gnutls_prf_rfc5705(3)                gnutls                gnutls_prf_rfc5705(3)

       gnutls_prf_rfc5705 - API function

       #include <gnutls/gnutls.h>

       int gnutls_prf_rfc5705(gnutls_session_t session, size_t label_size, const
       char * label, size_t context_size, const char * context, size_t outsize,
       char * out);

       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 context_size
                   length of the  extra variable.

       const char * context
                   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.

       Exports keying material from TLS/DTLS session to an application, as
       specified in RFC5705.

       In the TLS versions prior to 1.3, it applies the TLS
       Pseudo-Random-Function (PRF) on the master secret and the provided data,
       seeded with the client and server random fields.

       In TLS 1.3, it applies HKDF on the exporter master secret derived from
       the master secret.

       The  label variable usually contains a string denoting the purpose for
       the generated data.

       The  context variable can be used to add more data to the seed, after the
       random variables.  It can be used to make sure the generated output is
       strongly connected to some additional data (e.g., a string used in user

       The output is placed in  out , which must be pre-allocated.

       Note that, to provide the RFC5705 context, the  context variable must be

       GNUTLS_E_SUCCESS on success, or an error code.


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gnutls                               3.6.13                gnutls_prf_rfc5705(3)