/*

 * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#ifndef _GNU_SOURCE

# define _GNU_SOURCE

#endif

#include <stdlib.h>

#include "internal/cryptlib.h"

#include "internal/e_os.h"

char *ossl_safe_getenv(const char *name)

{

#if defined(_WIN32) && defined(CP_UTF8) && !defined(_WIN32_WCE)

    if (GetEnvironmentVariableW(L"OPENSSL_WIN32_UTF8", NULL, 0) != 0) {

        char *val = NULL;

        int vallen = 0;

        WCHAR *namew = NULL;

        WCHAR *valw = NULL;

        DWORD envlen = 0;

        DWORD dwFlags = MB_ERR_INVALID_CHARS;

        int rsize, fsize;

        UINT curacp;

        curacp = GetACP();

        /*

         * For the code pages listed below, dwFlags must be set to 0.

         * Otherwise, the function fails with ERROR_INVALID_FLAGS.

         */

        if (curacp == 50220 || curacp == 50221 || curacp == 50222 ||

            curacp == 50225 || curacp == 50227 || curacp == 50229 ||

            (57002 <= curacp && curacp <=57011) || curacp == 65000 ||

            curacp == 42)

            dwFlags = 0;

        /* query for buffer len */

        rsize = MultiByteToWideChar(curacp, dwFlags, name, -1, NULL, 0);

        /* if name is valid string and can be converted to wide string */

        if (rsize > 0)

            namew = _malloca(rsize * sizeof(WCHAR));

        if (NULL != namew) {

            /* convert name to wide string */

            fsize = MultiByteToWideChar(curacp, dwFlags, name, -1, namew, rsize);

            /* if conversion is ok, then determine value string size in wchars */

            if (fsize > 0)

                envlen = GetEnvironmentVariableW(namew, NULL, 0);

        }

        if (envlen > 0)

            valw = _malloca(envlen * sizeof(WCHAR));

        if (NULL != valw) {

            /* if can get env value as wide string */

            if (GetEnvironmentVariableW(namew, valw, envlen) < envlen) {

                /* determine value string size in utf-8 */

                vallen = WideCharToMultiByte(CP_UTF8, 0, valw, -1, NULL, 0,

                                             NULL, NULL);

            }

        }

        if (vallen > 0)

            val = OPENSSL_malloc(vallen);

        if (NULL != val) {

            /* convert value string from wide to utf-8 */

            if (WideCharToMultiByte(CP_UTF8, 0, valw, -1, val, vallen,

                                    NULL, NULL) == 0) {

                OPENSSL_free(val);

                val = NULL;

            }

        }

        if (NULL != namew)

            _freea(namew);

        if (NULL != valw)

            _freea(valw);

        return val;

    }

#endif

#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)

# if __GLIBC_PREREQ(2, 17)

#  define SECURE_GETENV

    return secure_getenv(name);

# endif

#endif

#ifndef SECURE_GETENV

    if (OPENSSL_issetugid())

        return NULL;

    return getenv(name);

#endif

}