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