crypto/o_fopen.c

   1 /*
   2  * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 #include "internal/cryptlib.h"
  11
  12 #if !defined(OPENSSL_NO_STDIO)
  13
  14 # include <stdio.h>
  15
  16 FILE *openssl_fopen(const char *filename, const char *mode)
  17 {
  18     FILE *file = NULL;
  19 # if defined(_WIN32) && defined(CP_UTF8)
  20     int sz, len_0 = (int)strlen(filename) + 1;
  21     DWORD flags;
  22
  23     /*
  24      * Basically there are three cases to cover: a) filename is
  25      * pure ASCII string; b) actual UTF-8 encoded string and
  26      * c) locale-ized string, i.e. one containing 8-bit
  27      * characters that are meaningful in current system locale.
  28      * If filename is pure ASCII or real UTF-8 encoded string,
  29      * MultiByteToWideChar succeeds and _wfopen works. If
  30      * filename is locale-ized string, chances are that
  31      * MultiByteToWideChar fails reporting
  32      * ERROR_NO_UNICODE_TRANSLATION, in which case we fall
  33      * back to fopen...
  34      */
  35     if ((sz = MultiByteToWideChar(CP_UTF8, (flags = MB_ERR_INVALID_CHARS),
  36                                   filename, len_0, NULL, 0)) > 0 ||
  37         (GetLastError() == ERROR_INVALID_FLAGS &&
  38          (sz = MultiByteToWideChar(CP_UTF8, (flags = 0),
  39                                    filename, len_0, NULL, 0)) > 0)
  40         ) {
  41         WCHAR wmode[8];
  42         WCHAR *wfilename = _alloca(sz * sizeof(WCHAR));
  43
  44         if (MultiByteToWideChar(CP_UTF8, flags,
  45                                 filename, len_0, wfilename, sz) &&
  46             MultiByteToWideChar(CP_UTF8, 0, mode, strlen(mode) + 1,
  47                                 wmode, OSSL_NELEM(wmode)) &&
  48             (file = _wfopen(wfilename, wmode)) == NULL &&
  49             (errno == ENOENT || errno == EBADF)
  50             ) {
  51             /*
  52              * UTF-8 decode succeeded, but no file, filename
  53              * could still have been locale-ized...
  54              */
  55             file = fopen(filename, mode);
  56         }
  57     } else if (GetLastError() == ERROR_NO_UNICODE_TRANSLATION) {
  58         file = fopen(filename, mode);
  59     }
  60 # elif defined(__DJGPP__)
  61     {
  62         char *newname = NULL;
  63
  64         if (!HAS_LFN_SUPPORT(filename)) {
  65             char *iterator;
  66             char lastchar;
  67
  68             newname = OPENSSL_malloc(strlen(filename) + 1);
  69             if (newname == NULL)
  70                 return NULL;
  71
  72             for (iterator = newname, lastchar = '\0';
  73                 *filename; filename++, iterator++) {
  74                 if (lastchar == '/' && filename[0] == '.'
  75                     && filename[1] != '.' && filename[1] != '/') {
  76                     /* Leading dots are not permitted in plain DOS. */
  77                     *iterator = '_';
  78                 } else {
  79                     *iterator = *filename;
  80                 }
  81                 lastchar = *filename;
  82             }
  83             *iterator = '\0';
  84             filename = newname;
  85         }
  86         file = fopen(filename, mode);
  87
  88         OPENSSL_free(newname);
  89     }
  90 # else
  91     file = fopen(filename, mode);
  92 # endif
  93     return file;
  94 }
  95
  96 #else
  97
  98 void *openssl_fopen(const char *filename, const char *mode)
  99 {
 100     return NULL;
 101 }
 102
 103 #endif