vc-verifier

VC Verifier Library is a comprehensive Java/Kotlin library designed to enable the validation and verification of Verifiable Credentials (VCs), a crucial component in modern decentralized identity systems. This library provides a robust mechanism for verifying the authenticity and integrity of VCs, ensuring that the claims made within the credential are both valid and trustworthy.

🚨 Breaking Changes

From Version release-1.5.x onward:

❗ Required Update in Imports

Replace:

import io.mosip.vercred.vcverifier.publicKey.PublicKeyGetterFactory;
import io.mosip.vercred.vcverifier.publicKey.PublicKeyGetter;
import io.mosip.vercred.vcverifier.DidWebResolver;
import io.mosip.vercred.vcverifier.publicKey.impl.DidWebPublicKeyGetter;
import io.mosip.vercred.vcverifier.publicKey.impl.DidJwkPublicKeyGetter;
import io.mosip.vercred.vcverifier.publicKey.impl.DidKeyPublicKeyGetter;
import io.mosip.vercred.vcverifier.publicKey.impl.HttpsPublicKeyGetter;

With:

import io.mosip.vercred.vcverifier.keyResolver.PublicKeyResolverFactory;
import io.mosip.vercred.vcverifier.keyResolver.PublicKeyResolver;
import io.mosip.vercred.vcverifier.keyResolver.types.did.DidPublicKeyResolver;
import io.mosip.vercred.vcverifier.keyResolver.types.did.DidWebPublicKeyResolver;
import io.mosip.vercred.vcverifier.keyResolver.types.did.DidJwkPublicKeyResolver;
import io.mosip.vercred.vcverifier.keyResolver.types.did.DidKeyPublicKeyResolver;
import io.mosip.vercred.vcverifier.keyResolver.types.http.HttpsPublicKeyResolver;

Key Features:

• VC Validation: The library validates the structure, signatures, and expiration of Verifiable Credentials to ensure they conform to the W3C VC standards.
• Cryptographic Signature Verification: Supports the verification of cryptographic signatures using public keys, including EdDSA, RSA, and other supported algorithms, ensuring the integrity of the credential.
• Status Check: It includes mechanisms to check the current status of credentials, allowing applications to determine if a credential is still valid or has been invalidated.
• Compatibility with Various Data Models: It supports multiple VC data models (e.g., VC 1.1, VC 2.0), ensuring compatibility across various decentralized identity systems.

Supported VC Formats and Their Signature Mechanisms

VC format	Issuer Signature Mechanism	Verification Algorithms	Signature Suites / Proof Types
ldp_vc	Linked Data Proof	PS256, RS256, EdDSA (Ed25519)	RsaSignature2018, Ed25519Signature2018, Ed25519Signature2020, EcdsaSecp256k1Signature2019
mso_mdoc	COSE (CBOR Object Signing and Encryption)	ES256	Uses COSE_Sign1
vc+sd-jwt	X.509 Certificate (Currently, JWT VC Issuer Metadata is not supported)	PS256, RS256,ES256, EdDSA (Ed25519)	-
dc+sd-jwt	X.509 Certificate (Currently, JWT VC Issuer Metadata is not supported)	PS256, RS256,ES256, EdDSA (Ed25519)	-

Project Structure

io.mosip.vercred.vcverifier

• constants
• credentialverifier
  • types
  • validator
  • verifier
  • statusChecker
• data
• exception
• keyResolver
• signature
  • impl
• utils
• CredentialVerifier.kt
• PresentationVerifier.kt

Package Description

• constants - All Validator and Verifier constants are declared in this package.
• credentialverifier - CredentialFactory for different credential formats are declared in this package. It also consists of classes for different credential formats.
• data - It has data classes for Validation Status and Verification Result.
• exception - Custom exceptions are defined in this package.
• keyResolver - PublicKeyResolverFactory for different type of verification method types are declared in this package. It has support for DID(web, key, jwk) and HTTP verification methods.
• signature - Interface and Implementations for multiple Signature Verification are available in this package.
• utils - It helper classes and methods that provide reusable and general-purpose functionalities across the project.
• CredentialVerifier.kt - The CredentialVerifier.kt file serves as the main entry point to the VC Verifier Library. This class provides the primary interface for interacting with the library and encapsulates all the core functionalities related to validating and verifying Verifiable Credentials (VCs). It also performs a revocation check by calling the method isRevoked(credential).
• PresentationVerifier.kt - The PresentationVerifier.kt file is a dedicated class within the VC Verifier Library that focuses on the verification of Verifiable Presentations (VPs). This class provides methods and functionalities specifically designed to handle the unique aspects of VPs, including their structure, proof mechanisms, and the embedded Verifiable Credentials they may contain.

Integrating jar to Maven Project

Add Vc-Verifier in pom.xml

    <dependency>
        <groupId>io.mosip</groupId>
        <artifactId>vcverifier-jar</artifactId>
        <version>{{version-number}}</version>
    </dependency>

To integrate vc-verifier library into a Maven project , include below additional dependencies that are not managed via the pom.xml file of vc-verifier library.

    <dependency>
        <groupId>com.android.identity</groupId>
        <artifactId>identity-credential</artifactId>
        <version>20231002</version>
    </dependency>
    <dependency>
        <groupId>info.weboftrust</groupId>
        <artifactId>ld-signatures-java</artifactId>
        <version>1.5.0</version>
    </dependency>
    <dependency>
        <groupId>decentralized-identity</groupId>
        <artifactId>jsonld-common-java</artifactId>
        <version>1.8.0</version>
    </dependency>

Integrating aar to Gradle Project

To integrate vc-verifier library into a Gradle project , add below line in module level build.gradle.

dependencies {
	implementation("io.mosip:vc-verifier-aar:{{version-number}}")
}

To avoid Duplicate classes error while building the application, include the below exclusion strategy in the build.gradle file.

configurations.all {  
  resolutionStrategy {  
  exclude(module = "bcprov-jdk15to18")  
  exclude(module = "bcutil-jdk18on")  
  exclude(module = "bcprov-jdk15on")  
  exclude(module = "bcutil-jdk15on")  
  exclude(module = "titanium-json-ld")  
  }  
}

Note: version-number should be replaced with the actual version of the library from Maven Central.

References:

• Data Model 1.1
• Data Model 2.0
• IETF SD-JWT DRAFT