crypto/getenv.c

   1 /*
   2  * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #ifndef _GNU_SOURCE
  11 # define _GNU_SOURCE
  12 #endif
  13
  14 #include <stdlib.h>
  15 #include "internal/cryptlib.h"
  16 #include "internal/e_os.h"
  17
  18 char *ossl_safe_getenv(const char *name)
  19 {
  20 #if defined(_WIN32) && defined(CP_UTF8) && !defined(_WIN32_WCE)
  21     if (GetEnvironmentVariableW(L"OPENSSL_WIN32_UTF8", NULL, 0) != 0) {
  22         char *val = NULL;
  23         int vallen = 0;
  24         WCHAR *namew = NULL;
  25         WCHAR *valw = NULL;
  26         DWORD envlen = 0;
  27         DWORD dwFlags = MB_ERR_INVALID_CHARS;
  28         int rsize, fsize;
  29         UINT curacp;
  30
  31         curacp = GetACP();
  32
  33         /*
  34          * For the code pages listed below, dwFlags must be set to 0.
  35          * Otherwise, the function fails with ERROR_INVALID_FLAGS.
  36          */
  37         if (curacp == 50220 || curacp == 50221 || curacp == 50222 ||
  38             curacp == 50225 || curacp == 50227 || curacp == 50229 ||
  39             (57002 <= curacp && curacp <=57011) || curacp == 65000 ||
  40             curacp == 42)
  41             dwFlags = 0;
  42
  43         /* query for buffer len */
  44         rsize = MultiByteToWideChar(curacp, dwFlags, name, -1, NULL, 0);
  45         /* if name is valid string and can be converted to wide string */
  46         if (rsize > 0)
  47             namew = _malloca(rsize * sizeof(WCHAR));
  48
  49         if (NULL != namew) {
  50             /* convert name to wide string */
  51             fsize = MultiByteToWideChar(curacp, dwFlags, name, -1, namew, rsize);
  52             /* if conversion is ok, then determine value string size in wchars */
  53             if (fsize > 0)
  54                 envlen = GetEnvironmentVariableW(namew, NULL, 0);
  55         }
  56
  57         if (envlen > 0)
  58             valw = _malloca(envlen * sizeof(WCHAR));
  59
  60         if (NULL != valw) {
  61             /* if can get env value as wide string */
  62             if (GetEnvironmentVariableW(namew, valw, envlen) < envlen) {
  63                 /* determine value string size in utf-8 */
  64                 vallen = WideCharToMultiByte(CP_UTF8, 0, valw, -1, NULL, 0,
  65                                              NULL, NULL);
  66             }
  67         }
  68
  69         if (vallen > 0)
  70             val = OPENSSL_malloc(vallen);
  71
  72         if (NULL != val) {
  73             /* convert value string from wide to utf-8 */
  74             if (WideCharToMultiByte(CP_UTF8, 0, valw, -1, val, vallen,
  75                                     NULL, NULL) == 0) {
  76                 OPENSSL_free(val);
  77                 val = NULL;
  78             }
  79         }
  80
  81         if (NULL != namew)
  82             _freea(namew);
  83
  84         if (NULL != valw)
  85             _freea(valw);
  86
  87         return val;
  88     }
  89 #endif
  90
  91 #if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
  92 # if __GLIBC_PREREQ(2, 17)
  93 #  define SECURE_GETENV
  94     return secure_getenv(name);
  95 # endif
  96 #endif
  97
  98 #ifndef SECURE_GETENV
  99     if (OPENSSL_issetugid())
 100         return NULL;
 101     return getenv(name);
 102 #endif
 103 }