Additional work done as part of merge:
- Run ./tests/scripts/check-generated-files.sh and check in the
resulting changes to programs/ssl/query_config.c
In places where we detect a context is in a bad state and there is no
sensitive data to clear, simply return PSA_ERROR_BAD_STATE and don't
abort on behalf of the application. The application will choose what to
do when it gets a bad state error.
The motivation for this change is that an application should decide what
to do when it misuses the API and encounters a PSA_ERROR_BAD_STATE
error. The library should not attempt to abort on behalf of the
application, as that may not be the correct thing to do in all
circumstances.
Calling psa_*_setup() twice on a MAC, cipher, or hash context should
result in a PSA_ERROR_BAD_STATE error because the operation has already
been set up.
Fixes#10
When building for the PSA crypto service (defined(PSA_CRYPTO_SECURE)),
define psa_key_owner_id_t as int32_t, which is how a PSA platform
encodes partition identity. Note that this only takes effect when the
build option MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER is active.
Support this configuration in the ITS backend.
Declare the owner as psa_key_owner_id_t, of which an implementation
must be provided separately.
Make this a configuration option
MBEDTLS_PSA_CRYPTO_KEY_FILE_ID_ENCODES_OWNER, to make the conditional
compilation flow easier to follow. Declare it in config.h to
pacify check_names.sh.
Support for a specific implementation of psa_key_owner_id_t in storage
backends will come in a subsequent commit.
Differentiate between _key identifiers_, which are always `uint32_t`,
and _key file identifiers_, which are platform-dependent. Normally,
the two are the same.
In `psa/crypto_platform.h`, define `psa_app_key_id_t` (which is always
32 bits, the standard key identifier type) and
`psa_key_file_id_t` (which will be different in some service builds).
A subsequent commit will introduce a platform where the two are different.
It would make sense for the function declarations in `psa/crypto.h` to
use `psa_key_file_id_t`. However this file is currently part of the
PSA Crypto API specification, so it must stick to the standard type
`psa_key_id_t`. Hence, as long as the specification and Mbed Crypto
are not separate, use the implementation-specific file
`psa/crypto_platform.h` to define `psa_key_id_t` as `psa_key_file_id_t`.
In the library, systematically use `psa_key_file_id_t`.
perl -i -pe 's/psa_key_id_t/psa_key_file_id_t/g' library/*.[hc]
PSA_MAX_PERSISTENT_KEY_IDENTIFIER was actually one plus the maximum
key identifier. Change it to be the maximum value, and change the code
that uses it accordingly.
There is no semantic change here (the maximum value hasn't changed).
This commit only makes the implementation clearer.
Check generator validity (i.e. that alg has been initialized) before
allowing reads from the generator or allowing reads of the generator's
capacity.
This aligns our implementation with the documented error code behavior
in our crypto.h and the PSA Crypto API.
- Populate the ECDH private key slot with a fresh private EC key
designated for the correct algorithm.
- Export the public part of the ECDH private key from PSA and
reformat it to suite the format of the ClientKeyExchange message.
- Perform the PSA-based ECDH key agreement and store the result
as the premaster secret for the connection.
- Reformat the server's ECDH public key to make it suitable
for the PSA key agreement API. Currently, the key agreement
API needs a full SubjectPublicKeyInfo structure, while the
TLS ServerKeyExchange message only contains a ECPoint structure.
PSA spec now defines more generic PSA storage types instead of the ITS
specific ones. This is necessary in order to integrate with
the newer implementation of PSA ITS landing in Mbed OS soon.
Changes include the following:
- psa_status_t replaces psa_its_status_t
- psa_storage_info_t replaces psa_its_info_t
- psa_storage_uid_t replaces psa_its_uid_t
When `MBEDTLS_PLATFORM_C` is not enabled, our PSA Crypto implementation
depends on the standard C library for functions like snprintf() and
exit(). However, our implementation was not including the proper header
files nor redefining all `mbedtls_*` symbols properly to ensure
successful builds without MBEDTLS_PLATFORM_C. Add the necessary header
files and macro definitions to our PSA Crypto implementation.
Mbed TLS has deprecated a few module specific error codes in favor of
more general-purpose or cross-module error codes. Use these new error
codes instead of the deprecated error codes.
Resolve conflicts by performing the following.
- Take the upstream Mbed TLS ChangeLog verbatim.
- Reject changes to Makefiles and CMake that are related to using Mbed
Crypto as a submodule. It doesn't make sense to use Mbed Crypto as a
submodule of itself.
- Reject README changes, as Mbed Crypto has its own, different README.
- Reject PSA-related changes to config.h. We don't want to disable the
availability of the PSA Crypto API by default in the Mbed Crypto
config.h.
- Don't inadvertently revert dead code removal in
mbedtls_cipher_write_tag() which was added in f2a7529403 ("Fix
double return statement in cipher.c")
- Where Mbed Crypto already had some MBEDTLS_USE_PSA_CRYPTO code (from
past companion PRs) take the latest version from Mbed TLS which
includes integration with MBEDTLS_CHECK_PARAMS.
- Update the version of the shared library files to match what's
currently present in Mbed TLS.
- Reject removal of testing with PSA from config full tests.
- Resolve conflicts in test tests/suites/helpers.function, where both
Mbed Crypto and Mbed TLS both added documentation for TEST_ASSERT.
Combine text from both documentation efforts.
- Reject adding a submodule of ourselves.
- Reject addition of submodule tests in all.sh.
- Reject addition of submodule to library path in
tests/scripts/run-test-suites.pl.
- Avoid using USE_CRYPTO_SUBMODULE=1 in
component_test_use_psa_crypto_full_cmake_asan() in all.sh.
Enable handling of zero-length null output in PKCS1 v1.5 decryption.
Prevent undefined behavior by avoiding a memcpy() to zero-length null
output buffers.
In mbedtls_rsa_rsaes_oaep_encrypt and
mbedtls_rsa_rsaes_pkcs1_v15_encrypt, if the input length is 0 (which
is unusual and mostly useless, but permitted) then it is fine for the
input pointer to be NULL. Don't return an error in this case.
When `input` is NULL, `memcpy( p, input, ilen )` has undefined behavior
even if `ilen` is zero. So skip the `memcpy` call in this case.
Likewise, in `mbedtls_rsa_rsaes_oaep_decrypt`, skip the `memcpy` call if
`*olen` is zero.
Context: During a handshake, the SSL/TLS handshake logic constructs
an instance of ::mbedtls_ssl_session representing the SSL session
being established. This structure contains information such as the
session's master secret, the peer certificate, or the session ticket
issues by the server (if applicable).
During a renegotiation, the new session is constructed aside the existing
one and destroys and replaces the latter only when the renegotiation is
complete. While conceptually clear, this means that during the renegotiation,
large pieces of information such as the peer's CRT or the session ticket
exist twice in memory, even though the original versions are removed
eventually.
This commit removes the simultaneous presence of two peer CRT chains
in memory during renegotiation, in the following way:
- Unlike in the case of SessionTickets handled in the previous commit,
we cannot simply free the peer's CRT chain from the previous handshake
before parsing the new one, as we need to verify that the peer's end-CRT
hasn't changed to mitigate the 'Triple Handshake Attack'.
- Instead, we perform a binary comparison of the original peer end-CRT
with the one presented during renegotiation, and if it succeeds, we
avoid re-parsing CRT by moving the corresponding CRT pointer from the
old to the new session structure.
- The remaining CRTs in the peer's chain are not affected by the triple
handshake attack protection, and for them we may employ the canonical
approach of freeing them before parsing the remainder of the new chain.
Note that this commit intends to not change any observable behavior
of the stack. In particular:
- The peer's CRT chain is still verified during renegotiation.
- The tail of the peer's CRT chain may change during renegotiation.
Context: During a handshake, the SSL/TLS handshake logic constructs
an instance of ::mbedtls_ssl_session representing the SSL session
being established. This structure contains information such as the
session's master secret, the peer certificate, or the session ticket
issues by the server (if applicable).
During a renegotiation, the new session is constructed aside the existing
one and destroys and replaces the latter only when the renegotiation is
complete. While conceptually clear, this means that during the renegotiation,
large pieces of information such as the peer's CRT or the session ticket
exist twice in memory, even though the original versions are removed
eventually.
This commit starts removing this memory inefficiency by freeing the old
session's SessionTicket before the one for the new session is allocated.
Context:
The existing API `mbedtls_x509_parse_crt_der()` for parsing DER
encoded X.509 CRTs unconditionally makes creates a copy of the
input buffer in RAM. While this comes at the benefit of easy use,
-- specifically: allowing the user to free or re-use the input
buffer right after the call -- it creates a significant memory
overhead, as the CRT is duplicated in memory (at least temporarily).
This might not be tolerable a resource constrained device.
As a remedy, this commit adds a new X.509 API call
`mbedtls_x509_parse_crt_der_nocopy()`
which has the same signature as `mbedtls_x509_parse_crt_der()`
and almost the same semantics, with one difference: The input
buffer must persist and be unmodified for the lifetime of the
established instance of `mbedtls_x509_crt`, that is, until
`mbedtls_x509_crt_free()` is called.
Resolve incompatibilties in the RSA module where changes made for
parameter validation prevent Mbed Crypto from working. Mbed Crypto
depends on being able to pass zero-length buffers that are NULL to RSA
encryption functions.
This reverts commit 2f660d047d.
