BIO_find_type(3)                    OpenSSL                   BIO_find_type(3)



NNAAMMEE
       BIO_find_type, BIO_next, BIO_method_type - BIO chain traversal

SSYYNNOOPPSSIISS
        #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

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

       Note: not all the BBIIOO__TTYYPPEE__** types above have corresponding BIO imple-
       mentations.

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

       _B_I_O___m_e_t_h_o_d___t_y_p_e_(_) returns the type of a BIO.

RREETTUURRNN VVAALLUUEESS
       _B_I_O___f_i_n_d___t_y_p_e_(_) returns a matching BIO or NULL for no match.

       _B_I_O___n_e_x_t_(_) returns the next BIO in a chain.

       _B_I_O___m_e_t_h_o_d___t_y_p_e_(_) returns the type of the BIO bb.

NNOOTTEESS
       _B_I_O___n_e_x_t_(_) was added to OpenSSL 0.9.6 to provide a 'clean' way to tra-
       verse a BIO chain or find multiple matches using _B_I_O___f_i_n_d___t_y_p_e_(_). Pre-
       vious versions had to use:

        next = bio->next_bio;

BBUUGGSS
       _B_I_O___f_i_n_d___t_y_p_e_(_) in OpenSSL 0.9.5a and earlier could not be safely
       passed a NULL pointer for the bb argument.

EEXXAAMMPPLLEE
       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);

SSEEEE AALLSSOO
       TBA



1.0.2u                            2019-12-20                  BIO_find_type(3)