tree a10e8191c2bed9d2ca5a43b7119739d050905257
parent 80e92ad43a380e15abe51ede57738471d9353b16
author Hanno Becker <hanno.becker@arm.com> 1548859595 +0000
committer Hanno Becker <hanno.becker@arm.com> 1559741128 +0100

SSL/TLS client: Remove old session ticket on renegotiation

Context: During a handshake, the SSL/TLS handshake logic constructs
an instance of ::mbedtls_ssl_session representing the SSL session
being established. This structure contains information such as the
session's master secret, the peer certificate, or the session ticket
issues by the server (if applicable).

During a renegotiation, the new session is constructed aside the existing
one and destroys and replaces the latter only when the renegotiation is
complete. While conceptually clear, this means that during the renegotiation,
large pieces of information such as the peer's CRT or the session ticket
exist twice in memory, even though the original versions are removed
eventually.

This commit starts removing this memory inefficiency by freeing the old
session's SessionTicket before the one for the new session is allocated.