MM-24467- Use new ServiceProviderIdentifier in AuthnRequest (#14725)

* add ServiceProviderIdentifier to config

* Update config, add unit test

* fix unit test, update i18n

* add english translation for error

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

model/config.go

@@ -2135,6 +2135,7 @@ type SamlSettings struct {
 	IdpUrl                      *string
 	IdpDescriptorUrl            *string
 	IdpMetadataUrl              *string
+	ServiceProviderIdentifier   *string
 	AssertionConsumerServiceURL *string
 
 	SignatureAlgorithm *string
@@ -2212,6 +2213,14 @@ func (s *SamlSettings) SetDefaults() {
 		s.IdpDescriptorUrl = NewString("")
 	}
 
+	if s.ServiceProviderIdentifier == nil {
+		if s.IdpDescriptorUrl != nil {
+			s.ServiceProviderIdentifier = NewString(*s.IdpDescriptorUrl)
+		} else {
+			s.ServiceProviderIdentifier = NewString("")
+		}
+	}
+
 	if s.IdpMetadataUrl == nil {
 		s.IdpMetadataUrl = NewString("")
 	}
@@ -3126,6 +3135,10 @@ func (s *SamlSettings) isValid() *AppError {
 			return NewAppError("Config.IsValid", "model.config.is_valid.saml_username_attribute.app_error", nil, "", http.StatusBadRequest)
 		}
 
+		if len(*s.ServiceProviderIdentifier) == 0 {
+			return NewAppError("Config.IsValid", "model.config.is_valid.saml_spidentifier_attribute.app_error", nil, "", http.StatusBadRequest)
+		}
+
 		if *s.Verify {
 			if len(*s.AssertionConsumerServiceURL) == 0 || !IsValidHttpUrl(*s.AssertionConsumerServiceURL) {
 				return NewAppError("Config.IsValid", "model.config.is_valid.saml_assertion_consumer_service_url.app_error", nil, "", http.StatusBadRequest)