NAME
BIO_find_type,
BIO_next, BIO_method_type
— BIO chain traversal
SYNOPSIS
#include
<openssl/bio.h>
BIO *
BIO_find_type(BIO *b,
int bio_type);
BIO *
BIO_next(BIO *b);
int
BIO_method_type(const BIO
*b);
#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 functionBIO_find_type()
searches for a BIO of a given type in a chain, starting at BIO
b. If bio_type is a specific type
(such as BIO_TYPE_MEM), then a search is made for a
BIO of that type. If bio_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.
EXAMPLES
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
HISTORY
BIO_method_type() first appeared in SSLeay
0.6.0. BIO_find_type() first appeared in SSLeay
0.6.6. Both functions have been available since OpenBSD
2.4.
BIO_next() first appeared in OpenSSL 0.9.6
and has been available since OpenBSD 2.9.
BUGS
BIO_find_type() in OpenSSL 0.9.5a and
earlier could not be safely passed a NULL pointer
for the b argument.