1 /*
2 * Copyright 2016-2024 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 # if defined(__linux) || defined(__sun) || defined(__hpux)
11 /*
12 * Following definition aliases fopen to fopen64 on above mentioned
13 * platforms. This makes it possible to open and sequentially access files
14 * larger than 2GB from 32-bit application. It does not allow one to traverse
15 * them beyond 2GB with fseek/ftell, but on the other hand *no* 32-bit
16 * platform permits that, not with fseek/ftell. Not to mention that breaking
17 * 2GB limit for seeking would require surgery to *our* API. But sequential
18 * access suffices for practical cases when you can run into large files,
19 * such as fingerprinting, so we can let API alone. For reference, the list
20 * of 32-bit platforms which allow for sequential access of large files
21 * without extra "magic" comprise *BSD, Darwin, IRIX...
22 */
23 # ifndef _FILE_OFFSET_BITS
24 # define _FILE_OFFSET_BITS 64
25 # endif
26 # endif
27
28 #include "internal/e_os.h"
29 #include "internal/cryptlib.h"
30
31 #if !defined(OPENSSL_NO_STDIO)
32
33 # include <stdio.h>
34 # ifdef __DJGPP__
35 # include <unistd.h>
36 # endif
37
openssl_fopen(const char * filename,const char * mode)38 FILE *openssl_fopen(const char *filename, const char *mode)
39 {
40 FILE *file = NULL;
41 # if defined(_WIN32) && defined(CP_UTF8)
42 int sz, len_0;
43 DWORD flags;
44 # endif
45
46 if (filename == NULL)
47 return NULL;
48 # if defined(_WIN32) && defined(CP_UTF8)
49 len_0 = (int)strlen(filename) + 1;
50
51 /*
52 * Basically there are three cases to cover: a) filename is
53 * pure ASCII string; b) actual UTF-8 encoded string and
54 * c) locale-ized string, i.e. one containing 8-bit
55 * characters that are meaningful in current system locale.
56 * If filename is pure ASCII or real UTF-8 encoded string,
57 * MultiByteToWideChar succeeds and _wfopen works. If
58 * filename is locale-ized string, chances are that
59 * MultiByteToWideChar fails reporting
60 * ERROR_NO_UNICODE_TRANSLATION, in which case we fall
61 * back to fopen...
62 */
63 if ((sz = MultiByteToWideChar(CP_UTF8, (flags = MB_ERR_INVALID_CHARS),
64 filename, len_0, NULL, 0)) > 0 ||
65 (GetLastError() == ERROR_INVALID_FLAGS &&
66 (sz = MultiByteToWideChar(CP_UTF8, (flags = 0),
67 filename, len_0, NULL, 0)) > 0)
68 ) {
69 WCHAR wmode[8];
70 WCHAR *wfilename = _alloca(sz * sizeof(WCHAR));
71
72 if (MultiByteToWideChar(CP_UTF8, flags,
73 filename, len_0, wfilename, sz) &&
74 MultiByteToWideChar(CP_UTF8, 0, mode, strlen(mode) + 1,
75 wmode, OSSL_NELEM(wmode)) &&
76 (file = _wfopen(wfilename, wmode)) == NULL &&
77 (errno == ENOENT || errno == EBADF)
78 ) {
79 /*
80 * UTF-8 decode succeeded, but no file, filename
81 * could still have been locale-ized...
82 */
83 file = fopen(filename, mode);
84 }
85 } else if (GetLastError() == ERROR_NO_UNICODE_TRANSLATION) {
86 file = fopen(filename, mode);
87 }
88 # elif defined(__DJGPP__)
89 {
90 char *newname = NULL;
91
92 if (pathconf(filename, _PC_NAME_MAX) <= 12) { /* 8.3 file system? */
93 char *iterator;
94 char lastchar;
95
96 if ((newname = OPENSSL_malloc(strlen(filename) + 1)) == NULL)
97 return NULL;
98
99 for (iterator = newname, lastchar = '\0';
100 *filename; filename++, iterator++) {
101 if (lastchar == '/' && filename[0] == '.'
102 && filename[1] != '.' && filename[1] != '/') {
103 /* Leading dots are not permitted in plain DOS. */
104 *iterator = '_';
105 } else {
106 *iterator = *filename;
107 }
108 lastchar = *filename;
109 }
110 *iterator = '\0';
111 filename = newname;
112 }
113 file = fopen(filename, mode);
114
115 OPENSSL_free(newname);
116 }
117 # else
118 file = fopen(filename, mode);
119 # endif
120 return file;
121 }
122
123 #else
124
openssl_fopen(const char * filename,const char * mode)125 void *openssl_fopen(const char *filename, const char *mode)
126 {
127 return NULL;
128 }
129
130 #endif
131
