BIO_find_type(3ssl)

1BIO_find_type(3)                    OpenSSL                   BIO_find_type(3)
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NAME

6       BIO_find_type, BIO_next - BIO chain traversal
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SYNOPSIS

9        #include <openssl/bio.h>
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11        BIO *  BIO_find_type(BIO *b,int bio_type);
12        BIO *  BIO_next(BIO *b);
13
14        #define BIO_method_type(b)             ((b)->method->type)
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16        #define BIO_TYPE_NONE          0
17        #define BIO_TYPE_MEM           (1⎪0x0400)
18        #define BIO_TYPE_FILE          (2⎪0x0400)
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20        #define BIO_TYPE_FD            (4⎪0x0400⎪0x0100)
21        #define BIO_TYPE_SOCKET                (5⎪0x0400⎪0x0100)
22        #define BIO_TYPE_NULL          (6⎪0x0400)
23        #define BIO_TYPE_SSL           (7⎪0x0200)
24        #define BIO_TYPE_MD            (8⎪0x0200)
25        #define BIO_TYPE_BUFFER                (9⎪0x0200)
26        #define BIO_TYPE_CIPHER                (10⎪0x0200)
27        #define BIO_TYPE_BASE64                (11⎪0x0200)
28        #define BIO_TYPE_CONNECT       (12⎪0x0400⎪0x0100)
29        #define BIO_TYPE_ACCEPT                (13⎪0x0400⎪0x0100)
30        #define BIO_TYPE_PROXY_CLIENT  (14⎪0x0200)
31        #define BIO_TYPE_PROXY_SERVER  (15⎪0x0200)
32        #define BIO_TYPE_NBIO_TEST     (16⎪0x0200)
33        #define BIO_TYPE_NULL_FILTER   (17⎪0x0200)
34        #define BIO_TYPE_BER           (18⎪0x0200)
35        #define BIO_TYPE_BIO           (19⎪0x0400)
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37        #define BIO_TYPE_DESCRIPTOR    0x0100
38        #define BIO_TYPE_FILTER                0x0200
39        #define BIO_TYPE_SOURCE_SINK   0x0400
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DESCRIPTION

42       The BIO_find_type() searches for a BIO of a given type in a chain,
43       starting at BIO b. If type is a specific type (such as BIO_TYPE_MEM)
44       then a search is made for a BIO of that type. If type is a general type
45       (such as BIO_TYPE_SOURCE_SINK) then the next matching BIO of the given
46       general type is searched for. BIO_find_type() returns the next matching
47       BIO or NULL if none is found.
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49       Note: not all the BIO_TYPE_* types above have corresponding BIO imple‐
50       mentations.
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52       BIO_next() returns the next BIO in a chain. It can be used to traverse
53       all BIOs in a chain or used in conjunction with BIO_find_type() to find
54       all BIOs of a certain type.
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56       BIO_method_type() returns the type of a BIO.
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RETURN VALUES

59       BIO_find_type() returns a matching BIO or NULL for no match.
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61       BIO_next() returns the next BIO in a chain.
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63       BIO_method_type() returns the type of the BIO b.
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NOTES

66       BIO_next() was added to OpenSSL 0.9.6 to provide a 'clean' way to tra‐
67       verse a BIO chain or find multiple matches using BIO_find_type(). Pre‐
68       vious versions had to use:
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70        next = bio->next_bio;
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BUGS

73       BIO_find_type() in OpenSSL 0.9.5a and earlier could not be safely
74       passed a NULL pointer for the b argument.
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EXAMPLE

77       Traverse a chain looking for digest BIOs:
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79        BIO *btmp;
80        btmp = in_bio; /* in_bio is chain to search through */
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82        do {
83               btmp = BIO_find_type(btmp, BIO_TYPE_MD);
84               if(btmp == NULL) break; /* Not found */
85               /* btmp is a digest BIO, do something with it ...*/
86               ...
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88               btmp = BIO_next(btmp);
89        } while(btmp);
90