1/*
2 * Copyright 2018-2020 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 "e_os.h"
17
18char *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}
104