altcp_tls_mbedtls: implement mbedTLS debug output, comment fixes

altcp_tls_mbedtls: update list of todos

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

bug #54744: if altcp_close() called from recv() callback, there is some write to freed memory

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>
(cherry picked from commit 6e994f9df2da80cae1f88e7b771c4b803af0ce0d)

altcp_tls: rename altcp_tls_new -> altcp_tls_wrap, add altcp_tls_new

The new altcp_tls_new() is a type safe version of altcp_tls_alloc()

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

altcp_tls_mbedtls: convert #error on too small TCP_WND to warning

Many TLS use cases are OK with a small TCP_WND, so don't prevent these
by having a preprocessor check that cannot be disabled.

Fix 2way-auth connections for TLS clients

TLS clients that need 2-way authentication (e.g. Amazon AWS IoT cloud mqtt)
need to pass a certificate and private key when creating the tls altcp_pcb.

Added a new function altcp_tls_create_config_client_2wayauth() for this that
replaces altcp_tls_create_config_client() for such clients.

See bug #54601.

Fix compiling with LWIP_NOASSERT defined

Signed-off-by: Axel Lin <axel.lin@ingics.com>

altcp_tls_mbedtls: restructure upper callbacks to prevent double-free

This fixes bug #53192: use-after-free in altcp_mbedtls

Signed-off-by: goldsimon <goldsimon@gmx.de>

altcp: mbedtls: move freeing state->rx from close to dealloc (catch-all)

altcp_tls_mbedtls.c: tiny function rename

altcp_mbedtls_sndbuf: use mbedtls_ssl_get_record_expansion()

altcp_tls_mbedtls: hide allocation strategy in altcp_tls_create_config()

altcp_tls: avoid use of static in altcp_tls_config

cert and pkey are allocated with the altcp_tls_config structure.

Signed-off-by: goldsimon <goldsimon@gmx.de>

altcp_tls: fix pbuf leaked when handshake failed

Signed-off-by: goldsimon <goldsimon@gmx.de>

altcp_mbedtls: added altcp_mbedtls_sndbuf implementation

Signed-off-by: goldsimon <goldsimon@gmx.de>

altcp_mbedtls: close and error related fixes

- call conn->err() instead of conn->recv() if handshake fail and free conn
- close inner_conn and free current conn in altcp_mbedtls_close()

Signed-off-by: goldsimon <goldsimon@gmx.de>

Fix double-free when closing mbedTLS connections

Partly revert commit 0486100a2bcbce74a7214ee4f11782a9441acbf0 from 07.08.2017 as it breaks layering: every layer must free its own altcp_pcb. Freeing the inner_conn is not the right way.

Reformat altcp_tls_mbedtls* using astylerc

Even more pbuf_header -> pbuf_add/remove_header replacements (also in strings)

More pbuf_header -> pbuf_add/remove_header replacements

Some cleanups after applying David Girault's altcp patches

altcp_tls_mbedtls: remove "rx pbufs left at end of handshake" assert

There is case where a close notify come right after the handshake and is in the same pbuf!
So just handle these data like any other data.

altcp_tls: some fixes

- added `altcp_tls_free_config()`.
- added `altcp_tls_context()` function to allow mbedtls parameter tweak.

Since state structure isn't exported, this allow application to get
internal context (port dependent) to tweak it.

- free altcp_pcb when lower error callback called.

altcp_tls_mbedtls: fix log messages by include a `\n`

work on -Wconversion...

Fix C++ style comment in altcp_tls_mbedtls.c

altcp_tls_mbedtls: fix TX when lower write returns ERR_MEM

altcp: added altcp_get_port()

Cleanup #include structure of altcp_tls a bit
(as discussed with Simon today)

httpd/altcp: add forgotten functions

altcp_get_ip: added altcp_get_ip(), added default functions that only defer a call to the inner_conn (moved from tls_mbedtls to generic altcp)

altcp_tls_mbedtls: fixed memory leak introduced by delayed deallocation

Prepare altcp_tls_mbedtls for TLS clients (not fully tested yet)

altcp_tls_mbedtls: improve sent/recved handling

renamed altcp_mbedtls files to altcp_tls_mbedtls