xref: /openssl/crypto/bio/bss_file.c (revision 1567a821)
1 /*
2  * Copyright 1995-2021 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 <stdio.h>
29 #include <errno.h>
30 #include "bio_local.h"
31 #include <openssl/err.h>
32 
33 #if !defined(OPENSSL_NO_STDIO)
34 
35 static int file_write(BIO *h, const char *buf, int num);
36 static int file_read(BIO *h, char *buf, int size);
37 static int file_puts(BIO *h, const char *str);
38 static int file_gets(BIO *h, char *str, int size);
39 static long file_ctrl(BIO *h, int cmd, long arg1, void *arg2);
40 static int file_new(BIO *h);
41 static int file_free(BIO *data);
42 static const BIO_METHOD methods_filep = {
43     BIO_TYPE_FILE,
44     "FILE pointer",
45     bwrite_conv,
46     file_write,
47     bread_conv,
48     file_read,
49     file_puts,
50     file_gets,
51     file_ctrl,
52     file_new,
53     file_free,
54     NULL,                      /* file_callback_ctrl */
55 };
56 
BIO_new_file(const char * filename,const char * mode)57 BIO *BIO_new_file(const char *filename, const char *mode)
58 {
59     BIO  *ret;
60     FILE *file = openssl_fopen(filename, mode);
61     int fp_flags = BIO_CLOSE;
62 
63     if (strchr(mode, 'b') == NULL)
64         fp_flags |= BIO_FP_TEXT;
65 
66     if (file == NULL) {
67         ERR_raise_data(ERR_LIB_SYS, get_last_sys_error(),
68                        "calling fopen(%s, %s)",
69                        filename, mode);
70         if (errno == ENOENT
71 #ifdef ENXIO
72             || errno == ENXIO
73 #endif
74             )
75             ERR_raise(ERR_LIB_BIO, BIO_R_NO_SUCH_FILE);
76         else
77             ERR_raise(ERR_LIB_BIO, ERR_R_SYS_LIB);
78         return NULL;
79     }
80     if ((ret = BIO_new(BIO_s_file())) == NULL) {
81         fclose(file);
82         return NULL;
83     }
84 
85     /* we did fopen -> we disengage UPLINK */
86     BIO_clear_flags(ret, BIO_FLAGS_UPLINK_INTERNAL);
87     BIO_set_fp(ret, file, fp_flags);
88     return ret;
89 }
90 
BIO_new_fp(FILE * stream,int close_flag)91 BIO *BIO_new_fp(FILE *stream, int close_flag)
92 {
93     BIO *ret;
94 
95     if ((ret = BIO_new(BIO_s_file())) == NULL)
96         return NULL;
97 
98     /* redundant flag, left for documentation purposes */
99     BIO_set_flags(ret, BIO_FLAGS_UPLINK_INTERNAL);
100     BIO_set_fp(ret, stream, close_flag);
101     return ret;
102 }
103 
BIO_s_file(void)104 const BIO_METHOD *BIO_s_file(void)
105 {
106     return &methods_filep;
107 }
108 
file_new(BIO * bi)109 static int file_new(BIO *bi)
110 {
111     bi->init = 0;
112     bi->num = 0;
113     bi->ptr = NULL;
114     bi->flags = BIO_FLAGS_UPLINK_INTERNAL; /* default to UPLINK */
115     return 1;
116 }
117 
file_free(BIO * a)118 static int file_free(BIO *a)
119 {
120     if (a == NULL)
121         return 0;
122     if (a->shutdown) {
123         if ((a->init) && (a->ptr != NULL)) {
124             if (a->flags & BIO_FLAGS_UPLINK_INTERNAL)
125                 UP_fclose(a->ptr);
126             else
127                 fclose(a->ptr);
128             a->ptr = NULL;
129             a->flags = BIO_FLAGS_UPLINK_INTERNAL;
130         }
131         a->init = 0;
132     }
133     return 1;
134 }
135 
file_read(BIO * b,char * out,int outl)136 static int file_read(BIO *b, char *out, int outl)
137 {
138     int ret = 0;
139 
140     if (b->init && (out != NULL)) {
141         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
142             ret = UP_fread(out, 1, (int)outl, b->ptr);
143         else
144             ret = fread(out, 1, (int)outl, (FILE *)b->ptr);
145         if (ret == 0
146             && (b->flags & BIO_FLAGS_UPLINK_INTERNAL
147                 ? UP_ferror((FILE *)b->ptr) : ferror((FILE *)b->ptr))) {
148             ERR_raise_data(ERR_LIB_SYS, get_last_sys_error(),
149                            "calling fread()");
150             ERR_raise(ERR_LIB_BIO, ERR_R_SYS_LIB);
151             ret = -1;
152         }
153     }
154     return ret;
155 }
156 
file_write(BIO * b,const char * in,int inl)157 static int file_write(BIO *b, const char *in, int inl)
158 {
159     int ret = 0;
160 
161     if (b->init && (in != NULL)) {
162         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
163             ret = UP_fwrite(in, (int)inl, 1, b->ptr);
164         else
165             ret = fwrite(in, (int)inl, 1, (FILE *)b->ptr);
166         if (ret)
167             ret = inl;
168         /* ret=fwrite(in,1,(int)inl,(FILE *)b->ptr); */
169         /*
170          * according to Tim Hudson <tjh@openssl.org>, the commented out
171          * version above can cause 'inl' write calls under some stupid stdio
172          * implementations (VMS)
173          */
174     }
175     return ret;
176 }
177 
file_ctrl(BIO * b,int cmd,long num,void * ptr)178 static long file_ctrl(BIO *b, int cmd, long num, void *ptr)
179 {
180     long ret = 1;
181     FILE *fp = (FILE *)b->ptr;
182     FILE **fpp;
183     char p[4];
184     int st;
185 
186     switch (cmd) {
187     case BIO_C_FILE_SEEK:
188     case BIO_CTRL_RESET:
189         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
190             ret = (long)UP_fseek(b->ptr, num, 0);
191         else
192             ret = (long)fseek(fp, num, 0);
193         break;
194     case BIO_CTRL_EOF:
195         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
196             ret = (long)UP_feof(fp);
197         else
198             ret = (long)feof(fp);
199         break;
200     case BIO_C_FILE_TELL:
201     case BIO_CTRL_INFO:
202         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
203             ret = UP_ftell(b->ptr);
204         else
205             ret = ftell(fp);
206         break;
207     case BIO_C_SET_FILE_PTR:
208         file_free(b);
209         b->shutdown = (int)num & BIO_CLOSE;
210         b->ptr = ptr;
211         b->init = 1;
212 # if BIO_FLAGS_UPLINK_INTERNAL!=0
213 #  if defined(__MINGW32__) && defined(__MSVCRT__) && !defined(_IOB_ENTRIES)
214 #   define _IOB_ENTRIES 20
215 #  endif
216         /* Safety net to catch purely internal BIO_set_fp calls */
217 #  if (defined(_MSC_VER) && _MSC_VER>=1900) || defined(__BORLANDC__)
218         if (ptr == stdin || ptr == stdout || ptr == stderr)
219             BIO_clear_flags(b, BIO_FLAGS_UPLINK_INTERNAL);
220 #  elif defined(_IOB_ENTRIES)
221         if ((size_t)ptr >= (size_t)stdin &&
222             (size_t)ptr < (size_t)(stdin + _IOB_ENTRIES))
223             BIO_clear_flags(b, BIO_FLAGS_UPLINK_INTERNAL);
224 #  endif
225 # endif
226 # ifdef UP_fsetmod
227         if (b->flags & BIO_FLAGS_UPLINK_INTERNAL)
228             UP_fsetmod(b->ptr, (char)((num & BIO_FP_TEXT) ? 't' : 'b'));
229         else
230 # endif
231         {
232 # if defined(OPENSSL_SYS_WINDOWS)
233             int fd = _fileno((FILE *)ptr);
234             if (num & BIO_FP_TEXT)
235                 _setmode(fd, _O_TEXT);
236             else
237                 _setmode(fd, _O_BINARY);
238             /*
239              * Reports show that ftell() isn't trustable in text mode.
240              * This has been confirmed as a bug in the Universal C RTL, see
241              * https://developercommunity.visualstudio.com/content/problem/425878/fseek-ftell-fail-in-text-mode-for-unix-style-text.html
242              * The suggested work-around from Microsoft engineering is to
243              * turn off buffering until the bug is resolved.
244              */
245             if ((num & BIO_FP_TEXT) != 0)
246                 setvbuf((FILE *)ptr, NULL, _IONBF, 0);
247 # elif defined(OPENSSL_SYS_MSDOS)
248             int fd = fileno((FILE *)ptr);
249             /* Set correct text/binary mode */
250             if (num & BIO_FP_TEXT)
251                 _setmode(fd, _O_TEXT);
252             /* Dangerous to set stdin/stdout to raw (unless redirected) */
253             else {
254                 if (fd == STDIN_FILENO || fd == STDOUT_FILENO) {
255                     if (isatty(fd) <= 0)
256                         _setmode(fd, _O_BINARY);
257                 } else
258                     _setmode(fd, _O_BINARY);
259             }
260 # elif defined(OPENSSL_SYS_WIN32_CYGWIN)
261             int fd = fileno((FILE *)ptr);
262             if (!(num & BIO_FP_TEXT))
263                 setmode(fd, O_BINARY);
264 # endif
265         }
266         break;
267     case BIO_C_SET_FILENAME:
268         file_free(b);
269         b->shutdown = (int)num & BIO_CLOSE;
270         if (num & BIO_FP_APPEND) {
271             if (num & BIO_FP_READ)
272                 OPENSSL_strlcpy(p, "a+", sizeof(p));
273             else
274                 OPENSSL_strlcpy(p, "a", sizeof(p));
275         } else if ((num & BIO_FP_READ) && (num & BIO_FP_WRITE))
276             OPENSSL_strlcpy(p, "r+", sizeof(p));
277         else if (num & BIO_FP_WRITE)
278             OPENSSL_strlcpy(p, "w", sizeof(p));
279         else if (num & BIO_FP_READ)
280             OPENSSL_strlcpy(p, "r", sizeof(p));
281         else {
282             ERR_raise(ERR_LIB_BIO, BIO_R_BAD_FOPEN_MODE);
283             ret = 0;
284             break;
285         }
286 # if defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_WINDOWS)
287         if (!(num & BIO_FP_TEXT))
288             OPENSSL_strlcat(p, "b", sizeof(p));
289         else
290             OPENSSL_strlcat(p, "t", sizeof(p));
291 # elif defined(OPENSSL_SYS_WIN32_CYGWIN)
292         if (!(num & BIO_FP_TEXT))
293             OPENSSL_strlcat(p, "b", sizeof(p));
294 # endif
295         fp = openssl_fopen(ptr, p);
296         if (fp == NULL) {
297             ERR_raise_data(ERR_LIB_SYS, get_last_sys_error(),
298                            "calling fopen(%s, %s)",
299                            ptr, p);
300             ERR_raise(ERR_LIB_BIO, ERR_R_SYS_LIB);
301             ret = 0;
302             break;
303         }
304         b->ptr = fp;
305         b->init = 1;
306         /* we did fopen -> we disengage UPLINK */
307         BIO_clear_flags(b, BIO_FLAGS_UPLINK_INTERNAL);
308         break;
309     case BIO_C_GET_FILE_PTR:
310         /* the ptr parameter is actually a FILE ** in this case. */
311         if (ptr != NULL) {
312             fpp = (FILE **)ptr;
313             *fpp = (FILE *)b->ptr;
314         }
315         break;
316     case BIO_CTRL_GET_CLOSE:
317         ret = (long)b->shutdown;
318         break;
319     case BIO_CTRL_SET_CLOSE:
320         b->shutdown = (int)num;
321         break;
322     case BIO_CTRL_FLUSH:
323         st = b->flags & BIO_FLAGS_UPLINK_INTERNAL
324                 ? UP_fflush(b->ptr) : fflush((FILE *)b->ptr);
325         if (st == EOF) {
326             ERR_raise_data(ERR_LIB_SYS, get_last_sys_error(),
327                            "calling fflush()");
328             ERR_raise(ERR_LIB_BIO, ERR_R_SYS_LIB);
329             ret = 0;
330         }
331         break;
332     case BIO_CTRL_DUP:
333         ret = 1;
334         break;
335 
336     case BIO_CTRL_WPENDING:
337     case BIO_CTRL_PENDING:
338     case BIO_CTRL_PUSH:
339     case BIO_CTRL_POP:
340     default:
341         ret = 0;
342         break;
343     }
344     return ret;
345 }
346 
file_gets(BIO * bp,char * buf,int size)347 static int file_gets(BIO *bp, char *buf, int size)
348 {
349     int ret = 0;
350 
351     buf[0] = '\0';
352     if (bp->flags & BIO_FLAGS_UPLINK_INTERNAL) {
353         if (!UP_fgets(buf, size, bp->ptr))
354             goto err;
355     } else {
356         if (!fgets(buf, size, (FILE *)bp->ptr))
357             goto err;
358     }
359     if (buf[0] != '\0')
360         ret = strlen(buf);
361  err:
362     return ret;
363 }
364 
file_puts(BIO * bp,const char * str)365 static int file_puts(BIO *bp, const char *str)
366 {
367     int n, ret;
368 
369     n = strlen(str);
370     ret = file_write(bp, str, n);
371     return ret;
372 }
373 
374 #else
375 
file_write(BIO * b,const char * in,int inl)376 static int file_write(BIO *b, const char *in, int inl)
377 {
378     return -1;
379 }
file_read(BIO * b,char * out,int outl)380 static int file_read(BIO *b, char *out, int outl)
381 {
382     return -1;
383 }
file_puts(BIO * bp,const char * str)384 static int file_puts(BIO *bp, const char *str)
385 {
386     return -1;
387 }
file_gets(BIO * bp,char * buf,int size)388 static int file_gets(BIO *bp, char *buf, int size)
389 {
390     return 0;
391 }
file_ctrl(BIO * b,int cmd,long num,void * ptr)392 static long file_ctrl(BIO *b, int cmd, long num, void *ptr)
393 {
394     return 0;
395 }
file_new(BIO * bi)396 static int file_new(BIO *bi)
397 {
398     return 0;
399 }
file_free(BIO * a)400 static int file_free(BIO *a)
401 {
402     return 0;
403 }
404 
405 static const BIO_METHOD methods_filep = {
406     BIO_TYPE_FILE,
407     "FILE pointer",
408     bwrite_conv,
409     file_write,
410     bread_conv,
411     file_read,
412     file_puts,
413     file_gets,
414     file_ctrl,
415     file_new,
416     file_free,
417     NULL,                      /* file_callback_ctrl */
418 };
419 
BIO_s_file(void)420 const BIO_METHOD *BIO_s_file(void)
421 {
422     return &methods_filep;
423 }
424 
BIO_new_file(const char * filename,const char * mode)425 BIO *BIO_new_file(const char *filename, const char *mode)
426 {
427     return NULL;
428 }
429 
430 #endif                         /* OPENSSL_NO_STDIO */
431