add basic auth support

src/main/java/sh/libre/scim/core/BasicAuthentication.java

@@ -0,0 +1,23 @@
+package sh.libre.scim.core;
+
+import java.io.IOException;
+import java.util.Base64;
+
+import javax.ws.rs.client.ClientRequestContext;
+import javax.ws.rs.client.ClientRequestFilter;
+
+public class BasicAuthentication implements ClientRequestFilter {
+    private final String user;
+    private final String password;
+
+    BasicAuthentication(String user, String password) {
+        this.user = user;
+        this.password = password;
+    }
+
+    @Override
+    public void filter(ClientRequestContext requestContext) throws IOException {
+        var token = Base64.getEncoder().encodeToString((user + ":" + password).getBytes());
+        requestContext.getHeaders().add("Authorization", "Basic " + token);
+    }
+}

src/main/java/sh/libre/scim/core/ScimClient.java

@@ -36,8 +36,14 @@ public class ScimClient {
 
         this.session = session;
         var target = client.target(model.get("endpoint"));
-        if (model.get("auth-mode").equals("BEARER")) {
+        switch (model.get("auth-mode")) {
+            case "BEARER":
                 target = target.register(new BearerAuthentication(model.get("auth-bearer-token")));
+                break;
+            case "BASIC_AUTH":
+                target = target.register(new BasicAuthentication(
+                        model.get("auth-basic-auth-user"),
+                        model.get("auth-basic-auth-pass")));
         }
 
         scimService = new ScimService(target);

src/main/java/sh/libre/scim/storage/ScimStorageProviderFactory.java

@@ -52,7 +52,7 @@ public class ScimStorageProviderFactory
                 .type(ProviderConfigProperty.LIST_TYPE)
                 .label("Auth mode")
                 .helpText("Select the authorization mode")
-                .options("NONE", "BEARER")
+                .options("NONE", "BEARER", "BASIC_AUTH")
                 .defaultValue("NONE")
                 .add()
                 .property()
@@ -62,6 +62,16 @@ public class ScimStorageProviderFactory
                 .helpText("Add a bearer token in the authorization header")
                 .add()
                 .property()
+                .name("auth-basic-auth-user")
+                .type(ProviderConfigProperty.STRING_TYPE)
+                .label("BasicAuth user")
+                .add()
+                .property()
+                .name("auth-basic-auth-pass")
+                .type(ProviderConfigProperty.PASSWORD)
+                .label("BasicAuth password")
+                .add()
+                .property()
                 .name("sync-import")
                 .type(ProviderConfigProperty.BOOLEAN_TYPE)
                 .label("Enable import during sync")