tree c466b32349b29bc68c8221e093c23945be537107
parent f661c9c39cf75fa2f2c233dbc8d736fed7faae1d
author Hanno Becker <hanno.becker@arm.com> 1556891198 +0100
committer Hanno Becker <hanno.becker@arm.com> 1559574470 +0100

Split mbedtls_ssl_hdr_len() in separate functions for in/out records

The function mbedtls_ssl_hdr_len() returns the length of the record
header (so far: always 13 Bytes for DTLS, and always 5 Bytes for TLS).

With the introduction of the CID extension, the lengths of record
headers depends on whether the records are incoming or outgoing,
and also on the current transform.

Preparing for this, this commit splits mbedtls_ssl_hdr_len() in two
-- so far unmodified -- functions mbedtls_ssl_in_hdr_len() and
mbedtls_ssl_out_hdr_len() and replaces the uses of mbedtls_ssl_hdr_len()
according to whether they are about incoming or outgoing records.

There is no need to change the signature of mbedtls_ssl_{in/out}_hdr_len()
in preparation for its dependency on the currently active transform,
since the SSL context is passed as an argument, and the currently
active transform is referenced from that.