reactos/dll/3rdparty/mbedtls/_reactos_strsafe_wrapper.c

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1.9 KiB
C

/*
* Handy secure string adapter functions for mbedTLS,
* converting from `StringCchVPrintfEx` to `_vsnprintf_s`.
*
* Copyright 2015 Ismael Ferreras Morezuelas <swyterzone+ros@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <windef.h>
#include <strsafe.h>
int _vsnprintf_s(char *buffer, size_t sizeOfBuffer, size_t count, const char *format, va_list argptr)
{
size_t cchRemaining;
HRESULT ret = StringCchVPrintfEx(buffer, sizeOfBuffer, NULL, &cchRemaining, 0, format, argptr);
// EXAMPLE //////////////////////////
// -------- > Size of provided buffer in chars (8).
// ABC0____ > Buffer contents after StringCchVPrintfEx gets called.
// --- > What we actually need to return (3).
// ----- > Remaining chars in buffer, including post string NULL, returned by StringCchVPrintfEx (5).
/* _vsnprintf_s returns the number of characters written, not including
the terminating null, or a negative value if an output error occurs. */
switch (ret)
{
case S_OK:
return (sizeOfBuffer - cchRemaining);
case STRSAFE_E_INVALID_PARAMETER:
case STRSAFE_E_INSUFFICIENT_BUFFER:
default:
return -1;
}
}