Still check that encryption and decryption are inverse to each other
if the granularity does not match the one used in the KAT.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
This commit adds four known answer tests for TLS 1.3 record protection
from the following sources:
- RFC 8448 "Example Handshake Traces for TLS 1.3"
- tls13.ulfheim.net "The New Illustrated TLS Connection"
It extends the test coverage of the existing record protection tests
in the following ways:
- The existing record protection tests hand-craft record transform
structures; the new tests use the function
mbedtls_ssl_tls13_populate_transform()
from library source to create an TLS 1.3 transform from raw
key material and connection information.
- The existing record protection tests only check that encryption
and decryption are inverse to each other; as such, they don't
catch non-compliant implementations of encryption and decryption
which happen to be inverse to each other. By adding a known answer
test for TLS 1.3 record protection, can gain confidence that our
implementation is indeed standards-compliant.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
The AEAD additional data (AAD) is computed differently in TLS 1.3
compared to TLS 1.2, but this change hasn't yet been reflected in
the codee, rendering the current implementation of
```
mbedtls_ssl_{encrypt,decrypt}_buf()
```
not standard compliant.
This commit fixes this by adjusting the AAD extraction function
ssl_extract_add_data_from_record() and its call-sites.
Please see the documentation of the code for an explanation
of how the AAD has changed from TLS 1.2 to TLS 1.3.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
This commit adds the TLS 1.3 specific internal function
```
mbedtls_ssl_tls13_populate_transform()
```
which creates an instance of the SSL transform structure
`mbedtls_ssl_transform` representing a TLS 1.3 record protection
mechanism.
It is analogous to the existing internal helper function
```
ssl_tls12_populate_transform()
```
which creates transform structures representing record
protection mechanisms in TLS 1.2 and earlier.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
In TLS 1.2 specific code, the internal helper functions
ssl_populate_transform() builds an SSL transform structure,
representing a specific record protection mechanism.
In preparation for a subsequent commit which will introduce
a similar helper function specific to TLS 1.3, this commmit
renames ssl_populate_transform() to ssl_tls12_populate_transform().
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
Instances of `mbedtls_ssl_session` represent data enabling session resumption.
With the introduction of TLS 1.3, the format of this data changes. We therefore
need TLS-version field as part of `mbedtlsl_ssl_session` which allows distinguish
1.2 and 1.3 sessions.
This commit introduces such a TLS-version field to mbedtls_ssl_session.
The change has a few ramifications:
- Session serialization/deserialization routines need to be adjusted.
This is achieved by adding the TLS-version after the header of
Mbed TLS version+config, and by having the subsequent structure
of the serialized data depend on the value of this field.
The details are described in terms of the RFC 8446 presentation language.
The 1.2 session (de)serialization are moved into static helper functions,
while the top-level session (de)serialization only parses the Mbed TLS
version+config header and the TLS-version field, and dispatches according
to the found version.
This way, it will be easy to add support for TLS 1.3 sessions in the future.
- Tests for session serialization need to be adjusted
- Once we add support for TLS 1.3, with runtime negotiation of 1.2 vs. 1.3,
we will need to have some logic comparing the TLS version of the proposed session
to the negotiated TLS version. For now, however, we only support TLS 1.2,
and no such logic is needed. Instead, we just store the TLS version in the
session structure at the same point when we populate mbedtls_ssl_context.minor_ver.
The change introduces some overlap between `mbedtls_ssl_session.minor_ver` and
`mbedtls_ssl_context.minor_ver`, which should be studied and potentially resolved.
However, with both fields being private and explicitly marked so, this can happen
in a later change.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
The previous implementation was hard to understand and could in principle
fail to notice if there was a test case failure and the writing of the
line "Note: $TOTAL_FAIL failures." failed. KISS.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
What matters is that we validate that test data is not removed. Keeping the
test data is the most obvious way, but not the only way.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The import-and-save and load-and-check parts of the tests don't have to be
actually the same test cases.
Introduce the terms “forward compatibility” and “backward compatibility” and
relate them to import-and-save and load-and-check actions.
These are clarifications of intent that do not represent an intended change
in the strategy or intended coverage.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Previously the check was convoluted. This has been simplified
and given a more appropriate suggestion as per gilles suggestion
Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
Call the output size macros specifically with asymmetric keys, which
would cause a crash (and thus test fail) should this fix get regressed.
Signed-off-by: Paul Elliott <paul.elliott@arm.com>
