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pam/pam-1.4.0-pwhistory-helper.patch

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RHEL 9.0.0 Alpha bootstrap The content of this branch was automatically imported from Fedora ELN with the following as its source: https://src.fedoraproject.org/rpms/pam#767f761a2d5d99b87ebc44c4ad751467b46b1d97
2020-10-15 20:44:37 +00:00
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/Makefile.am.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/Makefile.am
--- Linux-PAM-1.4.0/modules/pam_pwhistory/Makefile.am.pwhhelper 2020-06-08 12:17:27.000000000 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/Makefile.am 2020-06-22 13:22:13.740840867 +0200
@@ -1,5 +1,6 @@
#
# Copyright (c) 2008, 2009 Thorsten Kukuk <kukuk@suse.de>
+# Copyright (c) 2013 Red Hat, Inc.
#
CLEANFILES = *~
@@ -8,9 +9,9 @@ MAINTAINERCLEANFILES = $(MANS) README
EXTRA_DIST = $(XMLS)
if HAVE_DOC
-dist_man_MANS = pam_pwhistory.8
+dist_man_MANS = pam_pwhistory.8 pwhistory_helper.8
endif
-XMLS = README.xml pam_pwhistory.8.xml
+XMLS = README.xml pam_pwhistory.8.xml pwhistory_helper.8.xml
dist_check_SCRIPTS = tst-pam_pwhistory
TESTS = $(dist_check_SCRIPTS)
@@ -18,18 +19,26 @@ securelibdir = $(SECUREDIR)
secureconfdir = $(SCONFIGDIR)
AM_CFLAGS = -I$(top_srcdir)/libpam/include -I$(top_srcdir)/libpamc/include \
- $(WARN_CFLAGS)
-AM_LDFLAGS = -no-undefined -avoid-version -module
+ $(WARN_CFLAGS) -DPWHISTORY_HELPER=\"$(sbindir)/pwhistory_helper\"
+
+pam_pwhistory_la_LDFLAGS = -no-undefined -avoid-version -module
if HAVE_VERSIONING
- AM_LDFLAGS += -Wl,--version-script=$(srcdir)/../modules.map
+ pam_pwhistory_la_LDFLAGS += -Wl,--version-script=$(srcdir)/../modules.map
endif
noinst_HEADERS = opasswd.h
securelib_LTLIBRARIES = pam_pwhistory.la
-pam_pwhistory_la_LIBADD = $(top_builddir)/libpam/libpam.la @LIBCRYPT@
+pam_pwhistory_la_CFLAGS = $(AM_CFLAGS)
+pam_pwhistory_la_LIBADD = $(top_builddir)/libpam/libpam.la @LIBCRYPT@ @LIBSELINUX@
pam_pwhistory_la_SOURCES = pam_pwhistory.c opasswd.c
+sbin_PROGRAMS = pwhistory_helper
+pwhistory_helper_CFLAGS = $(AM_CFLAGS) -DHELPER_COMPILE=\"pwhistory_helper\" @PIE_CFLAGS@
+pwhistory_helper_SOURCES = pwhistory_helper.c opasswd.c
+pwhistory_helper_LDFLAGS = -Wl,-z,now @PIE_LDFLAGS@
+pwhistory_helper_LDADD = $(top_builddir)/libpam/libpam.la @LIBCRYPT@
+
if ENABLE_REGENERATE_MAN
dist_noinst_DATA = README
-include $(top_srcdir)/Make.xml.rules
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.c.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.c
--- Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.c.pwhhelper 2020-06-08 12:17:27.000000000 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.c 2020-06-22 13:24:02.424365617 +0200
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2008 Thorsten Kukuk <kukuk@suse.de>
+ * Copyright (c) 2013 Red Hat, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -38,6 +39,7 @@
#endif
#include <pwd.h>
+#include <shadow.h>
#include <time.h>
#include <ctype.h>
#include <errno.h>
@@ -47,6 +49,7 @@
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
+#include <stdarg.h>
#include <sys/stat.h>
#if defined HAVE_LIBXCRYPT
@@ -55,7 +58,14 @@
#include <crypt.h>
#endif
+#ifdef HELPER_COMPILE
+#define pam_modutil_getpwnam(h,n) getpwnam(n)
+#define pam_modutil_getspnam(h,n) getspnam(n)
+#define pam_syslog(h,a,...) helper_log_err(a,__VA_ARGS__)
+#else
+#include <security/pam_modutil.h>
#include <security/pam_ext.h>
+#endif
#include <security/pam_modules.h>
#include "opasswd.h"
@@ -76,6 +86,19 @@ typedef struct {
char *old_passwords;
} opwd;
+#ifdef HELPER_COMPILE
+void
+helper_log_err(int err, const char *format, ...)
+{
+ va_list args;
+
+ va_start(args, format);
+ openlog(HELPER_COMPILE, LOG_CONS | LOG_PID, LOG_AUTHPRIV);
+ vsyslog(err, format, args);
+ va_end(args);
+ closelog();
+}
+#endif
static int
parse_entry (char *line, opwd *data)
@@ -117,8 +140,8 @@ compare_password(const char *newpass, co
}
/* Check, if the new password is already in the opasswd file. */
-int
-check_old_pass (pam_handle_t *pamh, const char *user,
+PAMH_ARG_DECL(int
+check_old_pass, const char *user,
const char *newpass, int debug)
{
int retval = PAM_SUCCESS;
@@ -128,6 +151,11 @@ check_old_pass (pam_handle_t *pamh, cons
opwd entry;
int found = 0;
+#ifndef HELPER_COMPILE
+ if (SELINUX_ENABLED)
+ return PAM_PWHISTORY_RUN_HELPER;
+#endif
+
if ((oldpf = fopen (OLD_PASSWORDS_FILE, "r")) == NULL)
{
if (errno != ENOENT)
@@ -213,9 +241,9 @@ check_old_pass (pam_handle_t *pamh, cons
return retval;
}
-int
-save_old_pass (pam_handle_t *pamh, const char *user, uid_t uid,
- const char *oldpass, int howmany, int debug UNUSED)
+PAMH_ARG_DECL(int
+save_old_pass, const char *user,
+ int howmany, int debug UNUSED)
{
char opasswd_tmp[] = TMP_PASSWORDS_FILE;
struct stat opasswd_stat;
@@ -226,10 +254,35 @@ save_old_pass (pam_handle_t *pamh, const
char *buf = NULL;
size_t buflen = 0;
int found = 0;
+ struct passwd *pwd;
+ const char *oldpass;
+
+ pwd = pam_modutil_getpwnam (pamh, user);
+ if (pwd == NULL)
+ return PAM_USER_UNKNOWN;
if (howmany <= 0)
return PAM_SUCCESS;
+#ifndef HELPER_COMPILE
+ if (SELINUX_ENABLED)
+ return PAM_PWHISTORY_RUN_HELPER;
+#endif
+
+ if ((strcmp(pwd->pw_passwd, "x") == 0) ||
+ ((pwd->pw_passwd[0] == '#') &&
+ (pwd->pw_passwd[1] == '#') &&
+ (strcmp(pwd->pw_name, pwd->pw_passwd + 2) == 0)))
+ {
+ struct spwd *spw = pam_modutil_getspnam (pamh, user);
+
+ if (spw == NULL)
+ return PAM_USER_UNKNOWN;
+ oldpass = spw->sp_pwdp;
+ }
+ else
+ oldpass = pwd->pw_passwd;
+
if (oldpass == NULL || *oldpass == '\0')
return PAM_SUCCESS;
@@ -452,7 +505,7 @@ save_old_pass (pam_handle_t *pamh, const
{
char *out;
- if (asprintf (&out, "%s:%d:1:%s\n", user, uid, oldpass) < 0)
+ if (asprintf (&out, "%s:%d:1:%s\n", user, pwd->pw_uid, oldpass) < 0)
{
retval = PAM_AUTHTOK_ERR;
if (oldpf)
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.h.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.h
--- Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.h.pwhhelper 2020-06-08 12:17:27.000000000 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/opasswd.h 2020-06-22 13:13:23.722445347 +0200
@@ -1,5 +1,6 @@
/*
* Copyright (c) 2008 Thorsten Kukuk <kukuk@suse.de>
+ * Copyright (c) 2013 Red Hat, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -36,10 +37,32 @@
#ifndef __OPASSWD_H__
#define __OPASSWD_H__
-extern int check_old_pass (pam_handle_t *pamh, const char *user,
- const char *newpass, int debug);
-extern int save_old_pass (pam_handle_t *pamh, const char *user,
- uid_t uid, const char *oldpass,
- int howmany, int debug);
+#define PAM_PWHISTORY_RUN_HELPER PAM_CRED_INSUFFICIENT
+
+#ifdef WITH_SELINUX
+#include <selinux/selinux.h>
+#define SELINUX_ENABLED is_selinux_enabled()>0
+#else
+#define SELINUX_ENABLED 0
+#endif
+
+#ifdef HELPER_COMPILE
+#define PAMH_ARG_DECL(fname, ...) fname(__VA_ARGS__)
+#define PAMH_ARG(...) __VA_ARGS__
+#else
+#define PAMH_ARG_DECL(fname, ...) fname(pam_handle_t *pamh, __VA_ARGS__)
+#define PAMH_ARG(...) pamh, __VA_ARGS__
+#endif
+
+#ifdef HELPER_COMPILE
+void
+helper_log_err(int err, const char *format, ...);
+#endif
+
+PAMH_ARG_DECL(int
+check_old_pass, const char *user, const char *newpass, int debug);
+
+PAMH_ARG_DECL(int
+save_old_pass, const char *user, int howmany, int debug);
#endif /* __OPASSWD_H__ */
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/pam_pwhistory.c.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/pam_pwhistory.c
--- Linux-PAM-1.4.0/modules/pam_pwhistory/pam_pwhistory.c.pwhhelper 2020-06-08 12:17:27.000000000 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/pam_pwhistory.c 2020-06-22 13:25:23.107497539 +0200
@@ -3,6 +3,7 @@
*
* Copyright (c) 2008, 2012 Thorsten Kukuk
* Author: Thorsten Kukuk <kukuk@thkukuk.de>
+ * Copyright (c) 2013 Red Hat, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -46,10 +47,14 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
-#include <shadow.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <fcntl.h>
#include <security/pam_modules.h>
#include <security/pam_modutil.h>
@@ -60,6 +65,7 @@
#include "pam_inline.h"
#define DEFAULT_BUFLEN 2048
+#define MAX_FD_NO 20000
struct options_t {
int debug;
@@ -105,6 +111,184 @@ parse_option (pam_handle_t *pamh, const
pam_syslog (pamh, LOG_ERR, "pam_pwhistory: unknown option: %s", argv);
}
+static int
+run_save_helper(pam_handle_t *pamh, const char *user,
+ int howmany, int debug)
+{
+ int retval, child;
+ struct sigaction newsa, oldsa;
+
+ memset(&newsa, '\0', sizeof(newsa));
+ newsa.sa_handler = SIG_DFL;
+ sigaction(SIGCHLD, &newsa, &oldsa);
+
+ child = fork();
+ if (child == 0)
+ {
+ int i = 0;
+ struct rlimit rlim;
+ int dummyfds[2];
+ static char *envp[] = { NULL };
+ char *args[] = { NULL, NULL, NULL, NULL, NULL, NULL };
+
+ /* replace std file descriptors with a dummy pipe */
+ if (pipe2(dummyfds, O_NONBLOCK) == 0)
+ {
+ dup2(dummyfds[0], STDIN_FILENO);
+ dup2(dummyfds[1], STDOUT_FILENO);
+ dup2(dummyfds[1], STDERR_FILENO);
+ }
+
+ if (getrlimit(RLIMIT_NOFILE,&rlim) == 0)
+ {
+ if (rlim.rlim_max >= MAX_FD_NO)
+ rlim.rlim_max = MAX_FD_NO;
+ for (i = STDERR_FILENO + 1; i < (int)rlim.rlim_max; i++)
+ {
+ if (i != dummyfds[0])
+ close(i);
+ }
+ }
+
+ /* exec binary helper */
+ args[0] = strdup(PWHISTORY_HELPER);
+ args[1] = strdup("save");
+ args[2] = x_strdup(user);
+ asprintf(&args[3], "%d", howmany);
+ asprintf(&args[4], "%d", debug);
+
+ execve(args[0], args, envp);
+
+ _exit(PAM_SYSTEM_ERR);
+ }
+ else if (child > 0)
+ {
+ /* wait for child */
+ int rc = 0;
+ rc = waitpid(child, &retval, 0); /* wait for helper to complete */
+ if (rc < 0)
+ {
+ pam_syslog(pamh, LOG_ERR, "pwhistory_helper save waitpid returned %d: %m", rc);
+ retval = PAM_SYSTEM_ERR;
+ }
+ else if (!WIFEXITED(retval))
+ {
+ pam_syslog(pamh, LOG_ERR, "pwhistory_helper save abnormal exit: %d", retval);
+ retval = PAM_SYSTEM_ERR;
+ }
+ else
+ {
+ retval = WEXITSTATUS(retval);
+ }
+ }
+ else
+ {
+ retval = PAM_SYSTEM_ERR;
+ }
+
+ sigaction(SIGCHLD, &oldsa, NULL); /* restore old signal handler */
+
+ return retval;
+}
+
+static int
+run_check_helper(pam_handle_t *pamh, const char *user,
+ const char *newpass, int debug)
+{
+ int retval, child, fds[2];
+ struct sigaction newsa, oldsa;
+
+ /* create a pipe for the password */
+ if (pipe(fds) != 0)
+ return PAM_SYSTEM_ERR;
+
+ memset(&newsa, '\0', sizeof(newsa));
+ newsa.sa_handler = SIG_DFL;
+ sigaction(SIGCHLD, &newsa, &oldsa);
+
+ child = fork();
+ if (child == 0)
+ {
+ int i = 0;
+ struct rlimit rlim;
+ int dummyfds[2];
+ static char *envp[] = { NULL };
+ char *args[] = { NULL, NULL, NULL, NULL, NULL };
+
+ /* reopen stdin as pipe */
+ dup2(fds[0], STDIN_FILENO);
+
+ /* replace std file descriptors with a dummy pipe */
+ if (pipe2(dummyfds, O_NONBLOCK) == 0)
+ {
+ dup2(dummyfds[1], STDOUT_FILENO);
+ dup2(dummyfds[1], STDERR_FILENO);
+ }
+
+ if (getrlimit(RLIMIT_NOFILE,&rlim) == 0)
+ {
+ if (rlim.rlim_max >= MAX_FD_NO)
+ rlim.rlim_max = MAX_FD_NO;
+ for (i = STDERR_FILENO + 1; i < (int)rlim.rlim_max; i++)
+ {
+ if (i != dummyfds[0])
+ close(i);
+ }
+ }
+
+ /* exec binary helper */
+ args[0] = strdup(PWHISTORY_HELPER);
+ args[1] = strdup("check");
+ args[2] = x_strdup(user);
+ asprintf(&args[3], "%d", debug);
+
+ execve(args[0], args, envp);
+
+ _exit(PAM_SYSTEM_ERR);
+ }
+ else if (child > 0)
+ {
+ /* wait for child */
+ int rc = 0;
+ if (newpass == NULL)
+ newpass = "";
+
+ /* send the password to the child */
+ if (write(fds[1], newpass, strlen(newpass)+1) == -1)
+ {
+ pam_syslog(pamh, LOG_ERR, "Cannot send password to helper: %m");
+ retval = PAM_SYSTEM_ERR;
+ }
+ newpass = NULL;
+ close(fds[0]); /* close here to avoid possible SIGPIPE above */
+ close(fds[1]);
+ rc = waitpid(child, &retval, 0); /* wait for helper to complete */
+ if (rc < 0)
+ {
+ pam_syslog(pamh, LOG_ERR, "pwhistory_helper check waitpid returned %d: %m", rc);
+ retval = PAM_SYSTEM_ERR;
+ }
+ else if (!WIFEXITED(retval))
+ {
+ pam_syslog(pamh, LOG_ERR, "pwhistory_helper check abnormal exit: %d", retval);
+ retval = PAM_SYSTEM_ERR;
+ }
+ else
+ {
+ retval = WEXITSTATUS(retval);
+ }
+ }
+ else
+ {
+ close(fds[0]);
+ close(fds[1]);
+ retval = PAM_SYSTEM_ERR;
+ }
+
+ sigaction(SIGCHLD, &oldsa, NULL); /* restore old signal handler */
+
+ return retval;
+}
/* This module saves the current crypted password in /etc/security/opasswd
and then compares the new password with all entries in this file. */
@@ -112,7 +296,6 @@ parse_option (pam_handle_t *pamh, const
int
pam_sm_chauthtok (pam_handle_t *pamh, int flags, int argc, const char **argv)
{
- struct passwd *pwd;
const char *newpass;
const char *user;
int retval, tries;
@@ -148,31 +331,13 @@ pam_sm_chauthtok (pam_handle_t *pamh, in
return PAM_SUCCESS;
}
- pwd = pam_modutil_getpwnam (pamh, user);
- if (pwd == NULL)
- return PAM_USER_UNKNOWN;
-
- if ((strcmp(pwd->pw_passwd, "x") == 0) ||
- ((pwd->pw_passwd[0] == '#') &&
- (pwd->pw_passwd[1] == '#') &&
- (strcmp(pwd->pw_name, pwd->pw_passwd + 2) == 0)))
- {
- struct spwd *spw = pam_modutil_getspnam (pamh, user);
- if (spw == NULL)
- return PAM_USER_UNKNOWN;
+ retval = save_old_pass (pamh, user, options.remember, options.debug);
- retval = save_old_pass (pamh, user, pwd->pw_uid, spw->sp_pwdp,
- options.remember, options.debug);
- if (retval != PAM_SUCCESS)
- return retval;
- }
- else
- {
- retval = save_old_pass (pamh, user, pwd->pw_uid, pwd->pw_passwd,
- options.remember, options.debug);
- if (retval != PAM_SUCCESS)
- return retval;
- }
+ if (retval == PAM_PWHISTORY_RUN_HELPER)
+ retval = run_save_helper(pamh, user, options.remember, options.debug);
+
+ if (retval != PAM_SUCCESS)
+ return retval;
newpass = NULL;
tries = 0;
@@ -201,8 +366,11 @@ pam_sm_chauthtok (pam_handle_t *pamh, in
if (options.debug)
pam_syslog (pamh, LOG_DEBUG, "check against old password file");
- if (check_old_pass (pamh, user, newpass,
- options.debug) != PAM_SUCCESS)
+ retval = check_old_pass (pamh, user, newpass, options.debug);
+ if (retval == PAM_PWHISTORY_RUN_HELPER)
+ retval = run_check_helper(pamh, user, newpass, options.debug);
+
+ if (retval != PAM_SUCCESS)
{
if (getuid() || options.enforce_for_root ||
(flags & PAM_CHANGE_EXPIRED_AUTHTOK))
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.8.xml.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.8.xml
--- Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.8.xml.pwhhelper 2020-06-22 13:13:23.723445361 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.8.xml 2020-06-22 13:13:23.723445361 +0200
@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding='UTF-8'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+ "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
+
+<refentry id="pwhistory_helper">
+
+ <refmeta>
+ <refentrytitle>pwhistory_helper</refentrytitle>
+ <manvolnum>8</manvolnum>
+ <refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
+ </refmeta>
+
+ <refnamediv id="pwhistory_helper-name">
+ <refname>pwhistory_helper</refname>
+ <refpurpose>Helper binary that transfers password hashes from passwd or shadow to opasswd</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis id="pwhistory_helper-cmdsynopsis">
+ <command>pwhistory_helper</command>
+ <arg choice="opt">
+ ...
+ </arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1 id="pwhistory_helper-description">
+
+ <title>DESCRIPTION</title>
+
+ <para>
+ <emphasis>pwhistory_helper</emphasis> is a helper program for the
+ <emphasis>pam_pwhistory</emphasis> module that transfers password hashes
+ from passwd or shadow file to the opasswd file and checks a password
+ supplied by user against the existing hashes in the opasswd file.
+ </para>
+
+ <para>
+ The purpose of the helper is to enable tighter confinement of
+ login and password changing services. The helper is thus called only
+ when SELinux is enabled on the system.
+ </para>
+
+ <para>
+ The interface of the helper - command line options, and input/output
+ data format are internal to the <emphasis>pam_pwhistory</emphasis>
+ module and it should not be called directly from applications.
+ </para>
+ </refsect1>
+
+ <refsect1 id='pwhistory_helper-see_also'>
+ <title>SEE ALSO</title>
+ <para>
+ <citerefentry>
+ <refentrytitle>pam_pwhistory</refentrytitle><manvolnum>8</manvolnum>
+ </citerefentry>
+ </para>
+ </refsect1>
+
+ <refsect1 id='pwhistory_helper-author'>
+ <title>AUTHOR</title>
+ <para>
+ Written by Tomas Mraz based on the code originally in
+ <emphasis>pam_pwhistory and pam_unix</emphasis> modules.
+ </para>
+ </refsect1>
+
+</refentry>
diff -up Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.c.pwhhelper Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.c
--- Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.c.pwhhelper 2020-06-22 13:13:23.723445361 +0200
+++ Linux-PAM-1.4.0/modules/pam_pwhistory/pwhistory_helper.c 2020-06-22 13:13:23.723445361 +0200
@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2013 Red Hat, Inc.
+ * Author: Tomas Mraz <tmraz@redhat.com>
+ *
+ * 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.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+#include <security/_pam_types.h>
+#include <security/_pam_macros.h>
+#include "opasswd.h"
+
+#define MAXPASS 200
+
+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 ) {
+ struct sigaction sa;
+ memset(&sa, '\0', sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ sigaction(sig, &sa, NULL);
+ }
+#endif
+ if (sig > 0) {
+ _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
+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;
+}
+
+
+static int
+check_history(const char *user, const char *debug)
+{
+ char pass[MAXPASS + 1];
+ char *passwords[] = { pass };
+ int npass;
+ int dbg = atoi(debug); /* no need to be too fancy here */
+ int retval;
+
+ /* read the password from stdin (a pipe from the pam_pwhistory module) */
+ npass = read_passwords(STDIN_FILENO, 1, passwords);
+
+ if (npass != 1)
+ { /* is it a valid password? */
+ helper_log_err(LOG_DEBUG, "no password supplied");
+ return PAM_AUTHTOK_ERR;
+ }
+
+ retval = check_old_pass(user, pass, dbg);
+
+ memset(pass, '\0', MAXPASS); /* clear memory of the password */
+
+ return retval;
+}
+
+static int
+save_history(const char *user, const char *howmany, const char *debug)
+{
+ int num = atoi(howmany);
+ int dbg = atoi(debug); /* no need to be too fancy here */
+ int retval;
+
+ retval = save_old_pass(user, num, dbg);
+
+ return retval;
+}
+
+int
+main(int argc, char *argv[])
+{
+ const char *option;
+ const char *user;
+
+ /*
+ * 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.
+ */
+
+ if (isatty(STDIN_FILENO) || argc < 4)
+ {
+ fprintf(stderr,
+ "This binary is not designed for running in this way.\n");
+ sleep(10); /* this should discourage/annoy the user */
+ return PAM_SYSTEM_ERR;
+ }
+
+ option = argv[1];
+ user = argv[2];
+
+ if (strcmp(option, "check") == 0 && argc == 4)
+ return check_history(user, argv[3]);
+ else if (strcmp(option, "save") == 0 && argc == 5)
+ return save_history(user, argv[3], argv[4]);
+
+ return PAM_SYSTEM_ERR;
+}
+
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