Our current behaviour is a bit inconsistent here:
- when the bad signature is made by a trusted CA, we stop here and don't
include the trusted CA in the chain (don't call vrfy on it)
- otherwise, we just add NOT_TRUSTED to the flags but keep building the chain
and call vrfy on the upper certs
This ensures that the callback can actually clear that flag, and that it is
seen by the callback at the right level. This flag is not set at the same
place than others, and this difference will get bigger in the upcoming
refactor, so let's ensure we don't break anything here.
When a trusted CA is rolling its root keys, it could happen that for some
users the list of trusted roots contains two versions of the same CA with the
same name but different keys. Currently this is supported but wasn't tested.
Note: the intermediate file test-ca-alt.csr is commited on purpose, as not
commiting intermediate files causes make to regenerate files that we don't
want it to touch.
As we accept EE certs that are explicitly trusted (in the list of trusted
roots) and usually look for parent by subject, and in the future we might want
to avoid checking the self-signature on trusted certs, there could a risk that we
incorrectly accept a cert that looks like a trusted root except it doesn't
have the same key. This test ensures this will never happen.
The tests cover chains of length 0, 1 and 2, with one error, located at any of
the available levels in the chain. This exercises all three call sites of
f_vrfy (two in verify_top, one in verify_child). Chains of greater length
would not cover any new code path or behaviour that I can see.
So far there was no test ensuring that the flags passed to the vrfy callback
are correct (ie the flags for the current certificate, not including those of
the parent).
Actual tests case making use of that test function will be added in the next
commit.
We have code to skip them but didn't have explicit tests ensuring they are
(the corresponding branch was never taken).
While at it, remove extra copy of the chain in server10*.crt, which was
duplicated for no reason.
This shows inconsistencies in how flags are handled when callback fails:
- sometimes the flags set by the callback are transmitted, sometimes not
- when the cert if not trusted, sometimes BADCERT_NOT_TRUSTED is set,
sometimes not
This adds coverage for 9 lines and 9 branches. Now all lines related to
callback failure are covered.
Now all checks related to profile are covered in:
- verify_with_profile()
- verify_child()
- verify_top()
(that's 10 lines that were previously not covered)
Leaving aside profile enforcement in CRLs for now, as the focus is on
preparing to refactor cert verification.
Previously flags was left to whatever value it had before. It's cleaner to
make sure it has a definite value, and all bits set looks like the safest way
for when it went very wrong.
The X509 test suite assumes that MBEDTLS_X509_MAX_INTERMEDIATE_CA is below the
hardcoded threshold 20 used in the long certificate chain generating script
tests/data_files/dir-max/long.sh. This commit adds a compile-time check for
that.
If we didn't walk the whole chain, then there may be any kind of errors in the
part of the chain we didn't check, so setting all flags looks like the safe
thing to do.
Inspired by test code provided by Nicholas Wilson in PR #351.
The test will fail if someone sets MAX_INTERMEDIATE_CA to a value larger than
18 (default is 8), which is hopefully unlikely and can easily be fixed by
running long.sh again with a larger value if it ever happens.
Current behaviour is suboptimal as flags are not set, but currently the goal
is only to document/test existing behaviour.
By default, keep allowing SHA-1 in key exchange signatures. Disabling
it causes compatibility issues, especially with clients that use
TLS1.2 but don't send the signature_algorithms extension.
SHA-1 is forbidden in certificates by default, since it's vulnerable
to offline collision-based attacks.
There is now one test case to validate that SHA-1 is rejected in
certificates by default, and one test case to validate that SHA-1 is
supported if MBEDTLS_TLS_DEFAULT_ALLOW_SHA1 is #defined.
SHA-1 is now disabled by default in the X.509 layer. Explicitly enable
it in our tests for now. Updating all the test data to SHA-256 should
be done over time.
The ECJPAKE test suite uses a size zero array for the empty password
used in the tests, which is not valid C. This commit fixes this.
This originally showed up as a compilation failure on Visual Studio
2015, documented in IOTSSL-1242, but can also be observed with GCC
when using the -Wpedantic compilation option.
The test case was generated by modifying our signature code so that it
produces a 7-byte long padding (which also means garbage at the end, so it is
essential in to check that the error that is detected first is indeed the
padding rather than the final length check).
The modular inversion function hangs when provided with the modulus 1. This commit refuses this modulus with a BAD_INPUT error code. It also adds a test for this case.
Fix a buffer overflow when writting a string representation of an MPI
number to a buffer in hexadecimal. The problem occurs because hex
digits are written in pairs and this is not accounted for in the
calculation of the required buffer size when the number of digits is
odd.
The first three test cases from test_suites_pkparse.data failed because
the key file they read requires DES to be read. However, MBEDTLS_DES_C
was missing from the dependency list.
This curve has special arithmetic on 64 bit platforms and an untested
path lead to trying to free a buffer on the stack.
For the sake of completeness, a test case for a point with non-affine
coordinates has been added as well.
Fixes a regression introduced by an earlier commit that modified
x509_crt_verify_top() to ensure that valid certificates that are after past or
future valid in the chain are processed. However the change introduced a change
in behaviour that caused the verification flags MBEDTLS_X509_BADCERT_EXPIRED and
MBEDTLS_BADCERT_FUTURE to always be set whenever there is a failure in the
verification regardless of the cause.
The fix maintains both behaviours:
* Ensure that valid certificates after future and past are verified
* Ensure that the correct verification flags are set.
Modifies the function mbedtls_x509_crl_parse() to ensure that a CRL in PEM
format with trailing characters after the footer does not result in the
execution of an infinite loop.
Fix potential integer overflows in the following functions:
* mbedtls_md2_update() to be bypassed and cause
* mbedtls_cipher_update()
* mbedtls_ctr_drbg_reseed()
This overflows would mainly be exploitable in 32-bit systems and could
cause buffer bound checks to be bypassed.
