NAME

       gnutls_prf_raw - API function

SYNOPSIS

       #include <gnutls/gnutls.h>

       int  gnutls_prf_raw(gnutls_session_t  session,  size_t  label_size, const char * label, size_t seed_size,
       const char * seed, size_t outsize, char * out);

ARGUMENTS

       gnutls_session_t session
                   is a gnutls_session_t type.

       size_t label_size
                   length of the  label variable.

       const char * label
                   label used in PRF computation, typically a short string.

       size_t seed_size
                   length of the  seed variable.

       const char * seed
                   optional extra data to seed the PRF with.

       size_t outsize
                   size of pre-allocated output buffer to hold the output.

       char * out  pre-allocated buffer to hold the generated data.

DESCRIPTION

       Apply the TLS Pseudo-Random-Function (PRF) on the master secret and the provided data.

       The  label variable usually contains a string denoting the purpose for the  generated  data.   The   seed
       usually  contains  data  such as the client and server random, perhaps together with some additional data
       that is added to guarantee uniqueness of the output for a particular purpose.

       Because the output is not guaranteed to be unique for a particular  session  unless   seed  includes  the
       client  random and server random fields (the PRF would output the same data on another connection resumed
       from the first one), it is not recommended to use this  function  directly.   The  gnutls_prf()  function
       seeds  the  PRF  with  the  client  and  server random fields directly, and is recommended if you want to
       generate pseudo random data unique for each session.

NOTE

       This function will only operate under TLS versions prior to 1.3.  In TLS1.3 the use of  PRF  is  replaced
       with  HKDF  and the generic exporters like gnutls_prf_rfc5705() should be used instead. Under TLS1.3 this
       function returns GNUTLS_E_INVALID_REQUEST.

RETURNS

       GNUTLS_E_SUCCESS on success, or an error code.

REPORTING BUGS

       Report bugs to <bugs@gnutls.org>.
       Home page: https://www.gnutls.org

COPYRIGHT

       Copyright © 2001-2023 Free Software Foundation, Inc., and others.
       Copying and distribution of this file, with or without modification, are permitted in any medium  without
       royalty provided the copyright notice and this notice are preserved.

SEE ALSO

       The  full  documentation  for  gnutls  is  maintained as a Texinfo manual.  If the /usr/share/doc/gnutls/
       directory does not contain the HTML form visit

       https://www.gnutls.org/manual/

gnutls                                                3.8.9                                    gnutls_prf_raw(3)