HKDF-Expand can produce at most 255 * hash_size bytes of key material,
so this limit applies to the TLS 1.3 key material exporter.
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
Add the option MBEDTLS_SSL_KEYING_MATERIAL_EXPORT to mbedtls_config.h
to control if the function mbedtls_ssl_export_keying_material() should
be available. By default, the option is disabled.
This is because the exporter for TLS 1.2 requires client_random and
server_random need to be stored after the handshake is complete.
Signed-off-by: Max Fillinger <max@max-fillinger.net>
The TLS-Exporter in TLS 1.2 requires client_random and server_random.
Unless MBEDTLS_SSL_CONTEXT_SERIALIZATION is defined, these aren't stored
after the handshake is completed.
Therefore, mbedtls_ssl_export_keying_material() exists only if either
MBEDTLS_SSL_CONTEXT_SERIALIZATION is defined or MBEDTLS_SSL_PROTO_TLS1_2
is *not* defined.
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
This way, it's not required that the label is null-terminated. This
allows us to avoid an allocation in
mbedtls_ssl_tls12_export_keying_material().
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
Previously, if MBEDTLS_SSL_CONTEXT_SERIALIZATION is not defined,
randbytes are not stored after the handshake is done, but they are
needed for TLS-Exporter in TLS 1.2.
This commit also saves randbytes if MBEDTLS_SSL_PROTO_TLS1_2 is defined.
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
The length of the generated key must fit into a uint16_t, so it must not
be larger than 0xffff.
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
The TLS-Exporter is a function to derive shared symmetric keys for the
server and client from the secrets generated during the handshake.
It is defined in RFC 8446, Section 7.5 for TLS 1.3 and in RFC 5705 for
TLS 1.2.
Signed-off-by: Max Fillinger <maximilian.fillinger@foxcrypto.com>
If the calc_finished function returns an error code, don't ignore it but
instead return the error code to stop the handshake as the Finished
message may be incorrect.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
In the `mbedtls_ssl_context` structure, merge the field `in_hsfraglen` into
`badmac_seen_or_in_hsfraglen`. This restores the ABI of `libmbedtls` as it
was in Mbed TLS 3.6.0 through 3.6.2.
The field `badmac_seen_or_in_hsfraglen` (formerly `badmac_seen`) was only
used for DTLS (despite being present in non-DTLS builds), and the field
`in_hsfraglen` was only used in non-DTLS TLS. Therefore the two values can
be stored in the same field.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Prepare to unify two fields of the `mbedtls_ssl_context` structure:
`badmac_seen` (always present but only used in DTLS) and
`in_hsfraglen` (always present but only used in non-DTLS TLS).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The first fragment of a fragmented handshake message always starts at the beginning of the buffer so there's no need to store it.
Signed-off-by: Deomid rojer Ryabkov <rojer@rojer.me>
In a TLS client, when using certificate authentication, the client should
check that the certificate is valid for the server name that the client
expects. Otherwise, in most scenarios, a malicious server can impersonate
another server.
Normally, the application code should call mbedtls_ssl_set_hostname().
However, it's easy to forget. So raise an error if mandatory certificate
authentication is in effect and mbedtls_ssl_set_hostname() has not been
called. Raise the new error code
MBEDTLS_ERR_SSL_CERTIFICATE_VERIFICATION_WITHOUT_HOSTNAME, for easy
identification.
But don't raise the error if the backward compatibility option
MBEDTLS_SSL_CLI_ALLOW_WEAK_CERTIFICATE_VERIFICATION_WITHOUT_HOSTNAME is
enabled.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Use a special marker as ssl->hostname if mbedtls_ssl_set_hostname() has been
called with NULL. If mbedtls_ssl_set_hostname() has never been called, the
field is NULL, as before.
No behavior change apart from now emitting a different log message depending
on whether mbedtls_ssl_set_hostname() has been called with NULL or not at all.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
New abstractions to access ssl->hostname:
mbedtls_ssl_has_set_hostname_been_called() (only implemented approximatively
for now), mbedtls_ssl_get_hostname_pointer(), mbedtls_ssl_free_hostname().
Only access ssl->hostname directly in these functions and in
mbedtls_ssl_set_hostname().
Use these abstractions to access the hostname with the opportunity for
extra checks in mbedtls_ssl_verify_certificate().
No behavior change except for a new log message.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Add mbedtls_ssl_conf_enable_new_session_tickets() API
to be able to enable and disable the handling of TLS 1.3
NewSessionTicket messages.
The TLS 1.2 equivalent function is named
mbedtls_ssl_conf_session_tickets() thus the most
natural name would have been
mbedtls_ssl_conf_new_session_tickets() but it is
already used on server side thus rather
mbedtls_ssl_conf_enable_new_session_tickets().
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Actually moved the function rather than trying to edit guards around it,
because the relevant guards are not nearby, the function was part of
larger blocks, so it seemed risky.
Also, that seems logically correct: the function is no longer part of
the "TLS 1.2 handshake functions common to server and client" section,
it's part of the "helper functions common to 1.2 and 1.3 server and
client" block. Ideally in the future perhaps the file structure should
reflect that (`ssl_generic.c` vs `ssl_tls12_generic.c`?) but that's out
of scope here.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Rename as there was a name collision with a static function in another
file: ssl_parse_certificate_verify in ssl_tls12_server.c is the function
that parses the CertificateVerify message, which seems appropriate. Here
it meant "the 'verify' step after parsing the Certificate message".
Use a name that focuses on what it does: verify, not parse.
Also, take ciphersuite_info as an argument: when TLS 1.3 calls this
function, it can pass NULL as the ciphersuite has no influence there.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
In particular, make sure pointer variables are initialized right after
being declared.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This is for compatibility, for people transitioning from 1.2 to 1.3.
See https://github.com/Mbed-TLS/mbedtls/issues/9223 "Mandatory server
authentication" and reports linked from there.
In the future we're likely to make server authentication mandatory in
both 1.2 and 1.3. See https://github.com/Mbed-TLS/mbedtls/issues/7080
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
We don't check the non-standard nsCertType extension, so this flag can't
be set, so checking if it's set is useless.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The comments were about the time we were using mbedtls_pk_ec(), which
can return NULL, which we don't want to propagate to other functions.
Now we're using mbedtls_pk_get_ec_group_id() with is a safer interface
(and works even when EC is provided by drivers).
The check for GROUP_NONE was an heritage from the previous NULL check.
However it's actually useless: if NONE were returned (which can't happen
or parsing of the certificate would have failed and we wouldn't be
here), then mbedtls_ssl_check_curve() would work and just say that the
curve wasn't valid, which is OK.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Issue #9179 (MBEDTLS_SSL_CID_OUT_LEN_MAX changed to
MBEDTLS_SSL_CID_IN_LEN_MAX in library\ssl.h and library\ssl_tls.c)
Signed-off-by: Sam Berry <sam.berry@arm.com>
