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066478f634

Viktor Szakats

2026-05-16

SUCCESS Duration: 261s

Subject

src: add `curlx_memzero()` to clear buffers securely

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

.github/workflows/macos.yml +1 -1 CMake/unix-cache.cmake +10 -0 CMakeLists.txt +5 -0 configure.ac +5 -0 lib/cf-socket.c +0 -5 lib/curl_config-cmake.h.in +6 -0 lib/curl_setup.h +52 -0 lib/curl_sha512_256.c +1 -2 lib/curlx/strdup.c +29 -0 m4/curl-functions.m4 +86 -1

.github/workflows/macos.yml+1 -1

@@ -36,7 +36,7 @@ permissions: {}
	# or runtime:
	#
	# - 10.7 Lion (2011) - GSS (build-time, deprecated MIT Kerberos shim)
-	# - 10.9 Mavericks (2013) - LDAP (build-time, deprecated), OCSP (runtime)
+	# - 10.9 Mavericks (2013) - LDAP (build-time, deprecated), memset_s(), OCSP (runtime)
	# - 10.11 El Capitan (2015) - connectx() (runtime)
	# - 10.12 Sierra (2016) - clock_gettime() (build-time, runtime)
	# - 10.14 Mojave (2018) - SecTrustEvaluateWithError() (runtime)

CMake/unix-cache.cmake+10 -0

@@ -65,6 +65,16 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux" OR
	CMAKE_SYSTEM_NAME STREQUAL "NetBSD")
	set(HAVE_EVENTFD 1)
	endif()
+	if(ANDROID AND ANDROID_PLATFORM_LEVEL GREATER_EQUAL 34)
+	set(HAVE_MEMSET_EXPLICIT 1)
+	endif()
+	if((APPLE AND CMAKE_OSX_DEPLOYMENT_TARGET VERSION_GREATER_EQUAL 10.9) OR
+	CMAKE_SYSTEM_NAME STREQUAL "DragonFlyBSD" OR # v6+
+	CMAKE_SYSTEM_NAME STREQUAL "FreeBSD") # v11.2+
+	set(HAVE_MEMSET_S 1)
+	elseif(NOT APPLE)
+	set(HAVE_MEMSET_S 0)
+	endif()
	set(HAVE_FCNTL 1)
	set(HAVE_FCNTL_H 1)
	set(HAVE_FCNTL_O_NONBLOCK 1)

CMakeLists.txt+5 -0

@@ -1672,6 +1672,11 @@ if(NOT WIN32)
	check_symbol_exists("strcasecmp" "string.h" HAVE_STRCASECMP)
	check_symbol_exists("stricmp" "string.h" HAVE_STRICMP)
	check_symbol_exists("strcmpi" "string.h" HAVE_STRCMPI)
+
+	check_symbol_exists("memset_s" "string.h" HAVE_MEMSET_S)
+	if(NOT HAVE_MEMSET_S)
+	check_function_exists("memset_explicit" HAVE_MEMSET_EXPLICIT)
+	endif()
	endif()

	if(AMIGA)

configure.ac+5 -0

@@ -4152,6 +4152,11 @@ if test "$curl_cv_native_windows" != "yes"; then
	CURL_CHECK_FUNC_STRCASECMP
	CURL_CHECK_FUNC_STRCMPI
	CURL_CHECK_FUNC_STRICMP
+
+	CURL_CHECK_FUNC_MEMSET_S
+	if test "$curl_cv_func_memset_s" = "no"; then
+	AC_CHECK_FUNCS([memset_explicit])
+	fi
	fi

	if test -z "$ssl_backends"; then

lib/cf-socket.c+0 -5

@@ -49,11 +49,6 @@
	#include <inet.h>
	#endif

-	#ifdef __DragonFly__
-	/* Required for __DragonFly_version */
-	#include <sys/param.h>
-	#endif
-
	#include "urldata.h"
	#include "curl_trc.h"
	#include "if2ip.h"

lib/curl_config-cmake.h.in+6 -0

@@ -234,6 +234,12 @@
	/* Define to 1 if you have the `opendir' function. */
	#cmakedefine HAVE_OPENDIR 1

+	/* Define to 1 if you have the memset_explicit (C23) function. */
+	#cmakedefine HAVE_MEMSET_EXPLICIT 1
+
+	/* Define to 1 if you have the memset_s (C11) function. */
+	#cmakedefine HAVE_MEMSET_S 1
+
	/* Define to 1 if you have the fcntl function. */
	#cmakedefine HAVE_FCNTL 1

lib/curl_setup.h+52 -0

@@ -1329,6 +1329,20 @@ extern curl_calloc_callback Curl_ccalloc;
	(ptr) = NULL; \
	} while(0)

+	/* Same as curlx_safefree() but zeroes memory before freeing */
+	#define curlx_safefreezero(ptr, size) \
+	do { \
+	curlx_freezero(ptr, size); \
+	(ptr) = NULL; \
+	} while(0)
+
+	/* Same as curlx_safefreezero() but determines length with strlen() */
+	#define curlx_safefreezeroz(ptr) \
+	do { \
+	curlx_freezeroz(ptr); \
+	(ptr) = NULL; \
+	} while(0)
+
	#include <curl/curl.h> /* for CURL_EXTERN, curl_socket_t, mprintf.h */

	#ifdef DEBUGBUILD
@@ -1608,4 +1622,42 @@ typedef struct sockaddr_un {
	#define NOVERBOSE(x) x
	#endif

+	/* For FreeBSD it is included from curl/curl.h */
+	#if defined(__DragonFly__) \|\| defined(__OpenBSD__) \|\| defined(__NetBSD__)
+	#include <sys/param.h> /* for __DragonFly_version, OpenBSD,
+	__NetBSD_Version__ */
+	#endif
+
+	#ifndef _CURL_LOCAL_MEMZERO /* to be removed after a couple of releases */
+	#ifdef _WIN32
+	#if defined(_MSC_VER) && defined(NTDDI_VERSION) && \
+	(NTDDI_VERSION >= 0x0A000010) /* MS SDK 10.0.26100.0+ */
+	#pragma comment(lib, "volatileaccessu.lib")
+	#define curlx_memzero(buf, size) SecureZeroMemory2(buf, size)
+	#else
+	#define curlx_memzero(buf, size) SecureZeroMemory(buf, size)
+	#endif
+	#elif defined(HAVE_MEMSET_S)
+	#define curlx_memzero(buf, size) (void)memset_s(buf, size, 0, size)
+	#elif defined(HAVE_MEMSET_EXPLICIT)
+	#define curlx_memzero(buf, size) (void)memset_explicit(buf, 0, size)
+	#elif defined(__CYGWIN__) \|\| defined(__NEWLIB__) \|\| \
+	(defined(__GLIBC__) && \
+	(__GLIBC__ > 2 \|\| (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25))) \|\| \
+	(defined(__DragonFly__) && __DragonFly_version >= 500600 /* v5.6+ */) \|\| \
+	(defined(__FreeBSD__) && __FreeBSD_version >= 1100037 /* v11.0+ */) \|\| \
+	(defined(__OpenBSD__) && OpenBSD >= 201405 /* v5.5+ */)
+	#define curlx_memzero(buf, size) explicit_bzero(buf, size)
+	#elif defined(__NetBSD__) && __NetBSD_Version__ >= 702000000 /* v7.2+ */
+	#define curlx_memzero(buf, size) (void)explicit_memset(buf, 0, size)
+	#endif
+	#endif /* !_CURL_LOCAL_MEMZERO */
+
+	#ifndef curlx_memzero
+	#define USE_CURLX_MEMZERO
+	void curlx_memzero(void *buf, size_t size);
+	#endif
+	void curlx_freezero(void *buf, size_t size);
+	void curlx_freezeroz(void *buf);
+
	#endif /* HEADER_CURL_SETUP_H */

lib/curl_sha512_256.c+1 -2

@@ -54,7 +54,6 @@
	* NetBSD 10.99.11 development.
	* It is safe to apply the workaround even if the bug is not present, as
	* the workaround reduces performance slightly. */
-	# include <sys/param.h>
	# if __NetBSD_Version__ < 904000000 \|\| \
	(__NetBSD_Version__ >= 999000000 && \
	__NetBSD_Version__ < 1000000000) \|\| \
@@ -173,7 +172,7 @@ static CURLcode Curl_sha512_256_finish(unsigned char digest, void context)
	tmp_digest, NULL) ? CURLE_OK : CURLE_SSL_CIPHER;
	if(result == CURLE_OK)
	memcpy(digest, tmp_digest, CURL_SHA512_256_DIGEST_SIZE);
-	explicit_memset(tmp_digest, 0, sizeof(tmp_digest));
+	curlx_memzero(tmp_digest, sizeof(tmp_digest));
	#else /* !NEED_NETBSD_SHA512_256_WORKAROUND */
	result = EVP_DigestFinal_ex(*ctx, digest, NULL) ?
	CURLE_OK : CURLE_SSL_CIPHER;

lib/curlx/strdup.c+29 -0

@@ -94,3 +94,32 @@ void curlx_memdup0(const char src, size_t length)
	buf[length] = 0;
	return buf;
	}
+
+	#ifdef USE_CURLX_MEMZERO
+	static void ( const volatile p_curlx_memset)(void *buf, int val,
+	size_t size) = memset;
+
+	/* Local fallback in case there is no system function to securely zero a memory
+	buffer. */
+	void curlx_memzero(void *buf, size_t size)
+	{
+	if(buf)
+	p_curlx_memset(buf, 0, size);
+	}
+	#endif
+
+	/* Free 'buf' after zeroing its content. */
+	void curlx_freezero(void *buf, size_t size)
+	{
+	if(buf)
+	curlx_memzero(buf, size);
+	curlx_free(buf);
+	}
+
+	/* Free 'buf' after zeroing its content, where 'buf' is null-terminated. */
+	void curlx_freezeroz(void *buf)
+	{
+	if(buf)
+	curlx_memzero(buf, strlen(buf));
+	curlx_free(buf);
+	}

m4/curl-functions.m4+86 -1

@@ -4111,7 +4111,6 @@ AC_DEFUN([CURL_CHECK_FUNC_STRERROR_R], [
	test "$tst_allow_strerror_r" = "unknown"; then
	AC_MSG_WARN([cannot determine strerror_r() style: edit lib/curl_config.h manually.])
	fi
-
	])


@@ -4199,6 +4198,92 @@ AC_DEFUN([CURL_CHECK_FUNC_STRICMP], [
	fi
	])

+
+	dnl CURL_CHECK_FUNC_MEMSET_S
+	dnl -------------------------------------------------
+	dnl Verify if memset_s is available, prototyped, and
+	dnl can be compiled. If all of these are true, and
+	dnl usage has not been previously disallowed with
+	dnl shell variable curl_disallow_memset_s, then
+	dnl HAVE_MEMSET_S will be defined.
+
+	AC_DEFUN([CURL_CHECK_FUNC_MEMSET_S], [
+	AC_REQUIRE([CURL_INCLUDES_STRING])
+
+	tst_links_memset_s="unknown"
+	tst_proto_memset_s="unknown"
+	tst_compi_memset_s="unknown"
+	tst_allow_memset_s="unknown"
+
+	AC_MSG_CHECKING([if memset_s can be linked])
+	AC_LINK_IFELSE([
+	AC_LANG_FUNC_LINK_TRY([memset_s])
+	],[
+	AC_MSG_RESULT([yes])
+	tst_links_memset_s="yes"
+	],[
+	AC_MSG_RESULT([no])
+	tst_links_memset_s="no"
+	])
+
+	if test "$tst_links_memset_s" = "yes"; then
+	AC_MSG_CHECKING([if memset_s is prototyped])
+	AC_EGREP_CPP([memset_s],[
+	$curl_includes_string
+	],[
+	AC_MSG_RESULT([yes])
+	tst_proto_memset_s="yes"
+	],[
+	AC_MSG_RESULT([no])
+	tst_proto_memset_s="no"
+	])
+	fi
+
+	if test "$tst_proto_memset_s" = "yes"; then
+	AC_MSG_CHECKING([if memset_s is compilable])
+	AC_COMPILE_IFELSE([
+	AC_LANG_PROGRAM([[
+	$curl_includes_string
+	]],[[
+	char buf[2];
+	if(memset_s(buf, sizeof(buf), 0, sizeof(buf)) != 0)
+	return 1;
+	]])
+	],[
+	AC_MSG_RESULT([yes])
+	tst_compi_memset_s="yes"
+	],[
+	AC_MSG_RESULT([no])
+	tst_compi_memset_s="no"
+	])
+	fi
+
+	if test "$tst_compi_memset_s" = "yes"; then
+	AC_MSG_CHECKING([if memset_s usage allowed])
+	if test "x$curl_disallow_memset_s" != "xyes"; then
+	AC_MSG_RESULT([yes])
+	tst_allow_memset_s="yes"
+	else
+	AC_MSG_RESULT([no])
+	tst_allow_memset_s="no"
+	fi
+	fi
+
+	AC_MSG_CHECKING([if memset_s might be used])
+	if test "$tst_links_memset_s" = "yes" &&
+	test "$tst_proto_memset_s" = "yes" &&
+	test "$tst_compi_memset_s" = "yes" &&
+	test "$tst_allow_memset_s" = "yes"; then
+	AC_MSG_RESULT([yes])
+	AC_DEFINE_UNQUOTED(HAVE_MEMSET_S, 1,
+	[Define to 1 if you have the memset_s function.])
+	curl_cv_func_memset_s="yes"
+	else
+	AC_MSG_RESULT([no])
+	curl_cv_func_memset_s="no"
+	fi
+	])
+
	dnl CURL_RUN_IFELSE
	dnl -------------------------------------------------
	dnl Wrapper macro to use instead of AC_RUN_IFELSE. It