Add the Issuing Distribution Point extension to all of our end-entity
CRLs. The extension contains the Distribution Point, the URL from
which this CRL is meant to be downloaded. Because our CRLs are
sharded, this URL prevents an on-path attacker from substituting a
different shard than the client expected in order to hide a revocation.
The extension also contains the OnlyContainsUserCerts boolean,
because our CRLs only contain end-entity certificates.
The Distribution Point url is constructed from a configurable base URI,
the issuer's NameID, the shard index, and the suffix ".crl". The base
URI must use the "http://" scheme and must not end with a slash.
openssl displays the IDP extension as:
```
X509v3 Issuing Distribution Point: critical
Full Name:
URI:http://c.boulder.test/66283756913588288/0.crl Only User Certificates
```
Fixes#6410
Add a collection of lints (structured similarly, but not identically,
to zlint's certificate lints) which check a variety of requirements
based on RFC 5280, the Baseline Requirements, and the Mozilla
Root Store Policy.
Add a method to lint CRLs to the existing linter package which
uses its fake issuer to sign the CRL, calls all of the above lints,
and returns all of their findings. Call this new method from within
the CA's new GenerateCRL method immediately before signing
the real CRL using the real issuer.
Fixes#6188
These hashes are useful for OCSP computations, as they are the two
values that are used to uniquely identify the issuer of the given cert in
an OCSP request. Here, they are restricted to SHA1 only, as Boulder
only supports SHA1 for OCSP, as per RFC 5019.
In addition, because the `ID`, `NameID`, `NameHash`, and `KeyHash`
are relatively expensive to compute, introduce a new constructor for
`issuance.Certificate` that computes all four values at startup time and
then simply returns the precomputed values when asked.
Add a check to `wfe2.Certificate` to ensure that the chain we select to
serve with the end-entity cert actually validates the end-entity's
signature. Add new test certificates, generated to match our actual
hierarchy. Update wfe2 tests to use the new test certificates, as well
as new mocks, in order to properly test the new check.
The new test certs and overhauled tests are necessary because the prior
wfe2 tests built and served chains that were not valid, and in
fact could not be valid because they were built with self-signed certs.
Fixes#5225
Aaron Gable