The hash contexts `ssl_transform->md_ctx_{enc/dec}` are not used if
only AEAD ciphersuites are enabled. This commit removes them from the
`ssl_transform` struct in this case, saving a few bytes.
Analogous to the previous commit, but concerning the record decryption
routine `ssl_decrypt_buf`.
An important change regards the checking of CBC padding:
Prior to this commit, the CBC padding check always read 256 bytes at
the end of the internal record buffer, almost always going past the
boundaries of the record under consideration. In order to stay within
the bounds of the given record, this commit changes this behavior by
always reading the last min(256, plaintext_len) bytes of the record
plaintext buffer and taking into consideration the last `padlen` of
these for the padding check. With this change, the memory access
pattern and runtime of the padding check is entirely determined by
the size of the encrypted record, in particular not giving away
any information on the validity of the padding.
The following depicts the different behaviors:
1) Previous CBC padding check
1.a) Claimed padding length <= plaintext length
+----------------------------------------+----+
| Record plaintext buffer | | PL |
+----------------------------------------+----+
\__ PL __/
+------------------------------------...
| read for padding check ...
+------------------------------------...
|
contents discarded
from here
1.b) Claimed padding length > plaintext length
+----------------------------------------+----+
| Record plaintext buffer | PL |
+----------------------------------------+----+
+-------------------------...
| read for padding check ...
+-------------------------...
|
contents discarded
from here
2) New CBC padding check
+----------------------------------------+----+
| Record plaintext buffer | | PL |
+----------------------------------------+----+
\__ PL __/
+---------------------------------------+
| read for padding check |
+---------------------------------------+
|
contents discarded
until here
The previous version of the record encryption function
`ssl_encrypt_buf` takes the entire SSL context as an argument,
while intuitively, it should only depend on the current security
parameters and the record buffer.
Analyzing the exact dependencies, it turned out that in addition
to the currently active `ssl_transform` instance and the record
information, the encryption function needs access to
- the negotiated protocol version, and
- the status of the encrypt-then-MAC extension.
This commit moves these two fields into `ssl_transform` and
changes the signature of `ssl_encrypt_buf` to only use an instance
of `ssl_transform` and an instance of the new `ssl_record` type.
The `ssl_context` instance is *solely* kept for the debugging macros
which need an SSL context instance.
The benefit of the change is twofold:
1) It avoids the need of the MPS to deal with instances of
`ssl_context`. The MPS should only work with records and
opaque security parameters, which is what the change in
this commit makes progress towards.
2) It significantly eases testing of the encryption function:
independent of any SSL context, the encryption function can
be passed some record buffer to encrypt alongside some arbitrary
choice of parameters, and e.g. be checked to not overflow the
provided memory.
This commit adds a structure `mbedtls_record` whose instances
represent (D)TLS records. This structure will be used in the
subsequent adaptions of the record encryption and decryption
routines `ssl_decrypt_buf` and `ssl_encrypt_buf`, which currently
take the entire SSL context as input, but should only use the
record to be acted on as well as the record transformation to use.
The macro constant `MBEDTLS_SSL_MAC_ADD` defined in `ssl_internal.h`
defines an upper bound for the amount of space needed for the record
authentication tag. Its definition distinguishes between the
presence of an ARC4 or CBC ciphersuite suite, in which case the maximum
size of an enabled SHA digest is used; otherwise, `MBEDTLS_SSL_MAC_ADD`
is set to 16 to accomodate AEAD authentication tags.
This assignment has a flaw in the situation where confidentiality is
not needed and the NULL cipher is in use. In this case, the
authentication tag also uses a SHA digest, but the definition of
`MBEDTLS_SSL_MAC_ADD` doesn't guarantee enough space.
The present commit fixes this by distinguishing between the presence
of *some* ciphersuite using a MAC, including those using a NULL cipher.
For that, the previously internal macro `SSL_SOME_MODES_USE_MAC` from
`ssl_tls.c` is renamed and moved to the public macro
`MBEDTLS_SOME_MODES_USE_MAC` defined in `ssl_internal.h`.
Prior to this commit, the security parameter struct `ssl_transform`
contained a `ciphersuite_info` field pointing to the information
structure for the negotiated ciphersuite. However, the only
information extracted from that structure that was used in the core
encryption and decryption functions `ssl_encrypt_buf`/`ssl_decrypt_buf`
was the authentication tag length in case of an AEAD cipher.
The present commit removes the `ciphersuite_info` field from the
`ssl_transform` structure and adds an explicit `taglen` field
for AEAD authentication tag length.
This is in accordance with the principle that the `ssl_transform`
structure should contain the raw parameters needed for the record
encryption and decryption functions to work, but not the higher-level
information that gave rise to them. For example, the `ssl_transform`
structure implicitly contains the encryption/decryption keys within
their cipher contexts, but it doesn't contain the SSL master or
premaster secrets. Likewise, it contains an explicit `maclen`, while
the status of the 'Truncated HMAC' extension -- which determines the
value of `maclen` when the `ssl_transform` structure is created in
`ssl_derive_keys` -- is not contained in `ssl_transform`.
The `ciphersuite_info` pointer was used in other places outside
the encryption/decryption functions during the handshake, and for
these functions to work, this commit adds a `ciphersuite_info` pointer
field to the handshake-local `ssl_handshake_params` structure.
The `ssl_transform` security parameter structure contains opaque
cipher contexts for use by the record encryption/decryption functions
`ssl_decrypt_buf`/`ssl_encrypt_buf`, while the underlying key material
is configured once in `ssl_derive_keys` and is not explicitly dealt with
anymore afterwards. In particular, the key length is not needed
explicitly by the encryption/decryption functions but is nonetheless
stored in an explicit yet superfluous `keylen` field in `ssl_transform`.
This commit removes this field.
Resolve conflicts by performing the following:
- Ensure calls to mbedtls_x509_crt_verify_* are made with callbacks
* origin/pr/2539:
Make CRT callback tests more robust
Rename constant in client2.c
Fix typo
Add test for configuration specific CRT callback
Fix doxygen documentation of mbedtls_ssl_set_verify()
Add test exercising context-specific CRT callback to ssl-opt.sh
Add cmd to use context-specific CRT callback in ssl_client2
Implement context-specific verification callbacks
Add context-specific CRT verification callbacks
Improve documentation of mbedtls_ssl_conf_verify()
* origin/pr/2532: (29 commits)
Document and test flags in x509_verify
Fix style issues and a typo
Fix name to function call
Address comments for x509 tests
Address review comments regarding ssl_client2 and ssl tests
Remove mbedtls_ from the static function name
Change docs according to review comments
Change the verify function naming
Fix ssl_client2 and ssl_server2 if !PLATFORM_C
Correct placement of usage macro in ssl_client2
Update version_features.c
Remove trailing whitespace in test_suite_x509parse.function
Update query_config.c
Add ssl-opt.sh tests for trusted CA callbacks
Only run X.509 CRT verification tests with CA callback tests if !CRL
Minor fixes to CA callback tests
Declare CA callback type even if feature is disabled
Implement X.509 CRT verification using CA callback
Add prototype for CRT verification with static and dynamic CA list
Make use of CA callback if present when verifying peer CRT chain
...
This commit applies the documentation improvements noticed and applied
while adding the documentation for the new X.509 CRT verification API
mbedtls_x509_crt_verify_with_cb() to the existing verification APIs.
* restricted/pr/551:
ECP: Clarify test descriptions
ECP: remove extra whitespaces
Fix ECDH secret export for Mongomery curves
Improve ECP test names
Make ecp_get_type public
Add more tests for ecp_read_key
ECP: Catch unsupported import/export
Improve documentation of mbedtls_ecp_read_key
Fix typo in ECP module
Remove unnecessary cast from ECP test
Improve mbedtls_ecp_point_read_binary tests
Add Montgomery points to ecp_point_write_binary
ECDH: Add test vectors for Curve25519
Add little endian export to Bignum
Add mbedtls_ecp_read_key
Add Montgomery points to ecp_point_read_binary
Add little endian import to Bignum
Ensure this merge passes tests by auto-generating query_config.c, adding
MBEDTLS_ECDH_LEGACY_CONTEXT to it.
* restricted/pr/552:
Fix mbedtls_ecdh_get_params with new ECDH context
Test undefining MBEDTLS_ECDH_LEGACY_CONTEXT in all.sh
Define MBEDTLS_ECDH_LEGACY_CONTEXT in config.h
Add changelog entry for mbedtls_ecdh_get_params robustness
Fix ecdh_get_params with mismatching group
Add test case for ecdh_get_params with mismatching group
Add test case for ecdh_calc_secret
Fix typo in documentation
Ensure tests pass when the submodule is used by updating the list of
crypto tests to include test_suite_oid in both tests/CMakeLists.txt and
tests/Makefile.
* origin/pr/2531:
Add changeLog entry
Add certificate policy of type any policy id
* origin/pr/2509:
all.sh: Generate seedfile for crypto submodule tests
Update crypto submodule to test with private headers
tests: Use globbing in test suite exclusion list
Update crypto submodule to Mbed Crypto development
tests: Test crypto via the crypto submodule
Update the crypto submodule to the top of the Mbed Crypto development
branch. This brings in a version of Mbed Crypto that enables building
Mbed Crypto tests that depend on private headers, like
'psa_crypto_invasive.h'.
This also requires updating our config.h to include new configuration
options added to Mbed Crypto. MBEDTLS_PSA_ITS_FILE_C replaces
MBEDTLS_PSA_CRYPTO_STORAGE_FILE_C and MBEDTLS_PSA_CRYPTO_STORAGE_ITS_C.
MBEDTLS_PSA_INJECT_ENTROPY replaces MBEDTLS_PSA_HAS_ITS_IO.
* public/pr/2421: (68 commits)
Fix unused variable warning in ssl_parse_certificate_coordinate()
Add missing compile time guard in ssl_client2
Update programs/ssl/query_config.c
ssl_client2: Reset peer CRT info string on reconnect
Add further debug statements on assertion failures
Fix typo in documentation of ssl_parse_certificate_chain()
Add debug output in case of assertion failure
Fix typo in SSL ticket documentation
Add config sanity check for !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
ssl_client2: Zeroize peer CRT info buffer when reconnecting
Reintroduce numerous ssl-opt.sh tests if !MBEDTLS_SSL_KEEP_PEER_CERT
ssl_client2: Extract peer CRT info from verification callback
Improve documentation of mbedtls_ssl_get_peer_cert()
Improve documentation of MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
Fix indentation of Doxygen comment in ssl_internal.h
Set peer CRT length only after successful allocation
Remove question in comment about verify flags on cli vs. server
Remove misleading and redundant guard around restartable ECC field
Add test for !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE to all.sh
Free peer CRT chain immediately after verifying it
...
* restricted/pr/528:
Update query_config.c
Fix failure in SSLv3 per-version suites test
Adjust DES exclude lists in test scripts
Clarify 3DES changes in ChangeLog
Fix documentation for 3DES removal
Exclude 3DES tests in test scripts
Fix wording of ChangeLog and 3DES_REMOVE docs
Reduce priority of 3DES ciphersuites
* public/pr/2028:
Update the crypto submodule to a78c958
Fix ChangeLog entry to correct release version
Fix typo in x509write test data
Add ChangeLog entry for unused bits in bitstrings
Improve docs for named bitstrings and their usage
Add tests for (named) bitstring to suite_asn1write
Add new function mbedtls_asn1_write_named_bitstring()
Add a new function mbedtls_asn1_write_named_bitstring() that removes
trailing 0s at the end of DER encoded bitstrings. The function is
implemented according to Hanno Becker's suggestions.
This commit also changes the functions x509write_crt_set_ns_cert_type
and crt_set_key_usage to call the new function as the use named
bitstrings instead of the regular bitstrings.
The ecp_get_type function comes handy in higher level modules and tests
as well. It is not inline anymore, to enable alternative implementations
to implement it for themselves.
mbedtls_ecp_read_key() module returned without an error even when
importing keys corresponding to the requested group was not
implemented.
We change this and return an error when the requested group is not
supported and make the remaining import/export functions more robust.
