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 imple‐
mentations.
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 VALUESBIO_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.
NOTESBIO_next() was added to OpenSSL 0.9.6 to provide a 'clean' way to tra‐
verse a BIO chain or find multiple matches using BIO_find_type(). Pre‐
vious versions had to use:
next = bio->next_bio;
BUGSBIO_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
0.9.8k 2009-05-20 BIO_find_type(3)
