Package-level declarations

This package provides function for working with verifiable credentials, status list credentials, and verifiable presentations.

Specifically, it includes:

• Creation, signing, verification, and general processing of Verifiable Credentials (VCs).

• Creation of StatusList2021Credential

• Presentation Exchange evaluation.

Verifiable Credential

Features

• Create Verifiable Credentials with flexible data types.

• Sign credentials using decentralized identifiers (DIDs).

• Verify the integrity and authenticity of VCs encoded as JSON Web Tokens (JWTs).

• Parse JWT and JSON representations of VCs into VerifiableCredential instances.

Usage:

Creating a Verifiable Credential

Create a new VerifiableCredential with the following parameters:

• type: Type of the credential.

• issuer: Issuer URI.

• subject: Subject URI.

• data: Credential data.

data class StreetCredibility(val localRespect: String, val legit: Boolean)

val vc = VerifiableCredential.create(
  type = "StreetCred",
  issuer = "did:example:issuer",
  subject = "did:example:subject",
  data = StreetCredibility(localRespect = "high", legit = true)
)

Signing a Verifiable Credential

Sign a VerifiableCredential with a DID:

• did: The DID used to sign the credential.

• assertionMethodId: Optional identifier for the assertion method used for signature verification.

val vcJwt = vc.sign(myDid)

Verifying a Verifiable Credential

Verify the integrity and authenticity of a VC JWT:

• vcJwt: The VC in JWT format as a String.

try {
  VerifiableCredential.verify(signedVcJwt)
  println("VC Verification successful!")
} catch (e: SignatureException) {
  println("VC Verification failed: ${e.message}")
}

Parsing a JWT into a Verifiable Credential

Parse a JWT into a VerifiableCredential instance:

vcJwt: The VC JWT as a String.

val vc = VerifiableCredential.parseJwt(vcJwt)

Parsing a JSON into a Verifiable Credential

Parse a JSON string into a VerifiableCredential instance:

• vcJson: The VC JSON as a String.

val vc = VerifiableCredential.fromJson(vcJsonString)

Status List Credentials

StatusListCredentials allows for the creation of status list credentials, such as revocation lists, and the validation of credentials against such lists.

Features

• Create status list credentials with a simple API, allowing the declaration of revocation or suspension status for a list of credentials.

• Validate individual credentials against a status list to check for revocation or suspension.

Usage

Creating a Status List Credential

Creates a new status list credential (e.g., for revocation), use the create method:

• statusListCredentialId: The id used for the resolvable path to the status list credential.

• issuer: The issuer URI of the status list credential.

• statusPurpose: The status purpose of the status list cred, eg: revocation,

• issuedCredentials: The credentials to be included in the status list credential, eg: revoked credentials.

val statusListCredential = StatusListCredential.create(
  "http://example.com/statuslistcred/id123",
  "did:example:issuer",
  StatusPurpose.REVOCATION,
  listOf(vc1, vc2)
)

Validating a Verifiable Credential Against a Credential Status List

To validate whether a credential is part of a status list, you can use the validateCredentialInStatusList method:

val isRevoked = StatusListCredential.validateCredentialInStatusList(vc1, statusListCredential)

Alternatively, to validate a credential against a status list by fetching the status list credential from a URL:

val isRevoked = StatusListCredential.validateCredentialInStatusList(vc1)

Presentation Exchange

PresentationExchange is designed to facilitate the creation of a Verifiable Presentation by providing tools to select and validate Verifiable Credentials against defined criteria.

Features

• Select credentials that satisfy a given presentation definition.

• Validate if a Verifiable Credential JWT satisfies a Presentation Definition.

• Validate input descriptors within Verifiable Credentials.

Usage

Selecting Credentials

Select Verifiable Credentials that meet the criteria of a given presentation definition.

val selectedCredentials = PresentationExchange.selectCredentials(
  credentialsList,
  presentationDefinition
)

Satisfying a Presentation Definition

Validate if a Verifiable Credential JWT satisfies the given presentation definition.

PresentationExchange.satisfiesPresentationDefinition(vcJwt, presentationDefinition)