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738 lines
25 KiB
738 lines
25 KiB
From b3bb13e18a74e9ece825b7de1b81db97ebb107a0 Mon Sep 17 00:00:00 2001 |
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From: Iker Pedrosa <ipedrosa@redhat.com> |
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Date: Thu, 25 Mar 2021 09:43:30 +0100 |
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Subject: [PATCH] pam_timestamp: replace hmac implementation |
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|
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sha1 is no longer recommended as a cryptographic algorithm for |
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authentication. Thus, the idea of this change is to replace the |
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implementation provided by hmacsha1 included in pam_timestamp module by |
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the one in the openssl library. This way, there's no need to maintain |
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the cryptographic algorithm implementation and it can be easily changed |
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with a single configuration change. |
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|
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modules/pam_timestamp/hmac_openssl_wrapper.c: implement wrapper |
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functions around openssl's hmac implementation. Moreover, manage the key |
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generation and its read and write in a file. Include an option to |
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configure the cryptographic algorithm in login.defs file. |
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modules/pam_timestamp/hmac_openssl_wrapper.h: likewise. |
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modules/pam_timestamp/pam_timestamp.c: replace calls to functions |
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provided by hmacsha1 by functions provided by openssl's wrapper. |
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configure.ac: include openssl dependecy if it is enabled. |
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modules/pam_timestamp/Makefile.am: include new files and openssl library |
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to compilation. |
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ci/install-dependencies.sh: include openssl library to dependencies. |
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NEWS: add new item to next release. |
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Make.xml.rules.in: add stringparam profiling for hmac |
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doc/custom-man.xsl: change import docbook to one with profiling |
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modules/pam_timestamp/pam_timestamp.8.xml: add conditional paragraph to |
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indicate the value in /etc/login.defs that holds the value for the |
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encryption algorithm |
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|
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Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1947294 |
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--- |
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Make.xml.rules.in | 2 +- |
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NEWS | 5 + |
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configure.ac | 16 + |
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doc/custom-man.xsl | 2 +- |
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modules/pam_timestamp/Makefile.am | 15 +- |
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modules/pam_timestamp/hmac_openssl_wrapper.c | 381 +++++++++++++++++++ |
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modules/pam_timestamp/hmac_openssl_wrapper.h | 57 +++ |
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modules/pam_timestamp/pam_timestamp.8.xml | 5 + |
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modules/pam_timestamp/pam_timestamp.c | 53 ++- |
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10 files changed, 524 insertions(+), 13 deletions(-) |
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create mode 100644 modules/pam_timestamp/hmac_openssl_wrapper.c |
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create mode 100644 modules/pam_timestamp/hmac_openssl_wrapper.h |
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|
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diff --git a/Make.xml.rules.in b/Make.xml.rules.in |
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index daa1b97b..27bb510e 100644 |
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--- a/Make.xml.rules.in |
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+++ b/Make.xml.rules.in |
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@@ -21,6 +21,6 @@ README: README.xml |
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|
|
%.8: %.8.xml |
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$(XMLLINT) --nonet --xinclude --postvalid --noout $< |
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- $(XSLTPROC) -o $(srcdir)/$@ --path $(srcdir) --xinclude @STRINGPARAM_VENDORDIR@ --nonet $(top_srcdir)/doc/custom-man.xsl $< |
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+ $(XSLTPROC) -o $(srcdir)/$@ --path $(srcdir) --xinclude @STRINGPARAM_VENDORDIR@ @STRINGPARAM_HMAC@ --nonet $(top_srcdir)/doc/custom-man.xsl $< |
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|
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#CLEANFILES += $(man_MANS) README |
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diff --git a/NEWS b/NEWS |
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index 2d49ec39..f4d11303 100644 |
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--- a/NEWS |
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+++ b/NEWS |
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@@ -1,5 +1,10 @@ |
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Linux-PAM NEWS -- history of user-visible changes. |
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|
|
+Release next |
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+* pam_timestamp: change hmac algorithm to call openssl instead of the bundled |
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+ sha1 implementation if selected. Add option to select the hash |
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+ algorithm to use with HMAC. |
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+ |
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Release 1.5.1 |
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* pam_unix: fixed CVE-2020-27780 - authentication bypass when a user |
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doesn't exist and root password is blank |
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diff --git a/configure.ac b/configure.ac |
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index bd806473..9c92d0de 100644 |
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--- a/configure.ac |
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+++ b/configure.ac |
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@@ -504,6 +504,22 @@ else |
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fi |
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AC_SUBST([STRINGPARAM_VENDORDIR]) |
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|
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+AC_ARG_ENABLE([openssl], |
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+ AS_HELP_STRING([--enable-openssl],[use OpenSSL crypto libraries]), |
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+ [OPENSSL_ENABLED=$enableval], OPENSSL_ENABLED=no) |
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+if test "$OPENSSL_ENABLED" = "yes" ; then |
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+ AC_CHECK_LIB([crypto], [EVP_MAC_CTX_new], |
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+ [CRYPTO_LIBS="-lcrypto" |
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+ use_openssl=yes |
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+ AC_DEFINE([WITH_OPENSSL], 1, [OpenSSL provides crypto algorithm for hmac]) |
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+ STRINGPARAM_HMAC="--stringparam profile.condition 'openssl_hmac'"], |
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+ [CRYPTO_LIBS="" |
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+ STRINGPARAM_HMAC="--stringparam profile.condition 'no_openssl_hmac'"]) |
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+fi |
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+AC_SUBST([CRYPTO_LIBS]) |
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+AC_SUBST([STRINGPARAM_HMAC]) |
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+AM_CONDITIONAL([COND_USE_OPENSSL], [test "x$use_openssl" = "xyes"]) |
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+ |
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dnl Checks for header files. |
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AC_HEADER_DIRENT |
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AC_HEADER_STDC |
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diff --git a/doc/custom-man.xsl b/doc/custom-man.xsl |
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index 4c35e839..a3408e6c 100644 |
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--- a/doc/custom-man.xsl |
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+++ b/doc/custom-man.xsl |
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@@ -1,6 +1,6 @@ |
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<?xml version='1.0'?> |
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<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:ss="http://docbook.sf.net/xmlns/string.subst/1.0" version="1.0"> |
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- <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"/> |
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+ <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/manpages/profile-docbook.xsl"/> |
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<xsl:param name="vendordir"/> |
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|
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<xsl:param name="man.string.subst.map.local.pre"> |
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diff --git a/modules/pam_timestamp/Makefile.am b/modules/pam_timestamp/Makefile.am |
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index 1faa324a..d290b85f 100644 |
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--- a/modules/pam_timestamp/Makefile.am |
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+++ b/modules/pam_timestamp/Makefile.am |
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@@ -18,12 +18,12 @@ TESTS = $(dist_check_SCRIPTS) $(check_PROGRAMS) |
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securelibdir = $(SECUREDIR) |
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secureconfdir = $(SCONFIGDIR) |
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|
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-noinst_HEADERS = hmacsha1.h sha1.h |
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+noinst_HEADERS = hmacsha1.h sha1.h hmac_openssl_wrapper.h |
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|
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AM_CFLAGS = -I$(top_srcdir)/libpam/include -I$(top_srcdir)/libpamc/include \ |
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$(WARN_CFLAGS) |
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|
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-pam_timestamp_la_LDFLAGS = -no-undefined -avoid-version -module $(AM_LDFLAGS) |
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+pam_timestamp_la_LDFLAGS = -no-undefined -avoid-version -module $(AM_LDFLAGS) $(CRYPTO_LIBS) |
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pam_timestamp_la_LIBADD = $(top_builddir)/libpam/libpam.la |
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if HAVE_VERSIONING |
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pam_timestamp_la_LDFLAGS += -Wl,--version-script=$(srcdir)/../modules.map |
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@@ -32,7 +32,12 @@ endif |
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securelib_LTLIBRARIES = pam_timestamp.la |
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sbin_PROGRAMS = pam_timestamp_check |
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|
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-pam_timestamp_la_SOURCES = pam_timestamp.c hmacsha1.c sha1.c |
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+pam_timestamp_la_SOURCES = pam_timestamp.c |
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+if COND_USE_OPENSSL |
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+pam_timestamp_la_SOURCES += hmac_openssl_wrapper.c |
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+else |
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+pam_timestamp_la_SOURCES += hmacsha1.c sha1.c |
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+endif |
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pam_timestamp_la_CFLAGS = $(AM_CFLAGS) |
|
|
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pam_timestamp_check_SOURCES = pam_timestamp_check.c |
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@@ -40,7 +45,11 @@ pam_timestamp_check_CFLAGS = $(AM_CFLAGS) @EXE_CFLAGS@ |
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pam_timestamp_check_LDADD = $(top_builddir)/libpam/libpam.la |
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pam_timestamp_check_LDFLAGS = @EXE_LDFLAGS@ |
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|
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+if COND_USE_OPENSSL |
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+hmacfile_SOURCES = hmac_openssl_wrapper.c |
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+else |
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hmacfile_SOURCES = hmacfile.c hmacsha1.c sha1.c |
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+endif |
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hmacfile_LDADD = $(top_builddir)/libpam/libpam.la |
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|
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check_PROGRAMS = hmacfile |
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diff --git a/modules/pam_timestamp/hmac_openssl_wrapper.c b/modules/pam_timestamp/hmac_openssl_wrapper.c |
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new file mode 100644 |
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index 00000000..926c2fb9 |
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--- /dev/null |
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+++ b/modules/pam_timestamp/hmac_openssl_wrapper.c |
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@@ -0,0 +1,381 @@ |
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+/* Wrapper for hmac openssl implementation. |
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+ * |
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+ * Copyright (c) 2021 Red Hat, Inc. |
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+ * Written by Iker Pedrosa <ipedrosa@redhat.com> |
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+ * |
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+ * Redistribution and use in source and binary forms, with or without |
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+ * modification, are permitted provided that the following conditions |
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+ * are met: |
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+ * 1. Redistributions of source code must retain the above copyright |
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+ * notice, and the entire permission notice in its entirety, |
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+ * including the disclaimer of warranties. |
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+ * 2. Redistributions in binary form must reproduce the above copyright |
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+ * notice, this list of conditions and the following disclaimer in the |
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+ * documentation and/or other materials provided with the distribution. |
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+ * 3. The name of the author may not be used to endorse or promote |
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+ * products derived from this software without specific prior |
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+ * written permission. |
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+ * |
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+ * ALTERNATIVELY, this product may be distributed under the terms of |
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+ * the GNU Public License, in which case the provisions of the GPL are |
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+ * required INSTEAD OF the above restrictions. (This clause is |
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+ * necessary due to a potential bad interaction between the GPL and |
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+ * the restrictions contained in a BSD-style copyright.) |
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+ * |
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+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, |
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+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
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+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
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+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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+ * OF THE POSSIBILITY OF SUCH DAMAGE. |
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+ * |
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+ */ |
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+ |
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+#include "config.h" |
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+ |
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+#ifdef WITH_OPENSSL |
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+ |
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+#include <sys/stat.h> |
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+#include <fcntl.h> |
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+#include <syslog.h> |
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+#include <unistd.h> |
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+#include <string.h> |
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+#include <errno.h> |
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+#include <openssl/evp.h> |
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+#include <openssl/params.h> |
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+#include <openssl/core_names.h> |
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+ |
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+#include <security/pam_ext.h> |
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+#include <security/pam_modutil.h> |
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+ |
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+#include "hmac_openssl_wrapper.h" |
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+ |
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+#define LOGIN_DEFS "/etc/login.defs" |
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+#define CRYPTO_KEY "HMAC_CRYPTO_ALGO" |
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+#define DEFAULT_ALGORITHM "SHA512" |
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+#define MAX_HMAC_LENGTH 512 |
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+#define MAX_KEY_LENGTH EVP_MAX_KEY_LENGTH |
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+ |
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+static char * |
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+get_crypto_algorithm(pam_handle_t *pamh, int debug){ |
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+ char *config_value = NULL; |
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+ |
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+ config_value = pam_modutil_search_key(pamh, LOGIN_DEFS, CRYPTO_KEY); |
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+ |
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+ if (config_value == NULL) { |
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+ config_value = strdup(DEFAULT_ALGORITHM); |
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+ if (debug) { |
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+ pam_syslog(pamh, LOG_DEBUG, |
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+ "Key [%s] not found, falling back to default algorithm [%s]\n", |
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+ CRYPTO_KEY, DEFAULT_ALGORITHM); |
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+ } |
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+ } |
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+ |
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+ return config_value; |
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+} |
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+ |
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+static int |
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+generate_key(pam_handle_t *pamh, char **key, size_t key_size) |
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+{ |
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+ int fd = 0; |
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+ size_t bytes_read = 0; |
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+ char * tmp = NULL; |
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+ |
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+ fd = open("/dev/urandom", O_RDONLY); |
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+ if (fd == -1) { |
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+ pam_syslog(pamh, LOG_ERR, "Cannot open /dev/urandom: %m"); |
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+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ tmp = malloc(key_size); |
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+ if (!tmp) { |
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+ pam_syslog(pamh, LOG_CRIT, "Not enough memory"); |
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+ close(fd); |
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+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ bytes_read = pam_modutil_read(fd, tmp, key_size); |
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+ close(fd); |
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+ |
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+ if (bytes_read < key_size) { |
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+ pam_syslog(pamh, LOG_ERR, "Short read on random device"); |
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+ free(tmp); |
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+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ *key = tmp; |
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+ |
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+ return PAM_SUCCESS; |
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+} |
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+ |
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+static int |
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+read_file(pam_handle_t *pamh, int fd, char **text, size_t *text_length) |
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+{ |
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+ struct stat st; |
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+ size_t bytes_read = 0; |
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+ char *tmp = NULL; |
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+ |
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+ if (fstat(fd, &st) == -1) { |
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+ pam_syslog(pamh, LOG_ERR, "Unable to stat file: %m"); |
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+ close(fd); |
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+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ if (st.st_size == 0) { |
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+ pam_syslog(pamh, LOG_ERR, "Key file size cannot be 0"); |
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+ close(fd); |
|
+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ tmp = malloc(st.st_size); |
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+ if (!tmp) { |
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+ pam_syslog(pamh, LOG_CRIT, "Not enough memory"); |
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+ close(fd); |
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+ return PAM_AUTH_ERR; |
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+ } |
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+ |
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+ bytes_read = pam_modutil_read(fd, tmp, st.st_size); |
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+ close(fd); |
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+ |
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+ if (bytes_read < (size_t)st.st_size) { |
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+ pam_syslog(pamh, LOG_ERR, "Short read on key file"); |
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+ memset(tmp, 0, st.st_size); |
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+ free(tmp); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
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+ |
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+ *text = tmp; |
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+ *text_length = st.st_size; |
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+ |
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+ return PAM_SUCCESS; |
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+} |
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+ |
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+static int |
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+write_file(pam_handle_t *pamh, const char *file_name, char *text, |
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+ size_t text_length, uid_t owner, gid_t group) |
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+{ |
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+ int fd = 0; |
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+ size_t bytes_written = 0; |
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+ |
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+ fd = open(file_name, |
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+ O_WRONLY | O_CREAT | O_TRUNC, |
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+ S_IRUSR | S_IWUSR); |
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+ if (fd == -1) { |
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+ pam_syslog(pamh, LOG_ERR, "Unable to open [%s]: %m", file_name); |
|
+ memset(text, 0, text_length); |
|
+ free(text); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ |
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+ if (fchown(fd, owner, group) == -1) { |
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+ pam_syslog(pamh, LOG_ERR, "Unable to change ownership [%s]: %m", file_name); |
|
+ memset(text, 0, text_length); |
|
+ free(text); |
|
+ close(fd); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ |
|
+ bytes_written = pam_modutil_write(fd, text, text_length); |
|
+ close(fd); |
|
+ |
|
+ if (bytes_written < text_length) { |
|
+ pam_syslog(pamh, LOG_ERR, "Short write on %s", file_name); |
|
+ free(text); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
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+ |
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+ return PAM_SUCCESS; |
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+} |
|
+ |
|
+static int |
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+key_management(pam_handle_t *pamh, const char *file_name, char **text, |
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+ size_t text_length, uid_t owner, gid_t group) |
|
+{ |
|
+ int fd = 0; |
|
+ |
|
+ fd = open(file_name, O_RDONLY | O_NOFOLLOW); |
|
+ if (fd == -1) { |
|
+ if (errno == ENOENT) { |
|
+ if (generate_key(pamh, text, text_length)) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to generate key"); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ |
|
+ if (write_file(pamh, file_name, *text, text_length, owner, group)) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to write key"); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ } else { |
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+ pam_syslog(pamh, LOG_ERR, "Unable to open %s: %m", file_name); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ } else { |
|
+ if (read_file(pamh, fd, text, &text_length)) { |
|
+ pam_syslog(pamh, LOG_ERR, "Error reading key file %s\n", file_name); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ } |
|
+ |
|
+ return PAM_SUCCESS; |
|
+} |
|
+ |
|
+static int |
|
+hmac_management(pam_handle_t *pamh, int debug, void **out, size_t *out_length, |
|
+ char *key, size_t key_length, |
|
+ const void *text, size_t text_length) |
|
+{ |
|
+ int ret = PAM_AUTH_ERR; |
|
+ EVP_MAC *evp_mac = NULL; |
|
+ EVP_MAC_CTX *ctx = NULL; |
|
+ unsigned char *hmac_message = NULL; |
|
+ size_t hmac_length; |
|
+ char *algo = NULL; |
|
+ OSSL_PARAM subalg_param[] = { OSSL_PARAM_END, OSSL_PARAM_END }; |
|
+ |
|
+ algo = get_crypto_algorithm(pamh, debug); |
|
+ |
|
+ subalg_param[0] = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST, |
|
+ algo, |
|
+ 0); |
|
+ |
|
+ evp_mac = EVP_MAC_fetch(NULL, "HMAC", NULL); |
|
+ if (evp_mac == NULL) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to create hmac implementation"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ctx = EVP_MAC_CTX_new(evp_mac); |
|
+ if (ctx == NULL) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to create hmac context"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ret = EVP_MAC_init(ctx, (const unsigned char *)key, key_length, subalg_param); |
|
+ if (ret == 0) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to initialize hmac context"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ret = EVP_MAC_update(ctx, (const unsigned char *)text, text_length); |
|
+ if (ret == 0) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to update hmac context"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ hmac_message = (unsigned char*)malloc(sizeof(unsigned char) * MAX_HMAC_LENGTH); |
|
+ if (!hmac_message) { |
|
+ pam_syslog(pamh, LOG_CRIT, "Not enough memory"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ret = EVP_MAC_final(ctx, hmac_message, &hmac_length, MAX_HMAC_LENGTH); |
|
+ if (ret == 0) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to calculate hmac message"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ *out_length = hmac_length; |
|
+ *out = malloc(*out_length); |
|
+ if (*out == NULL) { |
|
+ pam_syslog(pamh, LOG_CRIT, "Not enough memory"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ memcpy(*out, hmac_message, *out_length); |
|
+ ret = PAM_SUCCESS; |
|
+ |
|
+done: |
|
+ if (hmac_message != NULL) { |
|
+ free(hmac_message); |
|
+ } |
|
+ if (key != NULL) { |
|
+ memset(key, 0, key_length); |
|
+ free(key); |
|
+ } |
|
+ if (ctx != NULL) { |
|
+ EVP_MAC_CTX_free(ctx); |
|
+ } |
|
+ if (evp_mac != NULL) { |
|
+ EVP_MAC_free(evp_mac); |
|
+ } |
|
+ free(algo); |
|
+ |
|
+ return ret; |
|
+} |
|
+ |
|
+int |
|
+hmac_size(pam_handle_t *pamh, int debug, size_t *hmac_length) |
|
+{ |
|
+ int ret = PAM_AUTH_ERR; |
|
+ EVP_MAC *evp_mac = NULL; |
|
+ EVP_MAC_CTX *ctx = NULL; |
|
+ const unsigned char key[] = "ThisIsJustAKey"; |
|
+ size_t key_length = MAX_KEY_LENGTH; |
|
+ char *algo = NULL; |
|
+ OSSL_PARAM subalg_param[] = { OSSL_PARAM_END, OSSL_PARAM_END }; |
|
+ |
|
+ algo = get_crypto_algorithm(pamh, debug); |
|
+ |
|
+ subalg_param[0] = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST, |
|
+ algo, |
|
+ 0); |
|
+ |
|
+ evp_mac = EVP_MAC_fetch(NULL, "HMAC", NULL); |
|
+ if (evp_mac == NULL) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to create hmac implementation"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ctx = EVP_MAC_CTX_new(evp_mac); |
|
+ if (ctx == NULL) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to create hmac context"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ ret = EVP_MAC_init(ctx, key, key_length, subalg_param); |
|
+ if (ret == 0) { |
|
+ pam_syslog(pamh, LOG_ERR, "Unable to initialize hmac context"); |
|
+ goto done; |
|
+ } |
|
+ |
|
+ *hmac_length = EVP_MAC_CTX_get_mac_size(ctx); |
|
+ ret = PAM_SUCCESS; |
|
+ |
|
+done: |
|
+ if (ctx != NULL) { |
|
+ EVP_MAC_CTX_free(ctx); |
|
+ } |
|
+ if (evp_mac != NULL) { |
|
+ EVP_MAC_free(evp_mac); |
|
+ } |
|
+ free(algo); |
|
+ |
|
+ return ret; |
|
+} |
|
+ |
|
+int |
|
+hmac_generate(pam_handle_t *pamh, int debug, void **mac, size_t *mac_length, |
|
+ const char *key_file, uid_t owner, gid_t group, |
|
+ const void *text, size_t text_length) |
|
+{ |
|
+ char *key = NULL; |
|
+ size_t key_length = MAX_KEY_LENGTH; |
|
+ |
|
+ if (key_management(pamh, key_file, &key, key_length, owner, group)) { |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ |
|
+ if (hmac_management(pamh, debug, mac, mac_length, key, key_length, |
|
+ text, text_length)) { |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+ |
|
+ return PAM_SUCCESS; |
|
+} |
|
+ |
|
+#endif /* WITH_OPENSSL */ |
|
diff --git a/modules/pam_timestamp/hmac_openssl_wrapper.h b/modules/pam_timestamp/hmac_openssl_wrapper.h |
|
new file mode 100644 |
|
index 00000000..cc27c811 |
|
--- /dev/null |
|
+++ b/modules/pam_timestamp/hmac_openssl_wrapper.h |
|
@@ -0,0 +1,57 @@ |
|
+/* Wrapper for hmac openssl implementation. |
|
+ * |
|
+ * Copyright (c) 2021 Red Hat, Inc. |
|
+ * Written by Iker Pedrosa <ipedrosa@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. |
|
+ * |
|
+ */ |
|
+#ifndef PAM_TIMESTAMP_HMAC_OPENSSL_WRAPPER_H |
|
+#define PAM_TIMESTAMP_HMAC_OPENSSL_WRAPPER_H |
|
+ |
|
+#include "config.h" |
|
+ |
|
+#ifdef WITH_OPENSSL |
|
+ |
|
+#include <openssl/hmac.h> |
|
+#include <security/pam_modules.h> |
|
+ |
|
+int |
|
+hmac_size(pam_handle_t *pamh, int debug, size_t *hmac_length); |
|
+ |
|
+int |
|
+hmac_generate(pam_handle_t *pamh, int debug, void **mac, size_t *mac_length, |
|
+ const char *key_file, uid_t owner, gid_t group, |
|
+ const void *text, size_t text_length); |
|
+ |
|
+#endif /* WITH_OPENSSL */ |
|
+#endif /* PAM_TIMESTAMP_HMAC_OPENSSL_WRAPPER_H */ |
|
diff --git a/modules/pam_timestamp/pam_timestamp.8.xml b/modules/pam_timestamp/pam_timestamp.8.xml |
|
index e19a0bcf..83e5aea8 100644 |
|
--- a/modules/pam_timestamp/pam_timestamp.8.xml |
|
+++ b/modules/pam_timestamp/pam_timestamp.8.xml |
|
@@ -50,6 +50,11 @@ for the user. When an application attempts to authenticate the user, a |
|
<emphasis>pam_timestamp</emphasis> will treat a sufficiently recent timestamp |
|
file as grounds for succeeding. |
|
</para> |
|
+ <para condition="openssl_hmac"> |
|
+ The default encryption hash is taken from the |
|
+ <emphasis remap='B'>HMAC_CRYPTO_ALGO</emphasis> variable from |
|
+ <emphasis>/etc/login.defs</emphasis>. |
|
+ </para> |
|
</refsect1> |
|
|
|
<refsect1 id="pam_timestamp-options"> |
|
diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c |
|
index 30be883c..01dd1385 100644 |
|
--- a/modules/pam_timestamp/pam_timestamp.c |
|
+++ b/modules/pam_timestamp/pam_timestamp.c |
|
@@ -56,7 +56,11 @@ |
|
#include <utmp.h> |
|
#include <syslog.h> |
|
#include <paths.h> |
|
+#ifdef WITH_OPENSSL |
|
+#include "hmac_openssl_wrapper.h" |
|
+#else |
|
#include "hmacsha1.h" |
|
+#endif /* WITH_OPENSSL */ |
|
|
|
#include <security/pam_modules.h> |
|
#include <security/_pam_macros.h> |
|
@@ -79,6 +83,9 @@ |
|
#define BUFLEN PATH_MAX |
|
#endif |
|
|
|
+#define ROOT_USER 0 |
|
+#define ROOT_GROUP 0 |
|
+ |
|
/* Return PAM_SUCCESS if the given directory looks "safe". */ |
|
static int |
|
check_dir_perms(pam_handle_t *pamh, const char *tdir) |
|
@@ -449,6 +456,13 @@ pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv) |
|
return PAM_AUTH_ERR; |
|
} |
|
|
|
+#ifdef WITH_OPENSSL |
|
+ if (hmac_size(pamh, debug, &maclen)) { |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+#else |
|
+ maclen = hmac_sha1_size(); |
|
+#endif /* WITH_OPENSSL */ |
|
/* Check that the file is the expected size. */ |
|
if (st.st_size == 0) { |
|
/* Invalid, but may have been created by sudo. */ |
|
@@ -456,7 +470,7 @@ pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv) |
|
return PAM_AUTH_ERR; |
|
} |
|
if (st.st_size != |
|
- (off_t)(strlen(path) + 1 + sizeof(then) + hmac_sha1_size())) { |
|
+ (off_t)(strlen(path) + 1 + sizeof(then) + maclen)) { |
|
pam_syslog(pamh, LOG_NOTICE, "timestamp file `%s' " |
|
"appears to be corrupted", path); |
|
close(fd); |
|
@@ -487,8 +501,17 @@ pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc, const char **argv) |
|
message_end = message + strlen(path) + 1 + sizeof(then); |
|
|
|
/* Regenerate the MAC. */ |
|
- hmac_sha1_generate_file(pamh, &mac, &maclen, TIMESTAMPKEY, 0, 0, |
|
- message, message_end - message); |
|
+#ifdef WITH_OPENSSL |
|
+ if (hmac_generate(pamh, debug, &mac, &maclen, TIMESTAMPKEY, |
|
+ ROOT_USER, ROOT_GROUP, message, message_end - message)) { |
|
+ close(fd); |
|
+ free(message); |
|
+ return PAM_AUTH_ERR; |
|
+ } |
|
+#else |
|
+ hmac_sha1_generate_file(pamh, &mac, &maclen, TIMESTAMPKEY, |
|
+ ROOT_USER, ROOT_GROUP, message, message_end - message); |
|
+#endif /* WITH_OPENSSL */ |
|
if ((mac == NULL) || |
|
(memcmp(path, message, strlen(path)) != 0) || |
|
(memcmp(mac, message_end, maclen) != 0)) { |
|
@@ -605,8 +628,16 @@ pam_sm_open_session(pam_handle_t *pamh, int flags UNUSED, int argc, const char * |
|
} |
|
} |
|
|
|
+#ifdef WITH_OPENSSL |
|
+ if (hmac_size(pamh, debug, &maclen)) { |
|
+ return PAM_SESSION_ERR; |
|
+ } |
|
+#else |
|
+ maclen = hmac_sha1_size(); |
|
+#endif /* WITH_OPENSSL */ |
|
+ |
|
/* Generate the message. */ |
|
- text = malloc(strlen(path) + 1 + sizeof(now) + hmac_sha1_size()); |
|
+ text = malloc(strlen(path) + 1 + sizeof(now) + maclen); |
|
if (text == NULL) { |
|
pam_syslog(pamh, LOG_CRIT, "unable to allocate memory: %m"); |
|
return PAM_SESSION_ERR; |
|
@@ -621,15 +652,21 @@ pam_sm_open_session(pam_handle_t *pamh, int flags UNUSED, int argc, const char * |
|
p += sizeof(now); |
|
|
|
/* Generate the MAC and append it to the plaintext. */ |
|
- hmac_sha1_generate_file(pamh, &mac, &maclen, |
|
- TIMESTAMPKEY, |
|
- 0, 0, |
|
- text, p - text); |
|
+#ifdef WITH_OPENSSL |
|
+ if (hmac_generate(pamh, debug, &mac, &maclen, TIMESTAMPKEY, |
|
+ ROOT_USER, ROOT_GROUP, text, p - text)) { |
|
+ free(text); |
|
+ return PAM_SESSION_ERR; |
|
+ } |
|
+#else |
|
+ hmac_sha1_generate_file(pamh, &mac, &maclen, TIMESTAMPKEY, |
|
+ ROOT_USER, ROOT_GROUP, text, p - text); |
|
if (mac == NULL) { |
|
pam_syslog(pamh, LOG_ERR, "failure generating MAC: %m"); |
|
free(text); |
|
return PAM_SESSION_ERR; |
|
} |
|
+#endif /* WITH_OPENSSL */ |
|
memmove(p, mac, maclen); |
|
p += maclen; |
|
free(mac); |
|
-- |
|
2.31.1 |
|
|
|
|