NAME
BIO_find_type,
BIO_next, BIO_method_type,
BIO_method_name —
BIO chain traversal
SYNOPSIS
#include
<openssl/bio.h>
BIO *
BIO_find_type(BIO *bio,
int type);
BIO *
BIO_next(BIO *bio);
int
BIO_method_type(const BIO
*bio);
const char *
BIO_method_name(const BIO
*bio);
#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_LINEBUFFER (20|0x0200)
#define BIO_TYPE_DGRAM (21|0x0400|0x0100)
#define BIO_TYPE_ASN1 (22|0x0200)
#define BIO_TYPE_COMP (23|0x0200)
#define BIO_TYPE_DESCRIPTOR 0x0100
#define BIO_TYPE_FILTER 0x0200
#define BIO_TYPE_SOURCE_SINK 0x0400
#define BIO_TYPE_START 128
DESCRIPTION
BIO_find_type()
searches for a BIO matching the given type in the
chain starting at bio. If the least significant byte
of the type argument is non-zero, only exact matches
of the type are accepted. Otherwise, a match only
requires that any of the bits set in the type argument
is also set in the candidate BIO.
Not all the BIO_TYPE_* types shown above
have corresponding BIO implementations.
Types with a least significant byte in the range from 0 to
BIO_TYPE_START, inclusive, are reserved for BIO
types built into the library. Types with a least significant byte greater
than BIO_TYPE_START are available for user-defined
BIO types; see
BIO_get_new_index(3) for details.
BIO_next()
returns the next BIO in the chain after bio. This
function can be used to traverse all BIOs in a chain or in conjunction with
BIO_find_type() to find all BIOs of a certain
type.
BIO_method_type()
returns the type of the given bio.
BIO_method_name()
returns an ASCII string representing the type of the
bio.
RETURN VALUES
BIO_find_type() returns the next matching
BIO or NULL if bio is a
NULL pointer or if no matching BIO is found.
BIO_next() returns the next BIO or
NULL if bio is a
NULL pointer or points to the last BIO in a
chain.
BIO_method_type() returns one of the
BIO_TYPE_* constants.
BIO_method_name() returns an internal
pointer to a string.
EXAMPLES
Traverse a chain looking for digest BIOs:
BIO *btmp;
btmp = in_bio; /* in_bio is the chain to search through */
while (btmp != NULL) {
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);
}
SEE ALSO
HISTORY
BIO_method_type() and
BIO_method_name() first appeared in SSLeay 0.6.0.
BIO_find_type() first appeared in SSLeay 0.6.6.
These 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.