Merge pull request #8145 from tom-cosgrove-arm/check-mbedtls_platform_zeroize-calls-2.28
Backport 2.28: Check mbedtls_platform_zeroize() calls
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 55fc431..62f6d70 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -221,6 +221,11 @@
#define MBEDTLS_IGNORE_RETURN(result) ((void) !(result))
#endif
+/* If the following macro is defined, the library is being built by the test
+ * framework, and the framework is going to provide a replacement
+ * mbedtls_platform_zeroize() using a preprocessor macro, so the function
+ * declaration should be omitted. */
+#if !defined(MBEDTLS_TEST_DEFINES_ZEROIZE) //no-check-names
/**
* \brief Securely zeroize a buffer
*
@@ -244,6 +249,7 @@
*
*/
void mbedtls_platform_zeroize(void *buf, size_t len);
+#endif
#if defined(MBEDTLS_HAVE_TIME_DATE)
/**
diff --git a/tests/configs/user-config-zeroize-memset.h b/tests/configs/user-config-zeroize-memset.h
new file mode 100644
index 0000000..fcdd1f0
--- /dev/null
+++ b/tests/configs/user-config-zeroize-memset.h
@@ -0,0 +1,29 @@
+/* mbedtls_config.h modifier that defines mbedtls_platform_zeroize() to be
+ * memset(), so that the compile can check arguments for us.
+ * Used for testing.
+ */
+/*
+ * Copyright The Mbed TLS Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <string.h>
+
+/* Define _ALT so we don't get the built-in implementation. The test code will
+ * also need to define MBEDTLS_TEST_DEFINES_ZEROIZE so we don't get the
+ * declaration. */
+#define MBEDTLS_PLATFORM_ZEROIZE_ALT
+
+#define mbedtls_platform_zeroize(buf, len) memset(buf, 0, len)
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 5cbf19e..4ed1949 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -3536,6 +3536,16 @@
}
+component_build_zeroize_checks () {
+ msg "build: check for obviously wrong calls to mbedtls_platform_zeroize()"
+
+ scripts/config.py full
+
+ # Only compile - we're looking for sizeof-pointer-memaccess warnings
+ make CC=gcc CFLAGS="'-DMBEDTLS_USER_CONFIG_FILE=\"../tests/configs/user-config-zeroize-memset.h\"' -DMBEDTLS_TEST_DEFINES_ZEROIZE -Werror -Wsizeof-pointer-memaccess"
+}
+
+
component_test_zeroize () {
# Test that the function mbedtls_platform_zeroize() is not optimized away by
# different combinations of compilers and optimization flags by using an
diff --git a/tests/suites/test_suite_pkwrite.function b/tests/suites/test_suite_pkwrite.function
index c5391ba..fb71d34 100644
--- a/tests/suites/test_suite_pkwrite.function
+++ b/tests/suites/test_suite_pkwrite.function
@@ -154,7 +154,7 @@
pub_key_raw, pub_key_len);
#if defined(MBEDTLS_USE_PSA_CRYPTO)
- mbedtls_platform_zeroize(derived_key_raw, sizeof(derived_key_raw));
+ mbedtls_platform_zeroize(derived_key_raw, derived_key_len);
TEST_EQUAL(mbedtls_pk_wrap_as_opaque(&priv_key, &opaque_key_id,
PSA_ALG_NONE), 0);