xref: /openbsd-src/lib/libcrypto/man/BIO_get_data.3 (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1.\" $OpenBSD: BIO_get_data.3,v 1.3 2018/03/23 23:18:17 schwarze Exp $
2.\" selective merge up to: OpenSSL e90fc053 Jul 15 09:39:45 2017 -0400
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68.Dd $Mdocdate: March 23 2018 $
69.Dt BIO_GET_DATA 3
70.Os
71.Sh NAME
72.Nm BIO_set_data ,
73.Nm BIO_get_data ,
74.Nm BIO_set_init ,
75.Nm BIO_set_shutdown ,
76.Nm BIO_get_shutdown
77.Nd manage BIO state information
78.Sh SYNOPSIS
79.In openssl/bio.h
80.Ft void
81.Fo BIO_set_data
82.Fa "BIO *a"
83.Fa "void *ptr"
84.Fc
85.Ft void *
86.Fo BIO_get_data
87.Fa "BIO *a"
88.Fc
89.Ft void
90.Fo BIO_set_init
91.Fa "BIO *a"
92.Fa "int init"
93.Fc
94.Ft void
95.Fo BIO_set_shutdown
96.Fa "BIO *a"
97.Fa "int shutdown"
98.Fc
99.Ft int
100.Fo BIO_get_shutdown
101.Fa "BIO *a"
102.Fc
103.Sh DESCRIPTION
104These functions are mainly useful when implementing a custom BIO.
105.Pp
106The
107.Fn BIO_set_data
108function associates the custom data pointed to by
109.Fa ptr
110with the
111.Fa "BIO a" .
112This data can subsequently be retrieved via a call to
113.Fn BIO_get_data .
114This can be used by custom BIOs for storing implementation specific
115information.
116.Pp
117The
118.Fn BIO_set_init
119function sets the
120.Fa init
121flag in
122.Fa a
123to the specified value.
124A non-zero value indicates that initialisation is complete,
125whilst zero indicates that it is not.
126Often initialisation will complete
127during initial construction of the BIO.
128For some BIOs however, initialisation may not be complete until
129additional steps have been taken, for example through calling custom
130ctrls.
131.Pp
132The
133.Fn BIO_set_shutdown
134and
135.Fn BIO_get_shutdown
136functions are low-level interfaces to forcefully set and get the
137.Fa shutdown
138flag of
139.Fa a ,
140circumventing type-dependent sanity checks,
141exclusively intended for implementing a new BIO type.
142The
143.Fa shutdown
144argument must be either
145.Dv BIO_CLOSE
146or
147.Dv BIO_NOCLOSE .
148When merely using a
149.Vt BIO
150object, call
151.Xr BIO_set_close 3
152and
153.Xr BIO_get_close 3
154instead.
155.Sh RETURN VALUES
156.Fn BIO_get_data
157returns a pointer to the implementation specific custom data associated
158with
159.Fa a ,
160or
161.Dv NULL
162if none is set.
163.Pp
164.Fn BIO_get_shutdown
165returns the value previously set with
166.Fn BIO_set_shutdown
167or with
168.Xr BIO_set_close 3 .
169.Sh SEE ALSO
170.Xr BIO_meth_new 3 ,
171.Xr BIO_new 3 ,
172.Xr BIO_set_close 3
173.Sh HISTORY
174These functions first appeared in OpenSSL 1.1.0
175and have been available since
176.Ox 6.3 .
177