Coverage Report

Created: 2025-06-22 06:56

/src/openssl/crypto/o_fopen.c
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Source (jump to first uncovered line)
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/*
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 * Copyright 2016-2024 The OpenSSL Project Authors. All Rights Reserved.
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 *
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 * Licensed under the Apache License 2.0 (the "License").  You may not use
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 * this file except in compliance with the License.  You can obtain a copy
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 * in the file LICENSE in the source distribution or at
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 * https://www.openssl.org/source/license.html
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 */
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# if defined(__linux) || defined(__sun) || defined(__hpux)
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/*
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 * Following definition aliases fopen to fopen64 on above mentioned
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 * platforms. This makes it possible to open and sequentially access files
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 * larger than 2GB from 32-bit application. It does not allow one to traverse
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 * them beyond 2GB with fseek/ftell, but on the other hand *no* 32-bit
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 * platform permits that, not with fseek/ftell. Not to mention that breaking
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 * 2GB limit for seeking would require surgery to *our* API. But sequential
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 * access suffices for practical cases when you can run into large files,
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 * such as fingerprinting, so we can let API alone. For reference, the list
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 * of 32-bit platforms which allow for sequential access of large files
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 * without extra "magic" comprise *BSD, Darwin, IRIX...
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 */
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#  ifndef _FILE_OFFSET_BITS
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#   define _FILE_OFFSET_BITS 64
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#  endif
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# endif
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#include "internal/e_os.h"
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#include "internal/cryptlib.h"
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#if !defined(OPENSSL_NO_STDIO)
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# include <stdio.h>
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# ifdef __DJGPP__
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#  include <unistd.h>
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# endif
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FILE *openssl_fopen(const char *filename, const char *mode)
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{
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    FILE *file = NULL;
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# if defined(_WIN32) && defined(CP_UTF8)
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    int sz, len_0;
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    DWORD flags;
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# endif
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    if (filename == NULL)
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        return NULL;
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# if defined(_WIN32) && defined(CP_UTF8)
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    len_0 = (int)strlen(filename) + 1;
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    /*
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     * Basically there are three cases to cover: a) filename is
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     * pure ASCII string; b) actual UTF-8 encoded string and
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     * c) locale-ized string, i.e. one containing 8-bit
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     * characters that are meaningful in current system locale.
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     * If filename is pure ASCII or real UTF-8 encoded string,
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     * MultiByteToWideChar succeeds and _wfopen works. If
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     * filename is locale-ized string, chances are that
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     * MultiByteToWideChar fails reporting
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     * ERROR_NO_UNICODE_TRANSLATION, in which case we fall
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     * back to fopen...
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     */
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    if ((sz = MultiByteToWideChar(CP_UTF8, (flags = MB_ERR_INVALID_CHARS),
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                                  filename, len_0, NULL, 0)) > 0 ||
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        (GetLastError() == ERROR_INVALID_FLAGS &&
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         (sz = MultiByteToWideChar(CP_UTF8, (flags = 0),
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                                   filename, len_0, NULL, 0)) > 0)
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        ) {
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        WCHAR wmode[8];
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        WCHAR *wfilename = _alloca(sz * sizeof(WCHAR));
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        if (MultiByteToWideChar(CP_UTF8, flags,
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                                filename, len_0, wfilename, sz) &&
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            MultiByteToWideChar(CP_UTF8, 0, mode, strlen(mode) + 1,
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                                wmode, OSSL_NELEM(wmode)) &&
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            (file = _wfopen(wfilename, wmode)) == NULL &&
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            (errno == ENOENT || errno == EBADF)
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            ) {
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            /*
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             * UTF-8 decode succeeded, but no file, filename
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             * could still have been locale-ized...
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             */
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            file = fopen(filename, mode);
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        }
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    } else if (GetLastError() == ERROR_NO_UNICODE_TRANSLATION) {
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        file = fopen(filename, mode);
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    }
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# elif defined(__DJGPP__)
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    {
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        char *newname = NULL;
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        if (pathconf(filename, _PC_NAME_MAX) <= 12) {  /* 8.3 file system? */
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            char *iterator;
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            char lastchar;
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            if ((newname = OPENSSL_malloc(strlen(filename) + 1)) == NULL)
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                return NULL;
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            for (iterator = newname, lastchar = '\0';
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                *filename; filename++, iterator++) {
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                if (lastchar == '/' && filename[0] == '.'
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                    && filename[1] != '.' && filename[1] != '/') {
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                    /* Leading dots are not permitted in plain DOS. */
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                    *iterator = '_';
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                } else {
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                    *iterator = *filename;
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                }
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                lastchar = *filename;
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            }
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            *iterator = '\0';
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            filename = newname;
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        }
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        file = fopen(filename, mode);
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        OPENSSL_free(newname);
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    }
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# else
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    file = fopen(filename, mode);
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# endif
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    return file;
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}
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#else
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void *openssl_fopen(const char *filename, const char *mode)
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{
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    return NULL;
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}
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#endif