Since we reference this error enum from mod.rs, it should not
be rego-specific. The error variants are not specific to OPA,
so lift them into mod.rs.

Now, someone writing an alternative policy engine
can use the same errors.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

This commit allows the AS to issue EAR tokens with the
help of the rust-ear crate.

EAR tokens require particular claims. This creates a binding
between the AS policy and the EAR token.
Specifically, the policy engine must return an EAR appraisal.
The policy engine is still generic. Multiple policy engines
could be implemented as long as they create an appraisal.

Token generation is no longer generic.
Since the policy engine, will always return an appraisal,
we must generate an EAR token.
This commit removes the simple token issuer
and replaces the TokenProvider trait with a struct.

The KBS will still be able to validate many different tokens,
but this commit changes the AS to only issue EAR tokens.

There are a few other changes, including that the policy engine
no longer takes multiple policies. For now, we only evaluate
the first policy in the policy list, but future commits will
change this convention so that we only ever think about one
policy for the attestation service (until we introduce support
for validating multiple devices at once).

This commit also removes the flattening of the tcb claims.
With the EAR tokens, we store the TEE pubkey the tcb claims.
If these claims are flattened, we will need to do some extra
work to deserialize the key.

The TCB claims are currently flattened so that we can use the
key names as the input to the RVPS. This commit breaks this
functionality, but a future commit will change the way
the RVPS works to accomodate. There isn't a direct pairing
between claim names and reference values, so there is no
reason to keep flattening all the claims, especially
because the flattening code has some corner cases
that it does not support.

This commit also adds the init_data_claims and
runtime_data_claims to the tcb claims as long as
the corresponding claims about the hashes are already there.
This will allow the init_data to travel with the token,
which will be convenient except if the init_data is too big.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

For EAR tokens we require the public key to be set.
There is no option to deserialize a token without
validating the signature.

The EAR verifier returns the submods as JSON.
This means that some information, such as the verifier id
is not propogated.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

A keypair is required to sign and validate the attestation token.
In the past this was optional, but now it is not.

Update the docker-compose manifest and configs to pass in this
new keypair and update the docs to tell people how to generate it.

This does complicate the user experience, but things are not secure
without it. That said, we may be able to implement this automatically
in a future PR.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

Now we need to provision a keypair for signing and
validatig the attestation tokens.

Add this keypair to the docker e2e test

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

The sample attester is enabled by default.
Remove setting the environment variable that used to
enable it.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

We now require a keypair for signing/validating the attestation
token. Add this keypair to our k8s deployment tooling.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

We now require a keypair to sign/validate the attestation
token. Add this keypair to the e2e test.

Interestingly, we were using a keypair for validating
the old CoCo token in this test, but only for the
passport mode. Even in background check mode, this keypair
is required or the token won't be validated at all.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

Previously we expected the caller of the RVPS to provide
a name for the reference value that they wanted.
In the AS we were flattening the TCB claims to get this name.
Ultimately, the names of the TCB claims do not map directly onto
the names of the required reference values.

This changes the interface to have the RVPS determine which
reference values to send. At the moment, it simply sends all of them.

This allows the reference values that are used to mostly be set within
the policy itself, which is probably a good idea.

In the future, the RVPS should be improved to include a context
abtraction that allows groups of reference values to be provided to the
AS.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

When generating EAR tokens, it seems best to only use one policy
at a time (per-submod).

In the commit that introduces EAR token generation in the AS,
we simply ignore all policies in the policy_ids list except
the first one.

Here, we change the interface so that only one policy can be
provided in an attestation request

The KBS always sets one policy ("default"), anyway.
In the future, we should figure out how to set this policy id
more dynamically.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

THe skeleton for a policy that can be used to validate the TCB
claims of all platforms in the context of confidential
containers.

Only sample and snp are supported currently, but this should give
a good idea of how to extend the policy to other platforms.

There are a few tweaks we can make later, such as supporting
`>` or `<` comparisons.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

Update the attestestion service policy docs to describe the
requirements for policies that will generate EAR tokens.

Also update various example and default policies.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

If we want to support multiple types of tokens,
we'll need to decouple the claims that are evaluated in the policy
from the poliicy engine.

This allows the token broker to specify a set of rules that
the policy engine will evaluate. Then, the token broker
will get the unprocessed output from the policy engine
and do what it needs to.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>

Add back the support for the EAR token. This commit is still rough.

Signed-off-by: Tobin Feldman-Fitzthum <tobin@ibm.com>