allow string for nonce and context in signature requests

irmago_test.go

@@ -246,10 +246,13 @@ func TestVerifyValidSig(t *testing.T) {
 	irmaSignedMessage := &IrmaSignedMessage{}
 	json.Unmarshal([]byte(irmaSignedMessageJson), irmaSignedMessage)
 
-	request := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you everything\",\"messageType\":\"STRING\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
+	request := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you everything\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
 	sigRequestJSON := []byte(request)
 	sigRequest := &SignatureRequest{}
 	json.Unmarshal(sigRequestJSON, sigRequest)
+	// Test marshalling of 'string' fields:
+	require.Equal(t, sigRequest.Nonce, big.NewInt(42))
+	require.Equal(t, sigRequest.Context, big.NewInt(1337))
 
 	// Test if we can verify it with the original request
 	sigProofResult := VerifySig(conf, irmaSignedMessage, sigRequest)
@@ -259,8 +262,25 @@ func TestVerifyValidSig(t *testing.T) {
 	require.Equal(t, attributeList[0].AttributeProofStatus, PRESENT)
 	require.Equal(t, attributeList[0].AttributeValue, "456")
 
+	// Test if we can verify it with a request that contains strings instead of ints for nonce and context
+	stringRequest := "{\"nonce\": \"42\", \"context\": \"1337\", \"message\":\"I owe you everything\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
+	stringSigRequestJSON := []byte(stringRequest)
+	stringSigRequest := &SignatureRequest{}
+	json.Unmarshal(stringSigRequestJSON, stringSigRequest)
+	// Test marshalling of 'string' fields:
+	require.Equal(t, stringSigRequest.Nonce, big.NewInt(42))
+	require.Equal(t, stringSigRequest.Context, big.NewInt(1337))
+
+	// Test if we can verify it with the original request
+	stringSigProofResult := VerifySig(conf, irmaSignedMessage, sigRequest)
+	require.Equal(t, stringSigProofResult.ProofStatus, VALID)
+	stringAttributeList := sigProofResult.ToAttributeResultList()
+	require.Len(t, stringAttributeList, 1)
+	require.Equal(t, stringAttributeList[0].AttributeProofStatus, PRESENT)
+	require.Equal(t, stringAttributeList[0].AttributeValue, "456")
+
 	// Test verify against unmatched request (i.e. different nonce, context or message)
-	unmatched := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you NOTHING\",\"messageType\":\"STRING\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
+	unmatched := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you NOTHING\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
 	unmatchedSigRequestJSON := []byte(unmatched)
 	unmatchedSigRequest := &SignatureRequest{}
 	json.Unmarshal(unmatchedSigRequestJSON, unmatchedSigRequest)
@@ -282,7 +302,7 @@ func TestVerifyInValidSig(t *testing.T) {
 	irmaSignedMessage := &IrmaSignedMessage{}
 	json.Unmarshal([]byte(irmaSignedMessageJson), irmaSignedMessage)
 
-	request := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you everything\",\"messageType\":\"STRING\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
+	request := "{\"nonce\": 42, \"context\": 1337, \"message\":\"I owe you everything\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
 	sigRequestJSON := []byte(request)
 	sigRequest := &SignatureRequest{}
 	json.Unmarshal(sigRequestJSON, sigRequest)
@@ -304,7 +324,7 @@ func TestVerifyInValidNonce(t *testing.T) {
 	json.Unmarshal([]byte(irmaSignedMessageJson), irmaSignedMessage)
 
 	// Original request also has the same invalid nonce (otherwise we would get unmatched_request)
-	request := "{\"nonce\": 4242, \"context\": 1337, \"message\":\"I owe you everything\",\"messageType\":\"STRING\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
+	request := "{\"nonce\": 4242, \"context\": 1337, \"message\":\"I owe you everything\",\"content\":[{\"label\":\"Student number (RU)\",\"attributes\":[\"irma-demo.RU.studentCard.studentID\"]}]}"
 	sigRequestJSON := []byte(request)
 	sigRequest := &SignatureRequest{}
 	json.Unmarshal(sigRequestJSON, sigRequest)

requests.go

@@ -6,6 +6,7 @@ import (
 	"strconv"
 	"time"
 
+	"encoding/json"
 	"github.com/go-errors/errors"
 )
 
@@ -290,6 +291,42 @@ func (sr *SignatureRequest) GetNonce() *big.Int {
 	return ASN1ConvertSignatureNonce(sr.Message, sr.Nonce)
 }
 
+// Convert fields in JSON string to BigInterger if they are string
+// Supply fieldnames as a slice as second argument
+func convertFieldsToBigInt(jsonString []byte, fieldNames []string) ([]byte, error) {
+	var rawRequest map[string]interface{}
+
+	err := json.Unmarshal(jsonString, &rawRequest)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, fieldName := range fieldNames {
+		field := new(big.Int)
+		fieldString := fmt.Sprintf("%v", rawRequest[fieldName])
+		field.SetString(fieldString, 10)
+		rawRequest[fieldName] = field
+	}
+
+	return json.Marshal(rawRequest)
+}
+
+// Custom Unmarshalling to support both json with string and int fields for nonce and context
+// i.e. {"nonce": "42", "context": "1337", ... } and {"nonce": 42, "context": 1337, ... }
+func (sr *SignatureRequest) UnmarshalJSON(b []byte) error {
+	type SignatureRequestTemp SignatureRequest // To avoid 'recursive unmarshalling'
+
+	fixedRequest, err := convertFieldsToBigInt(b, []string{"nonce", "context"})
+
+	var result SignatureRequestTemp
+	json.Unmarshal(fixedRequest, &result)
+
+	sr.DisclosureRequest = result.DisclosureRequest
+	sr.Message = result.Message
+
+	return err
+}
+
 // Check if Timestamp is before other Timestamp. Used for checking expiry of attributes
 func (t Timestamp) Before(u Timestamp) bool {
 	return time.Time(t).Before(time.Time(u))