Section: gnutls (3)
gnutls_prf_raw - API function
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);
- 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.
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
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.
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
on success, or an error code.
Report bugs to <email@example.com
Home page: https://www.gnutls.org
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