feat: add support of multibase encoding for proofValue.

Signed-off-by: Volodymyr Kubiv <volodymyr.kubiv@euristiq.com>

pkg/doc/did/doc.go

@@ -24,6 +24,7 @@ import (
 	"github.com/hyperledger/aries-framework-go/pkg/common/model"
 	"github.com/hyperledger/aries-framework-go/pkg/doc/jose/jwk"
 	"github.com/hyperledger/aries-framework-go/pkg/doc/signature/jsonld"
+	sigproof "github.com/hyperledger/aries-framework-go/pkg/doc/signature/proof"
 	"github.com/hyperledger/aries-framework-go/pkg/doc/signature/verifier"
 )
 
@@ -597,9 +598,9 @@ func populateProofs(context, didID, baseURI string, rawProofs []interface{}) ([]
 			proofKey = jsonldSignatureValue
 		}
 
-		proofValue, err := base64.RawURLEncoding.DecodeString(stringEntry(emap[proofKey]))
+		proofValue, err := sigproof.DecodeProofValue(stringEntry(emap[proofKey]), stringEntry(emap[jsonldType]))
 		if err != nil {
-			return nil, err
+			return nil, errors.New("unsupported encoding")
 		}
 
 		nonce, err := base64.RawURLEncoding.DecodeString(stringEntry(emap[jsonldNonce]))
@@ -1438,7 +1439,7 @@ func populateRawProofs(context, didID, baseURI string, proofs []Proof) []interfa
 			jsonldType:         p.Type,
 			jsonldCreated:      p.Created,
 			jsonldCreator:      creator,
-			k:                  base64.RawURLEncoding.EncodeToString(p.ProofValue),
+			k:                  sigproof.EncodeProofValue(p.ProofValue, p.Type),
 			jsonldDomain:       p.Domain,
 			jsonldNonce:        base64.RawURLEncoding.EncodeToString(p.Nonce),
 			jsonldProofPurpose: p.ProofPurpose,

pkg/doc/did/doc_test.go

@@ -357,7 +357,7 @@ func TestInvalidEncodingInProof(t *testing.T) {
 		doc, err = populateProofs(c, "", "", rawProofs)
 		require.NotNil(t, err)
 		require.Nil(t, doc)
-		require.Contains(t, err.Error(), "illegal base64 data")
+		require.Contains(t, err.Error(), "unsupported encoding")
 	}
 }
 

pkg/doc/did/testdata/valid_doc_with_base.jsonld

@@ -49,7 +49,7 @@
 		"creator": "#key-5",
 		"domain": "",
 		"nonce": "",
-		"proofValue": "6mdES87erjP5r1qCSRW__otj-A_Rj0YgRO7XU_0Amhwdfa7AAmtGUSFGflR_fZqPYrY9ceLRVQCJ49s0q7-LBA",
+		"proofValue": "u6mdES87erjP5r1qCSRW__otj-A_Rj0YgRO7XU_0Amhwdfa7AAmtGUSFGflR_fZqPYrY9ceLRVQCJ49s0q7-LBA",
 		"type": "Ed25519Signature2018"
 	}],
   "created": "2002-10-10T17:00:00Z"

pkg/doc/signature/proof/proof.go

@@ -10,6 +10,8 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/multiformats/go-multibase"
+
 	"github.com/hyperledger/aries-framework-go/pkg/doc/util"
 )
 
@@ -36,6 +38,8 @@ const (
 	jsonldChallenge = "challenge"
 	// jsonldCapabilityChain is a key for capabilityChain.
 	jsonldCapabilityChain = "capabilityChain"
+
+	ed25519Signature2020 = "Ed25519Signature2020"
 )
 
 // Proof is cryptographic proof of the integrity of the DID Document.
@@ -71,7 +75,7 @@ func NewProof(emap map[string]interface{}) (*Proof, error) {
 	)
 
 	if generalProof, ok := emap[jsonldProofValue]; ok {
-		proofValue, err = decodeBase64(stringEntry(generalProof))
+		proofValue, err = DecodeProofValue(stringEntry(generalProof), stringEntry(emap[jsonldType]))
 		if err != nil {
 			return nil, err
 		}
@@ -143,6 +147,20 @@ func decodeBase64(s string) ([]byte, error) {
 	return nil, errors.New("unsupported encoding")
 }
 
+// DecodeProofValue decodes proofValue basing on proof type.
+func DecodeProofValue(s, proofType string) ([]byte, error) {
+	if proofType == ed25519Signature2020 {
+		_, value, err := multibase.Decode(s)
+		if err == nil {
+			return value, nil
+		}
+
+		return nil, errors.New("unsupported encoding")
+	}
+
+	return decodeBase64(s)
+}
+
 // stringEntry.
 func stringEntry(entry interface{}) string {
 	if entry == nil {
@@ -170,7 +188,7 @@ func (p *Proof) JSONLdObject() map[string]interface{} { // nolint:gocyclo
 	}
 
 	if len(p.ProofValue) > 0 {
-		emap[jsonldProofValue] = base64.RawURLEncoding.EncodeToString(p.ProofValue)
+		emap[jsonldProofValue] = EncodeProofValue(p.ProofValue, p.Type)
 	}
 
 	if len(p.JWS) > 0 {
@@ -200,6 +218,16 @@ func (p *Proof) JSONLdObject() map[string]interface{} { // nolint:gocyclo
 	return emap
 }
 
+// EncodeProofValue decodes proofValue basing on proof type.
+func EncodeProofValue(proofValue []byte, proofType string) string {
+	if proofType == ed25519Signature2020 {
+		encoded, _ := multibase.Encode(multibase.Base58BTC, proofValue) //nolint: errcheck
+		return encoded
+	}
+
+	return base64.RawURLEncoding.EncodeToString(proofValue)
+}
+
 // PublicKeyID provides ID of public key to be used to independently verify the proof.
 // "verificationMethod" field is checked first. If not empty, its value is returned.
 // Otherwise, "creator" field is returned if not empty. Otherwise, error is returned.

pkg/doc/signature/proof/proof_test.go

@@ -10,12 +10,16 @@ import (
 	"testing"
 	"time"
 
+	"github.com/multiformats/go-multibase"
 	"github.com/stretchr/testify/require"
 
 	"github.com/hyperledger/aries-framework-go/pkg/doc/util"
 )
 
-const proofValueBase64 = "6mdES87erjP5r1qCSRW__otj-A_Rj0YgRO7XU_0Amhwdfa7AAmtGUSFGflR_fZqPYrY9ceLRVQCJ49s0q7-LBA"
+const (
+	proofValueBase64    = "6mdES87erjP5r1qCSRW__otj-A_Rj0YgRO7XU_0Amhwdfa7AAmtGUSFGflR_fZqPYrY9ceLRVQCJ49s0q7-LBA"
+	proofValueMultibase = "z5gpJQZoaLUXevXk2mYYbQE9krfaJYBBwQcJhhAvX3zs6daJ2Eb6VJoU46WkUYN8R1vgX7o8ktuUkzpRJS5aJRQyh"
+)
 
 func TestProof(t *testing.T) {
 	p, err := NewProof(map[string]interface{}{
@@ -44,6 +48,33 @@ func TestProof(t *testing.T) {
 	require.Equal(t, []byte(""), p.Nonce)
 	require.Equal(t, proofValueBytes, p.ProofValue)
 
+	// test proof with multibase encoding
+	p, err = NewProof(map[string]interface{}{
+		"type":               "Ed25519Signature2020",
+		"creator":            "didID",
+		"verificationMethod": "did:example:123456#key1",
+		"created":            "2018-03-15T00:00:00Z",
+		"domain":             "abc.com",
+		"nonce":              "",
+		"proofValue":         proofValueMultibase,
+	})
+	require.NoError(t, err)
+
+	// test proof
+	created, err = time.Parse(time.RFC3339, "2018-03-15T00:00:00Z")
+	require.NoError(t, err)
+
+	_, proofValueBytes, err = multibase.Decode(proofValueMultibase)
+	require.NoError(t, err)
+
+	require.Equal(t, "Ed25519Signature2020", p.Type)
+	require.Equal(t, "didID", p.Creator)
+	require.Equal(t, "did:example:123456#key1", p.VerificationMethod)
+	require.Equal(t, created, p.Created.Time)
+	require.Equal(t, "abc.com", p.Domain)
+	require.Equal(t, []byte(""), p.Nonce)
+	require.Equal(t, proofValueBytes, p.ProofValue)
+
 	// test created time with milliseconds section
 	p, err = NewProof(map[string]interface{}{
 		"type":               "type",
@@ -164,7 +195,7 @@ func TestInvalidNonce(t *testing.T) {
 func TestProof_JSONLdObject(t *testing.T) {
 	r := require.New(t)
 
-	proofValueBytes, err := base64.RawURLEncoding.DecodeString(proofValueBase64)
+	_, proofValueBytes, err := multibase.Decode(proofValueMultibase)
 	r.NoError(err)
 
 	nonceBase64, err := base64.RawURLEncoding.DecodeString("abc")
@@ -174,7 +205,7 @@ func TestProof_JSONLdObject(t *testing.T) {
 	r.NoError(err)
 
 	p := &Proof{
-		Type:         "Ed25519Signature2018",
+		Type:         "Ed25519Signature2020",
 		Created:      util.NewTime(created),
 		Creator:      "creator",
 		ProofValue:   proofValueBytes,
@@ -186,10 +217,10 @@ func TestProof_JSONLdObject(t *testing.T) {
 	}
 
 	pJSONLd := p.JSONLdObject()
-	r.Equal("Ed25519Signature2018", pJSONLd["type"])
+	r.Equal("Ed25519Signature2020", pJSONLd["type"])
 	r.Equal("2018-03-15T00:00:00Z", pJSONLd["created"])
 	r.Equal("creator", pJSONLd["creator"])
-	r.Equal(proofValueBase64, pJSONLd["proofValue"])
+	r.Equal(proofValueMultibase, pJSONLd["proofValue"])
 	r.Equal("test.jws.value", pJSONLd["jws"])
 	r.Equal("assertionMethod", pJSONLd["proofPurpose"])
 	r.Equal("internal", pJSONLd["domain"])

pkg/doc/signature/suite/bbsblssignatureproof2020/testdata/doc_with_many_proofs.jsonld

@@ -37,7 +37,7 @@
       "type": "BbsBlsSignature2020",
       "created": "2020-12-06T19:23:10Z",
       "proofPurpose": "assertionMethod",
-      "proofValue": "jj3Xd3+KxmbQo85PFDjQJ7dAZlhj8A8W1Um8Vk7Xoiv6+jWRx5d8s0rgPk5dAXy6HwaJ4fQOde/MBb7E4QaGMlfK6y5eEKDUYzoGG0DScWIvaGcSZug6DwvWVXi+214P5MtlKnNwO6gJdemEgj8T/A==",
+      "proofValue": "mjj3Xd3+KxmbQo85PFDjQJ7dAZlhj8A8W1Um8Vk7Xoiv6+jWRx5d8s0rgPk5dAXy6HwaJ4fQOde/MBb7E4QaGMlfK6y5eEKDUYzoGG0DScWIvaGcSZug6DwvWVXi+214P5MtlKnNwO6gJdemEgj8T/A==",
       "verificationMethod": "did:example:489398593#test"
     },
     {