label used in PRF computation, typically a short string.
length of the seed variable.
const char * seed
optional extra data to seed the PRF with.
size of pre-allocated output buffer to hold the output.
char * out
pre-allocate buffer to hold the generated data.
Apply the TLS Pseudo-Random-Function (PRF) using the master secret
on some data.
The label variable usually contain a string denoting the purpose
for the generated data. The seed usually contain 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 include 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 seed 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.