By default, this script looks for include/mbedtls/config.h relative to
the current directory. This allows running config.py from outside the
build tree.
To support out-of-tree builds where config.h and config.py are in the
source tree and the current directory is in the build tree, also try
DIRECTORY_CONTAINING_SCRIPT/../include/mbedtls/config.h, and the
equivalent with symbolic links traversed.
git grep -Fl /config.pl | xargs sed -i -e 's!/config\.pl!/config.py!g'
Also:
* Change one comment in include/mbedtls/check_config.h.
* Change PERL to PYTHON in CMakeLists.txt.
MBEDTLS_PK_SIGNATURE_MAX_SIZE is tested in Mbed Crypto. Its effect on
Mbed TLS is also tested via the X.509 tests. The case of
MBEDTLS_MPI_MAX_SIZE < MBEDTLS_ECDSA_MAX_LEN, for which this component
was added as a regression test, is covered by config-suite-b.h which
is tested via test-ref-configs.pl.
They're easier to maintain that way. The old lists were partly
alphabetized, partly based on config.h order, and partly in the order
in which symbols had been added to config.pl.
Also fix 'realfull' to only affect the appropriate sections.
Tested to produce the same results as config.pl on the default
configuration. This commit deliberately contains a direct copy the
lists of symbol names from config.pl.
This is meant to be a drop-in replacement for config.pl which can
additionally be used as a library in a Python script.
So far this script supports the commands 'get', 'set' and 'realfull'
but not the other built-in configurations.
* #292: Make psa_close_key(0) and psa_destroy_key(0) succeed
* #299: Allow xxx_drbg_set_entropy_len before xxx_drbg_seed
* #259: Check `len` against buffers size upper bound in PSA tests
* #288: Add ECDSA tests with hash and key of different lengths
* #305: CTR_DRBG: grab a nonce from the entropy source if needed
* #316: Stop transactions from being reentrant
* #317: getting_started: Make it clear that keys are passed in
* #314: Fix pk_write with EC key to use a constant size for the private value
* #298: Test a build without any asymmetric cryptography
* #284: Fix some possibly-undefined variable warnings
* #315: Define MBEDTLS_PK_SIGNATURE_MAX_SIZE
* #318: Finish side-porting commits from mbedtls-restricted that missed the split
Using 4096 bytes of stack for the temporary buffer used for holding a
throw-away DER-formatted CSR limits the portability of generating
certificate signing requests to only devices with lots of stack space.
To increase portability, use the mbedtls_pem_write_buffer() in-place
capability instead, using the same buffer for input and output. This
works since the DER encoding for some given data is always smaller than
that same data PEM-encoded.
PEM format is desirable to use even on stack-constrained devices as the
format is easy to work with (for example, copy-pasting from a tiny
device's serial console output, for CSRs generated on tiny devices
without the private key leaving said tiny device).
The initial value for the max calculation needs to be 0. The fallback
needs to come last. With the old code, the value was never smaller
than the fallback.
For RSA_ALT, use MPI_MAX_SIZE. Only use this if RSA_ALT is enabled.
For PSA, check PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE, and separately check
the special case of ECDSA where PSA and mbedtls have different
representations for the signature.
PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE was taking the maximum ECDSA key
size as the ECDSA signature size. Fix it to use the actual maximum
size of an ECDSA signature.
mbedtls_pk_sign does not take the size of its output buffer as a
parameter. We guarantee that MBEDTLS_PK_SIGNATURE_MAX_SIZE is enough.
For RSA and ECDSA signatures made in software, this is ensured by the
way MBEDTLS_PK_SIGNATURE_MAX_SIZE is defined at compile time. For
signatures made through RSA-alt and PSA, this is not guaranteed
robustly at compile time, but we can test it at runtime, so do that.
The original definition of MBEDTLS_PK_SIGNATURE_MAX_SIZE only took RSA
into account. An ECDSA signature may be larger than the maximum
possible RSA signature size, depending on build options; for example
this is the case with config-suite-b.h.
In pk_sign_verify, if mbedtls_pk_sign() failed, sig_len was passed to
mbedtls_pk_verify_restartable() without having been initialized. This
worked only because in the only test case that expects signature to
fail, the verify implementation doesn't look at sig_len before failing
for the expected reason.
The value of sig_len if sign() fails is undefined, so set sig_len to
something sensible.
This issue has been reported by Tuba Yavuz, Farhaan Fowze, Ken (Yihang) Bai,
Grant Hernandez, and Kevin Butler (University of Florida) and
Dave Tian (Purdue University).
In AES encrypt and decrypt some variables were left on the stack. The value
of these variables can be used to recover the last round key. To follow best
practice and to limit the impact of buffer overread vulnerabilities (like
Heartbleed) we need to zeroize them before exiting the function.
It was not obvious before that `AES_KEY` and `RSA_KEY` were shorthand
for key material. A user copy pasting the code snippet would run into a
compilation error if they didn't realize this. Make it more obvious that
key material must come from somewhere external by making the snippets
which use global keys into functions that take a key as a parameter.
