---
title:  Authentication Example
---

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This example demonstrates the basics of an implementation of the
`SecurityManager.authenticate` method.
The remainder of the example may be found in the <%=vars.product_name_long%>
source code in the
`geode-core/src/main/java/org/apache/geode/examples/security` directory.

Of course, the security implementation of every installation is unique,
so this example cannot be used in a production environment.
Its use of the user name as a returned principal upon successful
authentication is a particularly poor design choice,
as any attacker that discovers the implementation can potentially
spoof the system.

This example assumes that a set of user name and password pairs
representing users that may be successfully authenticated 
has been read into a data structure upon intialization.
Any component that presents the correct password for a user name
successfully authenticates,
and its identity is verified as that user.
Therefore, the implementation of the `authenticate` method
checks that the user name provided within the `credentials` parameter
 is in its data structure.
If the user name is present,
then the password provided within the `credentials` parameter 
is compared to the data structure's known password for that user name.
Upon a match, the authentication is successful.

``` pre
public Object authenticate(final Properties credentials)
         throws AuthenticationFailedException {
    String user = credentials.getProperty(ResourceConstants.USER_NAME);
    String password = credentials.getProperty(ResourceConstants.PASSWORD);

    User userObj = this.userNameToUser.get(user);
    if (userObj == null) {
        throw new AuthenticationFailedException(
                      "SampleSecurityManager: wrong username/password");
    }

    if (user != null 
        && !userObj.password.equals(password) 
        && !"".equals(user)) {
        throw new AuthenticationFailedException(
                      "SampleSecurityManager: wrong username/password");
    }

    return user;
}
```