) { - int fd, nchars; sig_t oldint; - char tbuf[256]; + FILE *f; + int ch; - if ((fd = open(motdfile, O_RDONLY, 0)) < 0) - return; + if ((f = fopen(motdfile, "r")) == NULL) + return (-1); motdinterrupt = 0; oldint = signal(SIGINT, sigint); - while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt) - (void)write(fileno(stdout), tbuf, nchars); - (void)signal(SIGINT, oldint); - (void)close(fd); + while ((ch = fgetc(f)) != EOF && !motdinterrupt) + putchar(ch); + signal(SIGINT, oldint); + if (ch != EOF || ferror(f)) { + fclose(f); + return (-1); + } + fclose(f); + return (0); } -/* ARGSUSED */ -void -timedout(signo) - int signo; +/* + * SIGALRM handler, to enforce login prompt timeout. + * + * XXX This can potentially confuse the hell out of PAM. We should + * XXX instead implement a conversation function that returns + * XXX PAM_CONV_ERR when interrupted by a signal, and have the signal + * XXX handler just set a flag. + */ +static void +timedout(int signo __unused) { longjmp(timeout_buf, signo); } - -void -dolastlog(quiet) - int quiet; -{ - struct lastlog ll; - int fd; - - if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { - (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); - if (!quiet) { - if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && - ll.ll_time != 0) { - (void)printf("Last login: %.*s ", - 24-5, (char *)ctime(&ll.ll_time)); - if (*ll.ll_host != '\0') - (void)printf("from %.*s\n", - (int)sizeof(ll.ll_host), - ll.ll_host); - else - (void)printf("on %.*s\n", - (int)sizeof(ll.ll_line), - ll.ll_line); - } - (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); - } - memset((void *)&ll, 0, sizeof(ll)); - (void)time(&ll.ll_time); - (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); - if (hostname) - (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); - (void)write(fd, (char *)&ll, sizeof(ll)); - (void)close(fd); - } else { - syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG); - } -} - void -badlogin(name) - char *name; +badlogin(char *name) { if (failures == 0) return; - if (hostname) { + if (hflag) { syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", - failures, failures > 1 ? "S" : "", full_hostname); + failures, failures > 1 ? "S" : "", hostname); syslog(LOG_AUTHPRIV|LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s, %s", - failures, failures > 1 ? "S" : "", full_hostname, name); + failures, failures > 1 ? "S" : "", hostname, name); } else { syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", failures, failures > 1 ? "S" : "", tty); @@ -1036,8 +843,7 @@ badlogin(name) } const char * -stypeof(ttyid) - char *ttyid; +stypeof(char *ttyid) { struct ttyent *t; @@ -1046,33 +852,67 @@ stypeof(ttyid) if (t != NULL && t->ty_type != NULL) return (t->ty_type); } - return (UNKNOWN); + return (TERM_UNKNOWN); } void -refused(msg, rtype, lout) - const char *msg; - const char *rtype; - int lout; +refused(const char *msg, const char *rtype, int lout) { if (msg != NULL) printf("%s.\n", msg); - if (hostname) + if (hflag) syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s", - pwd->pw_name, rtype, full_hostname, tty); + pwd->pw_name, rtype, hostname, tty); else syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s", pwd->pw_name, rtype, tty); if (lout) - sleepexit(1); + bail(SLEEP_EXIT, 1); +} + +/* + * Log a PAM error + */ +void +pam_syslog(const char *msg) +{ + syslog(LOG_ERR, "%s: %s", msg, pam_strerror(pamh, pam_err)); } +/* + * Shut down PAM + */ +void +pam_cleanup() +{ + + if (pamh != NULL) { + if (pam_session_established) { + pam_err = pam_close_session(pamh, 0); + if (pam_err != PAM_SUCCESS) + pam_syslog("pam_close_session()"); + } + pam_session_established = 0; + if (pam_cred_established) { + pam_err = pam_setcred(pamh, pam_silent|PAM_DELETE_CRED); + if (pam_err != PAM_SUCCESS) + pam_syslog("pam_setcred()"); + } + pam_cred_established = 0; + pam_end(pamh, pam_err); + pamh = NULL; + } +} + +/* + * Exit, optionally after sleeping a few seconds + */ void -sleepexit(eval) - int eval; +bail(int sec, int eval) { - (void)sleep(5); + pam_cleanup(); + (void)sleep(sec); exit(eval); } |