BIO_METH_NEW(3)            Library Functions Manual            BIO_METH_NEW(3)

NAME
     BIO_get_new_index, BIO_meth_new, BIO_meth_free, BIO_meth_get_write,
     BIO_meth_set_write, BIO_meth_get_read, BIO_meth_set_read,
     BIO_meth_get_puts, BIO_meth_set_puts, BIO_meth_get_gets,
     BIO_meth_set_gets, BIO_meth_get_ctrl, BIO_meth_set_ctrl,
     BIO_meth_get_create, BIO_meth_set_create, BIO_meth_get_destroy,
     BIO_meth_set_destroy, BIO_meth_get_callback_ctrl,
     BIO_meth_set_callback_ctrl - manipulate BIO_METHOD structures

SYNOPSIS
     #include <openssl/bio.h>

     int
     BIO_get_new_index(void);

     BIO_METHOD *
     BIO_meth_new(int type, const char *name);

     void
     BIO_meth_free(BIO_METHOD *biom);

     int
     (*BIO_meth_get_write(const BIO_METHOD *biom))(BIO *, const char *, int);

     int
     BIO_meth_set_write(BIO_METHOD *biom,
         int (*write)(BIO *, const char *, int));

     int
     (*BIO_meth_get_read(const BIO_METHOD *biom))(BIO *, char *, int);

     int
     BIO_meth_set_read(BIO_METHOD *biom, int (*read)(BIO *, char *, int));

     int
     (*BIO_meth_get_puts(const BIO_METHOD *biom))(BIO *, const char *);

     int
     BIO_meth_set_puts(BIO_METHOD *biom, int (*puts)(BIO *, const char *));

     int
     (*BIO_meth_get_gets(const BIO_METHOD *biom))(BIO *, char *, int);

     int
     BIO_meth_set_gets(BIO_METHOD *biom, int (*gets)(BIO *, char *, int));

     long
     (*BIO_meth_get_ctrl(const BIO_METHOD *biom))(BIO *, int, long, void *);

     int
     BIO_meth_set_ctrl(BIO_METHOD *biom,
         long (*ctrl)(BIO *, int, long, void *));

     int
     (*BIO_meth_get_create(const BIO_METHOD *biom))(BIO *);

     int
     BIO_meth_set_create(BIO_METHOD *biom, int (*create)(BIO *));

     int
     (*BIO_meth_get_destroy(const BIO_METHOD *biom))(BIO *);

     int
     BIO_meth_set_destroy(BIO_METHOD *biom, int (*destroy)(BIO *));

     long
     (*BIO_meth_get_callback_ctrl(const BIO_METHOD *biom))(BIO *, int,
         BIO_info_cb *);

     int
     BIO_meth_set_callback_ctrl(BIO_METHOD *biom,
         long (*callback_ctrl)(BIO *, int, BIO_info_cb *));

DESCRIPTION
     The BIO_METHOD structure stores function pointers implementing a BIO
     type.  See BIO_new(3) for more information about BIO objects.

     BIO_meth_new() creates a new BIO_METHOD structure.  It requires a unique
     integer type; use BIO_get_new_index() to get the value for type.
     Currently, the user can only create up to 127 different BIO types, and
     type is limited to the range 129-255.  The name pointer is stored in the
     structure and will not be freed by BIO_meth_free().

     The standard BIO types are listed in <openssl/bio.h>.  Some examples
     include BIO_TYPE_BUFFER and BIO_TYPE_CIPHER.  The type of filter BIOs
     should have the BIO_TYPE_FILTER bit set.  Source/sink BIOs should have
     the BIO_TYPE_SOURCE_SINK bit set.  File descriptor based BIOs (e.g.
     socket, fd, connect, accept etc.) should additionally have the
     BIO_TYPE_DESCRIPTOR bit set.  See BIO_find_type(3) for more information.

     BIO_meth_free() is an alias for free(3).

     BIO_meth_get_write(), BIO_meth_set_write(), BIO_meth_get_read(), and
     BIO_meth_set_read() get and set the functions write and read used for
     writing and reading arbitrary length data to and from the BIO.  These
     functions are called from BIO_write(3) and BIO_read(3), respectively.
     The parameters and return values of write and read have the same meaning
     as for BIO_write(3) and BIO_read(3).

     BIO_meth_get_puts() and BIO_meth_set_puts() get and set the function puts
     used for writing a NUL-terminated string to the BIO.  This function is
     called from BIO_puts(3).  The parameters and the return value of puts
     have the same meaning as for BIO_puts(3).

     BIO_meth_get_gets() and BIO_meth_set_gets() get and set the function gets
     used for reading a line of data from the BIO.  This function is called
     from BIO_gets(3).  The parameters and the return value of gets have the
     same meaning as for BIO_gets(3).

     BIO_meth_get_ctrl() and BIO_meth_set_ctrl() get and set the function ctrl
     used for processing control messages in the BIO.  This function is called
     from BIO_ctrl(3).  The parameters and return value of ctrl have the same
     meaning as for BIO_ctrl(3).

     BIO_meth_get_create() and BIO_meth_set_create() get and set a function
     create used while initializing a new instance of the BIO.  This function
     is called from BIO_new(3).  The BIO_new(3) function allocates the memory
     for the new BIO, and a pointer to this newly allocated structure is
     passed as the parameter to create.

     BIO_meth_get_destroy() and BIO_meth_set_destroy() get and set a function
     destroy used while destroying an instance of a BIO.  This function is
     called from BIO_free(3).  A pointer to the BIO to be destroyed is passed
     as the parameter.  The destroy function is intended to perform clean-up
     specific to the BIO type.  The memory for the BIO itself must not be
     freed by this function.

     BIO_meth_get_callback_ctrl() and BIO_meth_set_callback_ctrl() get and set
     the function callback_ctrl used for processing callback control messages
     in the BIO.  This function is called from BIO_callback_ctrl(3).  The
     parameters and return value of callback_ctrl have the same meaning as for
     BIO_callback_ctrl(3).

RETURN VALUES
     BIO_get_new_index() returns the new BIO type value or -1 if an error
     occurs.

     BIO_meth_new() returns the new BIO_METHOD structure or NULL if an error
     occurs.

     The BIO_meth_set_*() functions return 1 on success or 0 on error.
     Currently, they cannot fail.

     The BIO_meth_get_*() functions return function pointers.

SEE ALSO
     BIO_ctrl(3), BIO_find_type(3), BIO_new(3), BIO_read(3)

HISTORY
     These functions first appeared in OpenSSL 1.1.0 and have been available
     since OpenBSD 6.3.

Linux 6.8.2-arch2-1              July 9, 2018              Linux 6.8.2-arch2-1