updated COSE expiry header check

signature/cose/envelope.go

@@ -430,11 +430,13 @@ func parseProtectedHeaders(protected cose.ProtectedHeader, signerInfo *signature
 	signerInfo.SignedAttributes.SigningTime = time.Unix(signingTime, 0)
 
 	// populate signerInfo.SignedAttributes.Expiry
-	exp, ok := protected[headerLabelExpiry].(int64)
-	if !ok {
-		return &signature.MalformedSignatureError{Msg: "malformed expiry"}
+	if exp, ok := protected[headerLabelExpiry]; ok {
+		expiry, ok := exp.(int64)
+		if !ok {
+			return &signature.MalformedSignatureError{Msg: "expiry requires int64 type"}
+		}
+		signerInfo.SignedAttributes.Expiry = time.Unix(expiry, 0)
 	}
-	signerInfo.SignedAttributes.Expiry = time.Unix(exp, 0)
 
 	// populate signerInfo.SignedAttributes.ExtendedAttributes
 	signerInfo.SignedAttributes.ExtendedAttributes, err = generateExtendedAttributes(extendedAttributeKeys, protected)

signature/cose/envelope_test.go

@@ -34,7 +34,8 @@ func newSignRequest(signingScheme string) (*signature.SignRequest, error) {
 		Expiry:      time.Now().AddDate(0, 0, 1),
 		ExtendedSignedAttributes: []signature.Attribute{
 			{Key: "signedCritKey1", Value: "signedCritValue1", Critical: true},
-			{Key: "signedKey1", Value: "signedValue1", Critical: false}},
+			{Key: "signedKey1", Value: "signedValue1", Critical: false},
+		},
 		SigningAgent:  "NotationUnitTest/1.0.0",
 		SigningScheme: signature.SigningScheme(signingScheme),
 	}, nil