BIO_find

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HP Open Source Security for OpenVMS Volume 2:...

CRYPTO Application Programming Interface (API)...

BIO_f_ssl

BIO_new

BIO_find_type

Description
Notes
Example

Return Values
Restrictions
See Also

NAME

BIO_find_type, BIO_next - BIO chain traversal

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;

Restrictions

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);