From 960cb9a7db1950ad1414f70b0e3ec240542601ac Mon Sep 17 00:00:00 2001 From: Stef Walter Date: Thu, 2 Oct 2014 08:21:28 +0200 Subject: common: Use secure_getenv() implementation when setuid In anything security sensitive, use secure_getenv() implementation for retrieving environment variables. --- common/Makefile.am | 8 ++++++- common/compat.c | 8 +++++++ common/compat.h | 2 ++ common/debug.c | 3 ++- common/frob-getenv.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++ common/test-compat.c | 27 ++++++++++++++++++++++ common/test.c | 2 +- configure.ac | 2 +- 8 files changed, 113 insertions(+), 4 deletions(-) create mode 100644 common/frob-getenv.c diff --git a/common/Makefile.am b/common/Makefile.am index 47162dd..b053ec0 100644 --- a/common/Makefile.am +++ b/common/Makefile.am @@ -99,7 +99,13 @@ test_tests_LDADD = $(common_LIBS) test_url_SOURCES = common/test-url.c test_url_LDADD = $(common_LIBS) -noinst_PROGRAMS += frob-getauxval +noinst_PROGRAMS += \ + frob-getauxval \ + frob-getenv \ + $(NULL) frob_getauxval_SOURCES = common/frob-getauxval.c frob_getauxval_LDADD = $(common_LIBS) + +frob_getenv_SOURCES = common/frob-getenv.c +frob_getenv_LDADD = $(common_LIBS) diff --git a/common/compat.c b/common/compat.c index ce0ccab..768bb7d 100644 --- a/common/compat.c +++ b/common/compat.c @@ -845,6 +845,14 @@ getauxval (unsigned long type) #endif /* HAVE_GETAUXVAL */ +char * +secure_getenv (const char *name) +{ + if (getauxval (AT_SECURE)) + return NULL; + return getenv (name); +} + #ifndef HAVE_STRERROR_R int diff --git a/common/compat.h b/common/compat.h index 4771370..6483d4f 100644 --- a/common/compat.h +++ b/common/compat.h @@ -317,6 +317,8 @@ unsigned long getauxval (unsigned long type); #endif /* !HAVE_GETAUXVAL */ +char * secure_getenv (const char *name); + #ifndef HAVE_STRERROR_R int strerror_r (int errnum, diff --git a/common/debug.c b/common/debug.c index 1fbdc7f..47933fa 100644 --- a/common/debug.c +++ b/common/debug.c @@ -36,6 +36,7 @@ #include "config.h" +#include "compat.h" #include "debug.h" #include @@ -76,7 +77,7 @@ parse_environ_flags (void) const char *q; int i; - env = getenv ("P11_KIT_STRICT"); + env = secure_getenv ("P11_KIT_STRICT"); if (env && env[0] != '\0') debug_strict = true; diff --git a/common/frob-getenv.c b/common/frob-getenv.c new file mode 100644 index 0000000..a36594a --- /dev/null +++ b/common/frob-getenv.c @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2014 Red Hat Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above + * copyright notice, this list of conditions and the + * following disclaimer. + * * 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. + * * The names of contributors to this software may not be + * used to endorse or promote products derived from this + * software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * Author: Stef Walter + */ + +#include "config.h" +#include "compat.h" + +#include +#include +#include +#include + +int +main (int argc, + char *argv[]) +{ + int ret; + const char *val; + +fprintf (stderr, "calling secure_getenv(%s) getenv(%s) = %s\n", argv[1], argv[1], getenv(argv[1])); + val = secure_getenv (argv[1]); + if (val == NULL) { + printf ("%s=NULL\n", argv[1]); + return 0; + } + + ret = atoi (val); + if (ret == 0) { + fprintf (stderr, "usage: frob-getenv VAR"); + abort (); + } + + printf ("%s=%d\n", argv[1], ret); + return ret; +} diff --git a/common/test-compat.c b/common/test-compat.c index 42471ae..3af33ac 100644 --- a/common/test-compat.c +++ b/common/test-compat.c @@ -84,6 +84,32 @@ test_getauxval (void) } static void +test_secure_getenv (void) +{ + const char *args[] = { BUILDDIR "/frob-getenv", "BLAH", NULL }; + char *path; + int ret; + + setenv ("BLAH", "5", 1); + + ret = p11_test_run_child (args, true); + assert_num_eq (ret, 5); + + path = p11_test_copy_setgid (args[0]); + if (path == NULL) + return; + + args[0] = path; + ret = p11_test_run_child (args, true); + assert_num_cmp (ret, ==, 0); + +/* if (unlink (path) < 0) + assert_fail ("unlink failed", strerror (errno)); + */ + free (path); +} + +static void test_mmap (void) { p11_mmap *map; @@ -110,6 +136,7 @@ main (int argc, /* Don't run this test when under fakeroot */ if (!getenv ("FAKED_MODE")) { p11_test (test_getauxval, "/compat/getauxval"); + p11_test (test_secure_getenv, "/compat/secure_getenv"); } p11_test (test_mmap, "/compat/mmap"); #endif diff --git a/common/test.c b/common/test.c index 5a1cf72..9605d03 100644 --- a/common/test.c +++ b/common/test.c @@ -322,7 +322,7 @@ expand_tempdir (const char *name) { const char *env; - env = getenv ("TMPDIR"); + env = secure_getenv ("TMPDIR"); if (env && env[0]) { return p11_path_build (env, name, NULL); diff --git a/configure.ac b/configure.ac index b316d54..c151c9a 100644 --- a/configure.ac +++ b/configure.ac @@ -88,7 +88,7 @@ if test "$os_unix" = "yes"; then AC_CHECK_HEADERS([sys/resource.h]) AC_CHECK_MEMBERS([struct dirent.d_type],,,[#include ]) AC_CHECK_FUNCS([getprogname getexecname basename mkstemp mkdtemp]) - AC_CHECK_FUNCS([getauxval issetugid getresuid]) + AC_CHECK_FUNCS([getauxval issetugid getresuid secure_getenv]) AC_CHECK_FUNCS([strnstr memdup strndup strerror_r]) AC_CHECK_FUNCS([asprintf vasprintf vsnprintf]) AC_CHECK_FUNCS([timegm]) -- cgit v1.1