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