1=pod
2
3=head1 NAME
4
5CRYPTO_set_ex_data, CRYPTO_get_ex_data - internal application specific data functions
6
7=head1 SYNOPSIS
8
9 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *r, int idx, void *arg);
10
11 void *CRYPTO_get_ex_data(CRYPTO_EX_DATA *r, int idx);
12
13=head1 DESCRIPTION
14
15Several OpenSSL structures can have application specific data attached to them.
16These functions are used internally by OpenSSL to manipulate application
17specific data attached to a specific structure.
18
19These functions should only be used by applications to manipulate
20B<CRYPTO_EX_DATA> structures passed to the B<new_func()>, B<free_func()> and
21B<dup_func()> callbacks: as passed to B<RSA_get_ex_new_index()> for example.
22
23B<CRYPTO_set_ex_data()> is used to set application specific data, the data is
24supplied in the B<arg> parameter and its precise meaning is up to the
25application.
26
27B<CRYPTO_get_ex_data()> is used to retrieve application specific data. The data
28is returned to the application, this will be the same value as supplied to
29a previous B<CRYPTO_set_ex_data()> call.
30
31=head1 RETURN VALUES
32
33B<CRYPTO_set_ex_data()> returns 1 on success or 0 on failure.
34
35B<CRYPTO_get_ex_data()> returns the application data or 0 on failure. 0 may also
36be valid application data but currently it can only fail if given an invalid B<idx>
37parameter.
38
39On failure an error code can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>.
40
41=head1 SEE ALSO
42
43L<RSA_get_ex_new_index(3)|RSA_get_ex_new_index(3)>,
44L<DSA_get_ex_new_index(3)|DSA_get_ex_new_index(3)>,
45L<DH_get_ex_new_index(3)|DH_get_ex_new_index(3)>
46
47=head1 HISTORY
48
49CRYPTO_set_ex_data() and CRYPTO_get_ex_data() have been available since SSLeay 0.9.0.
50
51=cut
52