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 #include <openssl/crypto.h>
10
11 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *r, int idx, void *arg);
12
13 void *CRYPTO_get_ex_data(CRYPTO_EX_DATA *r, int idx);
14
15=head1 DESCRIPTION
16
17Several OpenSSL structures can have application specific data attached to them.
18These functions are used internally by OpenSSL to manipulate application
19specific data attached to a specific structure.
20
21These functions should only be used by applications to manipulate
22B<CRYPTO_EX_DATA> structures passed to the B<new_func()>, B<free_func()> and
23B<dup_func()> callbacks: as passed to B<RSA_get_ex_new_index()> for example.
24
25B<CRYPTO_set_ex_data()> is used to set application specific data, the data is
26supplied in the B<arg> parameter and its precise meaning is up to the
27application.
28
29B<CRYPTO_get_ex_data()> is used to retrieve application specific data. The data
30is returned to the application, this will be the same value as supplied to
31a previous B<CRYPTO_set_ex_data()> call.
32
33=head1 RETURN VALUES
34
35B<CRYPTO_set_ex_data()> returns 1 on success or 0 on failure.
36
37B<CRYPTO_get_ex_data()> returns the application data or 0 on failure. 0 may also
38be valid application data but currently it can only fail if given an invalid B<idx>
39parameter.
40
41On failure an error code can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>.
42
43=head1 SEE ALSO
44
45L<RSA_get_ex_new_index(3)|RSA_get_ex_new_index(3)>,
46L<DSA_get_ex_new_index(3)|DSA_get_ex_new_index(3)>,
47L<DH_get_ex_new_index(3)|DH_get_ex_new_index(3)>
48
49=head1 HISTORY
50
51CRYPTO_set_ex_data() and CRYPTO_get_ex_data() have been available since SSLeay 0.9.0.
52
53=cut
54