Relevant BUGIDs:pam_unix_ref_branch

Purpose of commit: new feature

Commit summary:
---------------
        * modules/pam_unix/Makefile.am: Add unix_update helper.
        * modules/pam_unix/pam_unix_passwd.c: Move functions i64c(),
        crypt_md5_wrapper(), save_old_password(), _update_passwd() and
        _update_shadow() to passverify.c file. Rename _unix_run_shadow_binary()
        to _unix_run_update_binary(), which also verifies old password and
        does all writing.
        (_do_setpass, pam_sm_chauthtok): lckpwdf()->lock_pwdf(), the same for unlock.
        Call _unix_run_update_binary() appropriately.
        _update_passwd()->unix_update_passwd(), the same for shadow.
        * modules/pam_unix/passverify.c: Add new functions moved from
        pam_unix_passwd.c and unix_chkpwd.c.
        * modules/pam_unix/passverify.h: Likewise.
        * modules/pam_unix/unix_chkpwd.c: Remove SELinux checks. Move
        su_sighandler(), setup_signals(), getuidname() to passverify.c.
        (main): Remove 'shadow' option. Refactor out read_passwords() and
        call it. More strict checking how the binary is called.
        * modules/pam_unix/unix_update.c: New helper binary - non-setuid,
        called from SELinux confined apps only.

6 files changed, 984 insertions, 790 deletions

diff --git a/modules/pam_unix/Makefile.am b/modules/pam_unix/Makefile.am
index 1770a375..34c5d8d2 100644
--- a/modules/pam_unix/Makefile.am
+++ b/modules/pam_unix/Makefile.am
@@ -16,7 +16,8 @@ securelibdir = $(SECUREDIR)
 secureconfdir = $(SCONFIGDIR)
 
 AM_CFLAGS = -I$(top_srcdir)/libpam/include -I$(top_srcdir)/libpamc/include \
-	-DCHKPWD_HELPER=\"$(sbindir)/unix_chkpwd\"
+	-DCHKPWD_HELPER=\"$(sbindir)/unix_chkpwd\" \
+	-DUPDATE_HELPER=\"$(sbindir)/unix_update\"
 
 if HAVE_LIBSELINUX
   AM_CFLAGS += -D"WITH_SELINUX"
@@ -36,7 +37,7 @@ securelib_LTLIBRARIES = pam_unix.la
 
 noinst_HEADERS = md5.h support.h yppasswd.h bigcrypt.h passverify.h
 
-sbin_PROGRAMS = unix_chkpwd
+sbin_PROGRAMS = unix_chkpwd unix_update
 
 noinst_PROGRAMS = bigcrypt
 
@@ -54,6 +55,12 @@ unix_chkpwd_CFLAGS = $(AM_CFLAGS) @PIE_CFLAGS@ -DHELPER_COMPILE=\"unix_chkpwd\"
 unix_chkpwd_LDFLAGS = @PIE_LDFLAGS@ 
 unix_chkpwd_LDADD = @LIBCRYPT@ @LIBSELINUX@
 
+unix_update_SOURCES = unix_update.c md5_good.c md5_broken.c bigcrypt.c \
+	passverify.c
+unix_update_CFLAGS = $(AM_CFLAGS) @PIE_CFLAGS@ -DHELPER_COMPILE=\"unix_update\"
+unix_update_LDFLAGS = @PIE_LDFLAGS@ 
+unix_update_LDADD = @LIBCRYPT@ @LIBSELINUX@
+
 if ENABLE_REGENERATE_MAN
 noinst_DATA = README
 README: pam_unix.8.xml
diff --git a/modules/pam_unix/pam_unix_passwd.c b/modules/pam_unix/pam_unix_passwd.c
index d61d2ce6..18b3d7b5 100644
--- a/modules/pam_unix/pam_unix_passwd.c
+++ b/modules/pam_unix/pam_unix_passwd.c
@@ -2,6 +2,7 @@
  * Main coding by Elliot Lee <sopwith@redhat.com>, Red Hat Software.
  * Copyright (C) 1996.
  * Copyright (c) Jan Rêkorajski, 1999.
+ * Copyright (c) Red Hat, Inc., 2007, 2008.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -63,7 +64,6 @@
 #ifdef WITH_SELINUX
 static int selinux_enabled=-1;
 #include <selinux/selinux.h>
-static security_context_t prev_context=NULL;
 #define SELINUX_ENABLED (selinux_enabled!=-1 ? selinux_enabled : (selinux_enabled=is_selinux_enabled()>0))
 #endif
 
@@ -93,15 +93,6 @@ extern int getrpcport(const char *host, unsigned long prognum,
 #endif				/* GNU libc 2.1 */
 
 /*
- * PAM framework looks for these entry-points to pass control to the
- * password changing module.
- */
-
-#if defined(USE_LCKPWDF) && !defined(HAVE_LCKPWDF)
-# include "./lckpwdf.-c"
-#endif
-
-/*
    How it works:
    Gets in username (has to be done) from the calling program
    Does authentication of user (only if we are not running as root)
@@ -109,82 +100,15 @@ extern int getrpcport(const char *host, unsigned long prognum,
    Sets it.
  */
 
-/* passwd/salt conversion macros */
-
-#define ascii_to_bin(c) ((c)>='a'?(c-59):(c)>='A'?((c)-53):(c)-'.')
-#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
-
 /* data tokens */
 
 #define _UNIX_OLD_AUTHTOK	"-UN*X-OLD-PASS"
 #define _UNIX_NEW_AUTHTOK	"-UN*X-NEW-PASS"
 
 #define MAX_PASSWD_TRIES	3
-#define PW_TMPFILE		"/etc/npasswd"
-#define SH_TMPFILE		"/etc/nshadow"
 #ifndef CRACKLIB_DICTS
 #define CRACKLIB_DICTS		NULL
 #endif
-#define OPW_TMPFILE		"/etc/security/nopasswd"
-#define OLD_PASSWORDS_FILE	"/etc/security/opasswd"
-
-/*
- * i64c - convert an integer to a radix 64 character
- */
-static int i64c(int i)
-{
-	if (i < 0)
-		return ('.');
-	else if (i > 63)
-		return ('z');
-	if (i == 0)
-		return ('.');
-	if (i == 1)
-		return ('/');
-	if (i >= 2 && i <= 11)
-		return ('0' - 2 + i);
-	if (i >= 12 && i <= 37)
-		return ('A' - 12 + i);
-	if (i >= 38 && i <= 63)
-		return ('a' - 38 + i);
-	return ('\0');
-}
-
-static char *crypt_md5_wrapper(const char *pass_new)
-{
-	/*
-	 * Code lifted from Marek Michalkiewicz's shadow suite. (CG)
-	 * removed use of static variables (AGM)
-	 */
-
-	struct timeval tv;
-	MD5_CTX ctx;
-	unsigned char result[16];
-	char *cp = (char *) result;
-	unsigned char tmp[16];
-	int i;
-	char *x = NULL;
-
-	GoodMD5Init(&ctx);
-	gettimeofday(&tv, (struct timezone *) 0);
-	GoodMD5Update(&ctx, (void *) &tv, sizeof tv);
-	i = getpid();
-	GoodMD5Update(&ctx, (void *) &i, sizeof i);
-	i = clock();
-	GoodMD5Update(&ctx, (void *) &i, sizeof i);
-	GoodMD5Update(&ctx, result, sizeof result);
-	GoodMD5Final(tmp, &ctx);
-	strcpy(cp, "$1$");	/* magic for the MD5 */
-	cp += strlen(cp);
-	for (i = 0; i < 8; i++)
-		*cp++ = i64c(tmp[i] & 077);
-	*cp = '\0';
-
-	/* no longer need cleartext */
-	x = Goodcrypt_md5(pass_new, (const char *) result);
-
-	return x;
-}
 
 static char *getNISserver(pam_handle_t *pamh)
 {
@@ -217,8 +141,8 @@ static char *getNISserver(pam_handle_t *pamh)
 }
 
 #ifdef WITH_SELINUX
-
-static int _unix_run_shadow_binary(pam_handle_t *pamh, unsigned int ctrl, const char *user, const char *fromwhat, const char *towhat)
+static int _unix_run_update_binary(pam_handle_t *pamh, unsigned int ctrl, const char *user,
+    const char *fromwhat, const char *towhat, int remember)
 {
     int retval, child, fds[2];
     void (*sighandler)(int) = NULL;
@@ -248,7 +172,8 @@ static int _unix_run_shadow_binary(pam_handle_t *pamh, unsigned int ctrl, const
         size_t i=0;
         struct rlimit rlim;
 	static char *envp[] = { NULL };
-	char *args[] = { NULL, NULL, NULL, NULL };
+	char *args[] = { NULL, NULL, NULL, NULL, NULL, NULL };
+        char buffer[16];
 
 	/* XXX - should really tidy up PAM here too */
 
@@ -271,11 +196,18 @@ static int _unix_run_shadow_binary(pam_handle_t *pamh, unsigned int ctrl, const
         }
 
 	/* exec binary helper */
-	args[0] = x_strdup(CHKPWD_HELPER);
+	args[0] = x_strdup(UPDATE_HELPER);
 	args[1] = x_strdup(user);
-	args[2] = x_strdup("shadow");
+	args[2] = x_strdup("update");
+	if (on(UNIX_SHADOW, ctrl))
+		args[3] = x_strdup("1");
+	else
+		args[3] = x_strdup("0");
 
-	execve(CHKPWD_HELPER, args, envp);
+        snprintf(buffer, sizeof(buffer), "%d", remember);
+        args[4] = x_strdup(buffer);
+	
+	execve(UPDATE_HELPER, args, envp);
 
 	/* should not get here: exit with error */
 	D(("helper binary is not available"));
@@ -298,7 +230,7 @@ static int _unix_run_shadow_binary(pam_handle_t *pamh, unsigned int ctrl, const
 	close(fds[1]);
 	rc=waitpid(child, &retval, 0);  /* wait for helper to complete */
 	if (rc<0) {
-	  pam_syslog(pamh, LOG_ERR, "unix_chkpwd waitpid returned %d: %m", rc);
+	  pam_syslog(pamh, LOG_ERR, "unix_update waitpid failed: %m");
 	  retval = PAM_AUTH_ERR;
 	} else {
 	  retval = WEXITSTATUS(retval);
@@ -355,393 +287,6 @@ static int check_old_password(const char *forwho, const char *newpass)
 	return retval;
 }
 
-static int save_old_password(pam_handle_t *pamh,
-			     const char *forwho, const char *oldpass,
-			     int howmany)
-{
-    static char buf[16384];
-    static char nbuf[16384];
-    char *s_luser, *s_uid, *s_npas, *s_pas, *pass;
-    int npas;
-    FILE *pwfile, *opwfile;
-    int err = 0;
-    int oldmask;
-    int found = 0;
-    struct passwd *pwd = NULL;
-    struct stat st;
-
-    if (howmany < 0) {
-	return PAM_SUCCESS;
-    }
-
-    if (oldpass == NULL) {
-	return PAM_SUCCESS;
-    }
-
-    oldmask = umask(077);
-
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      security_context_t passwd_context=NULL;
-      if (getfilecon("/etc/passwd",&passwd_context)<0) {
-        return PAM_AUTHTOK_ERR;
-      };
-      if (getfscreatecon(&prev_context)<0) {
-        freecon(passwd_context);
-        return PAM_AUTHTOK_ERR;
-      }
-      if (setfscreatecon(passwd_context)) {
-        freecon(passwd_context);
-        freecon(prev_context);
-        return PAM_AUTHTOK_ERR;
-      }
-      freecon(passwd_context);
-    }
-#endif
-    pwfile = fopen(OPW_TMPFILE, "w");
-    umask(oldmask);
-    if (pwfile == NULL) {
-      err = 1;
-      goto done;
-    }
-
-    opwfile = fopen(OLD_PASSWORDS_FILE, "r");
-    if (opwfile == NULL) {
-	fclose(pwfile);
-      err = 1;
-      goto done;
-    }
-
-    if (fstat(fileno(opwfile), &st) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    while (fgets(buf, 16380, opwfile)) {
-	if (!strncmp(buf, forwho, strlen(forwho))) {
-	    char *sptr;
-	    buf[strlen(buf) - 1] = '\0';
-	    s_luser = strtok_r(buf, ":", &sptr);
-	    s_uid = strtok_r(NULL, ":", &sptr);
-	    s_npas = strtok_r(NULL, ":", &sptr);
-	    s_pas = strtok_r(NULL, ":", &sptr);
-	    npas = strtol(s_npas, NULL, 10) + 1;
-	    while (npas > howmany) {
-		s_pas = strpbrk(s_pas, ",");
-		if (s_pas != NULL)
-		    s_pas++;
-		npas--;
-	    }
-	    pass = crypt_md5_wrapper(oldpass);
-	    if (s_pas == NULL)
-		snprintf(nbuf, sizeof(nbuf), "%s:%s:%d:%s\n",
-			 s_luser, s_uid, npas, pass);
-	    else
-		snprintf(nbuf, sizeof(nbuf),"%s:%s:%d:%s,%s\n",
-			 s_luser, s_uid, npas, s_pas, pass);
-	    _pam_delete(pass);
-	    if (fputs(nbuf, pwfile) < 0) {
-		err = 1;
-		break;
-	    }
-	    found = 1;
-	} else if (fputs(buf, pwfile) < 0) {
-	    err = 1;
-	    break;
-	}
-    }
-    fclose(opwfile);
-
-    if (!found) {
-	pwd = pam_modutil_getpwnam(pamh, forwho);
-	if (pwd == NULL) {
-	    err = 1;
-	} else {
-	    pass = crypt_md5_wrapper(oldpass);
-	    snprintf(nbuf, sizeof(nbuf), "%s:%lu:1:%s\n",
-		     forwho, (unsigned long)pwd->pw_uid, pass);
-	    _pam_delete(pass);
-	    if (fputs(nbuf, pwfile) < 0) {
-		err = 1;
-	    }
-	}
-    }
-
-    if (fclose(pwfile)) {
-	D(("error writing entries to old passwords file: %m"));
-	err = 1;
-    }
-
-done:
-    if (!err) {
-	if (rename(OPW_TMPFILE, OLD_PASSWORDS_FILE))
-	    err = 1;
-    }
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      if (setfscreatecon(prev_context)) {
-        err = 1;
-      }
-      if (prev_context)
-        freecon(prev_context);
-      prev_context=NULL;
-    }
-#endif
-    if (!err) {
-	return PAM_SUCCESS;
-    } else {
-	unlink(OPW_TMPFILE);
-	return PAM_AUTHTOK_ERR;
-    }
-}
-
-static int _update_passwd(pam_handle_t *pamh,
-			  const char *forwho, const char *towhat)
-{
-    struct passwd *tmpent = NULL;
-    struct stat st;
-    FILE *pwfile, *opwfile;
-    int err = 1;
-    int oldmask;
-
-    oldmask = umask(077);
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      security_context_t passwd_context=NULL;
-      if (getfilecon("/etc/passwd",&passwd_context)<0) {
-	return PAM_AUTHTOK_ERR;
-      };
-      if (getfscreatecon(&prev_context)<0) {
-	freecon(passwd_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      if (setfscreatecon(passwd_context)) {
-	freecon(passwd_context);
-	freecon(prev_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      freecon(passwd_context);
-    }
-#endif
-    pwfile = fopen(PW_TMPFILE, "w");
-    umask(oldmask);
-    if (pwfile == NULL) {
-      err = 1;
-      goto done;
-    }
-
-    opwfile = fopen("/etc/passwd", "r");
-    if (opwfile == NULL) {
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fstat(fileno(opwfile), &st) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    tmpent = fgetpwent(opwfile);
-    while (tmpent) {
-	if (!strcmp(tmpent->pw_name, forwho)) {
-	    /* To shut gcc up */
-	    union {
-		const char *const_charp;
-		char *charp;
-	    } assigned_passwd;
-	    assigned_passwd.const_charp = towhat;
-
-	    tmpent->pw_passwd = assigned_passwd.charp;
-	    err = 0;
-	}
-	if (putpwent(tmpent, pwfile)) {
-	    D(("error writing entry to password file: %m"));
-	    err = 1;
-	    break;
-	}
-	tmpent = fgetpwent(opwfile);
-    }
-    fclose(opwfile);
-
-    if (fclose(pwfile)) {
-	D(("error writing entries to password file: %m"));
-	err = 1;
-    }
-
-done:
-    if (!err) {
-	if (!rename(PW_TMPFILE, "/etc/passwd"))
-	    pam_syslog(pamh, LOG_NOTICE, "password changed for %s", forwho);
-	else
-	    err = 1;
-    }
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      if (setfscreatecon(prev_context)) {
-	err = 1;
-      }
-      if (prev_context)
-	freecon(prev_context);
-      prev_context=NULL;
-    }
-#endif
-    if (!err) {
-	return PAM_SUCCESS;
-    } else {
-	unlink(PW_TMPFILE);
-	return PAM_AUTHTOK_ERR;
-    }
-}
-
-static int _update_shadow(pam_handle_t *pamh, const char *forwho, char *towhat)
-{
-    struct spwd *spwdent = NULL, *stmpent = NULL;
-    struct stat st;
-    FILE *pwfile, *opwfile;
-    int err = 1;
-    int oldmask;
-
-    spwdent = getspnam(forwho);
-    if (spwdent == NULL) {
-	return PAM_USER_UNKNOWN;
-    }
-    oldmask = umask(077);
-
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      security_context_t shadow_context=NULL;
-      if (getfilecon("/etc/shadow",&shadow_context)<0) {
-	return PAM_AUTHTOK_ERR;
-      };
-      if (getfscreatecon(&prev_context)<0) {
-	freecon(shadow_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      if (setfscreatecon(shadow_context)) {
-	freecon(shadow_context);
-	freecon(prev_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      freecon(shadow_context);
-    }
-#endif
-    pwfile = fopen(SH_TMPFILE, "w");
-    umask(oldmask);
-    if (pwfile == NULL) {
-	err = 1;
-	goto done;
-    }
-
-    opwfile = fopen("/etc/shadow", "r");
-    if (opwfile == NULL) {
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fstat(fileno(opwfile), &st) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    stmpent = fgetspent(opwfile);
-    while (stmpent) {
-
-	if (!strcmp(stmpent->sp_namp, forwho)) {
-	    stmpent->sp_pwdp = towhat;
-	    stmpent->sp_lstchg = time(NULL) / (60 * 60 * 24);
-	    err = 0;
-	    D(("Set password %s for %s", stmpent->sp_pwdp, forwho));
-	}
-
-	if (putspent(stmpent, pwfile)) {
-	    D(("error writing entry to shadow file: %m"));
-	    err = 1;
-	    break;
-	}
-
-	stmpent = fgetspent(opwfile);
-    }
-    fclose(opwfile);
-
-    if (fclose(pwfile)) {
-	D(("error writing entries to shadow file: %m"));
-	err = 1;
-    }
-
- done:
-    if (!err) {
-	if (!rename(SH_TMPFILE, "/etc/shadow"))
-	    pam_syslog(pamh, LOG_NOTICE, "password changed for %s", forwho);
-	else
-	    err = 1;
-    }
-
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      if (setfscreatecon(prev_context)) {
-	err = 1;
-      }
-      if (prev_context)
-	freecon(prev_context);
-      prev_context=NULL;
-    }
-#endif
-
-    if (!err) {
-	return PAM_SUCCESS;
-    } else {
-	unlink(SH_TMPFILE);
-	return PAM_AUTHTOK_ERR;
-    }
-}
-
 static int _do_setpass(pam_handle_t* pamh, const char *forwho,
 		       const char *fromwhat,
 		       char *towhat, unsigned int ctrl, int remember)
@@ -769,9 +314,7 @@ static int _do_setpass(pam_handle_t* pamh, const char *forwho,
 		enum clnt_stat err;
 
 		/* Unlock passwd file to avoid deadlock */
-#ifdef USE_LCKPWDF
-		ulckpwdf();
-#endif
+		unlock_pwdf();
 		unlocked = 1;
 
 		/* Initialize password information */
@@ -831,48 +374,33 @@ static int _do_setpass(pam_handle_t* pamh, const char *forwho,
 	}
 
 	if (_unix_comesfromsource(pamh, forwho, 1, 0)) {
-#ifdef USE_LCKPWDF
 		if(unlocked) {
-			int i = 0;
-			/* These values for the number of attempts and the sleep time
-			   are, of course, completely arbitrary.
-			   My reading of the PAM docs is that, once pam_chauthtok() has been
-			   called with PAM_UPDATE_AUTHTOK, we are obliged to take any
-			   reasonable steps to make sure the token is updated; so retrying
-			   for 1/10 sec. isn't overdoing it. */
-			while((retval = lckpwdf()) != 0 && i < 100) {
-				usleep(1000);
-				i++;
-			}
-			if(retval != 0) {
+			if (lock_pwdf() != PAM_SUCCESS) {
 				return PAM_AUTHTOK_LOCK_BUSY;
 			}
 		}
+#ifdef WITH_SELINUX
+	        if (unix_selinux_confined())
+			  return _unix_run_update_binary(pamh, ctrl, forwho, fromwhat, towhat, remember);
 #endif
 		/* first, save old password */
-		if (save_old_password(pamh, forwho, fromwhat, remember)) {
+		if (save_old_password(forwho, fromwhat, remember)) {
 			retval = PAM_AUTHTOK_ERR;
 			goto done;
 		}
 		if (on(UNIX_SHADOW, ctrl) || is_pwd_shadowed(pwd)) {
-			retval = _update_shadow(pamh, forwho, towhat);
-#ifdef WITH_SELINUX
- 		        if (retval != PAM_SUCCESS && SELINUX_ENABLED)
-			  retval = _unix_run_shadow_binary(pamh, ctrl, forwho, fromwhat, towhat);
-#endif
+			retval = unix_update_shadow(pamh, forwho, towhat);
 			if (retval == PAM_SUCCESS)
 				if (!is_pwd_shadowed(pwd))
-					retval = _update_passwd(pamh, forwho, "x");
+					retval = unix_update_passwd(pamh, forwho, "x");
 		} else {
-			retval = _update_passwd(pamh, forwho, towhat);
+			retval = unix_update_passwd(pamh, forwho, towhat);
 		}
 	}
 
 
 done:
-#ifdef USE_LCKPWDF
-	ulckpwdf();
-#endif
+	unlock_pwdf();
 
 	return retval;
 }
@@ -970,7 +498,7 @@ PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
 				int argc, const char **argv)
 {
 	unsigned int ctrl, lctrl;
-	int retval, i;
+	int retval;
 	int remember = -1;
 
 	/* <DO NOT free() THESE> */
@@ -1189,40 +717,23 @@ PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
 			pass_new = pass_old = NULL;	/* tidy up */
 			return retval;
 		}
-#ifdef USE_LCKPWDF
-		/* These values for the number of attempts and the sleep time
-		   are, of course, completely arbitrary.
-		   My reading of the PAM docs is that, once pam_chauthtok() has been
-		   called with PAM_UPDATE_AUTHTOK, we are obliged to take any
-		   reasonable steps to make sure the token is updated; so retrying
-		   for 1/10 sec. isn't overdoing it. */
-		i=0;
-		while((retval = lckpwdf()) != 0 && i < 100) {
-			usleep(1000);
-			i++;
-		}
-		if(retval != 0) {
+		if (lock_pwdf() != PAM_SUCCESS) {
 			return PAM_AUTHTOK_LOCK_BUSY;
 		}
-#endif
 
 		if (pass_old) {
 			retval = _unix_verify_password(pamh, user, pass_old, ctrl);
 			if (retval != PAM_SUCCESS) {
 				pam_syslog(pamh, LOG_NOTICE, "user password changed by another process");
-#ifdef USE_LCKPWDF
-				ulckpwdf();
-#endif
+				unlock_pwdf();
 				return retval;
 			}
 		}
 
 		retval = _unix_verify_shadow(pamh, user, ctrl);
 		if (retval != PAM_SUCCESS) {
-			pam_syslog(pamh, LOG_NOTICE, "user not authenticated 2");
-#ifdef USE_LCKPWDF
-			ulckpwdf();
-#endif
+			pam_syslog(pamh, LOG_NOTICE, "user shadow entry expired");
+			unlock_pwdf();
 			return retval;
 		}
 
@@ -1231,9 +742,7 @@ PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
 			pam_syslog(pamh, LOG_NOTICE,
 			         "new password not acceptable 2");
 			pass_new = pass_old = NULL;	/* tidy up */
-#ifdef USE_LCKPWDF
-			ulckpwdf();
-#endif
+			unlock_pwdf();
 			return retval;
 		}
 
@@ -1275,9 +784,7 @@ PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
 					pam_syslog(pamh, LOG_CRIT,
 					         "out of memory for password");
 					pass_new = pass_old = NULL;	/* tidy up */
-#ifdef USE_LCKPWDF
-					ulckpwdf();
-#endif
+					unlock_pwdf();
 					return PAM_BUF_ERR;
 				}
 				/* copy first 8 bytes of password */
@@ -1299,7 +806,7 @@ PAM_EXTERN int pam_sm_chauthtok(pam_handle_t * pamh, int flags,
 
 		retval = _do_setpass(pamh, user, pass_old, tpass, ctrl,
 		                     remember);
-	        /* _do_setpass has called ulckpwdf for us */
+	        /* _do_setpass has called unlock_pwdf for us */
 
 		_pam_delete(tpass);
 		pass_old = pass_new = NULL;
diff --git a/modules/pam_unix/passverify.c b/modules/pam_unix/passverify.c
index 9a3d72e6..e379cf62 100644
--- a/modules/pam_unix/passverify.c
+++ b/modules/pam_unix/passverify.c
@@ -13,7 +13,12 @@
 #include <shadow.h>
 #include <syslog.h>
 #include <stdarg.h>
+#include <signal.h>
+#include <errno.h>
 #include <time.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 #include "md5.h"
 #include "bigcrypt.h"
@@ -35,6 +40,10 @@
 #include <security/pam_ext.h>
 #endif
 
+#if defined(USE_LCKPWDF) && !defined(HAVE_LCKPWDF)
+# include "./lckpwdf.-c"
+#endif
+
 int
 verify_pwd_hash(const char *p, const char *hash, unsigned int nullok)
 {
@@ -256,6 +265,588 @@ check_shadow_expiry(pam_handle_t *pamh, struct spwd *spent, int *daysleft)
 
 }
 
+/* passwd/salt conversion macros */
+
+#define PW_TMPFILE              "/etc/npasswd"
+#define SH_TMPFILE              "/etc/nshadow"
+#define OPW_TMPFILE             "/etc/security/nopasswd"
+
+/*
+ * i64c - convert an integer to a radix 64 character
+ */
+static int
+i64c(int i)
+{
+        if (i < 0)
+                return ('.');
+        else if (i > 63)
+                return ('z');
+        if (i == 0)
+                return ('.');
+        if (i == 1)
+                return ('/');
+        if (i >= 2 && i <= 11)
+                return ('0' - 2 + i);
+        if (i >= 12 && i <= 37)
+                return ('A' - 12 + i);
+        if (i >= 38 && i <= 63)
+                return ('a' - 38 + i);
+        return ('\0');
+}
+
+char *
+crypt_md5_wrapper(const char *pass_new)
+{
+        /*
+         * Code lifted from Marek Michalkiewicz's shadow suite. (CG)
+         * removed use of static variables (AGM)
+         */
+
+        struct timeval tv;
+        MD5_CTX ctx;
+        unsigned char result[16];
+        char *cp = (char *) result;
+        unsigned char tmp[16];
+        int i;
+        char *x = NULL;
+
+        GoodMD5Init(&ctx);
+        gettimeofday(&tv, (struct timezone *) 0);
+        GoodMD5Update(&ctx, (void *) &tv, sizeof tv);
+        i = getpid();
+        GoodMD5Update(&ctx, (void *) &i, sizeof i);
+        i = clock();
+        GoodMD5Update(&ctx, (void *) &i, sizeof i);
+        GoodMD5Update(&ctx, result, sizeof result);
+        GoodMD5Final(tmp, &ctx);
+        strcpy(cp, "$1$");      /* magic for the MD5 */
+        cp += strlen(cp);
+        for (i = 0; i < 8; i++)
+                *cp++ = i64c(tmp[i] & 077);
+        *cp = '\0';
+
+        /* no longer need cleartext */
+        x = Goodcrypt_md5(pass_new, (const char *) result);
+
+        return x;
+}
+
+#ifdef WITH_SELINUX
+int
+unix_selinux_confined(void)
+{
+    static int confined = -1;
+    int fd;
+    char tempfile[]="/etc/.pwdXXXXXX";
+
+    if (confined != -1)
+    	return confined;
+
+    /* cannot be confined without SELinux enabled */
+    if (!SELINUX_ENABLED){
+       	confined = 0;
+       	return confined;
+    }
+    
+    /* let's try opening shadow read only */
+    if ((fd=open("/etc/shadow", O_RDONLY)) != -1) {
+        close(fd);
+        confined = 0;
+        return confined;
+    }
+
+    if (errno == EACCES) {
+	confined = 1;
+	return confined;
+    }
+    
+    /* shadow opening failed because of other reasons let's try 
+       creating a file in /etc */
+    if ((fd=mkstemp(tempfile)) != -1) {
+        unlink(tempfile);
+        close(fd);
+        confined = 0;
+        return confined;
+    }
+    
+    confined = 1;
+    return confined;
+}
+
+#else
+int
+unix_selinux_confined(void)
+{
+    return 0;
+}
+#endif
+
+#ifdef USE_LCKPWDF
+int
+lock_pwdf(void)
+{
+        int i;
+        int retval;
+
+#ifndef HELPER_COMPILE
+        if (unix_selinux_confined()) {
+                return PAM_SUCCESS;
+        }
+#endif
+        /* These values for the number of attempts and the sleep time
+           are, of course, completely arbitrary.
+           My reading of the PAM docs is that, once pam_chauthtok() has been
+           called with PAM_UPDATE_AUTHTOK, we are obliged to take any
+           reasonable steps to make sure the token is updated; so retrying
+           for 1/10 sec. isn't overdoing it. */
+        i=0;
+        while((retval = lckpwdf()) != 0 && i < 100) {
+                usleep(1000);
+                i++;
+        }
+        if(retval != 0) {
+                return PAM_AUTHTOK_LOCK_BUSY;
+        }
+        return PAM_SUCCESS;
+}
+
+void
+unlock_pwdf(void)
+{
+#ifndef HELPER_COMPILE
+        if (unix_selinux_confined()) {
+                return;
+        }
+#endif
+        ulckpwdf();
+}
+#else
+int
+lock_pwdf(void)
+{
+	return PAM_SUCCESS;
+}
+
+void
+unlock_pwdf(void)
+{
+	return;
+}
+#endif
+
+int
+save_old_password(const char *forwho, const char *oldpass,
+		  int howmany)
+{
+    static char buf[16384];
+    static char nbuf[16384];
+    char *s_luser, *s_uid, *s_npas, *s_pas, *pass;
+    int npas;
+    FILE *pwfile, *opwfile;
+    int err = 0;
+    int oldmask;
+    int found = 0;
+    struct passwd *pwd = NULL;
+    struct stat st;
+    security_context_t prev_context=NULL;
+
+    if (howmany < 0) {
+	return PAM_SUCCESS;
+    }
+
+    if (oldpass == NULL) {
+	return PAM_SUCCESS;
+    }
+
+    oldmask = umask(077);
+
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      security_context_t passwd_context=NULL;
+      if (getfilecon("/etc/passwd",&passwd_context)<0) {
+        return PAM_AUTHTOK_ERR;
+      };
+      if (getfscreatecon(&prev_context)<0) {
+        freecon(passwd_context);
+        return PAM_AUTHTOK_ERR;
+      }
+      if (setfscreatecon(passwd_context)) {
+        freecon(passwd_context);
+        freecon(prev_context);
+        return PAM_AUTHTOK_ERR;
+      }
+      freecon(passwd_context);
+    }
+#endif
+    pwfile = fopen(OPW_TMPFILE, "w");
+    umask(oldmask);
+    if (pwfile == NULL) {
+      err = 1;
+      goto done;
+    }
+
+    opwfile = fopen(OLD_PASSWORDS_FILE, "r");
+    if (opwfile == NULL) {
+	fclose(pwfile);
+      err = 1;
+      goto done;
+    }
+
+    if (fstat(fileno(opwfile), &st) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    while (fgets(buf, 16380, opwfile)) {
+	if (!strncmp(buf, forwho, strlen(forwho))) {
+	    char *sptr = NULL;
+	    found = 1;
+	    if (howmany == 0)
+	    	continue;
+	    buf[strlen(buf) - 1] = '\0';
+	    s_luser = strtok_r(buf, ":", &sptr);
+	    s_uid = strtok_r(NULL, ":", &sptr);
+	    s_npas = strtok_r(NULL, ":", &sptr);
+	    s_pas = strtok_r(NULL, ":", &sptr);
+	    npas = strtol(s_npas, NULL, 10) + 1;
+	    while (npas > howmany) {
+		s_pas = strpbrk(s_pas, ",");
+		if (s_pas != NULL)
+		    s_pas++;
+		npas--;
+	    }
+	    pass = crypt_md5_wrapper(oldpass);
+	    if (s_pas == NULL)
+		snprintf(nbuf, sizeof(nbuf), "%s:%s:%d:%s\n",
+			 s_luser, s_uid, npas, pass);
+	    else
+		snprintf(nbuf, sizeof(nbuf),"%s:%s:%d:%s,%s\n",
+			 s_luser, s_uid, npas, s_pas, pass);
+	    _pam_delete(pass);
+	    if (fputs(nbuf, pwfile) < 0) {
+		err = 1;
+		break;
+	    }
+	} else if (fputs(buf, pwfile) < 0) {
+	    err = 1;
+	    break;
+	}
+    }
+    fclose(opwfile);
+
+    if (!found) {
+	pwd = getpwnam(forwho);
+	if (pwd == NULL) {
+	    err = 1;
+	} else {
+	    pass = crypt_md5_wrapper(oldpass);
+	    snprintf(nbuf, sizeof(nbuf), "%s:%lu:1:%s\n",
+		     forwho, (unsigned long)pwd->pw_uid, pass);
+	    _pam_delete(pass);
+	    if (fputs(nbuf, pwfile) < 0) {
+		err = 1;
+	    }
+	}
+    }
+
+    if (fclose(pwfile)) {
+	D(("error writing entries to old passwords file: %m"));
+	err = 1;
+    }
+
+done:
+    if (!err) {
+	if (rename(OPW_TMPFILE, OLD_PASSWORDS_FILE))
+	    err = 1;
+    }
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      if (setfscreatecon(prev_context)) {
+        err = 1;
+      }
+      if (prev_context)
+        freecon(prev_context);
+      prev_context=NULL;
+    }
+#endif
+    if (!err) {
+	return PAM_SUCCESS;
+    } else {
+	unlink(OPW_TMPFILE);
+	return PAM_AUTHTOK_ERR;
+    }
+}
+
+#ifdef HELPER_COMPILE
+int
+unix_update_passwd(const char *forwho, const char *towhat)
+#else
+int
+unix_update_passwd(pam_handle_t *pamh, const char *forwho, const char *towhat)
+#endif
+{
+    struct passwd *tmpent = NULL;
+    struct stat st;
+    FILE *pwfile, *opwfile;
+    int err = 1;
+    int oldmask;
+    security_context_t prev_context=NULL;
+
+    oldmask = umask(077);
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      security_context_t passwd_context=NULL;
+      if (getfilecon("/etc/passwd",&passwd_context)<0) {
+	return PAM_AUTHTOK_ERR;
+      };
+      if (getfscreatecon(&prev_context)<0) {
+	freecon(passwd_context);
+	return PAM_AUTHTOK_ERR;
+      }
+      if (setfscreatecon(passwd_context)) {
+	freecon(passwd_context);
+	freecon(prev_context);
+	return PAM_AUTHTOK_ERR;
+      }
+      freecon(passwd_context);
+    }
+#endif
+    pwfile = fopen(PW_TMPFILE, "w");
+    umask(oldmask);
+    if (pwfile == NULL) {
+      err = 1;
+      goto done;
+    }
+
+    opwfile = fopen("/etc/passwd", "r");
+    if (opwfile == NULL) {
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    if (fstat(fileno(opwfile), &st) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    tmpent = fgetpwent(opwfile);
+    while (tmpent) {
+	if (!strcmp(tmpent->pw_name, forwho)) {
+	    /* To shut gcc up */
+	    union {
+		const char *const_charp;
+		char *charp;
+	    } assigned_passwd;
+	    assigned_passwd.const_charp = towhat;
+
+	    tmpent->pw_passwd = assigned_passwd.charp;
+	    err = 0;
+	}
+	if (putpwent(tmpent, pwfile)) {
+	    D(("error writing entry to password file: %m"));
+	    err = 1;
+	    break;
+	}
+	tmpent = fgetpwent(opwfile);
+    }
+    fclose(opwfile);
+
+    if (fclose(pwfile)) {
+	D(("error writing entries to password file: %m"));
+	err = 1;
+    }
+
+done:
+    if (!err) {
+	if (!rename(PW_TMPFILE, "/etc/passwd"))
+#ifdef HELPER_COMPILE
+	    helper_log_err(
+#else
+	    pam_syslog(pamh, 
+#endif
+		LOG_NOTICE, "password changed for %s", forwho);
+	else
+	    err = 1;
+    }
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      if (setfscreatecon(prev_context)) {
+	err = 1;
+      }
+      if (prev_context)
+	freecon(prev_context);
+      prev_context=NULL;
+    }
+#endif
+    if (!err) {
+	return PAM_SUCCESS;
+    } else {
+	unlink(PW_TMPFILE);
+	return PAM_AUTHTOK_ERR;
+    }
+}
+
+#ifdef HELPER_COMPILE
+int
+unix_update_shadow(const char *forwho, char *towhat)
+#else
+int
+unix_update_shadow(pam_handle_t *pamh, const char *forwho, char *towhat)
+#endif
+{
+    struct spwd *spwdent = NULL, *stmpent = NULL;
+    struct stat st;
+    FILE *pwfile, *opwfile;
+    int err = 1;
+    int oldmask;
+    security_context_t prev_context=NULL;
+
+    spwdent = getspnam(forwho);
+    if (spwdent == NULL) {
+	return PAM_USER_UNKNOWN;
+    }
+    oldmask = umask(077);
+
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      security_context_t shadow_context=NULL;
+      if (getfilecon("/etc/shadow",&shadow_context)<0) {
+	return PAM_AUTHTOK_ERR;
+      };
+      if (getfscreatecon(&prev_context)<0) {
+	freecon(shadow_context);
+	return PAM_AUTHTOK_ERR;
+      }
+      if (setfscreatecon(shadow_context)) {
+	freecon(shadow_context);
+	freecon(prev_context);
+	return PAM_AUTHTOK_ERR;
+      }
+      freecon(shadow_context);
+    }
+#endif
+    pwfile = fopen(SH_TMPFILE, "w");
+    umask(oldmask);
+    if (pwfile == NULL) {
+	err = 1;
+	goto done;
+    }
+
+    opwfile = fopen("/etc/shadow", "r");
+    if (opwfile == NULL) {
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    if (fstat(fileno(opwfile), &st) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
+	fclose(opwfile);
+	fclose(pwfile);
+	err = 1;
+	goto done;
+    }
+
+    stmpent = fgetspent(opwfile);
+    while (stmpent) {
+
+	if (!strcmp(stmpent->sp_namp, forwho)) {
+	    stmpent->sp_pwdp = towhat;
+	    stmpent->sp_lstchg = time(NULL) / (60 * 60 * 24);
+	    err = 0;
+	    D(("Set password %s for %s", stmpent->sp_pwdp, forwho));
+	}
+
+	if (putspent(stmpent, pwfile)) {
+	    D(("error writing entry to shadow file: %m"));
+	    err = 1;
+	    break;
+	}
+
+	stmpent = fgetspent(opwfile);
+    }
+    fclose(opwfile);
+
+    if (fclose(pwfile)) {
+	D(("error writing entries to shadow file: %m"));
+	err = 1;
+    }
+
+ done:
+    if (!err) {
+	if (!rename(SH_TMPFILE, "/etc/shadow"))
+#ifdef HELPER_COMPILE
+	    helper_log_err(
+#else
+	    pam_syslog(pamh, 
+#endif
+		LOG_NOTICE, "password changed for %s", forwho);
+	else
+	    err = 1;
+    }
+
+#ifdef WITH_SELINUX
+    if (SELINUX_ENABLED) {
+      if (setfscreatecon(prev_context)) {
+	err = 1;
+      }
+      if (prev_context)
+	freecon(prev_context);
+      prev_context=NULL;
+    }
+#endif
+
+    if (!err) {
+	return PAM_SUCCESS;
+    } else {
+	unlink(SH_TMPFILE);
+	return PAM_AUTHTOK_ERR;
+    }
+}
+
 #ifdef HELPER_COMPILE
 
 int
@@ -296,13 +887,107 @@ helper_log_err(int err, const char *format, ...)
 	closelog();
 }
 
+static void
+su_sighandler(int sig)
+{
+#ifndef SA_RESETHAND
+        /* emulate the behaviour of the SA_RESETHAND flag */
+        if ( sig == SIGILL || sig == SIGTRAP || sig == SIGBUS || sig = SIGSERV )
+                signal(sig, SIG_DFL);
+#endif
+        if (sig > 0) {
+                _exit(sig);
+        }
+}
+
+void
+setup_signals(void)
+{
+        struct sigaction action;        /* posix signal structure */
+
+        /*
+         * Setup signal handlers
+         */
+        (void) memset((void *) &action, 0, sizeof(action));
+        action.sa_handler = su_sighandler;
+#ifdef SA_RESETHAND
+        action.sa_flags = SA_RESETHAND;
+#endif
+        (void) sigaction(SIGILL, &action, NULL);
+        (void) sigaction(SIGTRAP, &action, NULL);
+        (void) sigaction(SIGBUS, &action, NULL);
+        (void) sigaction(SIGSEGV, &action, NULL);
+        action.sa_handler = SIG_IGN;
+        action.sa_flags = 0;
+        (void) sigaction(SIGTERM, &action, NULL);
+        (void) sigaction(SIGHUP, &action, NULL);
+        (void) sigaction(SIGINT, &action, NULL);
+        (void) sigaction(SIGQUIT, &action, NULL);
+}
+
+char *
+getuidname(uid_t uid)
+{
+        struct passwd *pw;
+        static char username[256];
+
+        pw = getpwuid(uid);
+        if (pw == NULL)
+                return NULL;
+
+        strncpy(username, pw->pw_name, sizeof(username));
+        username[sizeof(username) - 1] = '\0';
+
+        return username;
+}
+
+int
+read_passwords(int fd, int npass, char **passwords)
+{
+        int rbytes = 0;
+        int offset = 0;
+        int i = 0;
+        char *pptr;
+        while (npass > 0) {
+                rbytes = read(fd, passwords[i]+offset, MAXPASS-offset);
+
+                if (rbytes < 0) {
+                        if (errno == EINTR) continue;
+                        break;
+                }
+                if (rbytes == 0)
+                        break;
+
+                while (npass > 0 && (pptr=memchr(passwords[i]+offset, '\0', rbytes))
+                        != NULL) {
+                        rbytes -= pptr - (passwords[i]+offset) + 1;
+                        i++;
+                        offset = 0;
+                        npass--;
+                        if (rbytes > 0) {
+                                if (npass > 0)
+                                        memcpy(passwords[i], pptr+1, rbytes);
+                                memset(pptr+1, '\0', rbytes);
+                        }
+                }
+                offset += rbytes;
+        }               
+
+        /* clear up */
+        if (offset > 0 && npass > 0) {
+                memset(passwords[i], '\0', offset);
+        }
+
+        return i;
+}
+
 #endif
 /* ****************************************************************** *
  * Copyright (c) Jan Rêkorajski 1999.
  * Copyright (c) Andrew G. Morgan 1996-8.
  * Copyright (c) Alex O. Yuriev, 1996.
  * Copyright (c) Cristian Gafton 1996.
- * Copyright (c) Red Hat, Inc. 2007.
+ * Copyright (c) Red Hat, Inc. 1996, 2007, 2008.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
diff --git a/modules/pam_unix/passverify.h b/modules/pam_unix/passverify.h
index 6b8c0c3e..55007a31 100644
--- a/modules/pam_unix/passverify.h
+++ b/modules/pam_unix/passverify.h
@@ -2,17 +2,41 @@
  * Copyright information at end of file.
  */
 
+#include <sys/types.h>
 #include <pwd.h>
 #include <security/pam_modules.h>
 
 #define PAM_UNIX_RUN_HELPER PAM_CRED_INSUFFICIENT
 
+#define MAXPASS		200	/* the maximum length of a password */
+
+#define OLD_PASSWORDS_FILE      "/etc/security/opasswd"
+
+#define ascii_to_bin(c) ((c)>='a'?(c-59):(c)>='A'?((c)-53):(c)-'.')
+#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
+
 int
 verify_pwd_hash(const char *p, const char *hash, unsigned int nullok);
 
 int
 is_pwd_shadowed(const struct passwd *pwd);
 
+char *
+crypt_md5_wrapper(const char *pass_new);
+
+int
+unix_selinux_confined(void);
+
+int
+lock_pwdf(void);
+
+void
+unlock_pwdf(void);
+
+int
+save_old_password(const char *forwho, const char *oldpass,
+		  int howmany);
+
 #ifdef HELPER_COMPILE
 void
 helper_log_err(int err, const char *format,...);
@@ -20,6 +44,15 @@ helper_log_err(int err, const char *format,...);
 int
 helper_verify_password(const char *name, const char *p, int nullok);
 
+void
+setup_signals(void);
+
+char *
+getuidname(uid_t uid);
+
+int
+read_passwords(int fd, int npass, char **passwords);
+
 int
 get_account_info(const char *name,
 	struct passwd **pwd, struct spwd **spwdent);
@@ -31,6 +64,11 @@ get_pwd_hash(const char *name,
 int
 check_shadow_expiry(struct spwd *spent, int *daysleft);
 
+int
+unix_update_passwd(const char *forwho, const char *towhat);
+
+int
+unix_update_shadow(const char *forwho, char *towhat);
 #else
 int
 get_account_info(pam_handle_t *pamh, const char *name,
@@ -42,6 +80,12 @@ get_pwd_hash(pam_handle_t *pamh, const char *name,
 
 int
 check_shadow_expiry(pam_handle_t *pamh, struct spwd *spent, int *daysleft);
+
+int
+unix_update_passwd(pam_handle_t *pamh, const char *forwho, const char *towhat);
+
+int
+unix_update_shadow(pam_handle_t *pamh, const char *forwho, char *towhat);
 #endif
 
 /* ****************************************************************** *
diff --git a/modules/pam_unix/unix_chkpwd.c b/modules/pam_unix/unix_chkpwd.c
index b6508b87..11ac3aac 100644
--- a/modules/pam_unix/unix_chkpwd.c
+++ b/modules/pam_unix/unix_chkpwd.c
@@ -24,61 +24,12 @@
 #include <shadow.h>
 #include <signal.h>
 #include <time.h>
-#ifdef WITH_SELINUX
-#include <selinux/selinux.h>
-#define SELINUX_ENABLED (selinux_enabled!=-1 ? selinux_enabled : (selinux_enabled=is_selinux_enabled()>0))
-static security_context_t prev_context=NULL;
-static int selinux_enabled=-1;
-#else
-#define SELINUX_ENABLED 0
-#endif
-
-#define MAXPASS		200	/* the maximum length of a password */
 
 #include <security/_pam_types.h>
 #include <security/_pam_macros.h>
 
 #include "passverify.h"
 
-/* syslogging function for errors and other information */
-
-static void su_sighandler(int sig)
-{
-#ifndef SA_RESETHAND
-	/* emulate the behaviour of the SA_RESETHAND flag */
-	if ( sig == SIGILL || sig == SIGTRAP || sig == SIGBUS || sig = SIGSERV )
-		signal(sig, SIG_DFL);
-#endif
-	if (sig > 0) {
-		helper_log_err(LOG_NOTICE, "caught signal %d.", sig);
-		exit(sig);
-	}
-}
-
-static void setup_signals(void)
-{
-	struct sigaction action;	/* posix signal structure */
-
-	/*
-	 * Setup signal handlers
-	 */
-	(void) memset((void *) &action, 0, sizeof(action));
-	action.sa_handler = su_sighandler;
-#ifdef SA_RESETHAND
-	action.sa_flags = SA_RESETHAND;
-#endif
-	(void) sigaction(SIGILL, &action, NULL);
-	(void) sigaction(SIGTRAP, &action, NULL);
-	(void) sigaction(SIGBUS, &action, NULL);
-	(void) sigaction(SIGSEGV, &action, NULL);
-	action.sa_handler = SIG_IGN;
-	action.sa_flags = 0;
-	(void) sigaction(SIGTERM, &action, NULL);
-	(void) sigaction(SIGHUP, &action, NULL);
-	(void) sigaction(SIGINT, &action, NULL);
-	(void) sigaction(SIGQUIT, &action, NULL);
-}
-
 static int _check_expiry(const char *uname)
 {
 	struct spwd *spent;
@@ -103,190 +54,15 @@ static int _check_expiry(const char *uname)
 	return retval;
 }
 
-static char *getuidname(uid_t uid)
-{
-	struct passwd *pw;
-	static char username[32];
-
-	pw = getpwuid(uid);
-	if (pw == NULL)
-		return NULL;
-
-	strncpy(username, pw->pw_name, sizeof(username));
-	username[sizeof(username) - 1] = '\0';
-
-	return username;
-}
-
-#define SH_TMPFILE		"/etc/nshadow"
-static int _update_shadow(const char *forwho)
-{
-    struct spwd *spwdent = NULL, *stmpent = NULL;
-    FILE *pwfile, *opwfile;
-    int err = 1;
-    int oldmask;
-    struct stat st;
-    char pass[MAXPASS + 1];
-    char towhat[MAXPASS + 1];
-    int npass=0;
-
-    /* read the password from stdin (a pipe from the pam_unix module) */
-
-    npass = read(STDIN_FILENO, pass, MAXPASS);
-
-    if (npass < 0) {	/* is it a valid password? */
-
-      helper_log_err(LOG_DEBUG, "no password supplied");
-      return PAM_AUTHTOK_ERR;
-
-    } else if (npass >= MAXPASS) {
-
-      helper_log_err(LOG_DEBUG, "password too long");
-      return PAM_AUTHTOK_ERR;
-
-    } else {
-      /* does pass agree with the official one? */
-      int retval=0;
-      pass[npass] = '\0';	/* NUL terminate */
-      retval = helper_verify_password(forwho, pass, 0);
-      if (retval != PAM_SUCCESS) {
-	return retval;
-      }
-    }
-
-    /* read the password from stdin (a pipe from the pam_unix module) */
-
-    npass = read(STDIN_FILENO, towhat, MAXPASS);
-
-    if (npass < 0) {	/* is it a valid password? */
-
-      helper_log_err(LOG_DEBUG, "no new password supplied");
-      return PAM_AUTHTOK_ERR;
-
-    } else if (npass >= MAXPASS) {
-
-      helper_log_err(LOG_DEBUG, "new password too long");
-      return PAM_AUTHTOK_ERR;
-
-    }
-
-    towhat[npass] = '\0';	/* NUL terminate */
-    spwdent = getspnam(forwho);
-    if (spwdent == NULL) {
-	return PAM_USER_UNKNOWN;
-    }
-    oldmask = umask(077);
-
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      security_context_t shadow_context=NULL;
-      if (getfilecon("/etc/shadow",&shadow_context)<0) {
-	return PAM_AUTHTOK_ERR;
-      };
-      if (getfscreatecon(&prev_context)<0) {
-	freecon(shadow_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      if (setfscreatecon(shadow_context)) {
-	freecon(shadow_context);
-	freecon(prev_context);
-	return PAM_AUTHTOK_ERR;
-      }
-      freecon(shadow_context);
-    }
-#endif
-    pwfile = fopen(SH_TMPFILE, "w");
-    umask(oldmask);
-    if (pwfile == NULL) {
-	err = 1;
-	goto done;
-    }
-
-    opwfile = fopen("/etc/shadow", "r");
-    if (opwfile == NULL) {
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fstat(fileno(opwfile), &st) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    if (fchown(fileno(pwfile), st.st_uid, st.st_gid) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-    if (fchmod(fileno(pwfile), st.st_mode) == -1) {
-	fclose(opwfile);
-	fclose(pwfile);
-	err = 1;
-	goto done;
-    }
-
-    stmpent = fgetspent(opwfile);
-    while (stmpent) {
-
-	if (!strcmp(stmpent->sp_namp, forwho)) {
-	    stmpent->sp_pwdp = towhat;
-	    stmpent->sp_lstchg = time(NULL) / (60 * 60 * 24);
-	    err = 0;
-	    D(("Set password %s for %s", stmpent->sp_pwdp, forwho));
-	}
-
-	if (putspent(stmpent, pwfile)) {
-	    D(("error writing entry to shadow file: %m"));
-	    err = 1;
-	    break;
-	}
-
-	stmpent = fgetspent(opwfile);
-    }
-    fclose(opwfile);
-
-    if (fclose(pwfile)) {
-	D(("error writing entries to shadow file: %m"));
-	err = 1;
-    }
-
- done:
-    if (!err) {
-	if (rename(SH_TMPFILE, "/etc/shadow"))
-	    err = 1;
-    }
-
-#ifdef WITH_SELINUX
-    if (SELINUX_ENABLED) {
-      if (setfscreatecon(prev_context)) {
-	err = 1;
-      }
-      if (prev_context)
-	freecon(prev_context);
-      prev_context=NULL;
-    }
-#endif
-
-    if (!err) {
-	return PAM_SUCCESS;
-    } else {
-	unlink(SH_TMPFILE);
-	return PAM_AUTHTOK_ERR;
-    }
-}
-
 int main(int argc, char *argv[])
 {
 	char pass[MAXPASS + 1];
 	char *option;
 	int npass, nullok;
-	int blankpass;
+	int blankpass = 0;
 	int retval = PAM_AUTH_ERR;
 	char *user;
+	char *passwords[] = { pass };
 
 	/*
 	 * Catch or ignore as many signal as possible.
@@ -331,51 +107,32 @@ int main(int argc, char *argv[])
 
 	option=argv[2];
 
-	if (strncmp(argv[2], "chkexpiry", 8) == 0) {
+	if (strcmp(option, "chkexpiry") == 0)
 	  /* Check account information from the shadow file */
-	  return _check_expiry(argv[1]);
-	  
-	}
-
-	if (strncmp(option, "shadow", 8) == 0) {
-	  /* Attempting to change the password */
-	  return _update_shadow(argv[1]);
-	}
-
+	  return _check_expiry(argv[1]);	  
 	/* read the nullok/nonull option */
-	if (strncmp(option, "nullok", 8) == 0)
+	else if (strcmp(option, "nullok") == 0)
 	  nullok = 1;
-	else
+	else if (strcmp(option, "nonull") == 0)
 	  nullok = 0;
+	else
+	  return PAM_SYSTEM_ERR;
 
 	/* read the password from stdin (a pipe from the pam_unix module) */
 
-	npass = read(STDIN_FILENO, pass, MAXPASS);
-
-	if (npass < 0) {	/* is it a valid password? */
+	npass = read_passwords(STDIN_FILENO, 1, passwords);
 
+	if (npass != 1) {	/* is it a valid password? */
 		helper_log_err(LOG_DEBUG, "no password supplied");
+		*pass = '\0';
+	}
 
-	} else if (npass >= MAXPASS) {
-
-		helper_log_err(LOG_DEBUG, "password too long");
-
-	} else {
-		if (npass == 0) {
-			/* the password is NULL */
-			blankpass = 1;
-			retval = helper_verify_password(user, NULL, nullok);
-
-		} else {
-			/* does pass agree with the official one? */
-			if (pass[0] == '\0')
-				blankpass = 1;
-			pass[npass] = '\0';	/* NUL terminate */
-			retval = helper_verify_password(user, pass, nullok);
-
-		}
+	if (*pass == '\0') {
+		blankpass = 1;
 	}
 
+	retval = helper_verify_password(user, pass, nullok);
+
 	memset(pass, '\0', MAXPASS);	/* clear memory of the password */
 
 	/* return pass or fail */
@@ -392,7 +149,7 @@ int main(int argc, char *argv[])
 
 /*
  * Copyright (c) Andrew G. Morgan, 1996. All rights reserved
- * Copyright (c) Red Hat, Inc., 2007. All rights reserved
+ * Copyright (c) Red Hat, Inc., 2007,2008. All rights reserved
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
diff --git a/modules/pam_unix/unix_update.c b/modules/pam_unix/unix_update.c
new file mode 100644
index 00000000..6dc8ace4
--- /dev/null
+++ b/modules/pam_unix/unix_update.c
@@ -0,0 +1,194 @@
+/*
+ * This program is designed to run setuid(root) or with sufficient
+ * privilege to read all of the unix password databases. It is designed
+ * to provide a mechanism for the current user (defined by this
+ * process' uid) to verify their own password.
+ *
+ * The password is read from the standard input. The exit status of
+ * this program indicates whether the user is authenticated or not.
+ *
+ * Copyright information is located at the end of the file.
+ *
+ */
+
+#include "config.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pwd.h>
+#include <shadow.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+#ifdef WITH_SELINUX
+#include <selinux/selinux.h>
+#define SELINUX_ENABLED (selinux_enabled!=-1 ? selinux_enabled : (selinux_enabled=is_selinux_enabled()>0))
+static int selinux_enabled=-1;
+#else
+#define SELINUX_ENABLED 0
+#endif
+
+#include <security/_pam_types.h>
+#include <security/_pam_macros.h>
+
+#include "passverify.h"
+
+static int
+set_password(const char *forwho, const char *shadow, const char *remember)
+{
+    struct passwd *pwd = NULL;
+    int retval;
+    char pass[MAXPASS + 1];
+    char towhat[MAXPASS + 1];
+    int npass = 0;
+    /* we don't care about number format errors because the helper
+       should be called internally only */
+    int doshadow = atoi(shadow);
+    int nremember = atoi(remember);
+    char *passwords[] = { pass, towhat };
+
+    /* read the password from stdin (a pipe from the pam_unix module) */
+
+    npass = read_passwords(STDIN_FILENO, 2, passwords);
+
+    if (npass != 2) {	/* is it a valid password? */
+      if (npass == 1) {
+        helper_log_err(LOG_DEBUG, "no new password supplied");
+	memset(pass, '\0', MAXPASS);
+      } else {
+        helper_log_err(LOG_DEBUG, "no valid passwords supplied");
+      }
+      return PAM_AUTHTOK_ERR;
+    }
+
+    if (lock_pwdf() != PAM_SUCCESS)
+    	return PAM_AUTHTOK_LOCK_BUSY;
+
+    pwd = getpwnam(forwho);
+    
+    if (pwd == NULL) {
+        retval = PAM_USER_UNKNOWN;
+        goto done;
+    }
+
+    /* does pass agree with the official one? 
+       we always allow change from null pass */
+    retval = helper_verify_password(forwho, pass, 1);
+    if (retval != PAM_SUCCESS) {
+	goto done;
+    }
+
+    /* first, save old password */
+    if (save_old_password(forwho, pass, nremember)) {
+	retval = PAM_AUTHTOK_ERR;
+	goto done;
+    }
+
+    if (doshadow || is_pwd_shadowed(pwd)) {
+	retval = unix_update_shadow(forwho, towhat);
+	if (retval == PAM_SUCCESS)
+	    if (!is_pwd_shadowed(pwd))
+		retval = unix_update_passwd(forwho, "x");
+    } else {
+	retval = unix_update_passwd(forwho, towhat);
+    }
+
+done:
+    memset(pass, '\0', MAXPASS);
+    memset(towhat, '\0', MAXPASS);
+
+    unlock_pwdf();
+
+    if (retval == PAM_SUCCESS) {
+	return PAM_SUCCESS;
+    } else {
+	return PAM_AUTHTOK_ERR;
+    }
+}
+
+int main(int argc, char *argv[])
+{
+	char *option;
+
+	/*
+	 * Catch or ignore as many signal as possible.
+	 */
+	setup_signals();
+
+	/*
+	 * we establish that this program is running with non-tty stdin.
+	 * this is to discourage casual use. It does *NOT* prevent an
+	 * intruder from repeatadly running this program to determine the
+	 * password of the current user (brute force attack, but one for
+	 * which the attacker must already have gained access to the user's
+	 * account).
+	 */
+
+	if (isatty(STDIN_FILENO) || argc != 5 ) {
+		helper_log_err(LOG_NOTICE
+		      ,"inappropriate use of Unix helper binary [UID=%d]"
+			 ,getuid());
+		fprintf(stderr
+		 ,"This binary is not designed for running in this way\n"
+		      "-- the system administrator has been informed\n");
+		sleep(10);	/* this should discourage/annoy the user */
+		return PAM_SYSTEM_ERR;
+	}
+
+	/* We must be root to read/update shadow.
+	 */
+	if (geteuid() != 0) {
+	    return PAM_CRED_INSUFFICIENT;
+	}
+	
+	option = argv[2];
+
+	if (strcmp(option, "update") == 0) {
+	    /* Attempting to change the password */
+	    return set_password(argv[1], argv[3], argv[4]);
+	}
+
+	return PAM_SYSTEM_ERR;
+}
+
+/*
+ * Copyright (c) Andrew G. Morgan, 1996. All rights reserved
+ * Copyright (c) Red Hat, Inc., 2007, 2008. 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, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 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 author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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.
+ */