In mpi_montmul, an auxiliary function for modular
exponentiation (mbedtls_mpi_mod_exp) that performs Montgomery
multiplication, the last step is a conditional subtraction to force
the result into the correct range. The current implementation uses a
branch and therefore may leak information about secret data to an
adversary who can observe what branch is taken through a side channel.
Avoid this potential leak by always doing the same subtraction and
doing a contant-trace conditional assignment to set the result.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Separate out a version of mpi_safe_cond_assign that works on
equal-sized limb arrays, without worrying about allocation sizes or
signs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This reverts commit 2cc69fffcf.
A check was added in mpi_montmul because clang-analyzer warned about a
possibly null pointer. However this was a false positive. Recent
versions of clang-analyzer no longer emit a warning (3.6 does, 6
doesn't).
Incidentally, the size check was wrong: mpi_montmul needs
T->n >= 2 * (N->n + 1), not just T->n >= N->n + 1.
Given that this is an internal function which is only used from one
public function and in a tightly controlled way, remove both the null
check (which is of low value to begin with) and the size check (which
would be slightly more valuable, but was wrong anyway). This allows
the function not to need to return an error, which makes the source
code a little easier to read and makes the object code a little
smaller.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The previous version attempted to write the explicit IV from
the destination buffer before it has been written there.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
* development: (44 commits)
Add test for building without CTR_DRBG
Add usage info of generate_psa_constants script
Fix undeclared deps on CTR_DRBG in programs/fuzz
Fix undeclared deps on MBEDTLS_CTR_DRBG in tests
Finish the documentation of normalize_path
Generate PSA constant names in CMake build dir
Run assemble_changelog.py in all.sh
Wrap line to 79 columns
Some .pem files are openssl output and have tabs and that's ok
.dsw files are Visual Studio stuff
Permit empty files
Normalize line endings
Check only files checked into Git
Exclude binary files from text checks
Regex mechanism for check-specific exemptions
Check all files by default
More accurate variable name
Fix article in documentation
Add output of `python3` version
Add output of make and cmake versions
...
Invasive testing strategy
Create a new header `common.h`.
Introduce a configuration option `MBEDTLS_TEST_HOOKS` for test-specific code, to be used in accordance with the invasive testing strategy.
The list in the pre-push hook was redundant with the list of `check_*`
components in all.sh, and unsurprisingly it was outdated.
Missing components were:
- check_recursion
- check_changelog
- check_test_cases
- check_python_files
- check_generate_test_code
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
The primary purpose is to use it to run all.sh -k -q in the pre-push hook, but
this can be useful in any circumstance where you're not interested in the full
output from each component and just want a short summary of which components
were run (and if any failed).
Note that only stdout from components is suppressed, stderr is preserved so
that errors are reported. This means components should avoid printing to
stderr in normal usage (ie in the absence of errors).
Currently all the `check_*` components obey this convention except:
- check_generate_test_code: unittest prints progress to stderr
- check_test_cases: lots of non-fatal warnings printed to stderr
These components will be fixed in follow-up commits.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
This is to avoid confusion with the class of macros
MBEDTLS_SSL_PROTO_TLS1_X
which have an underscore between major and minor version number.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
TLS 1.3 record protection allows the addition of an arbitrary amount
of padding.
This commit introduces a configuration option
```
MBEDTLS_SSL_TLS13_PADDING_GRANULARITY
```
The semantics of this option is that padding is chosen in a minimal
way so that the padded plaintext has a length which is a multiple of
MBEDTLS_SSL_TLS13_PADDING_GRANULARITY.
For example, setting MBEDTLS_SSL_TLS13_PADDING_GRANULARITY to 1024
means that padded plaintexts will have length 1024, 2048, ..., while
setting it to 1 means that no padding will be used.
Signed-off-by: Hanno Becker <hanno.becker@arm.com>
This commit adds an error condition for bad user configurations
and updates the number of SSL module errors in error.h.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
This commit uses the previously defined macro to uniformize
bounds checks in several places. It also adds bounds checks to
the ClientHello writing function that were previously missing.
Also, the functions adding extensions to the ClientHello message
can now fail if the buffer is too small or a different error
condition occurs, and moreover they take an additional buffer
end parameter to free them from the assumption that one is
writing to the default output buffer.
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
People who prefer to rely on HMAC_DRBG (for example because they use it for
deterministic ECDSA and don't want a second DRBG for code size reasons) should
be able to build and run the tests suites without CTR_DRBG.
Ideally we should make sure the level of testing (SSL) is the same regardless
of which DRBG modules is enabled, but that's a more significant piece of work.
For now, just ensure everything builds and `make test` passes.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
While at it, fix a few other obvious ones such as ENTROPY and TIMING_C when
applicable.
A non-regression test for CTR_DRBG will be added in a follow-up commit.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
While at it, declare deps on ENTROPY as well.
A non-regression test will be added in a follow-up commit.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
Detected by Travis
https://travis-ci.org/github/ARMmbed/mbedtls/jobs/692213150
/home/travis/build/ARMmbed/mbedtls/include/mbedtls/x509_crt.h:333:
warning: argument 'make_copy' of command @param is not found in the
argument list of mbedtls_x509_crt_parse_der_with_ext_cb(mbedtls_x509_crt
*chain, const unsigned char *buf, size_t buflen, int no_copy,
mbedtls_x509_crt_ext_cb_t cb)
Signed-off-by: Nicola Di Lieto <nicola.dilieto@gmail.com>
Enable branch coverage output in basic_build_test.sh. This
includes enabling branch coverage output to the lcov make target,
which is disabled by default.
Signed-off-by: Dan Handley <dan.handley@arm.com>
