=pod =head1 NAME CRYPTO_set_ex_data, CRYPTO_get_ex_data - internal application specific data functions =head1 SYNOPSIS int CRYPTO_set_ex_data(CRYPTO_EX_DATA *r, int idx, void *arg); void *CRYPTO_get_ex_data(CRYPTO_EX_DATA *r, int idx); =head1 DESCRIPTION Several OpenSSL structures can have application specific data attached to them. These functions are used internally by OpenSSL to manipulate application specific data attached to a specific structure. These functions should only be used by applications to manipulate B structures passed to the B, B and B callbacks: as passed to B for example. B is used to set application specific data, the data is supplied in the B parameter and its precise meaning is up to the application. B is used to retrieve application specific data. The data is returned to the application, this will be the same value as supplied to a previous B call. =head1 RETURN VALUES B returns 1 on success or 0 on failure. B returns the application data or 0 on failure. 0 may also be valid application data but currently it can only fail if given an invalid B parameter. On failure an error code can be obtained from L. =head1 SEE ALSO L, L, L =head1 HISTORY CRYPTO_set_ex_data() and CRYPTO_get_ex_data() have been available since SSLeay 0.9.0. =cut