nuts-foundation/nuts-node

/*
 * Copyright (C) 2022 Nuts community
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

package issuer

import (
    "context"
    "io"

    ssi "github.com/nuts-foundation/go-did"
    "github.com/nuts-foundation/go-did/did"
    "github.com/nuts-foundation/go-did/vc"
    "github.com/nuts-foundation/nuts-node/core"
    "github.com/nuts-foundation/nuts-node/crypto"
    "github.com/nuts-foundation/nuts-node/vcr/credential"
)

// Publisher publishes new credentials and revocations to a channel. Used by a credential issuer.
type Publisher interface {
    // PublishCredential publishes the credential to the outside world.
    // A public flag is used to indicate if everybody can see the credential, or just the involved parties.
    PublishCredential(ctx context.Context, verifiableCredential vc.VerifiableCredential, public bool) error
    // PublishRevocation publishes the revocation to the outside world.
    // It indicates to the network a credential can no longer be used.
    PublishRevocation(ctx context.Context, revocation credential.Revocation) error
}

type keyResolver interface {
    ResolveAssertionKey(ctx context.Context, issuerDID did.DID) (crypto.Key, error)
}

// Issuer is a role in the network for a party who issues credentials about a subject to a holder.
type Issuer interface {
    // Issue issues a credential by signing an unsigned credential.
    Issue(ctx context.Context, template vc.VerifiableCredential, options CredentialOptions) (*vc.VerifiableCredential, error)
    // Revoke credential with credentialID.
    // It returns types.ErrNotFound if the credential is not issued by this node, or types.ErrRevoked if already revoked.
    // The revocation will be published to the network by the issuers Publisher if issuer by did:nuts.
    Revoke(ctx context.Context, credentialID ssi.URI) (*credential.Revocation, error)
    // StatusList returns the StatusList2021Credential tracking status list revocations for this issuer at /iam/issuerID/status/page.
    // Returns types.ErrNotFound when no credential statuses have been published using the issuer and page combination.
    StatusList(ctx context.Context, issuer did.DID, page int) (*vc.VerifiableCredential, error)
    CredentialSearcher
}

// Store defines the interface for an issuer store.
// An implementation stores all the issued credentials and the revocations.
type Store interface {
    core.Diagnosable
    // GetCredential retrieves an issued credential by ID
    // Returns a types.ErrNotFound when the credential is not in the store
    // Returns a types.ErrMultipleFound when there are multiple credentials with this ID in the store
    GetCredential(id ssi.URI) (*vc.VerifiableCredential, error)
    // StoreCredential writes a VC to storage.
    StoreCredential(vc vc.VerifiableCredential) error
    // GetRevocation returns a revocation for a credential ID
    // Returns a types.ErrNotFound when the revocation is not in the store
    // Returns a types.ErrMultipleFound when there are multiple revocations for this credential ID in the store
    GetRevocation(id ssi.URI) (*credential.Revocation, error)
    // StoreRevocation writes a revocation to storage.
    StoreRevocation(r credential.Revocation) error
    CredentialSearcher
    // Closer closes and frees the underlying resources the store uses.
    io.Closer
}

// CredentialSearcher defines the functions to resolve or search for credentials.
// It is a separate interface from Store so when an object only needs resolving, it only needs the resolver.
type CredentialSearcher interface {
    // SearchCredential searches for issued credentials
    // If the passed context is empty, it'll not be part of the search query on the DB.
    SearchCredential(credentialType ssi.URI, issuer did.DID, subject *ssi.URI) ([]vc.VerifiableCredential, error)
}

// CredentialOptions specifies options for issuing a credential.
type CredentialOptions struct {
    // Format specifies the proof format for the issued credential. If not set, it defaults to JSON-LD.
    // Valid options are: ldp_vc or jwt_vc
    Format string
    // Publish param indicates if the credential should be published to the network.
    Publish bool
    // Public param instructs the Publisher to publish the param with a certain visibility.
    Public bool
    // WithStatusListRevocation adds a 'revocation' entry to the credential. Requires Publish to be False.
    WithStatusListRevocation bool
}