This PR is a small code change with a lot of new test data.
[In OpenSSL, there are two flags that configure CRL checks. Coping
relevant
section:](https://www.openssl.org/docs/man1.0.2/man3/X509_VERIFY_PARAM_get_depth.html)
> - X509_V_FLAG_CRL_CHECK enables CRL checking for the certificate chain
leaf certificate. An error occurs if a suitable CRL cannot be found.
> - X509_V_FLAG_CRL_CHECK_ALL enables CRL checking for the entire
certificate chain.
We currently only set `X509_V_FLAG_CRL_CHECK`, so we will only ever
check if the leaf certificate is revoked. We should check the whole
chain. I am open to making this a user configuration if we want to do it
that way, but we certainly need to be able to check the whole chain.
So, this PR contains the small code change in
`ssl_transport_security.cc` to use the `X509_V_FLAG_CRL_CHECK_ALL` flag.
Then the rest of the changes are in tests. I've added all the necessary
files to have a chain built that looks as follows
`Root CA -> Revoked Intermediate CA -> Leaf Certificate`, and added a
test for this case as well.
You can verify that on master this new test will fail (i.e. the
handshake will succeed even though the intermediate CA is revoked) by
checking out this branch, running `git checkout master --
./src/core/tsi/ssl_transport_security.cc`, then running the test.
I also slightly reorganized test/core/tsi/test_creds/ so that the CRLs
are in their own directory, which is the way our API intends to accept
CRLs.
Gregory Cooke
a4f345ff96