feat: improve saml idp err message (#1584)

object/saml_idp.go

@@ -230,16 +230,20 @@ func GetSamlResponse(application *Application, user *User, samlRequest string, h
 	// base64 decode
 	defated, err := base64.StdEncoding.DecodeString(samlRequest)
 	if err != nil {
-		return "", "", method, fmt.Errorf("err: %s", err.Error())
+		return "", "", method, fmt.Errorf("err: Failed to decode SAML request , %s", err.Error())
 	}
+
 	// decompress
 	var buffer bytes.Buffer
 	rdr := flate.NewReader(bytes.NewReader(defated))
-	io.Copy(&buffer, rdr)
+	_, err = io.Copy(&buffer, rdr)
+	if err != nil {
+		return "", "", "", err
+	}
 	var authnRequest saml.AuthnRequest
 	err = xml.Unmarshal(buffer.Bytes(), &authnRequest)
 	if err != nil {
-		return "", "", method, fmt.Errorf("err: %s", err.Error())
+		return "", "", method, fmt.Errorf("err: Failed to unmarshal AuthnRequest, please check the SAML request. %s", err.Error())
 	}
 
 	// verify samlRequest
@@ -252,14 +256,15 @@ func GetSamlResponse(application *Application, user *User, samlRequest string, h
 	block, _ := pem.Decode([]byte(cert.Certificate))
 	certificate := base64.StdEncoding.EncodeToString(block.Bytes)
 
-	_, originBackend := getOriginFromHost(host)
-
 	// redirect Url (Assertion Consumer Url)
 	if application.SamlReplyUrl != "" {
 		method = "POST"
 		authnRequest.AssertionConsumerServiceURL = application.SamlReplyUrl
+	} else if authnRequest.AssertionConsumerServiceURL == "" {
+		return "", "", "", fmt.Errorf("err: SAML request don't has attribute 'AssertionConsumerServiceURL' in <samlp:AuthnRequest>")
 	}
 
+	_, originBackend := getOriginFromHost(host)
 	// build signedResponse
 	samlResponse, _ := NewSamlResponse(user, originBackend, certificate, authnRequest.AssertionConsumerServiceURL, authnRequest.Issuer.Url, authnRequest.ID, application.RedirectUris)
 	randomKeyStore := &X509Key{
@@ -279,7 +284,7 @@ func GetSamlResponse(application *Application, user *User, samlRequest string, h
 	doc.SetRoot(samlResponse)
 	xmlBytes, err := doc.WriteToBytes()
 	if err != nil {
-		return "", "", method, fmt.Errorf("err: %s", err.Error())
+		return "", "", method, fmt.Errorf("err: Failed to serializes the SAML request into bytes, %s", err.Error())
 	}
 
 	// compress
@@ -287,15 +292,21 @@ func GetSamlResponse(application *Application, user *User, samlRequest string, h
 		flated := bytes.NewBuffer(nil)
 		writer, err := flate.NewWriter(flated, flate.DefaultCompression)
 		if err != nil {
-			return "", "", method, fmt.Errorf("err: %s", err.Error())
+			return "", "", method, err
+		}
+		_, err = writer.Write(xmlBytes)
+		if err != nil {
+			return "", "", "", err
+		}
+		err = writer.Close()
+		if err != nil {
+			return "", "", "", err
 		}
-		writer.Write(xmlBytes)
-		writer.Close()
 		xmlBytes = flated.Bytes()
 	}
 	// base64 encode
 	res := base64.StdEncoding.EncodeToString(xmlBytes)
-	return res, authnRequest.AssertionConsumerServiceURL, method, nil
+	return res, authnRequest.AssertionConsumerServiceURL, method, err
 }
 
 // NewSamlResponse11 return a saml1.1 response(not 2.0)
@@ -359,7 +370,10 @@ func NewSamlResponse11(user *User, requestID string, host string) *etree.Element
 
 	data, _ := json.Marshal(user)
 	tmp := map[string]string{}
-	json.Unmarshal(data, &tmp)
+	err := json.Unmarshal(data, &tmp)
+	if err != nil {
+		panic(err)
+	}
 
 	for k, v := range tmp {
 		if v != "" {