Complete Integration of Crypto Library into Kritis

[acamadeo]

This can be broken into stages:

Immediately:

• [x] Replace RawAttestation with cryptolib.Attestation (see #505).
• [x] Delete CreateAttestationSignature (unused except in tests), VerifySignature and VerifyPgpSignature in AtomicContainerSig.
• [x] Delete VerifyMessageAttestation, GetPlainMessage in attestation.go.
• [ ] Refactor validating_transport_test.

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After cryptolib's VerifyAttestation returns an AuthenticatedAttestation:

• [ ] Delete ValidatedAttestation (source).
• [ ] Refactor GetValidatedAttestations to return AuthenticatedAttestations (source).

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After implementing PGP signing:

• [x] Delete CreateMessageAttestation in attestation.go.
• [ ] Convert AtomicContainerSig into a simple payload constructor.

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If command line interface allows you to create new keys:

• [ ] Replace calls to NewPgpKey with calls to CLI.
• [ ] Delete pgpkey.go

[ooq]

Thanks for tracking this!

[acamadeo]

Completed "Replace RawAttestation..." with #519

[acamadeo]

Completed "Delete CreateAttestationSignature..." with #525

[acamadeo]

Completed "Delete VerifyMessageAttestation..." with #526