vck-longfellow/at.asitplus.wallet.lib.zk.iso/LongfellowBackend

LongfellowBackend

class LongfellowBackend : IsoMdocZkBackend(source)

An IsoMdocZkBackend implementation backed by the Longfellow-ZK zero-knowledge system (via the Multipaz library).

This class handles proof generation and verification for ISO/IEC 18013-5 mdoc credentials using Longfellow-ZK circuits. It bridges internal domain models (ZkSystemSpec, ZkDocument, SessionTranscript) to and from Multipaz-native data structures.

Lifecycle: Before invoking operations that rely on backend capabilities (e.g., supports, generate, load), the backend MUST be initialized by calling initialize.

Constructors

LongfellowBackend

constructor()

Types

Companion

object Companion

Properties

paramSerializers

open override val paramSerializers: Map<String, KSerializer<*>>

Maps parameter key names to their expected kotlinx KSerializer instances for serializing and deserializing zero-knowledge system specifications.

system

open override val system: String

The identifier string of the underlying zero-knowledge engine (e.g., "longfellow-libzk-v1").

zkSystemSpecs

open override val zkSystemSpecs: List<ZkSystemSpec>

The list of zero-knowledge system specifications available in this backend.

Functions

generate

open suspend override fun generate(request: PresentationRequestParameters, credential: SubjectCredentialStore.StoreEntry.Iso, requestedClaims: Collection<NormalizedJsonPath>, requestedZkSystemSpecs: List<ZkSystemSpec>, keyMaterial: KeyMaterial): KmmResult<IsoMdocZkProof>

Generates a zero-knowledge proof for a given credential and requested claim paths.

initialize

open suspend override fun initialize(): KmmResult<Unit>

Initializes the Longfellow-ZK backend engine safely across coroutines. Loads default circuits into memory. If already initialized, this operation is a no-op.

load

open override fun load(zkDocument: ZkDocument, sessionTranscript: SessionTranscript, zkSystemSpec: ZkSystemSpec): KmmResult<IsoMdocZkProof>

Constructs an IsoMdocZkProof handle from an existing ZkDocument for verification.

supports

open override fun supports(candidate: ZkSystemSpec): Boolean

Determines whether the given candidate specification is supported by this backend.