+++ /dev/null
-=pod
-
-=head1 NAME
-
-RSA_get_ex_new_index, RSA_set_ex_data, RSA_get_ex_data - add application specific data to RSA structures
-
-=head1 SYNOPSIS
-
- #include <openssl/rsa.h>
-
- int RSA_get_ex_new_index(long argl, void *argp,
- CRYPTO_EX_new *new_func,
- CRYPTO_EX_dup *dup_func,
- CRYPTO_EX_free *free_func);
-
- int RSA_set_ex_data(RSA *r, int idx, void *arg);
-
- void *RSA_get_ex_data(RSA *r, int idx);
-
- typedef int CRYPTO_EX_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad,
- int idx, long argl, void *argp);
- typedef void CRYPTO_EX_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad,
- int idx, long argl, void *argp);
- typedef int CRYPTO_EX_dup(CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from, void *from_d,
- int idx, long argl, void *argp);
-
-=head1 DESCRIPTION
-
-Several OpenSSL structures can have application specific data attached to them.
-This has several potential uses, it can be used to cache data associated with
-a structure (for example the hash of some part of the structure) or some
-additional data (for example a handle to the data in an external library).
-
-Since the application data can be anything at all it is passed and retrieved
-as a B<void *> type.
-
-The B<RSA_get_ex_new_index()> function is initially called to "register" some
-new application specific data. It takes three optional function pointers which
-are called when the parent structure (in this case an RSA structure) is
-initially created, when it is copied and when it is freed up. If any or all of
-these function pointer arguments are not used they should be set to NULL. The
-precise manner in which these function pointers are called is described in more
-detail below. B<RSA_get_ex_new_index()> also takes additional long and pointer
-parameters which will be passed to the supplied functions but which otherwise
-have no special meaning. It returns an B<index> which should be stored
-(typically in a static variable) and passed used in the B<idx> parameter in
-the remaining functions. Each successful call to B<RSA_get_ex_new_index()>
-will return an index greater than any previously returned, this is important
-because the optional functions are called in order of increasing index value.
-
-B<RSA_set_ex_data()> is used to set application specific data, the data is
-supplied in the B<arg> parameter and its precise meaning is up to the
-application.
-
-B<RSA_get_ex_data()> 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<RSA_set_ex_data()> call.
-
-B<new_func()> is called when a structure is initially allocated (for example
-with B<RSA_new()>. The parent structure members will not have any meaningful
-values at this point. This function will typically be used to allocate any
-application specific structure.
-
-B<free_func()> is called when a structure is being freed up. The dynamic parent
-structure members should not be accessed because they will be freed up when
-this function is called.
-
-B<new_func()> and B<free_func()> take the same parameters. B<parent> is a
-pointer to the parent RSA structure. B<ptr> is a the application specific data
-(this wont be of much use in B<new_func()>. B<ad> is a pointer to the
-B<CRYPTO_EX_DATA> structure from the parent RSA structure: the functions
-B<CRYPTO_get_ex_data()> and B<CRYPTO_set_ex_data()> can be called to manipulate
-it. The B<idx> parameter is the index: this will be the same value returned by
-B<RSA_get_ex_new_index()> when the functions were initially registered. Finally
-the B<argl> and B<argp> parameters are the values originally passed to the same
-corresponding parameters when B<RSA_get_ex_new_index()> was called.
-
-B<dup_func()> is called when a structure is being copied. Pointers to the
-destination and source B<CRYPTO_EX_DATA> structures are passed in the B<to> and
-B<from> parameters respectively. The B<from_d> parameter is passed a pointer to
-the source application data when the function is called, when the function returns
-the value is copied to the destination: the application can thus modify the data
-pointed to by B<from_d> and have different values in the source and destination.
-The B<idx>, B<argl> and B<argp> parameters are the same as those in B<new_func()>
-and B<free_func()>.
-
-=head1 RETURN VALUES
-
-B<RSA_get_ex_new_index()> returns a new index or -1 on failure (note 0 is a valid
-index value).
-
-B<RSA_set_ex_data()> returns 1 on success or 0 on failure.
-
-B<RSA_get_ex_data()> 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<idx>
-parameter.
-
-B<new_func()> and B<dup_func()> should return 0 for failure and 1 for success.
-
-On failure an error code can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>.
-
-=head1 BUGS
-
-B<dup_func()> is currently never called.
-
-The return value of B<new_func()> is ignored.
-
-The B<new_func()> function isn't very useful because no meaningful values are
-present in the parent RSA structure when it is called.
-
-=head1 SEE ALSO
-
-L<rsa(3)|rsa(3)>, L<CRYPTO_set_ex_data(3)|CRYPTO_set_ex_data(3)>
-
-=head1 HISTORY
-
-RSA_get_ex_new_index(), RSA_set_ex_data() and RSA_get_ex_data() are
-available since SSLeay 0.9.0.
-
-=cut
projects / cassiopeia.git / blobdiff