DIDComm V2 Integration Guide

Overview

The TrustWeave DIDComm plugin integrates didcomm-java (org.didcommx:didcomm:0.3.2) through DidCommCryptoDidcomm. Packing and unpacking use DIDComm.packEncrypted / UnpackParams with forward(false) so messages are not wrapped for mediators unless you add that layer yourself.

What you must provide

suspend (String) -> DidDocument? — Resolve each DID to a W3C-shaped DidDocument that includes key agreement verification methods compatible with the keys you use for encryption (see didcomm-java curve matching).
org.didcommx.didcomm.secret.SecretResolver — Resolve private key material for every kid involved (sender agreement key and recipient agreement key). For tests, use org.trustweave.credential.didcomm.crypto.interop.MapSecretResolver with org.didcommx.didcomm.secret.Secret entries (VerificationMethodType.JSON_WEB_KEY_2020 + JWK string including d is typical).
BlockingDidDocResolver is used internally: your resolver runs on Dispatchers.IO via runBlocking with a per-call timeout (default 30s) because didcomm-java’s DIDDocResolver API is synchronous. Do not call back into DIDComm pack/unpack from the resolver on the same thread (deadlock risk).

Factory methods

Goal	API
Interoperable service	`DidCommFactory.createInMemoryService(kms, resolveDid, secretResolver)`
Interoperable packer	`DidCommFactory.createPacker(kms, resolveDid, secretResolver)`
Unsafe placeholder (dev only)	`DidCommFactory.createInMemoryServiceWithPlaceholderCrypto(...)` / `createPackerWithPlaceholderCrypto(...)`

SPI (`DidCommExchangeProtocolProvider`)

Options map:

useProductionCrypto: defaults to false (placeholder crypto, no SecretResolver). Set to true only with secretResolver; otherwise the provider throws IllegalArgumentException.
secretResolver: SecretResolver — required when useProductionCrypto == true for didcomm-java.

DID document mapping

TrustWeaveDidDocMapper converts TrustWeave DidDocument → didcomm DIDDoc:

Verification methods with publicKeyJwk → JSON_WEB_KEY_2020 (JWK serialized as a string).
keyAgreement and authentication lists use full verification method IDs (did:…#fragment) as in didcomm-java.

Tests

See DidCommDidcommRoundTripTest in the plugin: X25519 OctetKeyPair (Nimbus), JsonWebKey2020 in DID docs, MapSecretResolver, then DidCommFactory.createPacker → pack / unpack.