Fix timestamp (de)serializing

protocol/protocol_test.go

@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"testing"
 
+	"time"
+
 	"github.com/credentials/irmago"
 	"github.com/stretchr/testify/require"
 )
@@ -50,6 +52,17 @@ func TestAttributeDisjunctionMarshaling(t *testing.T) {
 	require.True(t, disjunction.Satisfied())
 }
 
+func TestTimestamp(t *testing.T) {
+	mytime := Timestamp(time.Unix(1500000000, 0))
+	timestruct := struct{ Time *Timestamp }{Time: &mytime}
+	bytes, err := json.Marshal(timestruct)
+	require.NoError(t, err)
+
+	timestruct = struct{ Time *Timestamp }{}
+	require.NoError(t, json.Unmarshal(bytes, &timestruct))
+	require.Equal(t, time.Time(*timestruct.Time).Unix(), int64(1500000000))
+}
+
 func TestServiceProviderRequest(t *testing.T) {
 	var sprequest ServiceProviderRequest
 

protocol/requests.go

@@ -44,16 +44,16 @@ type SignatureRequest struct {
 }
 
 type CredentialRequest struct {
-	Validity   Timestamp
+	Validity   *Timestamp
 	KeyCounter int
 	Credential irmago.CredentialTypeIdentifier
 	Attributes map[string]string
 }
 
 type ServerRequest struct {
-	ServerName string    `json:"iss"`
-	IssuedAt   Timestamp `json:"iat"`
-	Type       string    `json:"subject"`
+	ServerName string     `json:"iss"`
+	IssuedAt   *Timestamp `json:"iat"`
+	Type       string     `json:"subject"`
 }
 
 type IssuanceRequest struct {