http://www.mongodb.org: The MongoDB Java Driver uber-artifact, containing the legacy driver, the mongodb-driver, mongodb-driver-core, and bson
  • Various (MongoDB) 
/*
 * Copyright 2008-present MongoDB, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   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 "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.mongodb;

import com.mongodb.annotations.Immutable;
import com.mongodb.lang.Nullable;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import static com.mongodb.AuthenticationMechanism.GSSAPI;
import static com.mongodb.AuthenticationMechanism.MONGODB_CR;
import static com.mongodb.AuthenticationMechanism.MONGODB_X509;
import static com.mongodb.AuthenticationMechanism.PLAIN;
import static com.mongodb.AuthenticationMechanism.SCRAM_SHA_1;
import static com.mongodb.AuthenticationMechanism.SCRAM_SHA_256;
import static com.mongodb.assertions.Assertions.notNull;


Represents credentials to authenticate to a mongo server,as well as the source of the credentials and the authentication mechanism to
use.

Since:2.11
/**
 * Represents credentials to authenticate to a mongo server,as well as the source of the credentials and the authentication mechanism to
 * use.
 *
 * @since 2.11
 */
@Immutable
public final class MongoCredential {

    private final AuthenticationMechanism mechanism;
    private final String userName;
    private final String source;
    private final char[] password;
    private final Map<String, Object> mechanismProperties;

    
The MongoDB Challenge Response mechanism.

@mongodb.driver.manualcore/authentication/#mongodb-cr-authentication MONGODB-CR
Deprecated:This mechanism was replaced by SCRAM_SHA_1_MECHANISM in MongoDB 3.0, and is now deprecated
/**
     * The MongoDB Challenge Response mechanism.
     * @mongodb.driver.manual core/authentication/#mongodb-cr-authentication MONGODB-CR
     * @deprecated This mechanism was replaced by {@link #SCRAM_SHA_1_MECHANISM} in MongoDB 3.0, and is now deprecated
     */
    @SuppressWarnings("deprecation")
    @Deprecated
    public static final String MONGODB_CR_MECHANISM = AuthenticationMechanism.MONGODB_CR.getMechanismName();

    
The GSSAPI mechanism.  See the RFC.

@mongodb.server.release2.4
@mongodb.driver.manualcore/authentication/#kerberos-authentication GSSAPI
/**
     * The GSSAPI mechanism.  See the <a href="http://tools.ietf.org/html/rfc4752">RFC</a>.
     *
     * @mongodb.server.release 2.4
     * @mongodb.driver.manual core/authentication/#kerberos-authentication GSSAPI
     */
    public static final String GSSAPI_MECHANISM = AuthenticationMechanism.GSSAPI.getMechanismName();

    
The PLAIN mechanism.  See the RFC.

Since:2.12
@mongodb.server.release2.6
@mongodb.driver.manualcore/authentication/#ldap-proxy-authority-authentication PLAIN
/**
     * The PLAIN mechanism.  See the <a href="http://www.ietf.org/rfc/rfc4616.txt">RFC</a>.
     *
     * @since 2.12
     * @mongodb.server.release 2.6
     * @mongodb.driver.manual core/authentication/#ldap-proxy-authority-authentication PLAIN
     */
    public static final String PLAIN_MECHANISM = AuthenticationMechanism.PLAIN.getMechanismName();

    
The MongoDB X.509

Since:2.12
@mongodb.server.release2.6
@mongodb.driver.manualcore/authentication/#x-509-certificate-authentication X-509
/**
     * The MongoDB X.509
     *
     * @since 2.12
     * @mongodb.server.release 2.6
     * @mongodb.driver.manual core/authentication/#x-509-certificate-authentication X-509
     */
    public static final String MONGODB_X509_MECHANISM = AuthenticationMechanism.MONGODB_X509.getMechanismName();

    
The SCRAM-SHA-1 Mechanism.

Since:2.13
@mongodb.server.release3.0
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
/**
     * The SCRAM-SHA-1 Mechanism.
     *
     * @since 2.13
     * @mongodb.server.release 3.0
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
     */
    public static final String SCRAM_SHA_1_MECHANISM = AuthenticationMechanism.SCRAM_SHA_1.getMechanismName();

    
The SCRAM-SHA-256 Mechanism.

Since:3.8
@mongodb.server.release4.0
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
/**
     * The SCRAM-SHA-256 Mechanism.
     *
     * @since 3.8
     * @mongodb.server.release 4.0
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
     */
    public static final String SCRAM_SHA_256_MECHANISM = AuthenticationMechanism.SCRAM_SHA_256.getMechanismName();

    
Mechanism property key for overriding the service name for GSSAPI authentication.

See Also:
Since:3.3
/**
     * Mechanism property key for overriding the service name for GSSAPI authentication.
     *
     * @see #createGSSAPICredential(String)
     * @see #withMechanismProperty(String, Object)
     * @since 3.3
     */
    public static final String SERVICE_NAME_KEY = "SERVICE_NAME";

    
Mechanism property key for specifying whether to canonicalize the host name for GSSAPI authentication.

See Also:
Since:3.3
/**
     * Mechanism property key for specifying whether to canonicalize the host name for GSSAPI authentication.
     *
     * @see #createGSSAPICredential(String)
     * @see #withMechanismProperty(String, Object)
     * @since 3.3
     */
    public static final String CANONICALIZE_HOST_NAME_KEY = "CANONICALIZE_HOST_NAME";

    
Mechanism property key for overriding the SaslClient properties for GSSAPI authentication. The value of this property must be a Map<String, Object>. In most cases there is no need to set this mechanism property. But if an application does: 

See Also:
Since:3.3
/**
     * Mechanism property key for overriding the SaslClient properties for GSSAPI authentication.
     *
     * The value of this property must be a {@code Map<String, Object>}.  In most cases there is no need to set this mechanism property.
     * But if an application does:
     * <ul>
     * <li>Generally it must set the {@link javax.security.sasl.Sasl#CREDENTIALS} property to an instance of
     * {@link org.ietf.jgss.GSSCredential}.</li>
     * <li>It's recommended that it set the {@link javax.security.sasl.Sasl#MAX_BUFFER} property to "0" to ensure compatibility with all
     * versions of MongoDB.</li>
     * </ul>
     *
     * @see #createGSSAPICredential(String)
     * @see #withMechanismProperty(String, Object)
     * @see javax.security.sasl.Sasl
     * @see javax.security.sasl.Sasl#CREDENTIALS
     * @see javax.security.sasl.Sasl#MAX_BUFFER
     * @since 3.3
     */
    public static final String JAVA_SASL_CLIENT_PROPERTIES_KEY = "JAVA_SASL_CLIENT_PROPERTIES";

    
Mechanism property key for overriding the Subject under which GSSAPI authentication executes. 
See Also:
Since:3.3
/**
     * Mechanism property key for overriding the {@link javax.security.auth.Subject} under which GSSAPI authentication executes.
     *
     * @see #createGSSAPICredential(String)
     * @see #withMechanismProperty(String, Object)
     * @since 3.3
     */
    public static final String JAVA_SUBJECT_KEY = "JAVA_SUBJECT";

    
Creates a MongoCredential instance with an unspecified mechanism.  The client will negotiate the best mechanism based on the
version of the server that the client is authenticating to.

If the server version is 4.0 or higher, the driver will negotiate with the server preferring the SCRAM-SHA-256 mechanism. 3.x
servers will authenticate using SCRAM-SHA-1, older servers will authenticate using the MONGODB_CR mechanism.


Params:
  • userName – the user name
  • database – the database where the user is defined
  • password – the user's password
Returns:the credential
Since:2.13
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
@mongodb.driver.manualcore/authentication/#mongodb-cr-authentication MONGODB-CR
/**
     * Creates a MongoCredential instance with an unspecified mechanism.  The client will negotiate the best mechanism based on the
     * version of the server that the client is authenticating to.
     *
     * <p>If the server version is 4.0 or higher, the driver will negotiate with the server preferring the SCRAM-SHA-256 mechanism. 3.x
     * servers will authenticate using SCRAM-SHA-1, older servers will authenticate using the MONGODB_CR mechanism.</p>
     *
     * @param userName the user name
     * @param database the database where the user is defined
     * @param password the user's password
     * @return the credential
     *
     * @since 2.13
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
     * @mongodb.driver.manual core/authentication/#mongodb-cr-authentication MONGODB-CR
     */
    public static MongoCredential createCredential(final String userName, final String database, final char[] password) {
        return new MongoCredential(null, userName, database, password);
    }

    
Creates a MongoCredential instance for the SCRAM-SHA-1 SASL mechanism. Use this method only if you want to ensure that the driver uses the SCRAM-SHA-1 mechanism regardless of whether the server you are connecting to supports the authentication mechanism. Otherwise use the createCredential(String, String, char[]) method to allow the driver to negotiate the best mechanism based on the server version. 
Params:
  • userName – the non-null user name
  • source – the source where the user is defined.
  • password – the non-null user password
See Also:
Returns:the credential
Since:2.13
@mongodb.server.release3.0
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
/**
     * Creates a MongoCredential instance for the SCRAM-SHA-1 SASL mechanism. Use this method only if you want to ensure that
     * the driver uses the SCRAM-SHA-1 mechanism regardless of whether the server you are connecting to supports the
     * authentication mechanism.  Otherwise use the {@link #createCredential(String, String, char[])} method to allow the driver to
     * negotiate the best mechanism based on the server version.
     *
     *
     * @param userName the non-null user name
     * @param source the source where the user is defined.
     * @param password the non-null user password
     * @return the credential
     * @see #createCredential(String, String, char[])
     *
     * @since 2.13
     * @mongodb.server.release 3.0
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-1 SCRAM-SHA-1
     */
    public static MongoCredential createScramSha1Credential(final String userName, final String source, final char[] password) {
        return new MongoCredential(SCRAM_SHA_1, userName, source, password);
    }

    
Creates a MongoCredential instance for the SCRAM-SHA-256 SASL mechanism.

Params:
  • userName – the non-null user name
  • source – the source where the user is defined.
  • password – the non-null user password
See Also:
Returns:the credential
Since:3.8
@mongodb.server.release4.0
@mongodb.driver.manualcore/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
/**
     * Creates a MongoCredential instance for the SCRAM-SHA-256 SASL mechanism.
     *
     * @param userName the non-null user name
     * @param source the source where the user is defined.
     * @param password the non-null user password
     * @return the credential
     * @see #createCredential(String, String, char[])
     *
     * @since 3.8
     * @mongodb.server.release 4.0
     * @mongodb.driver.manual core/authentication/#authentication-scram-sha-256 SCRAM-SHA-256
     */
    public static MongoCredential createScramSha256Credential(final String userName, final String source, final char[] password) {
        return new MongoCredential(SCRAM_SHA_256, userName, source, password);
    }

    
Creates a MongoCredential instance for the MongoDB Challenge Response protocol. Use this method only if you want to ensure that the driver uses the MONGODB_CR mechanism regardless of whether the server you are connecting to supports a more secure authentication mechanism. Otherwise use the createCredential(String, String, char[]) method to allow the driver to negotiate the best mechanism based on the server version. 
Params:
  • userName – the user name
  • database – the database where the user is defined
  • password – the user's password
See Also:
Returns:the credential
@mongodb.driver.manualcore/authentication/#mongodb-cr-authentication MONGODB-CR
Deprecated:MONGODB-CR was replaced by SCRAM-SHA-1 in MongoDB 3.0, and is now deprecated. Use the createCredential(String, String, char[]) factory method instead.
/**
     * Creates a MongoCredential instance for the MongoDB Challenge Response protocol. Use this method only if you want to ensure that
     * the driver uses the MONGODB_CR mechanism regardless of whether the server you are connecting to supports a more secure
     * authentication mechanism.  Otherwise use the {@link #createCredential(String, String, char[])} method to allow the driver to
     * negotiate the best mechanism based on the server version.
     *
     * @param userName the user name
     * @param database the database where the user is defined
     * @param password the user's password
     * @return the credential
     * @see #createCredential(String, String, char[])
     * @mongodb.driver.manual core/authentication/#mongodb-cr-authentication MONGODB-CR
     * @deprecated MONGODB-CR was replaced by SCRAM-SHA-1 in MongoDB 3.0, and is now deprecated. Use
     * the {@link #createCredential(String, String, char[])} factory method instead.
     */
    @SuppressWarnings("deprecation")
    @Deprecated
    public static MongoCredential createMongoCRCredential(final String userName, final String database, final char[] password) {
        return new MongoCredential(MONGODB_CR, userName, database, password);
    }

    
Creates a MongoCredential instance for the MongoDB X.509 protocol.

Params:
  • userName – the user name
Returns:the credential
Since:2.12
@mongodb.server.release2.6
@mongodb.driver.manualcore/authentication/#x-509-certificate-authentication X-509
/**
     * Creates a MongoCredential instance for the MongoDB X.509 protocol.
     *
     * @param userName the user name
     * @return the credential
     *
     * @since 2.12
     * @mongodb.server.release 2.6
     * @mongodb.driver.manual core/authentication/#x-509-certificate-authentication X-509
     */
    public static MongoCredential createMongoX509Credential(final String userName) {
        return new MongoCredential(MONGODB_X509, userName, "$external", null);
    }

    
Creates a MongoCredential instance for the MongoDB X.509 protocol where the distinguished subject name of the client certificate
acts as the userName.


    Available on MongoDB server versions >= 3.4.



Returns:the credential
Since:3.4
@mongodb.server.release3.4
@mongodb.driver.manualcore/authentication/#x-509-certificate-authentication X-509
/**
     * Creates a MongoCredential instance for the MongoDB X.509 protocol where the distinguished subject name of the client certificate
     * acts as the userName.
     * <p>
     *     Available on MongoDB server versions &gt;= 3.4.
     * </p>
     * @return the credential
     *
     * @since 3.4
     * @mongodb.server.release 3.4
     * @mongodb.driver.manual core/authentication/#x-509-certificate-authentication X-509
     */
    public static MongoCredential createMongoX509Credential() {
        return new MongoCredential(MONGODB_X509, null, "$external", null);
    }

    
Creates a MongoCredential instance for the PLAIN SASL mechanism.

Params:
  • userName – the non-null user name
  • source –  the source where the user is defined. This can be either "$external" or the name of a database.
  • password – the non-null user password
Returns:the credential
Since:2.12
@mongodb.server.release2.6
@mongodb.driver.manualcore/authentication/#ldap-proxy-authority-authentication PLAIN
/**
     * Creates a MongoCredential instance for the PLAIN SASL mechanism.
     *
     * @param userName the non-null user name
     * @param source   the source where the user is defined.  This can be either {@code "$external"} or the name of a database.
     * @param password the non-null user password
     * @return the credential
     *
     * @since 2.12
     * @mongodb.server.release 2.6
     * @mongodb.driver.manual core/authentication/#ldap-proxy-authority-authentication PLAIN
     */
    public static MongoCredential createPlainCredential(final String userName, final String source, final char[] password) {
        return new MongoCredential(PLAIN, userName, source, password);
    }

    
Creates a MongoCredential instance for the GSSAPI SASL mechanism.

 To override the default service name of "mongodb", add a mechanism property with the name "SERVICE_NAME". 
 To force canonicalization of the host name prior to authentication, add a mechanism property with the name "CANONICALIZE_HOST_NAME" with the valuetrue. 
 To override the Subject with which the authentication executes, add a mechanism property with the name "JAVA_SUBJECT" with the value of a Subject instance. 
 To override the properties of the SaslClient with which the authentication executes, add a mechanism property with the name "JAVA_SASL_CLIENT_PROPERTIES" with the value of a Map<String, Object instance containing the necessary properties. This can be useful if the application is customizing the default SaslClientFactory. 
Params:
  • userName – the non-null user name
See Also:
Returns:the credential
@mongodb.server.release2.4
@mongodb.driver.manualcore/authentication/#kerberos-authentication GSSAPI
/**
     * Creates a MongoCredential instance for the GSSAPI SASL mechanism.
     * <p>
     * To override the default service name of {@code "mongodb"}, add a mechanism property with the name {@code "SERVICE_NAME"}.
     * <p>
     * To force canonicalization of the host name prior to authentication, add a mechanism property with the name
     * {@code "CANONICALIZE_HOST_NAME"} with the value{@code true}.
     * <p>
     * To override the {@link javax.security.auth.Subject} with which the authentication executes, add a mechanism property with the name
     * {@code "JAVA_SUBJECT"} with the value of a {@code Subject} instance.
     * <p>
     * To override the properties of the {@link javax.security.sasl.SaslClient} with which the authentication executes, add a mechanism
     * property with the name {@code "JAVA_SASL_CLIENT_PROPERTIES"} with the value of a {@code Map<String, Object} instance containing the
     * necessary properties.  This can be useful if the application is customizing the default
     * {@link javax.security.sasl.SaslClientFactory}.
     *
     * @param userName the non-null user name
     * @return the credential
     * @mongodb.server.release 2.4
     * @mongodb.driver.manual core/authentication/#kerberos-authentication GSSAPI
     * @see #withMechanismProperty(String, Object)
     * @see #SERVICE_NAME_KEY
     * @see #CANONICALIZE_HOST_NAME_KEY
     * @see #JAVA_SUBJECT_KEY
     * @see #JAVA_SASL_CLIENT_PROPERTIES_KEY
     */
    public static MongoCredential createGSSAPICredential(final String userName) {
        return new MongoCredential(GSSAPI, userName, "$external", null);
    }

    
Creates a new MongoCredential as a copy of this instance, with the specified mechanism property added.

Params:
  • key –   the key to the property, which is treated as case-insensitive
  • value – the value of the property
Type parameters:
  • <T> –   the property type
Returns:the credential
Since:2.12
/**
     * Creates a new MongoCredential as a copy of this instance, with the specified mechanism property added.
     *
     * @param key   the key to the property, which is treated as case-insensitive
     * @param value the value of the property
     * @param <T>   the property type
     * @return the credential
     * @since 2.12
     */
    public <T> MongoCredential withMechanismProperty(final String key, final T value) {
        return new MongoCredential(this, key, value);
    }

    
Creates a new MongoCredential with the set mechanism. The existing mechanism must be null.

Params:
  • mechanism – the mechanism to set
Returns:the credential
Since:3.8
/**
     * Creates a new MongoCredential with the set mechanism. The existing mechanism must be null.
     *
     * @param mechanism the mechanism to set
     * @return the credential
     * @since 3.8
     */
    public MongoCredential withMechanism(final AuthenticationMechanism mechanism) {
        if (this.mechanism != null) {
            throw new IllegalArgumentException("Mechanism already set");
        }
        return new MongoCredential(mechanism, userName, source, password, mechanismProperties);
    }

    
Constructs a new instance using the given mechanism, userName, source, and password

Params:
  • mechanism – the authentication mechanism
  • userName –  the user name
  • source –    the source of the user name, typically a database name
  • password –  the password
/**
     * Constructs a new instance using the given mechanism, userName, source, and password
     *
     * @param mechanism the authentication mechanism
     * @param userName  the user name
     * @param source    the source of the user name, typically a database name
     * @param password  the password
     */
    MongoCredential(@Nullable final AuthenticationMechanism mechanism, @Nullable final String userName, final String source,
                    @Nullable final char[] password) {
        this(mechanism, userName, source, password, Collections.<String, Object>emptyMap());
    }

    MongoCredential(@Nullable final AuthenticationMechanism mechanism, @Nullable final String userName, final String source,
                    @Nullable final char[] password, final Map<String, Object> mechanismProperties) {
        if (mechanism != MONGODB_X509 && userName == null) {
            throw new IllegalArgumentException("username can not be null");
        }

        if (mechanism == null && password == null) {
            throw new IllegalArgumentException("Password can not be null when the authentication mechanism is unspecified");
        }

        if (mechanismRequiresPassword(mechanism) && password == null) {
            throw new IllegalArgumentException("Password can not be null for " + mechanism + " mechanism");
        }

        if ((mechanism == GSSAPI || mechanism == MONGODB_X509) && password != null) {
            throw new IllegalArgumentException("Password must be null for the " + mechanism + " mechanism");
        }

        this.mechanism = mechanism;
        this.userName = userName;
        this.source = notNull("source", source);

        this.password = password != null ? password.clone() : null;
        this.mechanismProperties = new HashMap<String, Object>(mechanismProperties);
    }

    @SuppressWarnings("deprecation")
    private boolean mechanismRequiresPassword(@Nullable final AuthenticationMechanism mechanism) {
        return mechanism == PLAIN || mechanism == MONGODB_CR || mechanism == SCRAM_SHA_1 || mechanism == SCRAM_SHA_256;

    }

    
Constructs a new instance using the given credential plus an additional mechanism property.

Params:
  • from –                   the credential to copy from
  • mechanismPropertyKey –   the new mechanism property key
  • mechanismPropertyValue – the new mechanism property value
Type parameters:
  • <T> –                    the mechanism property type
/**
     * Constructs a new instance using the given credential plus an additional mechanism property.
     *
     * @param from                   the credential to copy from
     * @param mechanismPropertyKey   the new mechanism property key
     * @param mechanismPropertyValue the new mechanism property value
     * @param <T>                    the mechanism property type
     */
    <T> MongoCredential(final MongoCredential from, final String mechanismPropertyKey, final T mechanismPropertyValue) {
        notNull("mechanismPropertyKey", mechanismPropertyKey);

        this.mechanism = from.mechanism;
        this.userName = from.userName;
        this.source = from.source;
        this.password = from.password;
        this.mechanismProperties = new HashMap<String, Object>(from.mechanismProperties);
        this.mechanismProperties.put(mechanismPropertyKey.toLowerCase(), mechanismPropertyValue);
    }

    
Gets the mechanism

Returns:the mechanism.
/**
     * Gets the mechanism
     *
     * @return the mechanism.
     */
    @Nullable
    public String getMechanism() {
        return mechanism == null ? null : mechanism.getMechanismName();
    }

    
Gets the mechanism

Returns:the mechanism.
Since:3.0
/**
     * Gets the mechanism
     *
     * @return the mechanism.
     * @since 3.0
     */
    @Nullable
    public AuthenticationMechanism getAuthenticationMechanism() {
        return mechanism;
    }

    
Gets the user name

Returns:the user name.
/**
     * Gets the user name
     *
     * @return the user name.
     */
    @Nullable
    public String getUserName() {
        return userName;
    }

    
Gets the source of the user name, typically the name of the database where the user is defined.

Returns:the user name.  Can never be null.
/**
     * Gets the source of the user name, typically the name of the database where the user is defined.
     *
     * @return the user name.  Can never be null.
     */
    public String getSource() {
        return source;
    }

    
Gets the password.

Returns:the password.  Can be null for some mechanisms.
/**
     * Gets the password.
     *
     * @return the password.  Can be null for some mechanisms.
     */
    @Nullable
    public char[] getPassword() {
        if (password == null) {
            return null;
        }
        return password.clone();
    }

    
Get the value of the given key to a mechanism property, or defaultValue if there is no mapping.

Params:
  • key –          the mechanism property key, which is treated as case-insensitive
  • defaultValue – the default value, if no mapping exists
Type parameters:
  • <T> –          the value type
Returns:the mechanism property value
Since:2.12
/**
     * Get the value of the given key to a mechanism property, or defaultValue if there is no mapping.
     *
     * @param key          the mechanism property key, which is treated as case-insensitive
     * @param defaultValue the default value, if no mapping exists
     * @param <T>          the value type
     * @return the mechanism property value
     * @since 2.12
     */
    @SuppressWarnings("unchecked")
    @Nullable
    public <T> T getMechanismProperty(final String key, @Nullable final T defaultValue) {
        notNull("key", key);

        T value = (T) mechanismProperties.get(key.toLowerCase());
        return (value == null) ? defaultValue : value;

    }

    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        MongoCredential that = (MongoCredential) o;

        if (mechanism != that.mechanism) {
            return false;
        }
        if (!Arrays.equals(password, that.password)) {
            return false;
        }
        if (!source.equals(that.source)) {
            return false;
        }
        if (userName != null ? !userName.equals(that.userName) : that.userName != null) {
            return false;
        }
        if (!mechanismProperties.equals(that.mechanismProperties)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        int result = mechanism != null ? mechanism.hashCode() : 0;
        result = 31 * result + (userName != null ? userName.hashCode() : 0);
        result = 31 * result + source.hashCode();
        result = 31 * result + (password != null ? Arrays.hashCode(password) : 0);
        result = 31 * result + mechanismProperties.hashCode();
        return result;
    }

    @Override
    public String toString() {
        return "MongoCredential{"
                + "mechanism=" + mechanism
                + ", userName='" + userName + '\''
                + ", source='" + source + '\''
                + ", password=<hidden>"
                + ", mechanismProperties=<hidden>"
                + '}';
    }
}