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.
* origin/pr/2547:
generate_visualc_files.pl: add mbedtls source shadowing by crypto
generate_errors.pl: refactor and simplify the code
generate_errors.pl: typo fix
revert changes to generate_features.pl and generate_query_config.pl
generate_errors.pl: add mbedtls header shadowing by crypto headers
Add an option to use crypto source files in generated visual c project
Add description of generate_query_config.pl argument
Add crypto includes when generating features in generate_features.pl
Include crypto config when generating query config
Add crypto includes when generating errors in generate_errors.pl
* origin/pr/2480: (22 commits)
Use check_output instead of Popen
Start unused variable with underscore
Correct documentation
Check that the report directory is a directory
Use namespaces instead of full classes
Fix pylint issues
Don't put abi dumps in subfolders
Add verbose switch to silence all output except the final report
Fetch the remote crypto branch, rather than cloning it
Prefix internal functions with underscore
Add RepoVersion class to make handling of many arguments easier
Reduce indentation levels
Improve documentation
Use optional arguments for setting repositories
Only build the library
Add ability to compare submodules from different repositories
Add handling for cases when not all .so files are present
Extend functionality to allow setting crypto submodule version
Simplify logic for checking if report folder can be removed
Add option for a brief report of problems only
...
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
...
The documentation doesn't explicitly say whether it's allowed or not.
This currently works with the default software implementation, but
only by accident. It isn't guaranteed to work with new ciphers or with
alternative implementations of individual ciphers, and it doesn't work
with the PSA wrappers. So don't do it.
Running the generation script with "include_crypto" input parameter set to 1
makes the mbedtls sources being overshadowed by crypto sources.
In case of any duplicate sources, crypto ones take precedence.
Run ssl-opt.sh on x86_32 with ASan. This may detect bugs that only
show up on 32-bit platforms, for example due to size_t overflow.
For this component, turn off some memory management features that are
not useful, potentially slow, and may reduce ASan's effectiveness at
catching buffer overflows.
