pkg/identity: support encode and decode functionality of Peer Identity information

pkg/identity/identity.go

@@ -9,6 +9,7 @@ import (
 	"crypto"
 	"crypto/x509"
 	"crypto/x509/pkix"
+	"encoding/asn1"
 	"fmt"
 	"io/ioutil"
 	"path/filepath"
@@ -527,3 +528,41 @@ func backupPath(path string) string {
 		pathExt,
 	)
 }
+
+// EncodePeerIdentity encodes the complete idenitity chain to bytes
+func EncodePeerIdentity(pi *PeerIdentity) []byte {
+	var chain []byte
+	chain = append(chain, pi.Leaf.Raw...)
+	chain = append(chain, pi.CA.Raw...)
+	for _, cert := range pi.RestChain {
+		chain = append(chain, cert.Raw...)
+	}
+	return chain
+}
+
+// DecodePeerIdentity Decodes the bytes into complete idenitity chain
+func DecodePeerIdentity(ctx context.Context, chain []byte) (_ *PeerIdentity, err error) {
+	defer mon.Task()(&ctx)(&err)
+
+	var certs []*x509.Certificate
+	for len(chain) > 0 {
+		var raw asn1.RawValue
+		var err error
+
+		chain, err = asn1.Unmarshal(chain, &raw)
+		if err != nil {
+			return nil, Error.Wrap(err)
+		}
+
+		cert, err := pkcrypto.CertFromDER(raw.FullBytes)
+		if err != nil {
+			return nil, Error.Wrap(err)
+		}
+
+		certs = append(certs, cert)
+	}
+	if len(certs) < 2 {
+		return nil, Error.New("not enough certificates")
+	}
+	return PeerIdentityFromChain(certs)
+}

pkg/identity/identity_test.go

@@ -304,3 +304,22 @@ func TestManageableFullIdentity_Revoke(t *testing.T) {
 	err = rev.Verify(manageableFullIdentity.CA.Cert)
 	require.NoError(t, err)
 }
+
+func TestEncodeDecodePeerIdentity(t *testing.T) {
+	ctx := testcontext.New(t)
+	defer ctx.Cleanup()
+
+	peerID, err := testidentity.NewTestIdentity(ctx)
+	require.NoError(t, err)
+	pi := peerID.PeerIdentity()
+
+	// encode the peer identity
+	encodedPiBytes := identity.EncodePeerIdentity(pi)
+	assert.NotNil(t, encodedPiBytes)
+	// decode the peer identity
+	decodedPi, err := identity.DecodePeerIdentity(ctx, encodedPiBytes)
+	assert.NoError(t, err)
+	// again encode the above decoded peer identity and compare
+	decodedPiBytes := identity.EncodePeerIdentity(decodedPi)
+	assert.Equal(t, encodedPiBytes, decodedPiBytes)
+}