Fix an issue that caused valid certificates being rejected whenever an
expired or not yet valid version of the trusted certificate was before the
valid version in the trusted certificate list.
Remove check on the pathLenConstraint value when looking for a parent to the
EE cert, as the constraint is on the number of intermediate certs below the
parent, and that number is always 0 at that point, so the constraint is always
satisfied.
The check was actually off-by-one, which caused valid chains to be rejected
under the following conditions:
- the parent certificate is not a trusted root, and
- it has pathLenConstraint == 0 (max_pathlen == 1 in our representation)
fixes#280
* mbedtls-1.3:
Use own implementation of strsep()
Add Changelog entries for this branch
Use symbolic constants in test data
Fixed pathlen contraint enforcement.
Additional corner cases for testing pathlen constrains. Just in case.
Added test case for pathlen constrains in intermediate certificates
If len is large enough, when cast to an int it will be negative and then the
test if( len > MAX_PATH - 3 ) will not behave as expected.
Ref: IOTSSL-518
backport of 261faed725
This helps in the case where an intermediate certificate is directly trusted.
In that case we want to ignore what comes after it in the chain, not only for
performance but also to avoid false negatives (eg an old root being no longer
trusted while the newer intermediate is directly trusted).
see #220
backport of fdbdd72
If the top certificate occurs twice in trust_ca (for example) it would
not be good for the second instance to be checked with check_path_cnt
reduced twice!
Still todo:
- handle MGF-hash != sign-hash
- check effective salt len == announced salt len
- add support in the PK layer so that we don't have to bypass it here
