org.apache.spark

Class SecurityManager

Object

org.apache.spark.SecurityManager

All Implemented Interfaces:

Logging, org.apache.spark.network.sasl.SecretKeyHolder

public class SecurityManager
extends Object
implements Logging, org.apache.spark.network.sasl.SecretKeyHolder

Spark class responsible for security.

In general this class should be instantiated by the SparkEnv and most components should access it from that. There are some cases where the SparkEnv hasn't been initialized yet and this class must be instantiated directly.

Spark currently supports authentication via a shared secret. Authentication can be configured to be on via the 'spark.authenticate' configuration parameter. This parameter controls whether the Spark communication protocols do authentication using the shared secret. This authentication is a basic handshake to make sure both sides have the same shared secret and are allowed to communicate. If the shared secret is not identical they will not be allowed to communicate.

The Spark UI can also be secured by using javax servlet filters. A user may want to secure the UI if it has data that other users should not be allowed to see. The javax servlet filter specified by the user can authenticate the user and then once the user is logged in, Spark can compare that user versus the view acls to make sure they are authorized to view the UI. The configs 'spark.acls.enable' and 'spark.ui.view.acls' control the behavior of the acls. Note that the person who started the application always has view access to the UI.

Spark has a set of modify acls (spark.modify.acls) that controls which users have permission to modify a single application. This would include things like killing the application. By default the person who started the application has modify access. For modify access through the UI, you must have a filter that does authentication in place for the modify acls to work properly.

Spark also has a set of admin acls (spark.admin.acls) which is a set of users/administrators who always have permission to view or modify the Spark application.

Spark does not currently support encryption after authentication.

At this point spark has multiple communication protocols that need to be secured and different underlying mechanisms are used depending on the protocol:

- Akka -> The only option here is to use the Akka Remote secure-cookie functionality. Akka remoting allows you to specify a secure cookie that will be exchanged and ensured to be identical in the connection handshake between the client and the server. If they are not identical then the client will be refused to connect to the server. There is no control of the underlying authentication mechanism so its not clear if the password is passed in plaintext or uses DIGEST-MD5 or some other mechanism. Akka also has an option to turn on SSL, this option is not currently supported but we could add a configuration option in the future.

- HTTP for broadcast and file server (via HttpServer) -> Spark currently uses Jetty for the HttpServer. Jetty supports multiple authentication mechanisms - Basic, Digest, Form, Spengo, etc. It also supports multiple different login services - Hash, JAAS, Spnego, JDBC, etc. Spark currently uses the HashLoginService to authenticate using DIGEST-MD5 via a single user and the shared secret. Since we are using DIGEST-MD5, the shared secret is not passed on the wire in plaintext. We currently do not support SSL (https), but Jetty can be configured to use it so we could add a configuration option for this in the future.

The Spark HttpServer installs the HashLoginServer and configures it to DIGEST-MD5. Any clients must specify the user and password. There is a default Authenticator installed in the SecurityManager to how it does the authentication and in this case gets the user name and password from the request.

- BlockTransferService -> The Spark BlockTransferServices uses java nio to asynchronously exchange messages. For this we use the Java SASL (Simple Authentication and Security Layer) API and again use DIGEST-MD5 as the authentication mechanism. This means the shared secret is not passed over the wire in plaintext. Note that SASL is pluggable as to what mechanism it uses. We currently use DIGEST-MD5 but this could be changed to use Kerberos or other in the future. Spark currently supports "auth" for the quality of protection, which means the connection does not support integrity or privacy protection (encryption) after authentication. SASL also supports "auth-int" and "auth-conf" which SPARK could support in the future to allow the user to specify the quality of protection they want. If we support those, the messages will also have to be wrapped and unwrapped via the SaslServer/SaslClient.wrap/unwrap API's.

Since the NioBlockTransferService does asynchronous messages passing, the SASL authentication is a bit more complex. A ConnectionManager can be both a client and a Server, so for a particular connection it has to determine what to do. A ConnectionId was added to be able to track connections and is used to match up incoming messages with connections waiting for authentication. The ConnectionManager tracks all the sendingConnections using the ConnectionId, waits for the response from the server, and does the handshake before sending the real message.

The NettyBlockTransferService ensures that SASL authentication is performed synchronously prior to any other communication on a connection. This is done in SaslClientBootstrap on the client side and SaslRpcHandler on the server side.

- HTTP for the Spark UI -> the UI was changed to use servlets so that javax servlet filters can be used. Yarn requires a specific AmIpFilter be installed for security to work properly. For non-Yarn deployments, users can write a filter to go through their organization's normal login service. If an authentication filter is in place then the SparkUI can be configured to check the logged in user against the list of users who have view acls to see if that user is authorized. The filters can also be used for many different purposes. For instance filters could be used for logging, encryption, or compression.

The exact mechanisms used to generate/distribute the shared secret are deployment-specific.

For Yarn deployments, the secret is automatically generated using the Akka remote Crypt.generateSecureCookie() API. The secret is placed in the Hadoop UGI which gets passed around via the Hadoop RPC mechanism. Hadoop RPC can be configured to support different levels of protection. See the Hadoop documentation for more details. Each Spark application on Yarn gets a different shared secret. On Yarn, the Spark UI gets configured to use the Hadoop Yarn AmIpFilter which requires the user to go through the ResourceManager Proxy. That Proxy is there to reduce the possibility of web based attacks through YARN. Hadoop can be configured to use filters to do authentication. That authentication then happens via the ResourceManager Proxy and Spark will use that to do authorization against the view acls.

For other Spark deployments, the shared secret must be specified via the spark.authenticate.secret config. All the nodes (Master and Workers) and the applications need to have the same shared secret. This again is not ideal as one user could potentially affect another users application. This should be enhanced in the future to provide better protection. If the UI needs to be secure, the user needs to install a javax servlet filter to do the authentication. Spark will then use that user to compare against the view acls to do authorization. If not filter is in place the user is generally null and no authorization can take place.

Constructor Summary

Constructors

Constructor and Description
SecurityManager(SparkConf sparkConf)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	aclsEnabled() Check to see if Acls for the UI are enabled
boolean	checkModifyPermissions(String user) Checks the given user against the modify acl list to see if they have authorization to modify the application.
boolean	checkUIViewPermissions(String user) Checks the given user against the view acl list to see if they have authorization to view the UI.
String	getHttpUser() Gets the user used for authenticating HTTP connections.
String	getModifyAcls()
String	getSaslUser() Gets the user used for authenticating SASL connections.
String	getSaslUser(String appId)
String	getSecretKey() Gets the secret key.
String	getSecretKey(String appId)
String	getViewAcls()
boolean	isAuthenticationEnabled() Check to see if authentication for the Spark communication protocols is enabled
void	setAcls(boolean aclSetting)
void	setAdminAcls(String adminUsers) Admin acls should be set before the view or modify acls.
void	setModifyAcls(scala.collection.immutable.Set<String> defaultUsers, String allowedUsers) Admin acls should be set before the view or modify acls.
void	setViewAcls(scala.collection.immutable.Set<String> defaultUsers, String allowedUsers) Admin acls should be set before the view or modify acls.
void	setViewAcls(String defaultUser, String allowedUsers)

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.spark.Logging

initializeIfNecessary, initializeLogging, isTraceEnabled, log_, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning

Constructor Detail

SecurityManager

public SecurityManager(SparkConf sparkConf)

Method Detail

setViewAcls

public void setViewAcls(scala.collection.immutable.Set<String> defaultUsers,
               String allowedUsers)

Admin acls should be set before the view or modify acls. If you modify the admin acls you should also set the view and modify acls again to pick up the changes.

setViewAcls

public void setViewAcls(String defaultUser,
               String allowedUsers)

getViewAcls

public String getViewAcls()

setModifyAcls

public void setModifyAcls(scala.collection.immutable.Set<String> defaultUsers,
                 String allowedUsers)

Admin acls should be set before the view or modify acls. If you modify the admin acls you should also set the view and modify acls again to pick up the changes.

getModifyAcls

public String getModifyAcls()

setAdminAcls

public void setAdminAcls(String adminUsers)

Admin acls should be set before the view or modify acls. If you modify the admin acls you should also set the view and modify acls again to pick up the changes.

setAcls

public void setAcls(boolean aclSetting)

aclsEnabled

public boolean aclsEnabled()

Check to see if Acls for the UI are enabled

Returns:

true if UI authentication is enabled, otherwise false

checkUIViewPermissions

public boolean checkUIViewPermissions(String user)

Checks the given user against the view acl list to see if they have authorization to view the UI. If the UI acls are disabled via spark.acls.enable, all users have view access. If the user is null it is assumed authentication is off and all users have access.

Parameters:

user - to see if is authorized

Returns:

true is the user has permission, otherwise false

checkModifyPermissions

public boolean checkModifyPermissions(String user)

Checks the given user against the modify acl list to see if they have authorization to modify the application. If the UI acls are disabled via spark.acls.enable, all users have modify access. If the user is null it is assumed authentication isn't turned on and all users have access.

Parameters:

user - to see if is authorized

Returns:

true is the user has permission, otherwise false

isAuthenticationEnabled

public boolean isAuthenticationEnabled()

Check to see if authentication for the Spark communication protocols is enabled

Returns:

true if authentication is enabled, otherwise false

getHttpUser

public String getHttpUser()

Gets the user used for authenticating HTTP connections. For now use a single hardcoded user.

Returns:

the HTTP user as a String

getSaslUser

public String getSaslUser()

Gets the user used for authenticating SASL connections. For now use a single hardcoded user.

Returns:

the SASL user as a String

getSecretKey

public String getSecretKey()

Gets the secret key.

Returns:

the secret key as a String if authentication is enabled, otherwise returns null

getSaslUser

public String getSaslUser(String appId)

Specified by:

getSaslUser in interface org.apache.spark.network.sasl.SecretKeyHolder

getSecretKey

public String getSecretKey(String appId)

Specified by:

getSecretKey in interface org.apache.spark.network.sasl.SecretKeyHolder