--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2010, 2012 Sonatype, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * Sonatype, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.aether.repository;
+
+import java.util.Map;
+
+/**
+ * The authentication to use for accessing a protected resource. This acts basically as an extensible callback mechanism
+ * from which network operations can request authentication data like username and password when needed.
+ */
+public interface Authentication
+{
+
+ /**
+ * Fills the given authentication context with the data from this authentication callback. To do so, implementors
+ * have to call {@link AuthenticationContext#put(String, Object)}. <br>
+ * <br>
+ * The {@code key} parameter supplied to this method acts merely as a hint for interactive callbacks that want to
+ * prompt the user for only that authentication data which is required. Implementations are free to ignore this
+ * parameter and put all the data they have into the authentication context at once.
+ *
+ * @param context The authentication context to populate, must not be {@code null}.
+ * @param key The key denoting a specific piece of authentication data that is being requested for a network
+ * operation, may be {@code null}.
+ * @param data Any (read-only) extra data in form of key value pairs that might be useful when getting the
+ * authentication data, may be {@code null}.
+ */
+ void fill( AuthenticationContext context, String key, Map<String, String> data );
+
+ /**
+ * Updates the given digest with data from this authentication callback. To do so, implementors have to call the
+ * {@code update()} methods in {@link AuthenticationDigest}.
+ *
+ * @param digest The digest to update, must not be {@code null}.
+ */
+ void digest( AuthenticationDigest digest );
+
+}