This commit enables support for DTLS, i.e. TLS over datagram transport
protocols like UDP. While support for DTLS is absent in CPython, it is
worth supporting it in MicroPython because it is the basis of the
ubiquitous CoAP protocol, used in many IoT projects.
To select DTLS, a new set of "protocols" are added to SSLContext:
- ssl.PROTOCOL_DTLS_CLIENT
- ssl.PROTOCOL_DTLS_SERVER
If one of these is set, the library assumes that the underlying socket is a
datagram-like socket (i.e. UDP or similar).
Our own timer callbacks are implemented because the out of the box
implementation relies on `gettimeofday()`.
This new DTLS feature is enabled on all ports that use mbedTLS.
This commit is an update to a previous PR #10062.
Addresses issue #5270 which requested DTLS support.
Signed-off-by: Keenan Johnson <keenan.johnson@gmail.com>
On mbedTLS ports with non-baremetal configs (mostly esp32, technically also
unix port), mbedTLS memory is allocated from the libc heap. This means an
old SSL socket may be holding large SSL buffers and preventing a new SSL
socket from being allocated.
As a workaround, trigger a GC pass and retry before failing outright.
This was originally implemented as a global mbedTLS calloc function, but
there is complexity around the possibility of C user modules calling into
mbedTLS without holding the GIL. It would be interesting to try making a
generic version for any malloc which fails, but this would require checking
for a Python thread and probably making the GIL recursive.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
This commit enables the implementation of alternative mbedTLS cryptography
functions, such as ECDSA sign and verify, in pure Python. Alternative
functions are implemented in Python callbacks, that get invoked from
wrapper functions when needed. The callback can return None to fall back
to the default mbedTLS function.
A common use case for this feature is with secure elements that have
drivers implemented in Python. Currently, only the ECDSA alternate sign
function wrapper is implemented.
Tested signing with a private EC key stored on an NXP SE05x secure element.
Signed-off-by: iabdalkader <i.abdalkader@gmail.com>
This is necessary for mbedTLS callbacks that do not carry any user state,
so those callbacks can be customised per SSL context.
Signed-off-by: iabdalkader <i.abdalkader@gmail.com>
Small code size and binary size optimisation for the fix merged in
4d6d84983f.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
`mbedtls_pk_parse_key()` expects `key_len` to include the NULL terminator
for PEM data but not for DER encoded data. This also applies to
`mbedtls_x509_crt_parse()` and `cert_len`.
Since all PEM data contains "-----BEGIN" this is used to check if the data
is PEM (as per mbedtls code).
This can be done for both v2 and v3 of mbedtls since the fundamental
behaviour/expectation did not change. What changed is that in v3 the
PKCS#8 DER parser now checks that the passed key buffer is fully utilized
and no bytes are remaining (all other DER formats still do not check this).
Signed-off-by: Peter Züger <zueger.peter@icloud.com>
Use new function mp_obj_new_str_from_cstr() where appropriate. It
simplifies the code, and makes it smaller too.
Signed-off-by: Jon Foster <jon@jon-foster.co.uk>
The STATIC macro was introduced a very long time ago in commit
d5df6cd44a. The original reason for this was
to have the option to define it to nothing so that all static functions
become global functions and therefore visible to certain debug tools, so
one could do function size comparison and other things.
This STATIC feature is rarely (if ever) used. And with the use of LTO and
heavy inline optimisation, analysing the size of individual functions when
they are not static is not a good representation of the size of code when
fully optimised.
So the macro does not have much use and it's simpler to just remove it.
Then you know exactly what it's doing. For example, newcomers don't have
to learn what the STATIC macro is and why it exists. Reading the code is
also less "loud" with a lowercase static.
One other minor point in favour of removing it, is that it stops bugs with
`STATIC inline`, which should always be `static inline`.
Methodology for this commit was:
1) git ls-files | egrep '\.[ch]$' | \
xargs sed -Ei "s/(^| )STATIC($| )/\1static\2/"
2) Do some manual cleanup in the diff by searching for the word STATIC in
comments and changing those back.
3) "git-grep STATIC docs/", manually fixed those cases.
4) "rg -t python STATIC", manually fixed codegen lines that used STATIC.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
The current `ssl` module has quite a few differences to the CPython
implementation. This change moves the MicroPython variant to a new `tls`
module and provides a wrapper module for `ssl` (in micropython-lib).
Users who only rely on implemented comparible behavior can continue to use
`ssl`, while users that rely on non-compatible behavior should switch to
`tls`. Then we can make the facade in `ssl` more strictly adhere to
CPython.
Signed-off-by: Felix Dörre <felix@dogcraft.de>
