Not related to the changes in this PR, except in the next commit I'll
update the strategy document for changes in this PR and to outline
likely follow-ups, and while looking at the document I noticed a few
things that needed updated, so here there are in their own commit.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Note: limitations of opaque PSKs changed from "TLS 1.2 only" to "none"
since TLS 1.3 does not support PSK at all so far, and it is expected to
support opaque PSKs as soon as it gains PSK support, it will be just a
matter of selecting between psa_key_derivation_input_bytes() and
psa_key_derivation_input_key() - and testing obviously.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The scope of the option has been expanded, now it makes more sense to
describe it as "everything except ...".
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
It was initially motivated by the fact that the PSA Crypto APIs
themselves were not stable. In the meantime, PSA Crypto has reached
1.0.0 so this no longer applies.
If we want user to be able to fully benefit from PSA in order to
isolate long-term secrets, they need to be able to use the new APIs with
confidence. There is no reason to think those APIs are any more likely
to change than any of our other APIs, and if they do, we'll follow the
normal process (deprecated in favour of a new variant).
For reference, the APIs in question are:
mbedtls_pk_setup_opaque() // to use PSA-held ECDSA/RSA keys in TLS
mbedtls_ssl_conf_psk_opaque() // for PSA-held PSKs in TLS
mbedtls_ssl_set_hs_psk_opaque() // for PSA-held PSKs in TLS
mbedtls_cipher_setup_psa() (deprecated in 3.2)
mbedtls_pk_wrap_as_opaque() (documented internal, to be removed in 3.2)
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Note: removed `mbedtls_x509write_crt_set_subject_key()` from the list of
things that should be tested, as it's taking public key rather than a
keypair.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Don't mention "TLS 1.2 only" for PSK, as that could give the impression
that the other things about TLS are supported beyond 1.2, which isn't
the case currently.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The section is about things that are not covered, but some lists are
about things that are covered, which was very confusing.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Also, remove the section about design considerations for now. It's
probably more suitable for a developer-oriented document that would also
include considerations about possible paths for the future, which would
better be separated from user documentation (separating the certain that
is now, from the uncertain that might or might not be later).
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
