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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
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package org.apache.shiro.realm.ldap;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.credential.AllowAllCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationException;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.ldap.UnsupportedAuthenticationMechanismException;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.naming.AuthenticationNotSupportedException;
import javax.naming.NamingException;
import javax.naming.ldap.LdapContext;
/**
* An LDAP {@link org.apache.shiro.realm.Realm Realm} implementation utilizing Sun's/Oracle's
* <a href="http://download-llnw.oracle.com/javase/tutorial/jndi/ldap/jndi.html">JNDI API as an LDAP API</a>. This is
* Shiro's default implementation for supporting LDAP, as using the JNDI API has been a common approach for Java LDAP
* support for many years.
* <p/>
* This realm implementation and its backing {@link JndiLdapContextFactory} should cover 99% of all Shiro-related LDAP
* authentication and authorization needs. However, if it does not suit your needs, you might want to look into
* creating your own realm using an alternative, perhaps more robust, LDAP communication API, such as the
* <a href="http://directory.apache.org/api/">Apache LDAP API</a>.
* <h2>Authentication</h2>
* During an authentication attempt, if the submitted {@code AuthenticationToken}'s
* {@link org.apache.shiro.authc.AuthenticationToken#getPrincipal() principal} is a simple username, but the
* LDAP directory expects a complete User Distinguished Name (User DN) to establish a connection, the
* {@link #setUserDnTemplate(String) userDnTemplate} property must be configured. If not configured,
* the property will pass the simple username directly as the User DN, which is often incorrect in most LDAP
* environments (maybe Microsoft ActiveDirectory being the exception).
* <h2>Authorization</h2>
* By default, authorization is effectively disabled due to the default
* {@link #doGetAuthorizationInfo(org.apache.shiro.subject.PrincipalCollection)} implementation returning {@code null}.
* If you wish to perform authorization based on an LDAP schema, you must subclass this one
* and override that method to reflect your organization's data model.
* <h2>Configuration</h2>
* This class primarily provides the {@link #setUserDnTemplate(String) userDnTemplate} property to allow you to specify
* the your LDAP server's User DN format. Most other configuration is performed via the nested
* {@link LdapContextFactory contextFactory} property.
* <p/>
* For example, defining this realm in Shiro .ini:
* <pre>
* [main]
* ldapRealm = org.apache.shiro.realm.ldap.DefaultLdapRealm
* ldapRealm.userDnTemplate = uid={0},ou=users,dc=mycompany,dc=com
* ldapRealm.contextFactory.url = ldap://ldapHost:389
* ldapRealm.contextFactory.authenticationMechanism = DIGEST-MD5
* ldapRealm.contextFactory.environment[some.obscure.jndi.key] = some value
* ...
* </pre>
* The default {@link #setContextFactory contextFactory} instance is a {@link JndiLdapContextFactory}. See that
* class's JavaDoc for more information on configuring the LDAP connection as well as specifying JNDI environment
* properties as necessary.
*
* @see JndiLdapContextFactory
*
* @since 1.3
*/
public class DefaultLdapRealm extends AuthorizingRealm {
private static final Logger log = LoggerFactory.getLogger(DefaultLdapRealm.class);
//The zero index currently means nothing, but could be utilized in the future for other substitution techniques.
private static final String USERDN_SUBSTITUTION_TOKEN = "{0}";
private String userDnPrefix;
private String userDnSuffix;
/*--------------------------------------------
| I N S T A N C E V A R I A B L E S |
============================================*/
/**
* The LdapContextFactory instance used to acquire {@link javax.naming.ldap.LdapContext LdapContext}'s at runtime
* to acquire connections to the LDAP directory to perform authentication attempts and authorizatino queries.
*/
private LdapContextFactory contextFactory;
/*--------------------------------------------
| C O N S T R U C T O R S |
============================================*/
/**
* Default no-argument constructor that defaults the internal {@link LdapContextFactory} instance to a
* {@link JndiLdapContextFactory}.
*/
public DefaultLdapRealm() {
//Credentials Matching is not necessary - the LDAP directory will do it automatically:
setCredentialsMatcher(new AllowAllCredentialsMatcher());
//Any Object principal and Object credentials may be passed to the LDAP provider, so accept any token:
setAuthenticationTokenClass(AuthenticationToken.class);
this.contextFactory = new JndiLdapContextFactory();
}
/*--------------------------------------------
| A C C E S S O R S / M O D I F I E R S |
============================================*/
/**
* Returns the User DN prefix to use when building a runtime User DN value or {@code null} if no
* {@link #getUserDnTemplate() userDnTemplate} has been configured. If configured, this value is the text that
* occurs before the {@link #USERDN_SUBSTITUTION_TOKEN} in the {@link #getUserDnTemplate() userDnTemplate} value.
*
* @return the the User DN prefix to use when building a runtime User DN value or {@code null} if no
* {@link #getUserDnTemplate() userDnTemplate} has been configured.
*/
protected String getUserDnPrefix() {
return userDnPrefix;
}
/**
* Returns the User DN suffix to use when building a runtime User DN value. or {@code null} if no
* {@link #getUserDnTemplate() userDnTemplate} has been configured. If configured, this value is the text that
* occurs after the {@link #USERDN_SUBSTITUTION_TOKEN} in the {@link #getUserDnTemplate() userDnTemplate} value.
*
* @return the User DN suffix to use when building a runtime User DN value or {@code null} if no
* {@link #getUserDnTemplate() userDnTemplate} has been configured.
*/
protected String getUserDnSuffix() {
return userDnSuffix;
}
/*--------------------------------------------
| M E T H O D S |
============================================*/
/**
* Sets the User Distinguished Name (DN) template to use when creating User DNs at runtime. A User DN is an LDAP
* fully-qualified unique user identifier which is required to establish a connection with the LDAP
* directory to authenticate users and query for authorization information.
* <h2>Usage</h2>
* User DN formats are unique to the LDAP directory's schema, and each environment differs - you will need to
* specify the format corresponding to your directory. You do this by specifying the full User DN as normal, but
* but you use a <b>{@code {0}}</b> placeholder token in the string representing the location where the
* user's submitted principal (usually a username or uid) will be substituted at runtime.
* <p/>
* For example, if your directory
* uses an LDAP {@code uid} attribute to represent usernames, the User DN for the {@code jsmith} user may look like
* this:
* <p/>
* <pre>uid=jsmith,ou=users,dc=mycompany,dc=com</pre>
* <p/>
* in which case you would set this property with the following template value:
* <p/>
* <pre>uid=<b>{0}</b>,ou=users,dc=mycompany,dc=com</pre>
* <p/>
* If no template is configured, the raw {@code AuthenticationToken}
* {@link AuthenticationToken#getPrincipal() principal} will be used as the LDAP principal. This is likely
* incorrect as most LDAP directories expect a fully-qualified User DN as opposed to the raw uid or username. So,
* ensure you set this property to match your environment!
*
* @param template the User Distinguished Name template to use for runtime substitution
* @throws IllegalArgumentException if the template is null, empty, or does not contain the
* {@code {0}} substitution token.
* @see LdapContextFactory#getLdapContext(Object,Object)
*/
public void setUserDnTemplate(String template) throws IllegalArgumentException {
if (!StringUtils.hasText(template)) {
String msg = "User DN template cannot be null or empty.";
throw new IllegalArgumentException(msg);
}
int index = template.indexOf(USERDN_SUBSTITUTION_TOKEN);
if (index < 0) {
String msg = "User DN template must contain the '" +
USERDN_SUBSTITUTION_TOKEN + "' replacement token to understand where to " +
"insert the runtime authentication principal.";
throw new IllegalArgumentException(msg);
}
String prefix = template.substring(0, index);
String suffix = template.substring(prefix.length() + USERDN_SUBSTITUTION_TOKEN.length());
if (log.isDebugEnabled()) {
log.debug("Determined user DN prefix [{}] and suffix [{}]", prefix, suffix);
}
this.userDnPrefix = prefix;
this.userDnSuffix = suffix;
}
/**
* Returns the User Distinguished Name (DN) template to use when creating User DNs at runtime - see the
* {@link #setUserDnTemplate(String) setUserDnTemplate} JavaDoc for a full explanation.
*
* @return the User Distinguished Name (DN) template to use when creating User DNs at runtime.
*/
public String getUserDnTemplate() {
return getUserDn(USERDN_SUBSTITUTION_TOKEN);
}
/**
* Returns the LDAP User Distinguished Name (DN) to use when acquiring an
* {@link javax.naming.ldap.LdapContext LdapContext} from the {@link LdapContextFactory}.
* <p/>
* If the the {@link #getUserDnTemplate() userDnTemplate} property has been set, this implementation will construct
* the User DN by substituting the specified {@code principal} into the configured template. If the
* {@link #getUserDnTemplate() userDnTemplate} has not been set, the method argument will be returned directly
* (indicating that the submitted authentication token principal <em>is</em> the User DN).
*
* @param principal the principal to substitute into the configured {@link #getUserDnTemplate() userDnTemplate}.
* @return the constructed User DN to use at runtime when acquiring an {@link javax.naming.ldap.LdapContext}.
* @throws IllegalArgumentException if the method argument is null or empty
* @throws IllegalStateException if the {@link #getUserDnTemplate userDnTemplate} has not been set.
* @see LdapContextFactory#getLdapContext(Object, Object)
*/
protected String getUserDn(String principal) throws IllegalArgumentException, IllegalStateException {
if (!StringUtils.hasText(principal)) {
throw new IllegalArgumentException("User principal cannot be null or empty for User DN construction.");
}
String prefix = getUserDnPrefix();
String suffix = getUserDnSuffix();
if (prefix == null && suffix == null) {
log.debug("userDnTemplate property has not been configured, indicating the submitted " +
"AuthenticationToken's principal is the same as the User DN. Returning the method argument " +
"as is.");
return principal;
}
int prefixLength = prefix != null ? prefix.length() : 0;
int suffixLength = suffix != null ? suffix.length() : 0;
StringBuilder sb = new StringBuilder(prefixLength + principal.length() + suffixLength);
if (prefixLength > 0) {
sb.append(prefix);
}
sb.append(principal);
if (suffixLength > 0) {
sb.append(suffix);
}
return sb.toString();
}
/**
* Sets the LdapContextFactory instance used to acquire connections to the LDAP directory during authentication
* attempts and authorization queries. Unless specified otherwise, the default is a {@link JndiLdapContextFactory}
* instance.
*
* @param contextFactory the LdapContextFactory instance used to acquire connections to the LDAP directory during
* authentication attempts and authorization queries
*/
@SuppressWarnings({"UnusedDeclaration"})
public void setContextFactory(LdapContextFactory contextFactory) {
this.contextFactory = contextFactory;
}
/**
* Returns the LdapContextFactory instance used to acquire connections to the LDAP directory during authentication
* attempts and authorization queries. Unless specified otherwise, the default is a {@link JndiLdapContextFactory}
* instance.
*
* @return the LdapContextFactory instance used to acquire connections to the LDAP directory during
* authentication attempts and authorization queries
*/
public LdapContextFactory getContextFactory() {
return this.contextFactory;
}
/*--------------------------------------------
| M E T H O D S |
============================================*/
/**
* Delegates to {@link #queryForAuthenticationInfo(org.apache.shiro.authc.AuthenticationToken, LdapContextFactory)},
* wrapping any {@link NamingException}s in a Shiro {@link AuthenticationException} to satisfy the parent method
* signature.
*
* @param token the authentication token containing the user's principal and credentials.
* @return the {@link AuthenticationInfo} acquired after a successful authentication attempt
* @throws AuthenticationException if the authentication attempt fails or if a
* {@link NamingException} occurs.
*/
protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
AuthenticationInfo info;
try {
info = queryForAuthenticationInfo(token, getContextFactory());
} catch (AuthenticationNotSupportedException e) {
String msg = "Unsupported configured authentication mechanism";
throw new UnsupportedAuthenticationMechanismException(msg, e);
} catch (javax.naming.AuthenticationException e) {
throw new AuthenticationException("LDAP authentication failed.", e);
} catch (NamingException e) {
String msg = "LDAP naming error while attempting to authenticate user.";
throw new AuthenticationException(msg, e);
}
return info;
}
protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
AuthorizationInfo info;
try {
info = queryForAuthorizationInfo(principals, getContextFactory());
} catch (NamingException e) {
String msg = "LDAP naming error while attempting to retrieve authorization for user [" + principals + "].";
throw new AuthorizationException(msg, e);
}
return info;
}
/**
* Returns the principal to use when creating the LDAP connection for an authentication attempt.
* <p/>
* This implementation uses a heuristic: it checks to see if the specified token's
* {@link AuthenticationToken#getPrincipal() principal} is a {@code String}, and if so,
* {@link #getUserDn(String) converts it} from what is
* assumed to be a raw uid or username {@code String} into a User DN {@code String}. Almost all LDAP directories
* expect the authentication connection to present a User DN and not an unqualified username or uid.
* <p/>
* If the token's {@code principal} is not a String, it is assumed to already be in the format supported by the
* underlying {@link LdapContextFactory} implementation and the raw principal is returned directly.
*
* @param token the {@link AuthenticationToken} submitted during the authentication process
* @return the User DN or raw principal to use to acquire the LdapContext.
* @see LdapContextFactory#getLdapContext(Object, Object)
*/
protected Object getLdapPrincipal(AuthenticationToken token) {
Object principal = token.getPrincipal();
if (principal instanceof String) {
String sPrincipal = (String) principal;
return getUserDn(sPrincipal);
}
return principal;
}
/**
* This implementation opens an LDAP connection using the token's
* {@link #getLdapPrincipal(org.apache.shiro.authc.AuthenticationToken) discovered principal} and provided
* {@link AuthenticationToken#getCredentials() credentials}. If the connection opens successfully, the
* authentication attempt is immediately considered successful and a new
* {@link AuthenticationInfo} instance is
* {@link #createAuthenticationInfo(org.apache.shiro.authc.AuthenticationToken, Object, Object, javax.naming.ldap.LdapContext) created}
* and returned. If the connection cannot be opened, either because LDAP authentication failed or some other
* JNDI problem, an {@link NamingException} will be thrown.
*
* @param token the submitted authentication token that triggered the authentication attempt.
* @param ldapContextFactory factory used to retrieve LDAP connections.
* @return an {@link AuthenticationInfo} instance representing the authenticated user's information.
* @throws NamingException if any LDAP errors occur.
*/
protected AuthenticationInfo queryForAuthenticationInfo(AuthenticationToken token,
LdapContextFactory ldapContextFactory)
throws NamingException {
Object principal = token.getPrincipal();
Object credentials = token.getCredentials();
log.debug("Authenticating user '{}' through LDAP", principal);
principal = getLdapPrincipal(token);
LdapContext ctx = null;
try {
ctx = ldapContextFactory.getLdapContext(principal, credentials);
//context was opened successfully, which means their credentials were valid. Return the AuthenticationInfo:
return createAuthenticationInfo(token, principal, credentials, ctx);
} finally {
LdapUtils.closeContext(ctx);
}
}
/**
* Returns the {@link AuthenticationInfo} resulting from a Subject's successful LDAP authentication attempt.
* <p/>
* This implementation ignores the {@code ldapPrincipal}, {@code ldapCredentials}, and the opened
* {@code ldapContext} arguments and merely returns an {@code AuthenticationInfo} instance mirroring the
* submitted token's principal and credentials. This is acceptable because this method is only ever invoked after
* a successful authentication attempt, which means the provided principal and credentials were correct, and can
* be used directly to populate the (now verified) {@code AuthenticationInfo}.
* <p/>
* Subclasses however are free to override this method for more advanced construction logic.
*
* @param token the submitted {@code AuthenticationToken} that resulted in a successful authentication
* @param ldapPrincipal the LDAP principal used when creating the LDAP connection. Unlike the token's
* {@link AuthenticationToken#getPrincipal() principal}, this value is usually a constructed
* User DN and not a simple username or uid. The exact value is depending on the
* configured
* <a href="http://download-llnw.oracle.com/javase/tutorial/jndi/ldap/auth_mechs.html">
* LDAP authentication mechanism</a> in use.
* @param ldapCredentials the LDAP credentials used when creating the LDAP connection.
* @param ldapContext the LdapContext created that resulted in a successful authentication. It can be used
* further by subclasses for more complex operations. It does not need to be closed -
* it will be closed automatically after this method returns.
* @return the {@link AuthenticationInfo} resulting from a Subject's successful LDAP authentication attempt.
* @throws NamingException if there was any problem using the {@code LdapContext}
*/
@SuppressWarnings({"UnusedDeclaration"})
protected AuthenticationInfo createAuthenticationInfo(AuthenticationToken token, Object ldapPrincipal,
Object ldapCredentials, LdapContext ldapContext)
throws NamingException {
return new SimpleAuthenticationInfo(token.getPrincipal(), token.getCredentials(), getName());
}
/**
* Method that should be implemented by subclasses to build an
* {@link AuthorizationInfo} object by querying the LDAP context for the
* specified principal.</p>
*
* @param principals the principals of the Subject whose AuthenticationInfo should be queried from the LDAP server.
* @param ldapContextFactory factory used to retrieve LDAP connections.
* @return an {@link AuthorizationInfo} instance containing information retrieved from the LDAP server.
* @throws NamingException if any LDAP errors occur during the search.
*/
protected AuthorizationInfo queryForAuthorizationInfo(PrincipalCollection principals,
LdapContextFactory ldapContextFactory) throws NamingException {
return null;
}
}