BIO_find_type 3 2001-04-11 0.9.9-dev OpenSSL

NAME

BIO_find_type, BIO_next - BIO chain traversal

LIBRARY

libcrypto, -lcrypto

SYNOPSIS


 #include 


 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 _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 implementations.

_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.

RETURN VALUES

_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.

NOTES

_B_I_O___n_e_x_t_(_) was added to OpenSSL 0.9.6 to provide a 'clean' way to traverse a BIO chain or find multiple matches using _B_I_O___f_i_n_d___t_y_p_e_(_). Previous versions had to use:


 next = bio->next_bio;

BUGS

_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.

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