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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) cryptsoft.com).
      6  * The implementation was written so as to conform with Netscapes SSL.
      7  *
      8  * This library is free for commercial and non-commercial use as long as
      9  * the following conditions are aheared to.  The following conditions
     10  * apply to all code found in this distribution, be it the RC4, RSA,
     11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     12  * included with this distribution is covered by the same copyright terms
     13  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     14  *
     15  * Copyright remains Eric Young's, and as such any Copyright notices in
     16  * the code are not to be removed.
     17  * If this package is used in a product, Eric Young should be given attribution
     18  * as the author of the parts of the library used.
     19  * This can be in the form of a textual message at program startup or
     20  * in documentation (online or textual) provided with the package.
     21  *
     22  * Redistribution and use in source and binary forms, with or without
     23  * modification, are permitted provided that the following conditions
     24  * are met:
     25  * 1. Redistributions of source code must retain the copyright
     26  *    notice, this list of conditions and the following disclaimer.
     27  * 2. Redistributions in binary form must reproduce the above copyright
     28  *    notice, this list of conditions and the following disclaimer in the
     29  *    documentation and/or other materials provided with the distribution.
     30  * 3. All advertising materials mentioning features or use of this software
     31  *    must display the following acknowledgement:
     32  *    "This product includes cryptographic software written by
     33  *     Eric Young (eay (at) cryptsoft.com)"
     34  *    The word 'cryptographic' can be left out if the rouines from the library
     35  *    being used are not cryptographic related :-).
     36  * 4. If you include any Windows specific code (or a derivative thereof) from
     37  *    the apps directory (application code) you must include an acknowledgement:
     38  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     39  *
     40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     50  * SUCH DAMAGE.
     51  *
     52  * The licence and distribution terms for any publically available version or
     53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     54  * copied and put under another distribution licence
     55  * [including the GNU Public Licence.] */
     56 
     57 #ifndef OPENSSL_HEADER_BIO_H
     58 #define OPENSSL_HEADER_BIO_H
     59 
     60 #include <openssl/base.h>
     61 
     62 #include <stdio.h>  /* For FILE */
     63 
     64 #include <openssl/buffer.h>
     65 #include <openssl/err.h> /* for ERR_print_errors_fp */
     66 #include <openssl/ex_data.h>
     67 #include <openssl/stack.h>
     68 #include <openssl/thread.h>
     69 
     70 #if defined(__cplusplus)
     71 extern "C" {
     72 #endif
     73 
     74 
     75 /* BIO abstracts over a file-descriptor like interface. */
     76 
     77 
     78 /* Allocation and freeing. */
     79 
     80 /* BIO_new creates a new BIO with the given type and a reference count of one.
     81  * It returns the fresh |BIO|, or NULL on error. */
     82 OPENSSL_EXPORT BIO *BIO_new(const BIO_METHOD *type);
     83 
     84 /* BIO_free decrements the reference count of |bio|. If the reference count
     85  * drops to zero, it (optionally) calls the BIO's callback with |BIO_CB_FREE|,
     86  * frees the ex_data and then, if the BIO has a destroy callback for the
     87  * method, calls it. Finally it frees |bio| itself. It then repeats that for
     88  * the next BIO in the chain, if any.
     89  *
     90  * It returns one on success or zero otherwise. */
     91 OPENSSL_EXPORT int BIO_free(BIO *bio);
     92 
     93 /* BIO_vfree performs the same actions as |BIO_free|, but has a void return
     94  * value. This is provided for API-compat.
     95  *
     96  * TODO(fork): remove. */
     97 OPENSSL_EXPORT void BIO_vfree(BIO *bio);
     98 
     99 /* BIO_up_ref increments the reference count of |bio| and returns one. */
    100 OPENSSL_EXPORT int BIO_up_ref(BIO *bio);
    101 
    102 
    103 /* Basic I/O. */
    104 
    105 /* BIO_read attempts to read |len| bytes into |data|. It returns the number of
    106  * bytes read, zero on EOF, or a negative number on error. */
    107 OPENSSL_EXPORT int BIO_read(BIO *bio, void *data, int len);
    108 
    109 /* BIO_gets "reads a line" from |bio| and puts at most |size| bytes into |buf|.
    110  * It returns the number of bytes read or a negative number on error. The
    111  * phrase "reads a line" is in quotes in the previous sentence because the
    112  * exact operation depends on the BIO's method. For example, a digest BIO will
    113  * return the digest in response to a |BIO_gets| call.
    114  *
    115  * TODO(fork): audit the set of BIOs that we end up needing. If all actually
    116  * return a line for this call, remove the warning above. */
    117 OPENSSL_EXPORT int BIO_gets(BIO *bio, char *buf, int size);
    118 
    119 /* BIO_write writes |len| bytes from |data| to BIO. It returns the number of
    120  * bytes written or a negative number on error. */
    121 OPENSSL_EXPORT int BIO_write(BIO *bio, const void *data, int len);
    122 
    123 /* BIO_puts writes a NUL terminated string from |buf| to |bio|. It returns the
    124  * number of bytes written or a negative number on error. */
    125 OPENSSL_EXPORT int BIO_puts(BIO *bio, const char *buf);
    126 
    127 /* BIO_flush flushes any buffered output. It returns one on success and zero
    128  * otherwise. */
    129 OPENSSL_EXPORT int BIO_flush(BIO *bio);
    130 
    131 
    132 /* Low-level control functions.
    133  *
    134  * These are generic functions for sending control requests to a BIO. In
    135  * general one should use the wrapper functions like |BIO_get_close|. */
    136 
    137 /* BIO_ctrl sends the control request |cmd| to |bio|. The |cmd| argument should
    138  * be one of the |BIO_C_*| values. */
    139 OPENSSL_EXPORT long BIO_ctrl(BIO *bio, int cmd, long larg, void *parg);
    140 
    141 /* BIO_ptr_ctrl acts like |BIO_ctrl| but passes the address of a |void*|
    142  * pointer as |parg| and returns the value that is written to it, or NULL if
    143  * the control request returns <= 0. */
    144 OPENSSL_EXPORT char *BIO_ptr_ctrl(BIO *bp, int cmd, long larg);
    145 
    146 /* BIO_int_ctrl acts like |BIO_ctrl| but passes the address of a copy of |iarg|
    147  * as |parg|. */
    148 OPENSSL_EXPORT long BIO_int_ctrl(BIO *bp, int cmd, long larg, int iarg);
    149 
    150 /* BIO_reset resets |bio| to its initial state, the precise meaning of which
    151  * depends on the concrete type of |bio|. It returns one on success and zero
    152  * otherwise. */
    153 OPENSSL_EXPORT int BIO_reset(BIO *bio);
    154 
    155 /* BIO_eof returns non-zero when |bio| has reached end-of-file. The precise
    156  * meaning of which depends on the concrete type of |bio|. Note that in the
    157  * case of BIO_pair this always returns non-zero. */
    158 OPENSSL_EXPORT int BIO_eof(BIO *bio);
    159 
    160 /* BIO_set_flags ORs |flags| with |bio->flags|. */
    161 OPENSSL_EXPORT void BIO_set_flags(BIO *bio, int flags);
    162 
    163 /* BIO_test_flags returns |bio->flags| AND |flags|. */
    164 OPENSSL_EXPORT int BIO_test_flags(const BIO *bio, int flags);
    165 
    166 /* BIO_should_read returns non-zero if |bio| encountered a temporary error
    167  * while reading (i.e. EAGAIN), indicating that the caller should retry the
    168  * read. */
    169 OPENSSL_EXPORT int BIO_should_read(const BIO *bio);
    170 
    171 /* BIO_should_write returns non-zero if |bio| encountered a temporary error
    172  * while writing (i.e. EAGAIN), indicating that the caller should retry the
    173  * write. */
    174 OPENSSL_EXPORT int BIO_should_write(const BIO *bio);
    175 
    176 /* BIO_should_retry returns non-zero if the reason that caused a failed I/O
    177  * operation is temporary and thus the operation should be retried. Otherwise,
    178  * it was a permanent error and it returns zero. */
    179 OPENSSL_EXPORT int BIO_should_retry(const BIO *bio);
    180 
    181 /* BIO_should_io_special returns non-zero if |bio| encountered a temporary
    182  * error while performing a special I/O operation, indicating that the caller
    183  * should retry. The operation that caused the error is returned by
    184  * |BIO_get_retry_reason|. */
    185 OPENSSL_EXPORT int BIO_should_io_special(const BIO *bio);
    186 
    187 /* BIO_RR_CONNECT indicates that a connect would have blocked */
    188 #define BIO_RR_CONNECT 0x02
    189 
    190 /* BIO_RR_ACCEPT indicates that an accept would have blocked */
    191 #define BIO_RR_ACCEPT 0x03
    192 
    193 /* BIO_get_retry_reason returns the special I/O operation that needs to be
    194  * retried. The return value is one of the |BIO_RR_*| values. */
    195 OPENSSL_EXPORT int BIO_get_retry_reason(const BIO *bio);
    196 
    197 /* BIO_clear_flags ANDs |bio->flags| with the bitwise-complement of |flags|. */
    198 OPENSSL_EXPORT void BIO_clear_flags(BIO *bio, int flags);
    199 
    200 /* BIO_set_retry_read sets the |BIO_FLAGS_READ| and |BIO_FLAGS_SHOULD_RETRY|
    201  * flags on |bio|. */
    202 OPENSSL_EXPORT void BIO_set_retry_read(BIO *bio);
    203 
    204 /* BIO_set_retry_write sets the |BIO_FLAGS_WRITE| and |BIO_FLAGS_SHOULD_RETRY|
    205  * flags on |bio|. */
    206 OPENSSL_EXPORT void BIO_set_retry_write(BIO *bio);
    207 
    208 /* BIO_get_retry_flags gets the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
    209  * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
    210 OPENSSL_EXPORT int BIO_get_retry_flags(BIO *bio);
    211 
    212 /* BIO_clear_retry_flags clears the |BIO_FLAGS_READ|, |BIO_FLAGS_WRITE|,
    213  * |BIO_FLAGS_IO_SPECIAL| and |BIO_FLAGS_SHOULD_RETRY| flags from |bio|. */
    214 OPENSSL_EXPORT void BIO_clear_retry_flags(BIO *bio);
    215 
    216 /* BIO_method_type returns the type of |bio|, which is one of the |BIO_TYPE_*|
    217  * values. */
    218 OPENSSL_EXPORT int BIO_method_type(const BIO *bio);
    219 
    220 /* bio_info_cb is the type of a callback function that can be called for most
    221  * BIO operations. The |event| argument is one of |BIO_CB_*| and can be ORed
    222  * with |BIO_CB_RETURN| if the callback is being made after the operation in
    223  * question. In that case, |return_value| will contain the return value from
    224  * the operation. */
    225 typedef long (*bio_info_cb)(BIO *bio, int event, const char *parg, int cmd,
    226                             long larg, long return_value);
    227 
    228 /* BIO_callback_ctrl allows the callback function to be manipulated. The |cmd|
    229  * arg will generally be |BIO_CTRL_SET_CALLBACK| but arbitrary command values
    230  * can be interpreted by the |BIO|. */
    231 OPENSSL_EXPORT long BIO_callback_ctrl(BIO *bio, int cmd, bio_info_cb fp);
    232 
    233 /* BIO_pending returns the number of bytes pending to be read. */
    234 OPENSSL_EXPORT size_t BIO_pending(const BIO *bio);
    235 
    236 /* BIO_ctrl_pending calls |BIO_pending| and exists only for compatibility with
    237  * OpenSSL. */
    238 OPENSSL_EXPORT size_t BIO_ctrl_pending(const BIO *bio);
    239 
    240 /* BIO_wpending returns the number of bytes pending to be written. */
    241 OPENSSL_EXPORT size_t BIO_wpending(const BIO *bio);
    242 
    243 /* BIO_set_close sets the close flag for |bio|. The meaning of which depends on
    244  * the type of |bio| but, for example, a memory BIO interprets the close flag
    245  * as meaning that it owns its buffer. It returns one on success and zero
    246  * otherwise. */
    247 OPENSSL_EXPORT int BIO_set_close(BIO *bio, int close_flag);
    248 
    249 /* BIO_set_callback sets a callback function that will be called before and
    250  * after most operations. See the comment above |bio_info_cb|. */
    251 OPENSSL_EXPORT void BIO_set_callback(BIO *bio, bio_info_cb callback_func);
    252 
    253 /* BIO_set_callback_arg sets the opaque pointer value that can be read within a
    254  * callback with |BIO_get_callback_arg|. */
    255 OPENSSL_EXPORT void BIO_set_callback_arg(BIO *bio, char *arg);
    256 
    257 /* BIO_get_callback_arg returns the last value of the opaque callback pointer
    258  * set by |BIO_set_callback_arg|. */
    259 OPENSSL_EXPORT char *BIO_get_callback_arg(const BIO *bio);
    260 
    261 /* BIO_number_read returns the number of bytes that have been read from
    262  * |bio|. */
    263 OPENSSL_EXPORT size_t BIO_number_read(const BIO *bio);
    264 
    265 /* BIO_number_written returns the number of bytes that have been written to
    266  * |bio|. */
    267 OPENSSL_EXPORT size_t BIO_number_written(const BIO *bio);
    268 
    269 
    270 /* Managing chains of BIOs.
    271  *
    272  * BIOs can be put into chains where the output of one is used as the input of
    273  * the next etc. The most common case is a buffering BIO, which accepts and
    274  * buffers writes until flushed into the next BIO in the chain. */
    275 
    276 /* BIO_push adds |appended_bio| to the end of the chain with |bio| at the head.
    277  * It returns |bio|. Note that |appended_bio| may be the head of a chain itself
    278  * and thus this function can be used to join two chains.
    279  *
    280  * BIO_push takes ownership of the caller's reference to |appended_bio|. */
    281 OPENSSL_EXPORT BIO *BIO_push(BIO *bio, BIO *appended_bio);
    282 
    283 /* BIO_pop removes |bio| from the head of a chain and returns the next BIO in
    284  * the chain, or NULL if there is no next BIO.
    285  *
    286  * The caller takes ownership of the chain's reference to |bio|. */
    287 OPENSSL_EXPORT BIO *BIO_pop(BIO *bio);
    288 
    289 /* BIO_next returns the next BIO in the chain after |bio|, or NULL if there is
    290  * no such BIO. */
    291 OPENSSL_EXPORT BIO *BIO_next(BIO *bio);
    292 
    293 /* BIO_free_all calls |BIO_free|.
    294  *
    295  * TODO(fork): update callers and remove. */
    296 OPENSSL_EXPORT void BIO_free_all(BIO *bio);
    297 
    298 /* BIO_find_type walks a chain of BIOs and returns the first that matches
    299  * |type|, which is one of the |BIO_TYPE_*| values. */
    300 OPENSSL_EXPORT BIO *BIO_find_type(BIO *bio, int type);
    301 
    302 /* BIO_copy_next_retry sets the retry flags and |retry_reason| of |bio| from
    303  * the next BIO in the chain. */
    304 OPENSSL_EXPORT void BIO_copy_next_retry(BIO *bio);
    305 
    306 
    307 /* Printf functions. */
    308 
    309 /* BIO_printf behaves like |printf| but outputs to |bio| rather than a |FILE|.
    310  * It returns the number of bytes written or a negative number on error. */
    311 OPENSSL_EXPORT int BIO_printf(BIO *bio, const char *format, ...)
    312     OPENSSL_PRINTF_FORMAT_FUNC(2, 3);
    313 
    314 
    315 /* Utility functions. */
    316 
    317 /* BIO_indent prints min(|indent|, |max_indent|) spaces. It returns one on
    318  * success and zero otherwise. */
    319 OPENSSL_EXPORT int BIO_indent(BIO *bio, unsigned indent, unsigned max_indent);
    320 
    321 /* BIO_hexdump writes a hex dump of |data| to |bio|. Each line will be indented
    322  * by |indent| spaces. */
    323 OPENSSL_EXPORT int BIO_hexdump(BIO *bio, const uint8_t *data, size_t len,
    324                                unsigned indent);
    325 
    326 /* ERR_print_errors prints the current contents of the error stack to |bio|
    327  * using human readable strings where possible. */
    328 OPENSSL_EXPORT void ERR_print_errors(BIO *bio);
    329 
    330 /* BIO_read_asn1 reads a single ASN.1 object from |bio|. If successful it sets
    331  * |*out| to be an allocated buffer (that should be freed with |OPENSSL_free|),
    332  * |*out_size| to the length, in bytes, of that buffer and returns one.
    333  * Otherwise it returns zero.
    334  *
    335  * If the length of the object is greater than |max_len| or 2^32 then the
    336  * function will fail. Long-form tags are not supported. If the length of the
    337  * object is indefinite the full contents of |bio| are read, unless it would be
    338  * greater than |max_len|, in which case the function fails.
    339  *
    340  * If the function fails then some unknown amount of data may have been read
    341  * from |bio|. */
    342 OPENSSL_EXPORT int BIO_read_asn1(BIO *bio, uint8_t **out, size_t *out_len,
    343                                  size_t max_len);
    344 
    345 
    346 /* Memory BIOs.
    347  *
    348  * Memory BIOs can be used as a read-only source (with |BIO_new_mem_buf|) or a
    349  * writable sink (with |BIO_new|, |BIO_s_mem| and |BIO_get_mem_buf|). Data
    350  * written to a writable, memory BIO can be recalled by reading from it.
    351  *
    352  * Calling |BIO_reset| on a read-only BIO resets it to the original contents.
    353  * On a writable BIO, it clears any data.
    354  *
    355  * If the close flag is set to |BIO_NOCLOSE| (not the default) then the
    356  * underlying |BUF_MEM| will not be freed when the |BIO| is freed.
    357  *
    358  * Memory BIOs support |BIO_gets| and |BIO_puts|.
    359  *
    360  * |BIO_ctrl_pending| returns the number of bytes currently stored. */
    361 
    362 /* BIO_s_mem returns a |BIO_METHOD| that uses a in-memory buffer. */
    363 OPENSSL_EXPORT const BIO_METHOD *BIO_s_mem(void);
    364 
    365 /* BIO_new_mem_buf creates read-only BIO that reads from |len| bytes at |buf|.
    366  * It does not take ownership of |buf|. It returns the BIO or NULL on error.
    367  *
    368  * If |len| is negative, then |buf| is treated as a NUL-terminated string, but
    369  * don't depend on this in new code. */
    370 OPENSSL_EXPORT BIO *BIO_new_mem_buf(const void *buf, int len);
    371 
    372 /* BIO_mem_contents sets |*out_contents| to point to the current contents of
    373  * |bio| and |*out_len| to contain the length of that data. It returns one on
    374  * success and zero otherwise. */
    375 OPENSSL_EXPORT int BIO_mem_contents(const BIO *bio,
    376                                     const uint8_t **out_contents,
    377                                     size_t *out_len);
    378 
    379 /* BIO_get_mem_data sets |*contents| to point to the current contents of |bio|
    380  * and returns the length of the data.
    381  *
    382  * WARNING: don't use this, use |BIO_mem_contents|. A return value of zero from
    383  * this function can mean either that it failed or that the memory buffer is
    384  * empty. */
    385 OPENSSL_EXPORT long BIO_get_mem_data(BIO *bio, char **contents);
    386 
    387 /* BIO_get_mem_ptr sets |*out| to a BUF_MEM containing the current contents of
    388  * |bio|. It returns one on success or zero on error. */
    389 OPENSSL_EXPORT int BIO_get_mem_ptr(BIO *bio, BUF_MEM **out);
    390 
    391 /* BIO_set_mem_buf sets |b| as the contents of |bio|. If |take_ownership| is
    392  * non-zero, then |b| will be freed when |bio| is closed. Returns one on
    393  * success or zero otherwise. */
    394 OPENSSL_EXPORT int BIO_set_mem_buf(BIO *bio, BUF_MEM *b, int take_ownership);
    395 
    396 /* BIO_set_mem_eof_return sets the value that will be returned from reading
    397  * |bio| when empty. If |eof_value| is zero then an empty memory BIO will
    398  * return EOF (that is it will return zero and |BIO_should_retry| will be
    399  * false). If |eof_value| is non zero then it will return |eof_value| when it
    400  * is empty and it will set the read retry flag (that is |BIO_read_retry| is
    401  * true). To avoid ambiguity with a normal positive return value, |eof_value|
    402  * should be set to a negative value, typically -1.
    403  *
    404  * For a read-only BIO, the default is zero (EOF). For a writable BIO, the
    405  * default is -1 so that additional data can be written once exhausted. */
    406 OPENSSL_EXPORT int BIO_set_mem_eof_return(BIO *bio, int eof_value);
    407 
    408 
    409 /* File descriptor BIOs.
    410  *
    411  * File descriptor BIOs are wrappers around the system's |read| and |write|
    412  * functions. If the close flag is set then then |close| is called on the
    413  * underlying file descriptor when the BIO is freed.
    414  *
    415  * |BIO_reset| attempts to seek the file pointer to the start of file using
    416  * |lseek|. */
    417 
    418 /* BIO_s_fd returns a |BIO_METHOD| for file descriptor fds. */
    419 OPENSSL_EXPORT const BIO_METHOD *BIO_s_fd(void);
    420 
    421 /* BIO_new_fd creates a new file descriptor BIO wrapping |fd|. If |close_flag|
    422  * is non-zero, then |fd| will be closed when the BIO is. */
    423 OPENSSL_EXPORT BIO *BIO_new_fd(int fd, int close_flag);
    424 
    425 /* BIO_set_fd sets the file descriptor of |bio| to |fd|. If |close_flag| is
    426  * non-zero then |fd| will be closed when |bio| is. It returns one on success
    427  * or zero on error.
    428  *
    429  * This function may also be used with socket BIOs (see |BIO_s_socket| and
    430  * |BIO_new_socket|). */
    431 OPENSSL_EXPORT int BIO_set_fd(BIO *bio, int fd, int close_flag);
    432 
    433 /* BIO_get_fd returns the file descriptor currently in use by |bio| or -1 if
    434  * |bio| does not wrap a file descriptor. If there is a file descriptor and
    435  * |out_fd| is not NULL, it also sets |*out_fd| to the file descriptor.
    436  *
    437  * This function may also be used with socket BIOs (see |BIO_s_socket| and
    438  * |BIO_new_socket|). */
    439 OPENSSL_EXPORT int BIO_get_fd(BIO *bio, int *out_fd);
    440 
    441 
    442 /* File BIOs.
    443  *
    444  * File BIOs are wrappers around a C |FILE| object.
    445  *
    446  * |BIO_flush| on a file BIO calls |fflush| on the wrapped stream.
    447  *
    448  * |BIO_reset| attempts to seek the file pointer to the start of file using
    449  * |fseek|.
    450  *
    451  * Setting the close flag causes |fclose| to be called on the stream when the
    452  * BIO is freed. */
    453 
    454 /* BIO_s_file returns a BIO_METHOD that wraps a |FILE|. */
    455 OPENSSL_EXPORT const BIO_METHOD *BIO_s_file(void);
    456 
    457 /* BIO_new_file creates a file BIO by opening |filename| with the given mode.
    458  * See the |fopen| manual page for details of the mode argument. */
    459 OPENSSL_EXPORT BIO *BIO_new_file(const char *filename, const char *mode);
    460 
    461 /* BIO_new_fp creates a new file BIO that wraps the given |FILE|. If
    462  * |close_flag| is |BIO_CLOSE|, then |fclose| will be called on |stream| when
    463  * the BIO is closed. */
    464 OPENSSL_EXPORT BIO *BIO_new_fp(FILE *stream, int close_flag);
    465 
    466 /* BIO_get_fp sets |*out_file| to the current |FILE| for |bio|. It returns one
    467  * on success and zero otherwise. */
    468 OPENSSL_EXPORT int BIO_get_fp(BIO *bio, FILE **out_file);
    469 
    470 /* BIO_set_fp sets the |FILE| for |bio|. If |close_flag| is |BIO_CLOSE| then
    471  * |fclose| will be called on |file| when |bio| is closed. It returns one on
    472  * success and zero otherwise. */
    473 OPENSSL_EXPORT int BIO_set_fp(BIO *bio, FILE *file, int close_flag);
    474 
    475 /* BIO_read_filename opens |filename| for reading and sets the result as the
    476  * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
    477  * will be closed when |bio| is freed. */
    478 OPENSSL_EXPORT int BIO_read_filename(BIO *bio, const char *filename);
    479 
    480 /* BIO_write_filename opens |filename| for writing and sets the result as the
    481  * |FILE| for |bio|. It returns one on success and zero otherwise. The |FILE|
    482  * will be closed when |bio| is freed. */
    483 OPENSSL_EXPORT int BIO_write_filename(BIO *bio, const char *filename);
    484 
    485 /* BIO_append_filename opens |filename| for appending and sets the result as
    486  * the |FILE| for |bio|. It returns one on success and zero otherwise. The
    487  * |FILE| will be closed when |bio| is freed. */
    488 OPENSSL_EXPORT int BIO_append_filename(BIO *bio, const char *filename);
    489 
    490 /* BIO_rw_filename opens |filename| for reading and writing and sets the result
    491  * as the |FILE| for |bio|. It returns one on success and zero otherwise. The
    492  * |FILE| will be closed when |bio| is freed. */
    493 OPENSSL_EXPORT int BIO_rw_filename(BIO *bio, const char *filename);
    494 
    495 
    496 /* Socket BIOs.
    497  *
    498  * Socket BIOs behave like file descriptor BIOs but, on Windows systems, wrap
    499  * the system's |recv| and |send| functions instead of |read| and |write|. On
    500  * Windows, file descriptors are provided by C runtime and are not
    501  * interchangeable with sockets.
    502  *
    503  * Socket BIOs may be used with |BIO_set_fd| and |BIO_get_fd|.
    504  *
    505  * TODO(davidben): Add separate APIs and fix the internals to use |SOCKET|s
    506  * around rather than rely on int casts. */
    507 
    508 OPENSSL_EXPORT const BIO_METHOD *BIO_s_socket(void);
    509 
    510 /* BIO_new_socket allocates and initialises a fresh BIO which will read and
    511  * write to the socket |fd|. If |close_flag| is |BIO_CLOSE| then closing the
    512  * BIO will close |fd|. It returns the fresh |BIO| or NULL on error. */
    513 OPENSSL_EXPORT BIO *BIO_new_socket(int fd, int close_flag);
    514 
    515 
    516 /* Connect BIOs.
    517  *
    518  * A connection BIO creates a network connection and transfers data over the
    519  * resulting socket. */
    520 
    521 OPENSSL_EXPORT const BIO_METHOD *BIO_s_connect(void);
    522 
    523 /* BIO_new_connect returns a BIO that connects to the given hostname and port.
    524  * The |host_and_optional_port| argument should be of the form
    525  * "www.example.com" or "www.example.com:443". If the port is omitted, it must
    526  * be provided with |BIO_set_conn_port|.
    527  *
    528  * It returns the new BIO on success, or NULL on error. */
    529 OPENSSL_EXPORT BIO *BIO_new_connect(const char *host_and_optional_port);
    530 
    531 /* BIO_set_conn_hostname sets |host_and_optional_port| as the hostname and
    532  * optional port that |bio| will connect to. If the port is omitted, it must be
    533  * provided with |BIO_set_conn_port|.
    534  *
    535  * It returns one on success and zero otherwise. */
    536 OPENSSL_EXPORT int BIO_set_conn_hostname(BIO *bio,
    537                                          const char *host_and_optional_port);
    538 
    539 /* BIO_set_conn_port sets |port_str| as the port or service name that |bio|
    540  * will connect to. It returns one on success and zero otherwise. */
    541 OPENSSL_EXPORT int BIO_set_conn_port(BIO *bio, const char *port_str);
    542 
    543 /* BIO_set_conn_int_port sets |*port| as the port that |bio| will connect to.
    544  * It returns one on success and zero otherwise. */
    545 OPENSSL_EXPORT int BIO_set_conn_int_port(BIO *bio, const int *port);
    546 
    547 /* BIO_set_nbio sets whether |bio| will use non-blocking I/O operations. It
    548  * returns one on success and zero otherwise. */
    549 OPENSSL_EXPORT int BIO_set_nbio(BIO *bio, int on);
    550 
    551 /* BIO_do_connect connects |bio| if it has not been connected yet. It returns
    552  * one on success and <= 0 otherwise. */
    553 OPENSSL_EXPORT int BIO_do_connect(BIO *bio);
    554 
    555 
    556 /* Datagram BIOs.
    557  *
    558  * TODO(fork): not implemented. */
    559 
    560 #define BIO_CTRL_DGRAM_QUERY_MTU 40 /* as kernel for current MTU */
    561 
    562 #define BIO_CTRL_DGRAM_SET_MTU 42 /* set cached value for  MTU. want to use
    563                                      this if asking the kernel fails */
    564 
    565 #define BIO_CTRL_DGRAM_MTU_EXCEEDED 43 /* check whether the MTU was exceed in
    566                                           the previous write operation. */
    567 
    568 /* BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT is unsupported as it is unused by consumers
    569  * and depends on |timeval|, which is not 2038-clean on all platforms. */
    570 
    571 #define BIO_CTRL_DGRAM_GET_PEER           46
    572 
    573 #define BIO_CTRL_DGRAM_GET_FALLBACK_MTU   47
    574 
    575 
    576 /* BIO Pairs.
    577  *
    578  * BIO pairs provide a "loopback" like system: a pair of BIOs where data
    579  * written to one can be read from the other and vice versa. */
    580 
    581 /* BIO_new_bio_pair sets |*out1| and |*out2| to two freshly created BIOs where
    582  * data written to one can be read from the other and vice versa. The
    583  * |writebuf1| argument gives the size of the buffer used in |*out1| and
    584  * |writebuf2| for |*out2|. It returns one on success and zero on error. */
    585 OPENSSL_EXPORT int BIO_new_bio_pair(BIO **out1, size_t writebuf1, BIO **out2,
    586                                     size_t writebuf2);
    587 
    588 /* BIO_ctrl_get_read_request returns the number of bytes that the other side of
    589  * |bio| tried (unsuccessfully) to read. */
    590 OPENSSL_EXPORT size_t BIO_ctrl_get_read_request(BIO *bio);
    591 
    592 /* BIO_ctrl_get_write_guarantee returns the number of bytes that |bio| (which
    593  * must have been returned by |BIO_new_bio_pair|) will accept on the next
    594  * |BIO_write| call. */
    595 OPENSSL_EXPORT size_t BIO_ctrl_get_write_guarantee(BIO *bio);
    596 
    597 /* BIO_shutdown_wr marks |bio| as closed, from the point of view of the other
    598  * side of the pair. Future |BIO_write| calls on |bio| will fail. It returns
    599  * one on success and zero otherwise. */
    600 OPENSSL_EXPORT int BIO_shutdown_wr(BIO *bio);
    601 
    602 
    603 /* BIO_NOCLOSE and |BIO_CLOSE| can be used as symbolic arguments when a "close
    604  * flag" is passed to a BIO function. */
    605 #define BIO_NOCLOSE 0
    606 #define BIO_CLOSE 1
    607 
    608 /* These are passed to the BIO callback */
    609 #define BIO_CB_FREE 0x01
    610 #define BIO_CB_READ 0x02
    611 #define BIO_CB_WRITE 0x03
    612 #define BIO_CB_PUTS 0x04
    613 #define BIO_CB_GETS 0x05
    614 #define BIO_CB_CTRL 0x06
    615 
    616 /* The callback is called before and after the underling operation,
    617  * The BIO_CB_RETURN flag indicates if it is after the call */
    618 #define BIO_CB_RETURN 0x80
    619 
    620 /* These are values of the |cmd| argument to |BIO_ctrl|. */
    621 #define BIO_CTRL_RESET		1  /* opt - rewind/zero etc */
    622 #define BIO_CTRL_EOF		2  /* opt - are we at the eof */
    623 #define BIO_CTRL_INFO		3  /* opt - extra tit-bits */
    624 #define BIO_CTRL_SET		4  /* man - set the 'IO' type */
    625 #define BIO_CTRL_GET		5  /* man - get the 'IO' type */
    626 #define BIO_CTRL_PUSH	6
    627 #define BIO_CTRL_POP	7
    628 #define BIO_CTRL_GET_CLOSE	8  /* man - set the 'close' on free */
    629 #define BIO_CTRL_SET_CLOSE	9  /* man - set the 'close' on free */
    630 #define BIO_CTRL_PENDING	10  /* opt - is their more data buffered */
    631 #define BIO_CTRL_FLUSH		11  /* opt - 'flush' buffered output */
    632 #define BIO_CTRL_WPENDING	13  /* opt - number of bytes still to write */
    633 /* callback is int cb(BIO *bio,state,ret); */
    634 #define BIO_CTRL_SET_CALLBACK	14  /* opt - set callback function */
    635 #define BIO_CTRL_GET_CALLBACK	15  /* opt - set callback function */
    636 #define BIO_CTRL_SET_FILENAME	30	/* BIO_s_file special */
    637 
    638 /* BIO_CTRL_DUP is never used, but exists to allow code to compile more
    639  * easily. */
    640 #define BIO_CTRL_DUP	12
    641 
    642 
    643 /* Deprecated functions. */
    644 
    645 /* BIO_f_base64 returns a filter |BIO| that base64-encodes data written into
    646  * it, and decodes data read from it. |BIO_gets| is not supported. Call
    647  * |BIO_flush| when done writing, to signal that no more data are to be
    648  * encoded. The flag |BIO_FLAGS_BASE64_NO_NL| may be set to encode all the data
    649  * on one line. */
    650 OPENSSL_EXPORT const BIO_METHOD *BIO_f_base64(void);
    651 
    652 OPENSSL_EXPORT void BIO_set_retry_special(BIO *bio);
    653 
    654 /* BIO_set_write_buffer_size returns zero. */
    655 OPENSSL_EXPORT int BIO_set_write_buffer_size(BIO *bio, int buffer_size);
    656 
    657 
    658 /* Private functions */
    659 
    660 #define BIO_FLAGS_READ 0x01
    661 #define BIO_FLAGS_WRITE 0x02
    662 #define BIO_FLAGS_IO_SPECIAL 0x04
    663 #define BIO_FLAGS_RWS (BIO_FLAGS_READ | BIO_FLAGS_WRITE | BIO_FLAGS_IO_SPECIAL)
    664 #define BIO_FLAGS_SHOULD_RETRY 0x08
    665 #define BIO_FLAGS_BASE64_NO_NL 0x100
    666 /* This is used with memory BIOs: it means we shouldn't free up or change the
    667  * data in any way. */
    668 #define BIO_FLAGS_MEM_RDONLY 0x200
    669 
    670 /* These are the 'types' of BIOs */
    671 #define BIO_TYPE_NONE 0
    672 #define BIO_TYPE_MEM (1 | 0x0400)
    673 #define BIO_TYPE_FILE (2 | 0x0400)
    674 #define BIO_TYPE_FD (4 | 0x0400 | 0x0100)
    675 #define BIO_TYPE_SOCKET (5 | 0x0400 | 0x0100)
    676 #define BIO_TYPE_NULL (6 | 0x0400)
    677 #define BIO_TYPE_SSL (7 | 0x0200)
    678 #define BIO_TYPE_MD (8 | 0x0200)                /* passive filter */
    679 #define BIO_TYPE_BUFFER (9 | 0x0200)            /* filter */
    680 #define BIO_TYPE_CIPHER (10 | 0x0200)           /* filter */
    681 #define BIO_TYPE_BASE64 (11 | 0x0200)           /* filter */
    682 #define BIO_TYPE_CONNECT (12 | 0x0400 | 0x0100) /* socket - connect */
    683 #define BIO_TYPE_ACCEPT (13 | 0x0400 | 0x0100)  /* socket for accept */
    684 #define BIO_TYPE_PROXY_CLIENT (14 | 0x0200)     /* client proxy BIO */
    685 #define BIO_TYPE_PROXY_SERVER (15 | 0x0200)     /* server proxy BIO */
    686 #define BIO_TYPE_NBIO_TEST (16 | 0x0200)        /* server proxy BIO */
    687 #define BIO_TYPE_NULL_FILTER (17 | 0x0200)
    688 #define BIO_TYPE_BER (18 | 0x0200)        /* BER -> bin filter */
    689 #define BIO_TYPE_BIO (19 | 0x0400)        /* (half a) BIO pair */
    690 #define BIO_TYPE_LINEBUFFER (20 | 0x0200) /* filter */
    691 #define BIO_TYPE_DGRAM (21 | 0x0400 | 0x0100)
    692 #define BIO_TYPE_ASN1 (22 | 0x0200) /* filter */
    693 #define BIO_TYPE_COMP (23 | 0x0200) /* filter */
    694 
    695 #define BIO_TYPE_DESCRIPTOR 0x0100 /* socket, fd, connect or accept */
    696 #define BIO_TYPE_FILTER 0x0200
    697 #define BIO_TYPE_SOURCE_SINK 0x0400
    698 
    699 struct bio_method_st {
    700   int type;
    701   const char *name;
    702   int (*bwrite)(BIO *, const char *, int);
    703   int (*bread)(BIO *, char *, int);
    704   /* TODO(fork): remove bputs. */
    705   int (*bputs)(BIO *, const char *);
    706   int (*bgets)(BIO *, char *, int);
    707   long (*ctrl)(BIO *, int, long, void *);
    708   int (*create)(BIO *);
    709   int (*destroy)(BIO *);
    710   long (*callback_ctrl)(BIO *, int, bio_info_cb);
    711 };
    712 
    713 struct bio_st {
    714   const BIO_METHOD *method;
    715   /* bio, mode, argp, argi, argl, ret */
    716   long (*callback)(BIO *, int, const char *, int, long, long);
    717   char *cb_arg; /* first argument for the callback */
    718 
    719   /* init is non-zero if this |BIO| has been initialised. */
    720   int init;
    721   /* shutdown is often used by specific |BIO_METHOD|s to determine whether
    722    * they own some underlying resource. This flag can often by controlled by
    723    * |BIO_set_close|. For example, whether an fd BIO closes the underlying fd
    724    * when it, itself, is closed. */
    725   int shutdown;
    726   int flags;
    727   int retry_reason;
    728   /* num is a BIO-specific value. For example, in fd BIOs it's used to store a
    729    * file descriptor. */
    730   int num;
    731   CRYPTO_refcount_t references;
    732   void *ptr;
    733   /* next_bio points to the next |BIO| in a chain. This |BIO| owns a reference
    734    * to |next_bio|. */
    735   BIO *next_bio; /* used by filter BIOs */
    736   size_t num_read, num_write;
    737 };
    738 
    739 #define BIO_C_SET_CONNECT			100
    740 #define BIO_C_DO_STATE_MACHINE			101
    741 #define BIO_C_SET_NBIO				102
    742 #define BIO_C_SET_PROXY_PARAM			103
    743 #define BIO_C_SET_FD				104
    744 #define BIO_C_GET_FD				105
    745 #define BIO_C_SET_FILE_PTR			106
    746 #define BIO_C_GET_FILE_PTR			107
    747 #define BIO_C_SET_FILENAME			108
    748 #define BIO_C_SET_SSL				109
    749 #define BIO_C_GET_SSL				110
    750 #define BIO_C_SET_MD				111
    751 #define BIO_C_GET_MD				112
    752 #define BIO_C_GET_CIPHER_STATUS			113
    753 #define BIO_C_SET_BUF_MEM			114
    754 #define BIO_C_GET_BUF_MEM_PTR			115
    755 #define BIO_C_GET_BUFF_NUM_LINES		116
    756 #define BIO_C_SET_BUFF_SIZE			117
    757 #define BIO_C_SET_ACCEPT			118
    758 #define BIO_C_SSL_MODE				119
    759 #define BIO_C_GET_MD_CTX			120
    760 #define BIO_C_GET_PROXY_PARAM			121
    761 #define BIO_C_SET_BUFF_READ_DATA		122 /* data to read first */
    762 #define BIO_C_GET_ACCEPT			124
    763 #define BIO_C_SET_SSL_RENEGOTIATE_BYTES		125
    764 #define BIO_C_GET_SSL_NUM_RENEGOTIATES		126
    765 #define BIO_C_SET_SSL_RENEGOTIATE_TIMEOUT	127
    766 #define BIO_C_FILE_SEEK				128
    767 #define BIO_C_GET_CIPHER_CTX			129
    768 #define BIO_C_SET_BUF_MEM_EOF_RETURN		130/*return end of input value*/
    769 #define BIO_C_SET_BIND_MODE			131
    770 #define BIO_C_GET_BIND_MODE			132
    771 #define BIO_C_FILE_TELL				133
    772 #define BIO_C_GET_SOCKS				134
    773 #define BIO_C_SET_SOCKS				135
    774 
    775 #define BIO_C_SET_WRITE_BUF_SIZE		136/* for BIO_s_bio */
    776 #define BIO_C_GET_WRITE_BUF_SIZE		137
    777 #define BIO_C_GET_WRITE_GUARANTEE		140
    778 #define BIO_C_GET_READ_REQUEST			141
    779 #define BIO_C_SHUTDOWN_WR			142
    780 #define BIO_C_NREAD0				143
    781 #define BIO_C_NREAD				144
    782 #define BIO_C_NWRITE0				145
    783 #define BIO_C_NWRITE				146
    784 #define BIO_C_RESET_READ_REQUEST		147
    785 #define BIO_C_SET_MD_CTX			148
    786 
    787 #define BIO_C_SET_PREFIX			149
    788 #define BIO_C_GET_PREFIX			150
    789 #define BIO_C_SET_SUFFIX			151
    790 #define BIO_C_GET_SUFFIX			152
    791 
    792 #define BIO_C_SET_EX_ARG			153
    793 #define BIO_C_GET_EX_ARG			154
    794 
    795 
    796 #if defined(__cplusplus)
    797 }  /* extern C */
    798 
    799 extern "C++" {
    800 
    801 namespace bssl {
    802 
    803 BORINGSSL_MAKE_DELETER(BIO, BIO_free)
    804 
    805 }  // namespace bssl
    806 
    807 }  /* extern C++ */
    808 
    809 #endif
    810 
    811 #define BIO_R_BAD_FOPEN_MODE 100
    812 #define BIO_R_BROKEN_PIPE 101
    813 #define BIO_R_CONNECT_ERROR 102
    814 #define BIO_R_ERROR_SETTING_NBIO 103
    815 #define BIO_R_INVALID_ARGUMENT 104
    816 #define BIO_R_IN_USE 105
    817 #define BIO_R_KEEPALIVE 106
    818 #define BIO_R_NBIO_CONNECT_ERROR 107
    819 #define BIO_R_NO_HOSTNAME_SPECIFIED 108
    820 #define BIO_R_NO_PORT_SPECIFIED 109
    821 #define BIO_R_NO_SUCH_FILE 110
    822 #define BIO_R_NULL_PARAMETER 111
    823 #define BIO_R_SYS_LIB 112
    824 #define BIO_R_UNABLE_TO_CREATE_SOCKET 113
    825 #define BIO_R_UNINITIALIZED 114
    826 #define BIO_R_UNSUPPORTED_METHOD 115
    827 #define BIO_R_WRITE_TO_READ_ONLY_BIO 116
    828 
    829 #endif  /* OPENSSL_HEADER_BIO_H */
    830