RSAgetexnewindex(3) OpenSSL RSAgetexnewindex(3)

NAME
       RSAgetexnewindex, RSAsetexdata, RSAgetexdata - add
       application specific data to RSA structures

SYNOPSIS
        #include 

        int RSAgetexnewindex(long argl, void *argp,
                       CRYPTOEXnew *newfunc,
                       CRYPTOEXdup *dupfunc,
                       CRYPTOEXfree *freefunc);

        int RSAsetexdata(RSA *r, int idx, void *arg);

        void *RSAgetexdata(RSA *r, int idx);

        typedef int newfunc(void *parent, void *ptr, CRYPTOEXDATA *ad,
                       int idx, long argl, void *argp);
        typedef void freefunc(void *parent, void *ptr, CRYPTOEXDATA *ad,
                       int idx, long argl, void *argp);
        typedef int dupfunc(CRYPTOEXDATA *to, CRYPTOEXDATA *from, void *fromd,
                       int idx, long argl, void *argp);

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 vvooiidd ** type.

       The RRSSAAggeetteexxnneewwiinnddeexx(()) 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.
       RRSSAAggeetteexxnneewwiinnddeexx(()) 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 iinnddeexx which should be
       stored (typically in a static variable) and passed used in the iiddxx
       parameter in the remaining functions. Each successful call to
       RRSSAAggeetteexxnneewwiinnddeexx(()) will return an index greater than any previously
       returned, this is important because the optional functions are called
       in order of increasing index value.

       RRSSAAsseetteexxddaattaa(()) is used to set application specific data, the data is
       supplied in the aarrgg parameter and its precise meaning is up to the
       application.

       RRSSAAggeetteexxddaattaa(()) 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 RRSSAAsseetteexxddaattaa(()) call.

       nneewwffuunncc(()) is called when a structure is initially allocated (for
       example with RRSSAAnneeww(()). 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.

       ffrreeeeffuunncc(()) 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.

       nneewwffuunncc(()) and ffrreeeeffuunncc(()) take the same parameters. ppaarreenntt is a
       pointer to the parent RSA structure. ppttrr is a the application specific
       data (this wont be of much use in nneewwffuunncc(()). aadd is a pointer to the
       CCRRYYPPTTOOEEXXDDAATTAA structure from the parent RSA structure: the functions
       CCRRYYPPTTOOggeetteexxddaattaa(()) and CCRRYYPPTTOOsseetteexxddaattaa(()) can be called to
       manipulate it. The iiddxx parameter is the index: this will be the same
       value returned by RRSSAAggeetteexxnneewwiinnddeexx(()) when the functions were
       initially registered. Finally the aarrggll and aarrggpp parameters are the
       values originally passed to the same corresponding parameters when
       RRSSAAggeetteexxnneewwiinnddeexx(()) was called.

       dduuppffuunncc(()) is called when a structure is being copied. Pointers to the
       destination and source CCRRYYPPTTOOEEXXDDAATTAA structures are passed in the ttoo
       and ffrroomm parameters respectively. The ffrroommdd 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 ffrroommdd and have
       different values in the source and destination.  The iiddxx, aarrggll and aarrggpp
       parameters are the same as those in nneewwffuunncc(()) and ffrreeeeffuunncc(()).

RETURN VALUES
       RRSSAAggeetteexxnneewwiinnddeexx(()) returns a new index or -1 on failure (note 0 is
       a valid index value).

       RRSSAAsseetteexxddaattaa(()) returns 1 on success or 0 on failure.

       RRSSAAggeetteexxddaattaa(()) 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 iiddxx parameter.

       nneewwffuunncc(()) and dduuppffuunncc(()) should return 0 for failure and 1 for
       success.

       On failure an error code can be obtained from ERRgeterror(3).

BUGS
       dduuppffuunncc(()) is currently never called.

       The return value of nneewwffuunncc(()) is ignored.

       The nneewwffuunncc(()) function isn't very useful because no meaningful values
       are present in the parent RSA structure when it is called.

SEE ALSO
       rsa(3), CRYPTOsetexdata(3)

HISTORY       RSAgetexnewindex(), RSAsetexdata() and RSAgetexdata() are
       available since SSLeay 0.9.0.



0.9.7l                            2000-09-14           RSAgetexnewindex(3)