verifiable

package main

import (
	"crypto/ed25519"
	"encoding/json"
	"errors"
	"fmt"
	"time"

	"github.com/hyperledger/aries-framework-go/pkg/doc/signature/ed25519signature2018"
	"github.com/hyperledger/aries-framework-go/pkg/doc/verifiable"
)

//nolint:gochecknoglobals
var (
	privIssuerKey = ed25519.PrivateKey{56, 237, 176, 143, 247, 162, 167, 111, 85, 161, 158, 14, 243, 173, 144, 51, 157, 109, 155, 228, 77, 170, 238, 85, 220, 144, 158, 51, 14, 40, 153, 141, 193, 179, 12, 234, 125, 193, 60, 56, 198, 150, 80, 93, 30, 58, 14, 152, 205, 6, 50, 98, 125, 212, 65, 17, 15, 11, 230, 3, 226, 187, 7, 89}
	issued        = time.Date(2010, time.January, 1, 19, 23, 24, 0, time.UTC)
)

func main() {
	vcJSON := `
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "credentialSchema": [],
  "credentialSubject": {
    "degree": {
      "type": "BachelorDegree",
      "university": "MIT"
    },
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "name": "Jayden Doe",
    "spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
  },
  "expirationDate": "2020-01-01T19:23:24Z",
  "id": "http://example.edu/credentials/1872",
  "issuanceDate": "2009-01-01T19:23:24Z",
  "issuer": {
    "id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
    "name": "Example University"
  },
  "referenceNumber": 83294849,
  "type": [
    "VerifiableCredential",
    "UniversityDegreeCredential"
  ]
}
`

	vc, _, err := verifiable.NewCredential([]byte(vcJSON))
	if err != nil {
		fmt.Println(fmt.Errorf("failed to decode VC JSON: %w", err))
	}

	err = vc.AddLinkedDataProof(&verifiable.LinkedDataProofContext{
		Created:                 &issued,
		SignatureType:           "Ed25519Signature2018",
		Suite:                   ed25519signature2018.New(ed25519signature2018.WithSigner(getSigner(privIssuerKey))),
		SignatureRepresentation: verifiable.SignatureJWS,
		VerificationMethod:      "did:example:123456#key1",
	})
	if err != nil {
		fmt.Println(fmt.Errorf("failed to add linked data proof: %w", err))
	}

	vcJSONWithProof, err := json.MarshalIndent(vc, "", "\t")
	if err != nil {
		fmt.Println(fmt.Errorf("failed to marshal VC to JSON: %w", err))
	}

	fmt.Println(string(vcJSONWithProof))

	//nolint
	

Output:

package main

import (
	"crypto/ed25519"
	"errors"
	"fmt"
	"time"

	"github.com/hyperledger/aries-framework-go/pkg/doc/verifiable"
)

//nolint:gochecknoglobals
var privIssuerKey = ed25519.PrivateKey{56, 237, 176, 143, 247, 162, 167, 111, 85, 161, 158, 14, 243, 173, 144, 51, 157, 109, 155, 228, 77, 170, 238, 85, 220, 144, 158, 51, 14, 40, 153, 141, 193, 179, 12, 234, 125, 193, 60, 56, 198, 150, 80, 93, 30, 58, 14, 152, 205, 6, 50, 98, 125, 212, 65, 17, 15, 11, 230, 3, 226, 187, 7, 89}

func main() {
	// The Holder kept the credential serialized to JSON in her personal verifiable credential wallet.
	vcStrFromWallet := `
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "credentialSchema": [],
  "credentialSubject": {
    "degree": {
      "type": "BachelorDegree",
      "university": "MIT"
    },
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "name": "Jayden Doe",
    "spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
  },
  "expirationDate": "2020-01-01T19:23:24Z",
  "id": "http://example.edu/credentials/1872",
  "issuanceDate": "2010-01-01T19:23:24Z",
  "issuer": {
    "id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
    "name": "Example University"
  },
  "referenceNumber": 83294847,
  "type": [
    "VerifiableCredential",
    "UniversityDegreeCredential"
  ]
}
`

	// The Holder wants to send the credential to the Verifier in JWS.
	vc, _, err := verifiable.NewCredential([]byte(vcStrFromWallet))
	if err != nil {
		fmt.Println(fmt.Errorf("failed to decode VC JSON: %w", err))
	}

	jwtClaims, err := vc.JWTClaims(true)
	if err != nil {
		fmt.Println(fmt.Errorf("failed to marshal JWT claims of VC: %w", err))
	}

	jws, err := jwtClaims.MarshalJWS(verifiable.EdDSA, getSigner(privIssuerKey), "")
	if err != nil {
		fmt.Println(fmt.Errorf("failed to sign VC inside JWT: %w", err))
	}
	// The Holder passes JWS to Verifier

	fmt.Println(jws)

	//nolint
	

Output:

// A Holder loads the credential from verifiable credential wallet in order to send to Verifier.
// She embedded the credential into presentation and sends it to the Verifier in JWS form.
vcStrFromWallet := `
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "credentialSchema": [],
  "credentialSubject": {
    "degree": {
      "type": "BachelorDegree",
      "university": "MIT"
    },
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "name": "Jayden Doe",
    "spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
  },
  "expirationDate": "2020-01-01T19:23:24Z",
  "id": "http://example.edu/credentials/1872",
  "issuanceDate": "2010-01-01T19:23:24Z",
  "issuer": {
    "id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
    "name": "Example University"
  },
  "referenceNumber": 83294847,
  "type": [
    "VerifiableCredential",
    "UniversityDegreeCredential"
  ]
}
`

vc, _, err := verifiable.NewCredential([]byte(vcStrFromWallet))
if err != nil {
	fmt.Println(fmt.Errorf("failed to decode VC JSON: %w", err))
}

vp, err := vc.Presentation()
if err != nil {
	fmt.Println(fmt.Errorf("failed to build VP from VC: %w", err))
}

vp.ID = "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c5"
vp.Holder = "did:example:ebfeb1f712ebc6f1c276e12ec21"

aud := []string{"did:example:4a57546973436f6f6c4a4a57573"}

jwtClaims, err := vp.JWTClaims(aud, true)
if err != nil {
	fmt.Println(fmt.Errorf("failed to create JWT claims of VP: %w", err))
}

jws, err := jwtClaims.MarshalJWS(verifiable.EdDSA, getSigner(privHolderKey), "")
if err != nil {
	fmt.Println(fmt.Errorf("failed to sign VP inside JWT: %w", err))
}

fmt.Println(jws)

//nolint

Output:

// The Holder kept the presentation serialized to JSON in her personal verifiable credential wallet.
vpStrFromWallet := `
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "id": "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c5",
  "type": [
    "VerifiablePresentation",
    "UniversityDegreeCredential"
  ],
  "verifiableCredential": [
    {
      "@context": [
        "https://www.w3.org/2018/credentials/v1",
        "https://www.w3.org/2018/credentials/examples/v1"
      ],
      "credentialSchema": [],
      "credentialSubject": {
        "degree": {
          "type": "BachelorDegree",
          "university": "MIT"
        },
        "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
        "name": "Jayden Doe",
        "spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
      },
      "expirationDate": "2020-01-01T19:23:24Z",
      "id": "http://example.edu/credentials/1872",
      "issuanceDate": "2010-01-01T19:23:24Z",
      "issuer": {
        "id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
        "name": "Example University"
      },
      "referenceNumber": 83294847,
      "type": [
        "VerifiableCredential",
        "UniversityDegreeCredential"
      ]
    }
  ],
  "holder": "did:example:ebfeb1f712ebc6f1c276e12ec21"
}
`

// The Holder wants to send the presentation to the Verifier in JWS.
vp, err := verifiable.NewPresentation([]byte(vpStrFromWallet))
if err != nil {
	fmt.Println(fmt.Errorf("failed to decode VP JSON: %w", err))
}

aud := []string{"did:example:4a57546973436f6f6c4a4a57573"}

jwtClaims, err := vp.JWTClaims(aud, true)
if err != nil {
	fmt.Println(fmt.Errorf("failed to create JWT claims of VP: %w", err))
}

jws, err := jwtClaims.MarshalJWS(verifiable.EdDSA, getSigner(privHolderKey), "")
if err != nil {
	fmt.Println(fmt.Errorf("failed to sign VP inside JWT: %w", err))
}

fmt.Println(jws)

//nolint

Output:

vp := &verifiable.Presentation{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1"},
	ID:     "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c",
	Type:   []string{"VerifiablePresentation"},
	Holder: "did:example:ebfeb1f712ebc6f1c276e12ec21",
}

vc := &verifiable.Credential{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1",
		"https://www.w3.org/2018/credentials/examples/v1"},
	ID: "http://example.edu/credentials/1872",
	Types: []string{
		"VerifiableCredential",
		"UniversityDegreeCredential"},
	Subject: UniversityDegreeSubject{
		ID:     "did:example:ebfeb1f712ebc6f1c276e12ec21",
		Name:   "Jayden Doe",
		Spouse: "did:example:c276e12ec21ebfeb1f712ebc6f1",
		Degree: UniversityDegree{
			Type:       "BachelorDegree",
			University: "MIT",
		},
	},
	Issuer: verifiable.Issuer{
		ID:   "did:example:76e12ec712ebc6f1c221ebfeb1f",
		Name: "Example University",
	},
	Issued:  &issued,
	Expired: &expired,
	Schemas: []verifiable.TypedID{},
	CustomFields: map[string]interface{}{
		"referenceNumber": 83294847,
	},
}

err := vp.SetCredentials(vc)
if err != nil {
	fmt.Println(fmt.Errorf("failed to set credentials of VP: %w", err))
}

// json.MarshalIndent() calls Presentation.MarshalJSON()
vpJSON, err := json.MarshalIndent(vp, "", "\t")
if err != nil {
	fmt.Println(fmt.Errorf("failed to marshal VP to JSON: %w", err))
}

fmt.Println(string(vpJSON))

Output:

{
	"@context": [
		"https://www.w3.org/2018/credentials/v1"
	],
	"id": "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c",
	"type": [
		"VerifiablePresentation"
	],
	"verifiableCredential": [
		{
			"@context": [
				"https://www.w3.org/2018/credentials/v1",
				"https://www.w3.org/2018/credentials/examples/v1"
			],
			"credentialSchema": [],
			"credentialSubject": {
				"degree": {
					"type": "BachelorDegree",
					"university": "MIT"
				},
				"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
				"name": "Jayden Doe",
				"spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
			},
			"expirationDate": "2020-01-01T19:23:24Z",
			"id": "http://example.edu/credentials/1872",
			"issuanceDate": "2010-01-01T19:23:24Z",
			"issuer": {
				"id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
				"name": "Example University"
			},
			"referenceNumber": 83294847,
			"type": [
				"VerifiableCredential",
				"UniversityDegreeCredential"
			]
		}
	],
	"holder": "did:example:ebfeb1f712ebc6f1c276e12ec21"
}

vp := &verifiable.Presentation{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1"},
	ID:     "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c",
	Type:   []string{"VerifiablePresentation"},
	Holder: "did:example:ebfeb1f712ebc6f1c276e12ec21",
}

vc := verifiable.Credential{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1",
		"https://www.w3.org/2018/credentials/examples/v1"},
	ID: "http://example.edu/credentials/1872",
	Types: []string{
		"VerifiableCredential",
		"UniversityDegreeCredential"},
	Subject: UniversityDegreeSubject{
		ID:     "did:example:ebfeb1f712ebc6f1c276e12ec21",
		Name:   "Jayden Doe",
		Spouse: "did:example:c276e12ec21ebfeb1f712ebc6f1",
		Degree: UniversityDegree{
			Type:       "BachelorDegree",
			University: "MIT",
		},
	},
	Issuer: verifiable.Issuer{
		ID:   "did:example:76e12ec712ebc6f1c221ebfeb1f",
		Name: "Example University",
	},
	Issued:  &issued,
	Expired: &expired,
	Schemas: []verifiable.TypedID{},
}

// Put JWS form of VC into VP.
vcJWTClaims, err := vc.JWTClaims(true)
if err != nil {
	fmt.Println(fmt.Errorf("failed to set credentials of VP: %w", err))
}

vcJWS, err := vcJWTClaims.MarshalJWS(verifiable.EdDSA, getSigner(privIssuerKey), "i-kid")
if err != nil {
	fmt.Println(fmt.Errorf("failed to sign VC JWT: %w", err))
}

err = vp.SetCredentials(vcJWS)
if err != nil {
	fmt.Println(fmt.Errorf("failed to set credentials of VP: %w", err))
}

// Marshal VP to JWS as well.

vpJWTClaims, err := vp.JWTClaims(nil, true)
if err != nil {
	fmt.Println(fmt.Errorf("failed to create JWT claims of VP: %w", err))
}

vpJWS, err := vpJWTClaims.MarshalJWS(verifiable.EdDSA, getSigner(privHolderKey), "h-kid")
if err != nil {
	fmt.Println(fmt.Errorf("failed to sign VP inside JWT: %w", err))
}

// Decode VP from JWS.
// Note that VC-s inside will be decoded as well. If they are JWS, their signature is verified
// and thus we need to make sure the public key fetcher can access the
vp, err = verifiable.NewPresentation(
	[]byte(vpJWS),
	verifiable.WithPresPublicKeyFetcher(func(issuerID, keyID string) (interface{}, error) {
		switch issuerID {
		case "did:example:76e12ec712ebc6f1c221ebfeb1f":
			return privIssuerKey.Public(), nil
		case "did:example:ebfeb1f712ebc6f1c276e12ec21":
			return privHolderKey.Public(), nil
		default:
			return nil, fmt.Errorf("unexpected key: %s", keyID)
		}
	}))
if err != nil {
	fmt.Println(fmt.Errorf("failed to decode VP JWS: %w", err))
}

// Get credentials in binary form.
vpCreds, err := vp.MarshalledCredentials()
if err != nil {
	fmt.Println(fmt.Errorf("failed to get marshalled credentials from decoded presentation: %w", err))
}

if len(vpCreds) != 1 {
	fmt.Println("Expected 1 credential inside presentation")
}

// Decoded credential. Note that no public key fetcher is passed as the VC was already decoded (and proof verified)
// when VP was decoded.
vcDecoded, _, err := verifiable.NewCredential(vpCreds[0])
if err != nil {
	fmt.Println(fmt.Errorf("failed to decode VC: %w", err))
}

vcDecodedJSON, err := json.MarshalIndent(vcDecoded, "", "\t")
if err != nil {
	fmt.Println(fmt.Errorf("failed to marshal VP to JSON: %w", err))
}

fmt.Println(string(vcDecodedJSON))

Output:

{
	"@context": [
		"https://www.w3.org/2018/credentials/v1",
		"https://www.w3.org/2018/credentials/examples/v1"
	],
	"credentialSchema": [],
	"credentialSubject": {
		"degree": {
			"type": "BachelorDegree",
			"university": "MIT"
		},
		"id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
		"name": "Jayden Doe",
		"spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
	},
	"expirationDate": "2020-01-01T19:23:24Z",
	"id": "http://example.edu/credentials/1872",
	"issuanceDate": "2010-01-01T19:23:24Z",
	"issuer": {
		"id": "did:example:76e12ec712ebc6f1c221ebfeb1f",
		"name": "Example University"
	},
	"type": [
		"VerifiableCredential",
		"UniversityDegreeCredential"
	]
}

// Holder wants to send 2 credentials to Verifier
vp := &verifiable.Presentation{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1"},
	ID:     "urn:uuid:3978344f-8596-4c3a-a978-8fcaba3903c",
	Type:   []string{"VerifiablePresentation"},
	Holder: "did:example:ebfeb1f712ebc6f1c276e12ec21",
}

// The first VC is created on fly (or just decoded using NewCredential).
vc := &verifiable.Credential{
	Context: []string{
		"https://www.w3.org/2018/credentials/v1",
		"https://www.w3.org/2018/credentials/examples/v1"},
	ID: "http://example.edu/credentials/1872",
	Types: []string{
		"VerifiableCredential",
		"UniversityDegreeCredential"},
	Subject: UniversityDegreeSubject{
		ID:     "did:example:ebfeb1f712ebc6f1c276e12ec21",
		Name:   "Jayden Doe",
		Spouse: "did:example:c276e12ec21ebfeb1f712ebc6f1",
		Degree: UniversityDegree{
			Type:       "BachelorDegree",
			University: "MIT",
		},
	},
	Issuer: verifiable.Issuer{
		ID:   "did:example:76e12ec712ebc6f1c221ebfeb1f",
		Name: "Example University",
	},
	Issued:  &issued,
	Expired: &expired,
	Schemas: []verifiable.TypedID{},
	CustomFields: map[string]interface{}{
		"referenceNumber": 83294847,
	},
}

// The second VC is provided in JWS form (e.g. kept in the wallet in that form).
vcJWS := "eyJhbGciOiJFZERTQSIsImtpZCI6IiIsInR5cCI6IkpXVCJ9.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.AHn2A2q5DL1heX3_izq_2yrsBDhoZ6BGGKhoRvhfMnMUuuOnBOdekdTg-dfUMJgipXRql_6WzBUIj4wTFehXCw" // nolint:lll

err := vp.SetCredentials(vc, vcJWS)
if err != nil {
	fmt.Println(fmt.Errorf("failed to set credentials of VP: %w", err))
}

Output: