Viktor Szakats 066478f634 src: add curlx_memzero() to clear buffers securely ... To safely zero memory, introduce `curlx_memzero()`, and map it to `memset_s()` (C11) or `memset_explicit()` (C23) if auto-detected, or `explicit_bzero()` or `explicit_memset()` for platforms opted-in, or fall back to a local workaround if all unavailable. On Windows, always use `SecureZeroMemory()`, or `SecureZeroMemory2()` with Visual Studio and Windows SDK 10.0.26100.0+. Details above are experimental and may change if they cause issues. Also add macros/functions that zero memory before freeing a buffer: - `curlx_safefreezero()`: for buffers with size. - `curlx_safefreezeroz()`: for null-terminated buffers. - `curlx_freezero()`: for buffers with size. - `curlx_freezeroz()`: for null-terminated buffers. `curlx_memzero()` must not be passed a NULL pointer because in some implementations it is undefined behavior. Also: - curl_sha512_256: Replace hard-wired `explicit_memset()` call with new `curlx_memzero()`. Refs: https://en.cppreference.com/c/string/byte/memset https://man7.org/linux/man-pages/man3/explicit_bzero.3.html https://man.freebsd.org/cgi/man.cgi?query=explicit_bzero https://man.netbsd.org/NetBSD-7.2/explicit_memset.3 https://learn.microsoft.com/previous-versions/windows/desktop/legacy/aa366877(v=vs.85) https://learn.microsoft.com/windows/win32/memory/winbase-securezeromemory2 https://learn.microsoft.com/cpp/overview/compiler-versions https://learn.microsoft.com/windows/apps/windows-sdk/downloads https://jtsoya539.github.io/windows-sdk-versions/ Credits-to: Daniel Gustafsson Credits-to: Will Cosgrove and co-authors in libssh2 Ref: #13589 (original attempt) Ref: #21588 Closes #21598		2026-05-16 00:26:46 +02:00
..
base64.c
base64.h
basename.c
basename.h
dynbuf.c
dynbuf.h	clang-tidy: enable more checks, fix fallouts	2026-04-14 02:20:16 +02:00
fopen.c
fopen.h	clang-tidy: enable more checks, fix fallouts	2026-04-14 02:20:16 +02:00
inet_ntop.c
inet_ntop.h	clang-tidy: enable more checks, fix fallouts	2026-04-14 02:20:16 +02:00
inet_pton.c
inet_pton.h
multibyte.c
multibyte.h
nonblock.c
nonblock.h
snprintf.c
snprintf.h
strcopy.c
strcopy.h
strdup.c	src: add curlx_memzero() to clear buffers securely	2026-05-16 00:26:46 +02:00
strdup.h
strerr.c	tidy-up: prefer "initialize" with a 'z'	2026-05-15 11:49:06 +02:00
strerr.h
strparse.c	strparse: make curlx_str_until() accept zero for 'max'	2026-05-15 13:28:03 +02:00
strparse.h
timediff.c
timediff.h
timeval.c
timeval.h
version_win32.c
version_win32.h
wait.c
wait.h
warnless.c
warnless.h
winapi.c
winapi.h