BIO_find_type(3)						      OpenSSL							  BIO_find_type(3)

NAME

       BIO_find_type, BIO_next - BIO chain traversal

SYNOPSIS

	#include <openssl/bio.h>

	BIO *  BIO_find_type(BIO *b,int bio_type);
	BIO *  BIO_next(BIO *b);

	#define BIO_method_type(b)	       ((b)->method->type)

	#define BIO_TYPE_NONE	       0
	#define BIO_TYPE_MEM	       (1|0x0400)
	#define BIO_TYPE_FILE	       (2|0x0400)

	#define BIO_TYPE_FD	       (4|0x0400|0x0100)
	#define BIO_TYPE_SOCKET 	       (5|0x0400|0x0100)
	#define BIO_TYPE_NULL	       (6|0x0400)
	#define BIO_TYPE_SSL	       (7|0x0200)
	#define BIO_TYPE_MD	       (8|0x0200)
	#define BIO_TYPE_BUFFER 	       (9|0x0200)
	#define BIO_TYPE_CIPHER 	       (10|0x0200)
	#define BIO_TYPE_BASE64 	       (11|0x0200)
	#define BIO_TYPE_CONNECT       (12|0x0400|0x0100)
	#define BIO_TYPE_ACCEPT 	       (13|0x0400|0x0100)
	#define BIO_TYPE_PROXY_CLIENT  (14|0x0200)
	#define BIO_TYPE_PROXY_SERVER  (15|0x0200)
	#define BIO_TYPE_NBIO_TEST     (16|0x0200)
	#define BIO_TYPE_NULL_FILTER   (17|0x0200)
	#define BIO_TYPE_BER	       (18|0x0200)
	#define BIO_TYPE_BIO	       (19|0x0400)

	#define BIO_TYPE_DESCRIPTOR    0x0100
	#define BIO_TYPE_FILTER 	       0x0200
	#define BIO_TYPE_SOURCE_SINK   0x0400

DESCRIPTION

       The BIO_find_type() searches for a BIO of a given type in a chain, starting at BIO b. If type is a specific type (such as BIO_TYPE_MEM)
       then a search is made for a BIO of that type. If type is a general type (such as BIO_TYPE_SOURCE_SINK) then the next matching BIO of the
       given general type is searched for. BIO_find_type() returns the next matching BIO or NULL if none is found.

       Note: not all the BIO_TYPE_* types above have corresponding BIO implementations.

       BIO_next() returns the next BIO in a chain. It can be used to traverse all BIOs in a chain or used in conjunction with BIO_find_type() to
       find all BIOs of a certain type.

       BIO_method_type() returns the type of a BIO.

RETURN VALUES

       BIO_find_type() returns a matching BIO or NULL for no match.

       BIO_next() returns the next BIO in a chain.

       BIO_method_type() returns the type of the BIO b.

NOTES

       BIO_next() was added to OpenSSL 0.9.6 to provide a 'clean' way to traverse a BIO chain or find multiple matches using BIO_find_type().
       Previous versions had to use:

	next = bio->next_bio;

BUGS

       BIO_find_type() in OpenSSL 0.9.5a and earlier could not be safely passed a NULL pointer for the b argument.

EXAMPLE

       Traverse a chain looking for digest BIOs:

	BIO *btmp;
	btmp = in_bio; /* in_bio is chain to search through */

	do {
	       btmp = BIO_find_type(btmp, BIO_TYPE_MD);
	       if(btmp == NULL) break; /* Not found */
	       /* btmp is a digest BIO, do something with it ...*/
	       ...

	       btmp = BIO_next(btmp);
	} while(btmp);

SEE ALSO

       TBA

50								    2013-03-05							  BIO_find_type(3)