NAME

SYNOPSIS

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);

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 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.

DESCRIPTION

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 authentication).

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

Note that, to provide the RFC5705 context, the context variable must be non-null.

RETURNS

SINCE

REPORTING BUGS

COPYRIGHT

SEE ALSO

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